U.S. patent application number 11/208369 was filed with the patent office on 2005-12-22 for imposition process and apparatus for variable imaging system.
This patent application is currently assigned to R.R. Donnelley & Sons Company. Invention is credited to Dreyer, Mark G., Shively, J. Thomas, Warmus, James L..
Application Number | 20050283722 11/208369 |
Document ID | / |
Family ID | 27413444 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050283722 |
Kind Code |
A1 |
Warmus, James L. ; et
al. |
December 22, 2005 |
Imposition process and apparatus for variable imaging system
Abstract
The present invention is useful for assembling a book. The
inventive method includes the steps of specifying pagination
information including an indication of whether a page is to be
selectively included in the book, determining whether the page is
to be assembled into the book based on the pagination information,
and generating page description language instructions for
production of the book in accordance with the pagination
information.
Inventors: |
Warmus, James L.; (LaGrange,
IL) ; Dreyer, Mark G.; (Aurora, IL) ; Shively,
J. Thomas; (Hinsdale, IL) |
Correspondence
Address: |
MCCRACKEN & FRANK LLP
200 W. ADAMS STREET
SUITE 2150
CHICAGO
IL
60606
US
|
Assignee: |
R.R. Donnelley & Sons
Company
|
Family ID: |
27413444 |
Appl. No.: |
11/208369 |
Filed: |
August 19, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11208369 |
Aug 19, 2005 |
|
|
|
09852581 |
May 10, 2001 |
|
|
|
6952801 |
|
|
|
|
09852581 |
May 10, 2001 |
|
|
|
08802337 |
Feb 11, 1997 |
|
|
|
6332149 |
|
|
|
|
08802337 |
Feb 11, 1997 |
|
|
|
08478397 |
Jun 7, 1995 |
|
|
|
6327599 |
|
|
|
|
08802337 |
Feb 11, 1997 |
|
|
|
08627724 |
Apr 2, 1996 |
|
|
|
5857209 |
|
|
|
|
Current U.S.
Class: |
715/251 ;
358/1.18; 715/243 |
Current CPC
Class: |
G06F 40/174 20200101;
G06K 15/1848 20130101; B65H 2301/4311 20130101; B65H 2511/415
20130101; B65H 2220/01 20130101; B65H 2511/415 20130101; G06F 40/10
20200101; G06K 15/1856 20130101; G06F 40/114 20200101; G06F 40/197
20200101; G06K 15/1857 20130101; G06F 40/123 20200101; G06F 40/103
20200101; G06K 15/1852 20130101; B42C 19/00 20130101 |
Class at
Publication: |
715/525 ;
715/517; 358/001.18 |
International
Class: |
G06F 017/00 |
Claims
1-13. (canceled)
14. An apparatus for preparing press commands for a raster image
processor (RIP) from template data, the template data having
reusable data to be printed on more than one output page and
position data representing a position on a page at which variable
information is to be printed, wherein the apparatus includes a
computer readable medium having stored thereon a program executable
by a computer comprising: a first routine that identifies the
reusable data in the template data; a second routine that reads
entries from a database, wherein each entry represents variable
information to be printed on output pages; and a third routine that
prepares the press commands in preparation for rasterization from
the identified reusable data, the position data, and the database
entries.
15. The apparatus of claim 14, including a fourth routine that
converts the template data and the database into press commands
specifying sequence and content of page production.
16. The apparatus of claim 14, including a fourth routine further
generates a reusable data set representing the identified reusable
data from the template data.
17. The apparatus of claim 16, wherein the fourth routine still
further generates a variable data set representing the variable
information from the template data.
18. The apparatus of claim 14, wherein an electronic press is
coupled to the apparatus and wherein the database includes control
information for controlling the electronic press.
19. The apparatus of claim 14, wherein an auxiliary production
device is coupled to the apparatus and wherein the database
includes control information for controlling the auxiliary
production device.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 08/802,337, filed Feb. 11, 1997, the disclosure of which is
hereby incorporated by reference, and which, in turn, is a
continuation-in-part of U.S. application Ser. No. 08/478,397, filed
Jun. 7, 1995 and a continuation-in-part of U.S. application Ser.
No. 08/627,724, filed Apr. 2, 1996, now U.S. Pat. No.
5,857,209.
TECHNICAL FIELD
[0002] The present invention relates generally to reproduction
methods and systems, and more particularly to a method of and
system for selectively reproducing images.
BACKGROUND ART
[0003] Most printing systems in use today utilize printing plates
or cylinders which are engraved or photochemically processed to
create an image thereon. Ink is then deposited on the plate or
cylinder and the ink is thereafter transferred to a substrate, such
as paper. In a conventional printing press, a number of pages are
printed on a sheet of paper to form a signature which is then
folded and assembled with other signatures. The assembled
signatures are then bound, trimmed and finished by finishing
apparatus to produce finished books, such as magazines, catalogs or
any other printed and bound matter.
[0004] Often, there is a need to produce different versions of
books and/or customized books within a single press run. For
example, it may be desirable to produce a number of standard books
together with a number of books having additional and/or different
signatures or pages therein. Also, it may be necessary or desirable
to provide customized information in the form of an address label,
personalized information or the like on the inside or outside of
finished books. In either case, conventional printing systems are
not easily adaptable to produce books of these types.
[0005] A printing system which has the ability to produce differing
book versions and/or books with customized information is disclosed
in Riley U.S. Pat. No. 4,121,818, assigned to the assignee of the
instant application. The printing system includes a number of
packer boxes disposed adjacent a binding chain wherein each packer
box stores a plurality of signatures. A control is included for
controlling the packer boxes to selectively feed signatures onto
chain spaces of the binding chain so that books of varying content
can be produced. Customized information can be printed on the
signatures by means of an ink jet printer which is selectively
operated by the control. Other types of customization can be
effectuated, such as by inserting or onserting cards or the
like.
[0006] Other systems for producing customized books are disclosed
in Abrams et al. U.S. Pat. No. 3,899,165, Wong et al. U.S. Pat.
Nos. 4,500,083 and 4,674,052, Wong U.S. Pat. No. Re 32,690 and
Berger et al. U.S. Pat. Nos. 4,768,766 and 4,789,147.
[0007] Image manipulating systems have been developed which permit
gathering of images in an office or home environment. For example,
conventional word processing programs, such as Microsoft.RTM.
Word.RTM., WordPerfect.RTM. and the like, permit a user to import
images into a page and also allow a user to command which pages of
a document to print. In addition, macros (i.e., a sequence of
commands) can be assembled and executed within these programs which
can allow printing of particular document pages in a certain order.
Still further, most word processing programs have merge capability
wherein a customized image is merged with other standardized
information and printed or displayed. As one example, customized
information in the form of addressee and address information may be
merged with standardized return address information and printed on
a series of envelopes.
[0008] A different image gathering capability provided by CAD
(computer aided design) software, sometimes referred to as
"layering," involves the creation and storage of a base page and
one or more layer pages. A user can issue commands to display or
print the base page and one or more of the layer pages
simultaneously atop one another to achieve an effect similar to the
overlay of transparencies so that a composite page appearance
results.
[0009] While the foregoing image manipulating systems allow some
image gathering capability, none is effective to assist in the
rapid production of different book versions. Of course, CAD systems
are primarily designed for line art and not text or graphic images,
and hence are of only limited use. Further, if one were to use word
processing software to produce book versions it would be necessary
to issue commands to separately print the pages of each book
version just before such version is to be produced. That is, a user
would have to create and store pages to be included in a first book
version and then command the software to print as many copies of
the first version as are needed. Thereafter, the user would have to
recall the pages of the first version from memory, edit and store
the pages to create pages to be included in a second book version
and then command the system to print the required number of books
of the second version. Similar steps would have to be undertaken
for each other book version to be produced. Alternatively, the
pages of the different book versions could be created and stored
and thereafter printed together. In either event, where many book
versions are to be produced, such a process would be quite
time-consuming. In addition, image importation and merge routines
provided as a part of word processing software are adapted for use
on a sub-page basis only and hence are of only limited usefulness
in the book production environment. Still further, data manipulated
by word processing software are largely (if not entirely) in
symbolic format. As a result, data to be displayed or printed must
be first rasterized by a raster image processor (RIP), which
utilizes complex and time-consuming computational routines which
further increase production time to an economically impractical
level.
[0010] Recently, new printing systems have been developed, called
"demand printers," which are capable of high speed printing of
images from electronic representations thereof. The demand printer
produces high quality color (or black and white) images using a set
of fusible toners in an electrophotographic process. More
particularly, a web of paper is passed adjacent a series of drums,
each of which has been electrostatically charged according to an
image pattern for a particular color to be applied to the web. The
charge is transferred to the paper and an oppositely charged toner
of the proper color is brought into contact with the paper. The
oppositely charged web and toner attract so that the toner is held
on the paper as other colors are applied thereto. The toners and
paper are thereafter heated to fuse the toners to the paper to
produce the final image. The web is then cut into sheets (or
"forms") and the forms are further processed as needed to produce a
final product.
[0011] Unlike conventional presses which utilize engraved or
photochemically prepared plates or cylinders, demand printers are
capable of rapidly printing high quality images of differing
content owing to the fact that the images are produced by an
electrophotographic process. That is, instead of the need to
replate and re-engrave a gravure cylinder when a different image is
to be printed therewith, it is only necessary to change the charge
applied to the drums of the printer in order to make such change.
Thus, different images can be printed by the same printer without
significant delays. This advantage makes the demand printer
desirable for use in certain production environments.
[0012] Warmus et al. U.S. patent application Ser. No. 08/478,397,
entitled "Variable Imaging Using An Electronic Press" discloses an
apparatus and method for controlling an electronic press so that
fixed and variable information may be printed in a simple and
effective manner. More particularly, first and second sets of
template data representing associated first and second template
pages, respectively, are developed. Each set of template data
includes master data representing fixed information and area data
representing an area of a page for variable information. A database
is also developed having a number of entries each of which
represents variable information. The printer is operated in
accordance with the sets of template data and the entries in the
database such that the first and second template pages are
displayed with selected variable information.
[0013] The Warmus et al. apparatus and method generates a page
definition language representation of each single page and
thereafter generates a page definition language representation of
each imposed flat, i.e., each side of a piece of paper to be
printed with two or more pages. Such a procedure can be
computationally expensive and may limit productivity.
SUMMARY OF THE INVENTION
[0014] According to one aspect of the present invention, a method
of assembling a book includes the steps of specifying pagination
information including an indication of whether a page is to be
selectively included in the book, determining whether the page is
to be assembled into the book based on the pagination information,
and generating page description language instructions for
production of the book in accordance with the pagination
information.
[0015] Preferably, the determining step includes the step of
analyzing variable information areas of the page. The inventive
method may further include the step of analyzing press commands
directed to production of the book to determine whether the page is
to be assembled into the book. The inventive method may still
further include the step of generating a pagination file having
data representative of the pagination information.
[0016] Preferably, the pagination information includes an
indication of a maximum number of pages for the book. The
pagination information may include filler page information. The
pagination information also preferably includes a specification of
whether the page should be forced to one of a right side and a left
side of the book.
[0017] In one embodiment, the inventive method further includes the
step of specifying page description language instructions to
produce a barcode on the page. The barcode may be indicative of
tracking information.
[0018] In another embodiment, the step of generating page
description language instructions includes the step of generating
instructions for production of page numbering information on the
page. The step of generating page description language instructions
may also include the step of generating instructions for insertion
of filler pages in accordance with the pagination information.
[0019] Preferably, the inventive method further includes the step
of delivering the page description language instructions to an
electronic press to print the book.
[0020] In yet another embodiment, the step of specifying the
pagination information includes the step of providing a user
interface for entry of the pagination information.
[0021] Other features and advantages are inherent in the apparatus
claimed and disclosed or will become apparent to those skilled in
the art from the following detailed description in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a block diagram illustrating a prior art method of
producing books;
[0023] FIG. 2 is a block diagram of a method of producing books
implementing the present invention;
[0024] FIG. 3 is a block diagram illustrating an exemplary system
for implementing the method of the present invention illustrated in
FIG. 2;
[0025] FIG. 4 is a block diagram illustrating one of the demand
printing systems of FIG. 3 in greater detail;
[0026] FIG. 5 is a generalized diagram of the steps implemented by
the method of the present invention;
[0027] FIGS. 6a and 6b are elevational views of portions of a
sample book that may be produced by the present invention;
[0028] FIGS. 7a, 7b and 8a, 8b are elevational views of portions of
other sample books that may be produced by the present
invention;
[0029] FIG. 9 is a flowchart illustrating programming that may be
execrated by a user on a personal computer to create the template
files 105 of FIG. 5;
[0030] FIGS. 10a-10f, when joined along similarly-lettered lines,
together represent programming executed by the control unit 52 of
FIG. 3;
[0031] FIG. 11 is a flowchart illustrating the programming
implemented by the control unit 52 to generate a page description
language instruction set specifying which pages should be printed
and how the pages should be positioned (or imposed) for
printing;
[0032] FIG. 12 is a sample window to prompt a user for the
information needed to create a pagination file;
[0033] FIG. 13 is a flowchart illustrating in detail the
programming implemented by the block 348 of FIG. 11 which
determines which pages should be printed for a particular record in
the press command file;
[0034] FIG. 14 is a flowchart illustrating in detail the
programming implemented by the block 350 of FIG. 11 to determine
whether the pages should be forced to the left or right-hand side
of the book;
[0035] FIG. 15 is a flowchart illustrating in detail the
programming implemented by the block 352 of FIG. 11 to pad the
pages included in the book into a multiple of the number of pages
to be printed on a sheet;
[0036] FIG. 16 is a sample window to prompt a user to provide
various information to select imposition and printing styles;
[0037] FIG. 17 is a flowchart illustrating the programming
implemented to RIP page files to Tiff format for use in "Get Tiff"
imposition in accordance with the present invention;
[0038] FIG. 18 is flowchart illustrating the programming
implemented to impose pages using "Get Tiff" imposition in
accordance with the present invention;
[0039] FIG. 19 is a more detailed block diagram of the print system
79 (shown in FIG. 4) incorporating the imposition-on-the-fly
procedures of the present invention;
[0040] FIG. 20 is a flowchart illustrating the standard operation
of the Level 2 PostScript.RTM. showpage operator;
[0041] FIG. 21 is a flowchart illustrating the program steps
implemented by the redefined Postscript.RTM. initclip operator
according to the imposition-on-the-fly procedures of the present
invention;
[0042] FIG. 22 is a flowchart illustrating the program steps
implemented by the redefined PostScript.RTM. transform operators
according to the imposition-on-the-fly procedures of the present
invention;
[0043] FIG. 23 is a flowchart illustrating the program steps
implemented by the EnableVirtualDevice procedure according to the
imposition-on-the-fly procedures of the present invention;
[0044] FIG. 24 is a flowchart illustrating the program steps
implemented by the DisablePageDevice procedure according to the
imposition-on-the-fly procedures of the present invention;
[0045] FIG. 25 is a flowchart illustrating the program steps
implemented by the SetPortrait procedure according to the
imposition-on-the-fly procedures of the present invention;
[0046] FIG. 26A is a diagram illustrating the conversion of a
portrait-oriented page to a landscape-oriented page according to
the SetPortrait procedure of FIG. 24;
[0047] FIG. 26B is a diagram illustrating the conversion of a
landscape-oriented page to a portrait-oriented page according to
the SetPortrait procedure of FIG. 24;
[0048] FIG. 27 is a flowchart illustrating the program steps
implemented by the setvirtualdevice procedure according to the
imposition-on-the-fly procedures of the present invention;
[0049] FIG. 28 is a flowchart illustrating the program steps
implemented by the ImposeJob procedure according to the
imposition-on-the-fly procedures of the present invention;
[0050] FIG. 29 is a flowchart illustrating the program steps
implemented by the ImposeFile procedure according to the
imposition-on-the-fly procedures of the present invention;
[0051] FIG. 30 is a flowchart illustrating the program steps
implemented by the MakeNull procedure according to the
imposition-on-the-fly procedures of the present invention;
[0052] FIG. 31 is a flowchart illustrating the program steps
implemented by the redefined EndPage procedure according to the
imposition-on-the-fly procedures of the present invention;
[0053] FIG. 32 is a flowchart illustrating the program steps
implemented by the redefined BeginPage procedure according to the
imposition-on-the-fly procedures of the present invention;
[0054] FIG. 33 is a flowchart illustrating the program steps
implemented by the Vsave procedure according to the
imposition-on-the-fly procedures of the present invention;
[0055] FIG. 34 is a flowchart illustrating the program steps
implemented by the Vrestore procedure according to the
imposition-on-the-fly procedures of the present invention;
[0056] FIG. 35 is a flowchart illustrating the program steps
implemented by the redefined Postscript.RTM. save operators
according to the imposition-on-the-fly procedures of the present
invention;
[0057] FIG. 36 is a flowchart illustrating the program steps
implemented by the redefined PostScript.RTM. restore operator
according to the imposition-on-the-fly procedures of the present
invention; and
[0058] FIG. 37 is a flowchart illustrating the program steps
implemented by the redefined PostScript.RTM. grestore and
grestoreall operators according to the imposition-on-the-fly
procedures of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0059] FIG. 1 illustrates a prior art method of producing books,
for example, as shown in the above-identified Riley et al. '818
patent. During a publishing step 20, the contents of one or more
book versions are determined. Each version may comprise, for
example, a set of standard or common pages. In addition, some of
the versions may include one or more additional pages or other
customized information. Thereafter, during a preliminary step 22,
color correction of color images is undertaken together with
undercolor removal and screening for halftone images. During a
prepress step 24, page imposition is effected and printing
cylinders or plates are prepared. The plates or cylinders are then
used during a printing step 26 to prepare signatures which are
loaded into packer boxes (not shown). As noted in the Riley et al.
'818 patent identified above, the signatures are then selectively
collected on a gathering chain (not shown) during a book assembly
step 28 and the gathered signatures are bound and trimmed to create
the books. The books are thereafter distributed during a step 30 to
users via one or more distribution systems, for example, the U.S.
Postal Service.
[0060] As should be evident from the foregoing, customization
occurs during the book assembly step 28, inasmuch as the choice of
particular signatures to be included in a book is made at that
time. In addition, customized information can be printed onto
selected signatures using an ink jet printer disposed adjacent the
gathering chain. Thus, for example, addressee information can be
printed by the ink jet printer on assembled books so that
preprinted addressee labels need not be used. Other types of
customization can be effected at this time, for example, by
inserting or onserting cards into or onto a stack of collected
signatures, affixing a specialized or customized cover on a
gathered stack of signatures, or the like. Customization at this
point in the production process is simpler and less expensive than,
for example, separately printing each book version with customized
information.
[0061] FIG. 2 illustrates a block diagram of a method 40 according
to the present invention which may be used in place of the method
of FIG. 1 to produce books. The method 40 includes a step 42 which
utilizes the output of publishing and preliminary steps 36, 38 and
produces books for distribution according to the step 30 of FIG. 1.
The step 42 creates one or more master and variable page files in,
for example, a page description language (PDL) such as
PostScript.RTM. (PostScript.RTM. is a trademark of Adobe Systems,
Inc. for its page description language) representing pages to be
produced. In addition, as noted in greater detail hereinafter, a
press command file (also referred to as a "book ticket" file) is
developed which specifies the manner in which data contained within
the master and variable page files are to be merged to produce
printed pages. The format of the press command file may be, for
example, of the form specified by Barco Graphics of Gent, Belgium,
which is particularly suited for control of a DCP-1 digital color
press manufactured by Xeikon of Mortsel, Belgium. Alternatively,
the format of the press command file may be of the form specified
for control of a DocuPrint printer, manufactured by Xerox
Corporation. Other demand printers include the IBM 3900 or Siemens
2090 Twin or 2140 Twin. It should be noted that the apparatus and
method of the present invention are not limited to use with a
particular type of demand printer or a particular system for
controlling such a printer, inasmuch as the invention can be
adapted for use with any type of printer or control whether located
locally or remotely.
[0062] The master and variable page files and the press command
file are converted by a collator and raster image processor (RIP)
into bitmaps which may be stored in a memory. The stored bitmaps
are used to control one or more demand printers and/or any other
type of display device, such as a laser printer, a CRT, an LCD
display or the like so that the device displays pages having fixed
and variable information thereon. Alternatively, the master and
variable page files may be premerged to create a plurality of
combined files each representing a page to be reproduced with
master and variable information. The combined files can be then
sent to any type of printer or other display device, whether local
or remote. Also, the combined files can be converted to a suitable
format (e.g., Acrobat.RTM. PDF format) and transmitted to a remote
location using a facsimile machine, e-mail, the internet/worldwide
web or other transmission medium, if desired. Advantageously, the
combined files may be transmitted over the Internet or any other
networked or linked computers, such as a company intranet. In this
case, as electronic page containing customized data can be sent
over the Internet/intranet to a user-based upon user
demographic(s), a user search and/or any other identifiable user
interest(s). For example, a customized internet page could be sent
with links to other web pages of interest to a user or a customized
page may be sent in response to a user search for information on a
particular subject. Alternatively, or in addition, ads could be
generated and sent as a web page to one or more users based upon
user demographics. As a further example, personnel information
concerning a particular employee may be sent to the employee in
response to a request for information.
[0063] If the pages are to be displayed by rendering the pages on
the demand printer, the assembled books may be bound and trimmed
and, if desired, further customized, during a finishing step.
[0064] FIG. 3 illustrates a system 50 which implements the steps
36, 38 and 42 in the method 40 of FIG. 2. A control unit 52, which
may be implemented by a personal computer or another type of
computer, includes a memory 53 and stores therein data representing
images to be printed. As noted in greater detail hereinafter, the
data may be specified by a publisher using a personal computer 54
or any other type of computer and may comprise one or more template
files specifying pages to be produced with master or fixed printed
information (i.e., printed information which does not vary from
book to book of the same version) and variable printed information
(which typically varies from book to book). The variable
information may be stored in a database created by the publisher
and the template file(s) specify the locations on particular pages
for variable information stored in the database, as noted in
greater detail hereinafter.
[0065] If desired, image data may be obtained from any other type
of device or devices, such as a scanner which scans input copy,
data supplied over a network or any other source. The control unit
52 is further responsive to control and makeready files and causes
one or more demand printing systems 62 to print desired pages.
While three demand printing systems 62a-62c are illustrated in FIG.
3, it should be understood that the control unit 52 may operate a
different number of demand printing systems, as desired. Also, the
control unit 52 may operate a fax machine 64 and/or may communicate
with other remote devices to send properly converted combined
files, as desired and as noted above. In the case of other remote
devices, a modem 65 may be operated by the control unit 52 to
transmit data representing one or more pages to be displaced by a
display device at a remote location over phone lines (land lines
and/or cellular) or a combination of phone lines and the Internet.
Alternatively or in addition, the data may be sent to a local or
remote location at least in part over an intranet or another
computer network through a direct connection therewith. The
combined files may be printed or may alternatively be reproducible
in a different medium and/or may comprise a non-static image or
other information, e.g., movies or audio.
[0066] The pages printed by the demand printing system 62 may be
supplied to a finishing apparatus 66 which includes various
auxiliary production devices and device interfaces for assembling
the pages to produce finished books which are ready for
distribution. The finishing apparatus 66 may include one or more
gathering devices 70 for gathering printed pages into books, one or
more ink jet printers 72 for printing additional customized
information, such as addressee information, on each book, one or
more label printers 74 for printing address labels and/or other
control devices 76. In addition, one or more detectors 78 may be
provided to sense when a defective book is produced. The control
unit 52 may be responsive to the output of the detector 78 to
reorder a defective book at an appropriate point in the production
sequence thereof so that advantage can be taken of postal
discounts, if possible.
[0067] One or more components of the finishing apparatus 66 may be
physically located on the demand printer (i.e. "online finishing").
Alternatively, the finishing apparatus 66 may be physically
separate from the demand printer (i.e. "offline finishing").
[0068] FIG. 4 illustrates the demand print system 62a of FIG. 3 in
greater detail, it being understood that the systems 62b and 62c
are functionally similar. The system 62a includes a print system 79
having a press controller 80, a collator 81 and a raster image
processor (RIP) 82 which are operable in response to press commands
generated by the control unit 52. A collator is an electronic
device for storing raster image processor files (i.e., bitmap
files) and delivering selected files to a digital press in real
time, such that the digital press can run at full speed while
processing and printing unique page data for each book produced on
the press. The RIP 82 converts the page files to bitmap format or
any other format, such as a symbolic printer control language. The
collator 81 includes memory in the form of mass storage drives and
physical memory and collates the bitmap page files. If desired, the
collator 81 and/or RIP 82 may comprise a part of the press
controller 80. The controller 80 instructs the collator 81 to send
page files to a demand printer 84. The print system 79 may comprise
the PrintStreamer system, manufactured and marketed by Barco
Graphics of Belgium, while the demand printer 84 may comprise the
Xeikon DCP-1 digital color press noted above. Alternatively, the
demand printer 84 may be a DocuPrint printer manufactured by Xerox
Corporation and the RIP 82 may be a Xerox DocuPrint RIP. It should
be noted that a different print system and/or demand printer may
alternatively be used, such as the Indigo printer manufactured by
Indigo NV, of Maastricht, Netherlands, if desired.
[0069] FIG. 5 illustrates in diagrammatic generalized form the
method of the present invention. For the purpose of explaining the
present invention, as an example, it will be assumed that the
demand print system 62a will be operated to produce a number of
multiple-page books in the form of a brochure in duplex (or
"saddle-stich") format. FIGS. 6a and 6b illustrate four pages P1-P4
printed on a single sheet of paper 100 and to be included in a
brochure. The sheet of paper 100 includes a first side 100a with
printed pages P1, P4 thereon and a second side 100b with pages P2,
P3 printed thereon. (As will become evident hereinafter, the use of
designations P1-P4 is not meant to imply that such pages will
necessarily become pages 1, 2, 3 and 4 of the finished book.) In
addition, pages P1-P4 are imposed such that the page P1 is placed
on a right-hand portion 100a-r of the side 100a while the page P4
is placed on a left-hand portion 100a-1 of the side 100a. Further,
the page P2 is placed on a left-hand portion 100b-1 of the side
100b while the page P3 is placed on a right-hand portion 100b-r of
the side 10b. In this fashion, when the sheet of paper 100 is
folded along a fold line 102 with the pages P1 and P4 on the
outside, the pages P1-P4 appear in sequence. (The format shown in
FIGS. 6A and 6B is often referred to as "saddle stitch" imposition
and is commonly used in magazines.) Because each book to be
produced in this example includes multiple sheets of paper (or
"forms"), each folded once along a fold line, the imposition
process takes into account shingling effects but not bottling
effects. It should be noted both of that such effects will
generally have to be taken into account when more than two pages
are to be printed on a single side of a sheet of paper and
thereafter folded multiple times and assembled with other
multiple-folded printed sheets of paper to create a book.
[0070] In addition to the foregoing, in the first example, assume
that the pages P1 and P4 will become the outside front and back
covers, respectively, of a finished book and include variable and
fixed information thereon. Further, assume that the pages P2 and P3
will become the inside front and back covers, respectively, (as
must be the case if P1 and P4 are the outside front covers) and
include fixed information only thereon. For example, the page P1
may include variable information in the form of a personalized
message, a variable image, or the like in an area 110 whereas the
page P4 may include other variable information in an area 112, for
example, postal information for mailing the brochure to an
addressee. Corresponding front and back pages of the remaining
books may include different variable information. The remaining
printed information on pages P1-P4 may be identical to the printed
information on corresponding pages of remaining books.
[0071] The books to be produced may include the same or differing
number of forms and may have the same or differing numbers of
pages. For example, the pages P1-P4 may be assembled with a first
number of other forms printed with twelve additional pages to
produce a first book having sixteen pages. Another book to be
produced in the same run may include some or all of pages P1-P4 and
a second number of forms printed with twenty other pages, some of
which may or may not be identical to the twelve additional pages of
the first book. Filler pages may be placed in some or all books to
cause such book(s) to have a certain number of pages. This may be
necessary or desirable to result in a book length which is evenly
divisible by four (in the event pages are imposed as two-page
spreads) and/or to insure that particular page(s) appear on the
left-hand or right-hand side in the finished book.
[0072] In fact, the books to be produced in the same press run may
be different in terms of page content and/or appearance, book
length, book size (by changing page imposition parameters), book
version, etc . . . Specifically, for example, the pages of FIGS.
7a, 7b and 8a, 8b may be produced and assembled in different book
versions together with the book version incorporating the pages of
FIGS. 6a and 6b in the same production run or job. Pages P5-P8 of
FIGS. 7a and 7b are identical to the pages P1-P4, respectively, of
FIGS. 6a and 6b except that an additional area 113 is provided on
the page P5 for placement of variable information, in addition to
the areas 110 and 112. Because of the addition of the area 113, the
remaining master information appearing in an area 114 differs from
master information appearing in an area 116 of the page P1 of FIG.
6a.
[0073] The book version incorporating eight pages P9-P16 of FIGS.
8a and 8b differs from the book versions incorporating the pages of
FIGS. 6a, 6b and 7a, 7b not only in terms of content of master and
variable information, but also number of pages and page size.
Specifically, the pages P9, P12, P13 and P16 are to be printed on a
first side 117a of a sheet of paper 118 and the remaining pages P1,
P11, P14 and P15 are to be printed on a second side 117b of the
sheet 118. In addition, the pages P11-P14 are printed upside down
relative to the remaining pages so that, when the sheet 118 is
folded first along a fold line 119a and then along a fold line
119b, the resulting pages P9-P16 appear in order. Thereafter, the
folded sheet 118 is trimmed to separate the pages P9-P16. As should
be evident, the pages P9-P16 are one-half the size of the pages
P1-P8, and further include different master and variable
information thereon. The demand printer may also have multiple
paper trays to select different paper sizes, stocks, colors, etc.
or preprinted sheets to be included in the finished book.
[0074] Referring again to FIG. 5, one or more template files 106
are developed by a publisher specifying the content (including
appearance) of fixed information and the positioning of all
information (i.e., fixed and variable) on the different books or
book versions. A database 108 is also developed by the publisher
using the personal computer 54 specifying the content of variable
information to be placed in variable information areas, for
example, the areas 110, 112 on the pages P1, P4, respectively, of
FIGS. 6a and 6b. The database 108 further includes control
information, as noted in greater detail hereinafter.
[0075] The template files 106 include data specifying the position
and content of fixed information on the pages to be printed.
Specifically, the template files 106 define template pages wherein
each template page includes data representing any fixed information
to be reproduced on corresponding pages of the books or book
versions and area data representing any area(s) on the
corresponding pages where variable information is to be reproduced.
The template files are duplicated to create working files. One set
of working files is stripped of all area data relating to placement
of variable information to create stripped master page files 120
defining template pages having only fixed information thereon. The
stripped master page files are then converted into PDL master page
files 122 expressed in a page description language, such as
PostScript.RTM..
[0076] Optionally, the PDL master page files 122 may be converted
into two-pages spreads by a page make-up program such as
QuarkXPress.RTM.. Preferably, however, the PDL master page files
122 are provided to the print system 79 and imposed according to
the imposition processes of the present invention, as explained in
detail below.
[0077] A further set of working files is stripped of all fixed
information to create stripped variable page files 126 defining
template pages having fixed information removed therefrom and
further having the area data defining the areas 110, 112. The data
representing template pages having variable information thereon are
expanded into a set of intermediate page files. In the example of
FIGS. 6a and 6b and under the assumption that three books are to be
printed, two intermediate page files 130, 132 are thus produced.
The file 130 includes a file portion P1-a defining the position of
variable information to be produced on the page P1 for the first
book. Two other file portions P1-b and P1-c define the position of
variable information to be produced on the front outside covers of
the remaining two books. In like fashion, file portions P4-a, P4-b
and P4-c represent the position of variable information to be
reproduced on the back outside covers of the three books. At this
point, data is also contained in each of the files 130, 132
identifying the entries in the database 108 to be placed in the
areas 110, 112 during printing.
[0078] The files 130, 132 are then converted into variable page
files 134, 136. The files 134, 136 are identical to the files 130,
132, respectively, except that the data in each file identifying
entries in the database are replaced by the actual data stored at
such entries. The files 134, 136 are then converted into files 137,
138 in a PDL format, for example, PostScript.RTM..
[0079] Like the master PDL files 122, the variable PDL files 137,
138 may be converted into two-page spreads by a page make-up
program such as QuarkXPress.RTM.. Preferably, however, the variable
PDL files 137, 138 are provided to the print system 79 and imposed
according to the imposition procedures of the present invention, as
explained in detail below.
[0080] The print system 79 operates in response to the press
commands in a press command file 140 and merges the PDL master page
files 122 with the PDL variable files 137, 138 to create the
finished books or book versions. Alternatively, the master page
files 122 may be premerged with the PDL variable files 137, 138
before the files are provided to the print system 79.
[0081] FIG. 9 illustrates a flow chart of programming executed by
the personal computer 54 for creating the template file(s) 106 of
FIG. 5. The programming may be written as an extension of
QuarkXPress.RTM., a page make-up program distributed by Quark, Inc.
of Denver, Colo. The QuarkXPress.RTM. program may be adapted for
operation on the Apple.RTM. Macintosh.RTM. operating system or any
other operating system, such as the Microsoft Windows.RTM.
operating system. Alternatively, a different page make-up program
may be used, if desired.
[0082] During the make-up process for a document consisting of one
or more pages, a template file is created for each book version to
be produced, or, where a book is to include two or more parts
(referred to as "sections" hereinafter) a template file may be
created for each section. At a block 150 a user may select an area
of a page for reproduction of variable information therein, at
which point a line object, a text object or an image object may be
selected. A block 152 then checks to determine which type of object
has been selected. If a text object has been selected, indicating
that variable text is to be inserted at a point defined by the
current cursor position on the computer display, the name of the
appropriate field in the database 108 is inserted into the template
file at the insertion point defined by the current cursor position
by a block 154. If the user wishes to designate more areas for
variable information (block 156) control returns to the block 150
to await selection by the user. If the user then selects an image
object, a box is defined by the user to contain an image at a
desired location on a selected page. Control from the block 152
thereafter passes to a block 158 which inserts a dummy picture file
and an indication of the proper database field name in the template
file for the page at the location indicated by the current cursor
position. The user will thereafter see the dummy picture file at
the insertion point on the display of the computer 54 when the page
is viewed. The dummy picture file will display an indication of
which database field will be used for insertion on the respective
pages.
[0083] Following the block 158, a block 160 prompts the user to
enter an indication of whether the image object is to be displayed
in one of several display formats. If the image is to be displayed
in other than the original size thereof, a block 162 sets a subname
defined for: the image to "fit," indicating that the image is to be
Scaled to fit the box. If the image is to be displayed in the
original size thereof, a block 163 prompts a user to select a
position for the image at a particular location in the box defined
therefor, such as the upper left-hand corner, the lower right-hand
corner, or the like. If the user does not select a position, the
image is placed in the upper left corner of the image box. Control
thereafter proceeds to the block 156.
[0084] If the block 152 determines that a line object has been
selected, control returns directly to the block 150, inasmuch as
variable information cannot be entered into a line object. The
resulting page template files(s) are stored on a storage medium,
such as an optical disc or other storage device, and/or the
files(s) are downloaded together with the database to the control
unit 52.
[0085] At any point during the page make-up process, other
functional aspects of the QuarkXPress.RTM. program may be invoked
to both master and variable aspects as necessary to produce
finished pages.
[0086] The database 108 is assembled by creating an ASCII file
having a plurality of records wherein each record includes one or
more fields entered into the database in tab-delimited format (i.e,
the fields are separated from one another in each record by tab
keystrokes and the records are separated from one another by line
returns) and wherein the fields are arranged under field names of a
header. Each field may include text to be reproduced on a page or a
name of an image file stored in the memory 53 and defining an image
to be reproduced on a page.
[0087] In addition to the foregoing data, the database 108 may
include an optional field designating the number of copies of each
book to be produced, an optional townsort image field, a version
identification field indicating book version number if multiple
book versions are to be produced, an optional distribution list
field, control data and the like.
[0088] A sample database is set out below having a header
consisting of twelve fields (i.e., "version," "addressline1,"
"addressline2," etc.) and a number of records, nine of which are
shown, each having twelve fields:
1 Version Addressline1 Addressline2 Addressline3 Addressline4
Addressline5 Price 1 Image 1 Price 2 Copies Barcode Townsort 01
William 123 Elm Chicago Illinois 606248923 $22.95 Shoes $21.95 1
!606248923! Doe 03 Hugh Jorgensen 56 Maple Chicago Illinois
606248923 $21.95 Shirt $20.95 1 !606248923! 02 Jay P. Morgan 1313
Park Chicago Illinois 606248924 $24.95 Pants $22.95 1 !606248924!
.box-solid. 02 Joe Louis 819 Elm LaGrange Illinois 605251093 $19.95
Pants $18.95 1 !605251093! 03 John 926 LaGrange Illinois 605251093
$19.95 Shoes $15.25 1 !605251093! Smith Cossit 01 Len 882 LaGrange
Illinois 605251093 $19.95 Shoes $17.25 1 !605251093! Johnson Monroe
02 Janet 916 LaGrange Illinois 605251094 $24.95 Pants $21.95 1
!605251094! .box-solid. Cizmar Monroe 03 Jay 88 W. Brookfield
Illinois 605241391 $21.95 Shirt $19.95 1 !605241391! Schroeder 77th
03 Danielle 129 Brookfield Illinois 605241391 $22.95 Shirt $19.95 1
!605241391! .box-solid. Johnston Madison
[0089] In the example of FIGS. 6a and 6b, the field names
ADDRESSLINE1 through ADDRESSLINE5, BARCODE and TOWNSORT may appear
in the area 112 and one or more of the field names PRICE1, IMAGE1
AND PRICE2 may appear in the area 110. The COPIES field may be used
as a control code to select the number of book copies to be
produced.
[0090] Once the template file(s) 106 and the database 108 are
assembled, the programming of FIGS. 10a-10f may be executed by the
control unit 52 to create the master page file 122, the
final-variable page files 137 and 138, and the press command file
140. Referring first to FIG. 10a, a block 170 prompts a user to
select a template file 106 and a block 172 opens the database 108.
A block 174 then reads and stores in a list the database field
names for later reference and a block 176 prompts a user to enter
information indicating a section number and whether pages are to be
printed in simplex (i.e., single-sided) or duplex (i.e.,
double-sided) format. The section number identifies the order in
which multiple sections are to be processed for a particular book.
The user may also be prompted to enter a selective processing code
identifying a particular book version to process if multiple
versions are to be produced during a single press run.
[0091] Following the block 176, a block 177 begins the process of
stripping variable information from the template file opened by the
block 170 to obtain the stripped master file 120 of FIG. 5. The
block 177 selects a first page for processing and a block 178
checks to determine whether there are any images in the template
file and, if images are located, a block 180 selects a first
image.
[0092] A block 182 identifies the file name for the image and a
block 184 checks the field list to determine whether the file name
is included therein. If the file name for the image is included in
the field list, then the image comprises variable information and a
block 186 deletes the image block. A block 187 then identifies and
saves the image box location on the page, the characteristics of
the image box, such as the size, skew, background color and subname
and the like and further saves the field name of the image from the
database 108. Also, a counter in the memory 53 which tracks the
number of variable image boxes on the page is incremented.
[0093] Otherwise, if the block 184 determines that the file name is
not in the field list, then the image contains only master
information. A block 188 then also saves the image box location on
the page and the characteristics of the image box. Also, a counter
in the memory 53 which tracks the number of master image boxes on
the page is incremented.
[0094] A block 189 then checks to determine whether all images have
been processed. If not, a block 190 selects a next image and
control returns to the blocks 182-189. Control remains with such
blocks until the block 189 determines that all images have been
processed and control then passes to a block 192. Control also
passes to the block 192 from the block 178 should the latter
determine that there are no images in the template file.
[0095] The block 192 determines whether any text boxes are present
in the open template file. If at least one text box is present, a
block 194 selects and parses a first text box and a block 196 (FIG.
10b) checks to determine whether the text box includes at least one
of the field names of the database 108. If so, then it has been
determined that the text box includes variable information and a
block 198 deletes the text box. A block 199 then stores the text
box location, the insertion points in the text box at which
variable information is to be printed and the characteristics of
the text box and the field names of the database 108 identified in
such text box in the memory 53. In addition, a variable text box
counter is incremented representing the number of variable text
boxes appearing on each page.
[0096] Otherwise, if the block 196 determines that the text box
does not include any field names from the database, then the text
box contains only master information. A block 200 stores the text
box location in the memory 53. In addition, a master text box
counter is incremented representing the number of master text boxes
appearing on each page.
[0097] Control then passes to a block 202, which checks to
determine whether all text boxes in the template file have been
processed. If not, a block 204 selects and parses the next text box
in the template file and control returns to the blocks 196-202.
Control remains with such blocks until all text boxes have been
processed, whereupon a block 206 determines whether all pages have
been processed. If not, a block 208 selects a next page and control
returns to the block 178 (FIG. 10a). Otherwise, a block 210 saves
the resulting file as the stripped master file.
[0098] Alternatively, if a page contains a lot of formatting
information (i.e. tabs, fonts, etc.), a rich text file (which
includes such formatting information) may be created offline from
the database. The text box may then open the rich text file and
read the information from the file. The use of the rich text file
speeds up the processing time.
[0099] Also, once a placeholder on a page has been "filled in" with
information from the database field, the program may mark the
corresponding text or image box as "touched." Thus, if the text or
image box is "untouched," the program can skip processing of that
text or image box, also speeding up the total processing time.
[0100] Control also bypasses the blocks 194-202 and proceeds
directly from the block 192 to the block 206 if the block 192
determines that there are no text boxes in the open template
file.
[0101] Following the block 210, a block 212 converts the stripped
master file into the PDL master page file 122 of FIG. 5. _At the
same time, an initialization (or INI) file may be created. The
format and existence of the INI file depends on the type of demand
printer utilized. For example, the DocuPrint demand printer does
not require the use of an INI file. However, the Barco RIP requires
the use of an INI file.
[0102] The INI file (in ASCII code) for the Barco RIP is created
according to the following format:
[0103] name: [file path.backslash.name]
[0104] psx: [dimension]
[0105] psy: [dimension]
[0106] ssx: [dimension]
[0107] ssy: [dimension]
[0108] posx: [dimension]
[0109] posy: [dimension]
[0110] duplex: [zero or one]
[0111] orientation: [zero or one]
[0112] output: [filename]
[0113] copies: [number]
[0114] Where "psx" and "psy" refer to finished page sizes in x and
y directions, "ssx" and "ssy" refer to cut sheet size in x and y
directions, "posx" and "posy" refer to offsets in x and y
directions specifying placement of each page on a cut sheet,
"duplex" refers to single or two-sided printing, "orientation"
refers to portrait or landscape printing, "output" refers to the
name of the output file and "copies" refers to the number of copies
to be printed. A sample INI file which specifies parameters for
printing of a file called MYJOB.PS is as follows:
[0115] Name: C:.backslash.jobs.backslash.myjob.ps
[0116] psx: 8000
[0117] psy: 11000
[0118] SSX: 11500
[0119] ssy: 9000
[0120] posx: 150
[0121] posy: 150
[0122] duplex: 1
[0123] orientation: 1
[0124] output: myjob.ps
[0125] copies: 1
[0126] In the foregoing example, one copy of the file MYJOB.PS is
to be printed in duplex and portrait formats at an offset of
0.15.times.0.15 inches from a corner of a finished sheet of paper
8.times.11 inches cut from a sheet originally having dimensions of
9.times.11.5 inches.
[0127] For the DocuPrint (or any other demand printer which does
not use an INI file), a queue is created which contains the same
parameters (and potentially additional parameters which may invoke
the functionality of an inline finisher, or other apparatus) as the
INI file.
[0128] Following the block 212, a block 214 then reopens the same
template file originally opened by the block 170 and deletes all
the master image and text boxes. A block 216 than saves the
resulting file as the stripped variable file 126 of FIG. 5.
[0129] A block 218 then creates a temporary file containing a table
of the current page number and a number representing the name of
the database field placed by the block 154 at the insertion point.
The file is called, for example, *.VARS (where * is a user-selected
file name). The *.VARS file thus contains pairs of page numbers and
database column numbers that indicate where in the database
variable information for the page comes from. For example, the
*.VARS file may contain the following information:
2 1 7 8 43 9 44 10 45 11 46 11 47 13 50 14 52 15 50 15 51
[0130] In the example above, page 1 contains variable data from
column 7 of the database, page 8 contains variable data from column
43 and page 11 contains variable data from column 46 and 47.
Further, the *.VARS file may contain separate pairings for images
and text.
[0131] Control then passes to block 242 (FIG. 10c) which creates a
working copy of the stripped variable file 126. A first page having
variable data thereon is selected and data representing the
remaining pages in the file are deleted by a block 244. In the
example of FIGS. 6a and 6b, the block 244 creates a file defining
the front cover of a book with all fixed information deleted
therefrom and an area reserved for variable information.
[0132] Following the block 244, a block 246 selects a first record
in the database 108 and a block 248 reads the record. An optional
block 250 checks to determine whether a selective processing code
has been entered by the user indicating that the page is to undergo
selective page processing. As noted above, the apparatus and method
of the present invention may be utilized to produce not only books
of a single version (i.e., where corresponding pages differ only in
terms of the variable information stored in the database) but also
books of different versions. In the latter case, the books of
different versions have different fixed and variable information.
The fixed and/or variable information may vary in terms of content
or appearance (i.e., style, location, rotation, position, etc.) or
both in different versions.
[0133] If the block 250 determines that selective page processing
is to be undertaken, then a block 252 checks to determine whether
the database record read by the block 248 is to be utilized on the
page currently under consideration. The block 252 accomplishes this
by checking the version identification field in the database to
determine if that version is being used. If this is not the case, a
block 253 checks to determine whether the record currently under
consideration is the last in the database. If so, control passes to
a block 294 of FIG. 10e. Otherwise, a block 254 selects a next
record in the database 108 and control returns to the block 248
where the next database record is read.
[0134] If the block 250 determines that selective page processing
is not to be undertaken, or if the block 252 determines that the
record read by the block 248 is to be used in the page currently
under consideration, a block 256 duplicates the data representing
the page remaining after execution by the block 244 to initiate
development of one of the files 130 or 132. In the first pass
through the program of FIG. 10c, and in connection with the example
of FIGS. 6a and 6b, the block 256 creates the file 130 and develops
page data representing a first version of the page P1-a and adds
further variable information to such page data during immediately
succeeding passes through the program. Thereafter, data
representing the remaining pages P1-b, P1-c and P4-a through P4-c
are created and variable information is added to such pages
serially during subsequent passes.
[0135] A block 258 checks to determine whether there are any image
boxes on the page and, if so, a block 260 selects a first image
box. A block 262 then inserts the image identified by the database
field into the image box. A block 264, FIG. 10d, checks the subname
to determine whether the block 162 of FIG. 9 has indicated that the
image should be sized to fit the image box. If this is true, a
block 266 performs the scaling. Otherwise, a block 268 positions
the image in the image box at the position specified by the user
and a block 270 checks to determine whether all image boxes have
been processed. Control also passes from the block 266 directly to
the block 270, thereby skipping the block 268. If not all image
boxes have been processed, a block 272 selects a next image box on
the page and control returns to the blocks 262-270 so that
remaining image boxes are serially processed.
[0136] Once the block 270 determines that all image boxes have been
processed, or immediately following the block 258 of FIG. 10c if no
image boxes are found on the page, a block 274 checks to determine
whether there are any text boxes on the page and, if so, a pair of
blocks 276, 278 select a first text box and a first insertion point
in such box. Blocks 280, 282 and 284 serially insert text data
stored in the database 108 at the appropriate insertion points in
the text box. Once all of the variable text data have been inserted
into the text box, a block 286 recomposes all text in the text box
so that the text obtains a neat finished appearance. The
recomposition process is automatically undertaken by the
QuarkXPress.RTM. program once the variable information is inserted
into each text box. The recomposition process is responsive to the
user commands as applied to the template file page, such as left,
right, center, or full justification, hyphenation and the like.
Following the block 286, a block 288, FIG. 10e, checks to determine
whether there are remaining text boxes to be processed on the page
and, if so, a block 290 selects the next text box on the page and
control returns to the blocks 278-288 to insert text information
into such text boxes.
[0137] Once the block 288 determines that all text boxes for the
page have been processed, the programming required to produce one
of the pages of the file 134 of FIG. 5 having variable information
only thereon is complete. A block 292 then determines whether all
records in the database have been considered for inclusion in
additional variable pages of the file 134 to be produced. If not
all records have been considered, control returns to the block 254,
FIG. 10c, where the next database record is identified and read. On
the other hand, if all pages of the file 134 have been produced by
considering all records in the database 108, a block 294 converts
the file data into postscript.RTM. or another PDL format to create
the variable page file 137 of FIG. 5. Also, an INI file is created
as before, except that the "duplex" or "twinplex" parameter is set
to command simplex printing only. If necessary or desirable, should
the press run length exceed a certain limit, the programming may be
modified to create more than one variable page file for each
variable page of the template file.
[0138] Following the block 294, a block 296 checks to determine
whether there are other variable pages in the stripped variable
page file to be processed. If this is true, a block 298 retrieves a
copy of the stripped variable file, selects the next variable page
therein and deletes remaining pages therefrom. Control then returns
to the block 246 of FIG. 10c. In the example of FIGS. 6a and 6b,
the back cover P4 and the corresponding pages of the remaining
books are now selected for processing. In the fashion noted above,
a file representing the variable portions of such pages is produced
by developing the file representing the pages P4-a through P4-c and
inserting the database information into such file to obtain the
variable page file 136 and the PDL version 138.
[0139] Following generation of the variable page files 134, 136,
and 137, 138 control passes to a block 300 which checks to
determine whether a press command file has already been created. If
not, a file is created by a block 302 having placeholder comments
indicating where in the press command file individual press
commands are to be placed for each book to be produced. The press
command file may also include data from one or more fields of the
database 108 identifying an intended recipient of each book to be
produced to assist in reproducing books found to be defective or to
produce sample books. At this point, the press command file for the
example of FIGS. 6a and 6b may be as follows (using data from the
sample database set out above):
3 ;RECORD1 ;:WILLIAM DOE:606248923 ;ENDRECORD ;RECORD2 ;:HUGH
JORGENSEN:606248923 ;END RECORD ;RECORD3 ;:JAY P. MORGAN:606248924
;END RECORD
[0140] Following the block 300 (if the press command file already
exists) or the block 302 a block 304 selects the first database
record and a corresponding first record in the press command file.
A block 306 then checks to determine whether the template file
currently being processed includes the selected database record. If
not, a block 308 determines whether all pages have been processed,
and if this is not the case, the next record in the database 108
and a corresponding record in the press command file are selected.
Control then returns to the block 306. If the block 306 ascertains
that the template file includes the selected record, a block 312
inserts an indication of the section number in the press command
file at an appropriate point if the section number is not already
present. If the section number is present already, the press
command identified by the section number entered by the user at the
block 176 is identified to be overwritten at a later point. The
press command file now appears as follows for the example of FIGS.
6a and 6b:
4 ;RECORD1 ;:WILLIAM DOE:606248923 ;SECTION 1 ;ENDSECTION
;ENDRECORD ;RECORD2 ;:HUGH JORGENSEN:6062488923 ;SECTION 1
;ENDSECTION ;END RECORD ;RECORD3 ;:JAY P. MORGAN:606248924 ;SECTION
1 ;END SECTION ;END RECORD
[0141] Following the block 312, a block 314, FIG. 10f, selects a
first page of the section and a block 316 checks the state of a
flag stored in the memory 53 to determine whether a simplex or
duplex job has been requested. If a simplex job has been requested,
the file name and page number of the master page file and, if
variable information is to appear on the page, the file name and
page number of the variable page file for the selected page are
stored as a single set pair in the memory 53 by a block 318. The
determination of whether variable information is to appear on the
selected page is accomplished by summing the contents of the
variable image box counter and the variable text box counter as
incremented by the blocks 220 and 234 of FIG. 10b.
[0142] A block 320 checks to determine whether all pages have been
processed and, if not, the next page is selected by a block 322 and
control returns to the block 316 for processing of such page. If
all pages have been processed, control passes to a block 324 which
determines whether all database and press command records have been
processed. Control also passes to the block 324 if the block 308
determines that all pages have been processed. If not all records
have been processed at this point, control returns to the block 310
where the next records in the database and press command file are
selected.
[0143] If the block 324 determines that all records for the current
section have been processed, a block 326 determines whether another
section is to be processed and, if so, control returns to the block
170 of FIG. 10a. If there is not another section to be processed,
the press command file has been fully assembled, and hence the
process terminates.
[0144] If the block 316 determines that a duplex job is to be
effected, control passes to a block 328 which stores in the memory
53 a command identifying the file names and page numbers of the
master page file (as well as corresponding information relative to
variable page files, if variable information is to appear) as
two-set pairs. Control from the block 328 then passes to the block
320 described above.
[0145] The result of the programming of FIGS. 10a-10f is a press
command file having a sequence of press commands which cause
printing of pages in a desired order. In order to print the sample
pages of FIGS. 6a and 6b, the press command file would read as
follows:
5 BOOK A ;RECORD1 ;:WILLIAM DOE:606248923 ;SECTION 1
"file.m"1@"file.v1"1.vertline."f- ile.m"2
"file.m"3.vertline."file.m"4@"file.v4"1 ;ENDSECTION ;ENDRECORD
;RECORD2 ;:HUGH JORGENSEN:606248923 ;SECTION 1
"file.m"1@"file.v1"2.vertl- ine."file.m"2
"file.m"3.vertline."file.m"4@"file.v4"2 ;ENDSECTION ;ENDRECORD
;RECORD3 ;:JAY P. MORGAN:606248924 ;SECTION 1
"file.m"1@"file.v1"3.vertline- ."file.m"2
"file.m"3.vertline."file.m"4@"file.v4"3 ;ENDSECTION ;ENDRECORD
ENDBOOK PRINTRUN R BOOK A END PRINTRUN
[0146] In the foregoing example, "file.m" is a file name
identifying the master page file 122 and "file.v1" and "file.v4"
are file names identifying the variable page files 137 and 138,
respectively. The number following each file name designates a
particular page of the file identified by the file name. Thus, for
example, "file.m"1 designates the first page of the master file
"file.m" and "file.v1"2 designates the second page of the variable
page file "file.v1." The @ sign means to associate the pages of the
files linked by such sign (i.e. overlay the variable pages on the
master pages). The vertical line in the commands indicates that the
page(s) on the left side of the vertical line are to be printed on
the front side of a piece of paper whereas the page(s) on the right
side of the vertical line are to be printed on the reverse side of
the piece of paper. In an example of simplex printing, no file name
would appear to the right of the vertical line in each command.
[0147] FIG. 11 illustrates the programming implemented by the
control unit 52 to generate a page description language instruction
set specifying which pages should be printed and how the pages
should be positioned (or imposed) for printing. The page
description language instruction set may be incorporated into the
press command file 140 or may be provided as a separate file to the
print system 79. For purposes of illustration, the page description
language instruction set is written in Postscript.RTM. in the
format dictated by the Xerox DocuPrint printer. Further, the
instruction set is directed to books printed in "saddle stitch"
imposition format (i.e. 2 pages on each side of sheet) as explained
in connection with FIGS. 6-8. It is understood, however, that the
invention could easily be modified for use with a different demand
printer (i.e. the Xeikon Barco printer) and/or imposition format
(i.e. 4 pages on each side of sheet).
[0148] Referring to FIG. 11, the programming begins at a block 340
which prompts a user to specify certain information to be used to
paginate the book. A variable ("MAXPGS") representing the maximum
number of supplied pages that may or may not be assembled into a
single book during the job is specified together with the
identification of a filler page that may or may not be printed and
assembled in a book either on a left-hand or a right-hand portion
thereof. Also, the user is prompted to specify for each page
whether such page will be forced to be on the left side of a book,
the right side of a book or will not be forced to a particular book
side. In the event a page is to be forced to a side, the user is
prompted to specify the page file name and page number for a filler
page to precede the forced page. Still further, the user is
prompted to specify for each page whether such page is:
[0149] 1) A Master Page--contains the same information and is
included in every book;
[0150] 2) An Always Variable Page--contains variable information
and is included in every book; or
[0151] 3) A Selectively Variable Page--contains variable
information and is selectively included in selected books.
[0152] In so specifying the foregoing, the user creates a
pagination file (called, for example, *.PAG, where * indicates a
file name selected by the user). A sample window generated by the
block 340 to prompt a user for the information needed to create the
pagination file is shown in FIG. 12.
[0153] Referring again to FIG. 11, following the block 340, a block
342 opens the press command file 140 and a block 344 selects the
appropriate database files, including the variable information file
(*.vars), the pagination file (*.pag), and (optionally) a barcode
file. As set forth above, the *.vars file is a temporary file of
pairs of page numbers and database column numbers that indicate
where in the database variable information for the page comes
from.
[0154] The barcode file is a page description language file (for
example, a PostScript.RTM. file) which contains instructions for
printing the sequential page numbers and/or a tracking bar code on
the pages of the completed book. The barcode file will be explained
in detail below.
[0155] The programming then proceeds to the loop containing blocks
346, 348, 350, 352 and 354. The block 346 takes each record (or
book) in the press command file 140 in sequential order. For each
record, the block 348 determines which pages should be printed to
generate that particular book. Next, the block 350 determines
whether the pages to be printed should be forced to the right hand
or left hand side of the book and the block 352 "pads" the pages to
be printed to be a multiples of the number of pages to be printed
on a sheet (in our example, 4) by adding appropriate filler pages.
Next, the block 354 generates the PostScript.RTM. instruction set
and the programming returns to the block 346 to retrieve the next
record in the press command file 140. The loop repeats for each
record in the press command file 140.
[0156] FIG. 13 illustrates in detail the programming steps
implemented by the block 348 of FIG. 11, which determines which
pages should be printed for a particular record in the press
command file 140. A block 360 first retrieves the first page in the
record. A decision-making block 362 then determines whether the
page is from a new file that is to be "imposed-on-the-fly with
offsets." (Imposition-on-the-fly with offsets is one of the
imposition formats of the present invention, which will be
explained in detail below). If yes, a block 364 calculates and
saves the offsets for all the pages in the file. After the block
364 calculates and saves the offsets or if the block 362 is false,
a decision-making block 366 then determines whether the page is a
master page (i.e. does not include any variable information
placeholders). If the page is a master page, the page should always
be printed and a block 368 "marks" the page to be printed. The
block 368 may "mark" the page by adding it to a page print array.
The page print array contains the page number and a marker to
indicate the disposition of the page. For example, pages that
should not be printed are designated with a "0"; master pages
(always printed) are designated with a "1"; and variable pages to
be printed are designated with a "2".
[0157] If the block 366 determines that the page is not a master
page (i.e. it's a variable page), a decision-making block 370
determines whether the variable page should be printed at all
times. (This was designated by the user at the block 340 in FIG. 11
during creation of the pagination file). If yes, the block 368
marks the page to be printed. If no, a decision-making block 372
determines whether the page has any variable placeholders with
valid data. In other words, the block 372 determines whether there
is any variable information from the database to be printed on the
page. If yes, the block 368 marks the page for printing. The
program then returns to the block 360 to retrieve the next page
from the record until all the appropriate pages have been marked
for printing.
[0158] FIG. 14 illustrates in detail the programming steps
implemented by the block 350 of FIG. 11 to determine whether the
pages should be forced to the left or right hand side of the book.
A block 380 first initializes a left/right (L/R) counter variable
to its default value of right because it is assumed that the first
page of the book will be one the right side. Next, a block 382
retrieves the first page from the record that is marked "should
print" and a block 384 determines whether the user has specified
whether the page should be forced to the left or right side. (This
was designated by the user during creation of the pagination file
at block 340 of FIG. 11). If the user has not specified that the
page should be forced, a block 386 flip-flops the L/R counter such
that if it was set to right it is changed to left and if it was set
to left, it is changed to right and the program returns to the
block 382 to retrieve the next "should print" page in the
record.
[0159] Alternatively, if the block 384 determines that the user has
specified that the page should be forced left or right, a block 388
determines whether the user specification matches the orientation
of the page (i.e. is it the same as the L/R counter). If yes, the
block 386 flip-flops the L/R counter and returns to the block 382
to retrieve the next "should print" page in the record. Otherwise,
a block 390 marks an appropriate filler page (which was identified
by the user during creation of the pagination file) to be printed
and the program returns to the block 382 to retrieve the next
"should print" page in the record.
[0160] FIG. 15 illustrates in detail the programming steps
implemented by the block 352 of FIG. 11 to "pad" the pages into a
multiple of the number of pages to be printed on a sheet. In our
example, using "saddle stitch" imposition, four pages are printed
on a sheet (2 pages per side). Therefore, filler pages may need to
be added to ensure that the total number of pages in the book is a
multiple of 4. A block 392 first counts the number of pages in the
record that have been marked to print. This includes all the master
and variable pages that were marked by the block 368 of FIG. 13 as
well as any filler pages that were marked by the block 390 of FIG.
14. Next, a block 394 determines whether the total number of pages
is a multiple of 4. If not, a block 396 adds the appropriate number
of filler pages to make the total number of pages a multiple of 4.
For example, if the block 392 determines that 18 pages are marked
to print, the block 396 will add 2 filler pages to make the total
number of pages in the book equal to 20 (a multiple of four). The
program then returns to the block 354 of FIG. 11 which generates
the postScript.RTM. instruction set.
[0161] The Postscript.RTM. instruction set specifies how the pages
marked to print should be positioned (or imposed) for printing. In
our example, for a "saddle-stitch" imposition format, and assuming
a 12 page book, the block 354 generates an instruction specifying
that the pages should be positioned as shown in the following
table:
6 Sheet No. Side No. Left Side Right Side 1 1 Page 12 Page 1 1 2
Page 2 Page 11 2 1 Page 10 Page 3 2 2 Page 4 Page 9 3 1 Page 8 Page
5 3 2 Page 6 Page 7
[0162] It is understood that a different instruction set could be
generated (by an imposition program) to impose and print the pages
in a different format (i.e. four pages per side) or alternatively,
a different number of total pages.
[0163] After the block 354 generates the imposition instruction
set, the pages are imposed and printed according to an imposition
procedure of the present invention. The first imposition procedure
of the present invention utilizes an artificial PostScript.RTM.
operator called "GetTIFF", which is recognized by the Xerox
DocuPrint RIP, wherein page files are preprocessed to TIFF ("tagged
image file format") format before being provided to the RIP. The
second imposition procedure of the present invention (referred to
as "imposition-on-the-fly") involves downloading imposition
programs to the RIP which redefine various PostScript.RTM.
operators to automatically position pages while each page is being
interpreted.
[0164] A user is prompted to specify various information needed for
imposition and printing, including the sheet size (i.e.
11.times.17), imposition style (imposition-on-the-fly or GetTIFF),
finishing style (online or offline), the output device (i.e. Xerox
DocuPrint or Barco Xeikon) and the name of the directory where the
master and variable page files are stored. A sample window to
prompt a user to provide this information is shown in FIG. 16.
[0165] GetTIFF Imposition
[0166] A TIFF (tagged image file format) file is a bitmap
representation of a page in the same screen format as the print
engine. Several commercially available RIPs (such as Image Alchemy
or TranverterPro) process pages represented in a page description
language format to TIFF format. The Xerox DocuPrint RIP recognizes
an artificial PostScript.RTM. operator called "GetTIFF" which
retrieves a specified TIFF file and quickly processes the file for
rendering by the DocuPrint demand printer. (Other demand printer
RIPs, including the Barco Xeikon, may also be modified to recognize
a GetTIFF-type operator).
[0167] In a preferred embodiment of the present invention, the
master page PDL files 122 and the variable page PDL files 137, 138
are preprocessed to TIFF format. Because the Xerox DocuPrint system
allows for only one input data stream (as opposed to the Barco
Xeikon system which allows two data streams--master and variable),
the master page PDL files 122 and the variable page PDL files 137,
138 may be premerged. This may be accomplished by forcing all of
the master data onto the variable template files. After the master
and variable pages are merged, the instruction set and GetTIFF
operator are used to quickly impose and process the pages for
printing.
[0168] Alternatively, the master and variable data streams may be
overlayed by first processing the master pages and then overlaying
the variable pages onto the master pages.
[0169] FIG. 17 illustrates programming which may be executed to
facilitate conversion of the page files into TIFF format. The
programming begins at a block 397 which opens the press command
file stored in the memory 53. A block 398 then prompts a user to
specify options which are available. The options include the
ability to convert only master page files, only variable page files
or both master and variable page files into bitmap format. A block
399 then selects the first line in the press command file having at
least one file name therein. Thereafter, a block 400 selects a
first file name and a block 401 checks a file list stored in the
memory 53 to see if the file name has been previously placed in the
list. If this is not the case, then this is the first time the file
name has been encountered in the programming of FIG. 17. Thus, a
block 402 adds the file name to the file list and a block 403
checks the user-specified options set by the block 398 to determine
whether the file should be converted into TIFF format. If so, a RIP
list stored in the memory 53 is updated by adding the file name
thereto (block 404) and control passes to a block 405. Control also
passes to the block 405 from the block 403 (bypassing the block
404) if the file is not to be converted into TIFF format, and from
the block 401 if the file name currently under consideration is
already in the file list.
[0170] The block 405 checks to determine whether the end of the
current line in the press command file has been reached. If not, a
block 406 selects the next file name in the line and control
returns to the block 401.
[0171] If the block 405 determines that the end of the current line
in the press command file has been reached, a block 407 checks to
determine whether the end of the press command file has been
reached. If not, a block 408 selects the next line in the press
command file having at least one file name and control returns to
the block 400. On the other hand, if the end of the file has been
reached, a block 409 causes the RIP 82 (or another RIP) to convert
the files identified in the RIP list into TIFF format.
[0172] The programming of FIG. 17 thus facilitates conversion of
files to TIFF format as required by the print system 79.
[0173] Referring to FIG. 18, if the user specified GetTIFF
imposition and after the page files have been RIPped to TIFF format
by the programming of FIG. 17, a block 410 retrieves the first page
pairing from the instruction set (in our example, page 12 as the
left hand page and page 1 as the right hand page). A block 412 then
retrieves a reference to the page description of the left hand page
in TIFF format from the page file and provides it to the RIP 82.
Assuming the default offset is positioned at the left side of the
sheet, the left hand page is positioned on the left side of the
sheet.
[0174] A block 414 then moves the offset to position the next page
onto the right side of the sheet. A block 416 retrieves the
reference to the page description in TIFF format of the right hand
page from the page file and provides it to the RIP 82. Next, a
block 418 may add page numbers and/or a bar tracking code to the
sheet, as explained below. The program then returns to the block
410 to retrieve the next page pair from the instruction set and the
program repeats until all pages and all books have been
processed.
[0175] After all pages have been processed, they are RIPped and
printed by the demand printer 84 in accordance with the
initialization (INI) file, which was created by the block 212 (FIG.
10b).
[0176] If, for example, the demand printer is a DocuPrint (i.e., no
INI file was created), the pages are submitted to the queue (which
contains the same parameters as the INI file) for RIPping and
printing.
[0177] A partial Postscript.RTM. instruction set for printing the
12-twelve page brochure in accordance with the table above
implementing the GetTIFF imposition according to FIG. 18 is set
forth below:
7 << /PageSize [1224 792] % set sheet size >>
setpagedevice % (11 .times. 17) (VERON12.V01_dir/ % get left page
VERON12.V01.00000002.tiff) GetTIFF 612 0 translate % move to right
(VERON01.V01_dir/ % get right page VERON01.V01.00000002.tiff)
GetTIFF showpage (VERON02.M_dir/ % get left page
VERON02.M.00000002.tiff) GetTIFF 612 0 translate % move to right
(VERON11.V01_dir/ % get right page VERON11.V01.00000002.tiff)
GetTIFF showpage . . . (VERON06.M_dir/ % get left page
VERON06.M.00000004.tiff) GetTiff 612 0 translate % move to right
(VERON07.V03_dir/ % get right page VERON07.V03.00000003.tiff)
GetTiff showpage % reset to left
[0178] In the instruction set, the "VERON*.*_dir/VERON*.*"
indicates the directory and filename where the page descriptions
are located. The suffix ".M" indicates a master page and the suffix
"V______" indicates a variable page (with the version number of the
variable page to be printed). The suffix "______.tiff" is the file
name created by the RIP which converted the page files to TIFF
files and indicates that the files are in TIFF format. The
artificial PostScript.RTM. "GetTIFF" operator interprets the TIFF
files. The "612 0 translate" command moves the offset to the right
hand side of the sheet (block 414) and the PostScript.RTM. showpage
operator transmits the page to the demand printer 84 for rendering,
prepares for interpreting the next page description and resets the
offset to the lefthand side.
[0179] Optionally, the block 418 may print page numbers and/or a
bar tracking code onto the sheets printed by the demand printer 84.
This may be accomplished by adding the following additional
Postscript.RTM. code before the showpage operator in the
instruction set shown above:
8 /C39P24Dm 24 selectfont % add bar code info 30 4.5 sub 18
translate 90 rotate % position on 0 0 moveto % side of sheet (1.12)
show % indicates sheet 1 of 12 % /Helvetica 12 selectfont % add
page numbers 320 780 moveto % center in middle of left page (12)
show % print page "12" -320 780 moveto % center in middle of right
page (1) show % print page "1"
[0180] The first section of code provides the command for printing
a bar code (indicating for example, the page number and the total
number of pages in the book). The second section of the code prints
page numbers centered at the bottom of each page. A similar
technique could be used to do any "post page" modifications, such
as watermarking samples or QC books, adding variable printers marks
or the like.
[0181] Imposition-on-the-Fly
[0182] The user may also specify that the pages be imposed and
printed using the imposition-on-the-fly technique of the present
invention. This technique positions the pages while the pages are
being interpreted by the RIP. FIG. 19 is a more detailed block
diagram of the print system 79 shown in FIG. 4. The PDL master page
files 122 and the PDL variable page files 137, 138 may be combined
into merged PDL files (such as merged PostScript file(s) 450),
which are then provided to the print system 79, comprised of RIP
82, collator 81, press controller 80 and demand printer 84. The
press command file 140, which includes the instruction set for
specifying how pages should be imposed, is also provided to the
print system 79.
[0183] Alternatively, as described above, the master page files 122
and the variable page files 137, 138 may be provided separately to
the print system 79 and overlayed.
[0184] The print system 79 may also include a raster memory 452
associated with the RIP 82 and the demand printer 84. The RIP 82
generates a raster description of the "current page" being
interpreted, which may be stored in the raster memory 452 or
provided to the demand printer 84 for rendering. The demand printer
84 physically renders pages 454 from the merged PostScript.RTM.
file 450 onto a "flat" (or other medium) 456.
[0185] For purposes of illustration, it is assumed that the RIP 82
interprets the widely used PostScript.RTM. PDL language.
(Postscript.RTM. is a registered trademark of Adobe Systems, Inc.)
The Postscript.RTM. language is fully described in the
Postscript.RTM. Language Reference Manual, Second Edition (1990),
from Adobe Systems, Inc., which is incorporated herein by
reference. Certain imposition-on-the-fly procedures 454 according
to the present invention are downloaded to the RIP 82. (The
procedures 454 include, for example, ImposeJob, ImposeFile and
various redefined Postscript.RTM. operators which are described in
detail below). The imposition-on-the-fly procedures 454 will be
used by the RIP 82 to process the instruction set and the page
descriptions contained in the merged PostScript.RTM. files 450 to
efficiently transmit pages for rendering by the demand printer 84.
(For ease in illustration, it is assumed the master and variable
page files were premerged into merged file 450. It is understood,
however, that the master and variable page files could also be
overlayed.)
[0186] PostScript.RTM. Background
[0187] In order to facilitate the explanation of
imposition-on-the-fly procedures of the present invention, some
background regarding the Postscript.RTM. language is provided.
Further background details may be found in the Postscript.RTM.
Language Reference Manual, Second Edition (1990), from Adobe
Systems, Inc., which was previously incorporated by reference.
[0188] The RIP 82 manages four different stacks, which are
"last-in-first-out" (LIFO) data structures. These stacks
include:
[0189] (1) an Operands Stack which holds (i) the input operands to
various PostScript.RTM. operators, and (ii) the results of the
operations;
[0190] (2) an Execution Stack which is controlled by the RIP 82 and
which holds executable objects (i.e. procedures and files) that are
in stages of execution;
[0191] (3) a Dictionary Stack which includes (i) a read only
dictionary ("systemdict") which defines the implementation of the
various Postscript.RTM. operators, (ii) a writable dictionary
("userdict") which stores all other definitions, and (iii)
specialized dictionaries created by the user (e.g., an imposition
dictionary); and
[0192] (4) a Graphics State Stack which is used to store graphics
information, such as the parameters of the demand printer 84.
[0193] The Postscript.RTM. language is device independent such that
the page descriptions contained in the merged PostScript.RTM. file
450 are specified in a coordinate system (called "user space") that
is independent of the particular demand printer 84. The coordinate
system (called "device space") used by the demand printer 84 varies
depending on the particular demand printer 84 (the "current
device") which is specified for rendering the current page. In
order to render the pages described in the merged PostScript.RTM.
file 450, the page descriptions (specified in user space) may be
transformed to the current device space by a Current Transformation
Matrix ([CTM]).
[0194] The PostScript.RTM. language uses the Current Transformation
Matrix ([CTM]) to describe scaling, rotation, and translation of
the page from user space to device space. For mapping the point (x,
y) in user space to the point (x', y') in device space:
9 [ (FileName) [ { user procedure 1 } page# { operands to
setvirtualdevice } { FileObject offset setfileposition } ] [ { user
procedure 1 } page# { operands to setvirtualdevice } { user
procedure 2 - barcodes, watermarks, etc. } ] ]
[0195] where a, b, c, and d determine the extent of scaling and
rotation and where t, and ty determine the extent of
translation.
[0196] The RIP 82 also maintains a data structure, called the
"graphics state," that holds various graphics control parameters,
including the [CTM]. The graphics state also includes (i) a
clipping path, which defines the rendering area in the raster
memory 452 for the current page; (ii) font and line definitions;
(iii) a color space (such as DeviceGray, RGB, CMYK or CIE); and
(iv) other graphics control parameters.
[0197] The Postscript.RTM. language includes several operators for
setting up the current demand printer 84 to fulfill the processing
requirements of the page descriptions contained in the merged
PostScript.RTM. file 450. The current device setup includes
establishing the Current Transformation Matrix ([CTM]) for the
current demand printer 84. The default transformation from user
space to device space for the current device is specified by a
"system default matrix." The system default matrix may be generated
by the Postscript.RTM. language, for example, by a defaultmatrix
operator. The [CTM] may be considered an alteration of the system
default matrix.
[0198] Once the current demand printer 84 has been set up, the RIP
82 can begin to interpret the page descriptions in the merged
Postscript.RTM. file 450. For each page in turn, everything that is
to appear on that page (including text, graphics, and images) is
"painted" into the raster memory 452 and stored and/or rendered by
the demand printer 84.
[0199] In the merged Postscript.RTM. file 450, each description of
a page to be rendered includes a Postscript.RTM. showpage operator.
The showpage operator, which is generally included at the end of
each page description, is used to transmit the raster description
of the current page (saved in the raster memory 452) to the demand
printer 84 for physical rendering of the current page. In general,
the showpage operator transmits the contents of the raster memory
452 to the demand printer 84, then erases the current page from the
raster memory 452 and partially resets the graphics state in
preparation for interpreting the next page description in the
merged Postscript.RTM. file 450.
[0200] In level 2 PostScript.RTM. implementations, the function of
the showpage operator is controlled by an EndPage procedure and a
BeginPage procedure that are defined according to the current
demand printer 84. In general, the EndPage procedure specifies the
disposition of the current page in the raster memory 452 and the
BeginPage procedure sets up and marks the beginning of the next
page description to be interpreted. These procedures may be
defined, for example, by a level 2 setpagedevice operator which
sets up the graphics state for the current demand printer 84 (the
"current graphics state").
[0201] During normal operation, the level 2 showpage operator
provides two operands to the EndPage procedure: a reason code and
Pagecount. The reason code operand specifies whether the EndPage
procedure is being called by the showpage operator, by a copypage
operator, or during a device deactivation. When the EndPage
procedure is called by the showpage operator, the reason operand is
set to 0. The Pagecount operand is the number of executions of the
showpage operator that have occurred since the current device was
activated, not including the present execution. Thus, Pagecount is
equal to the number of pages that have been rendered prior to the
current page. After the EndPage procedure is executed, Pagecount is
incremented by one and is provided as an operand to the BeginPage
procedure.
[0202] The operation of the level 2 showpage operator is
illustrated in the flowchart of FIG. 20. A block 500 first sets the
reason code operand equal to zero to specify that the EndPage
procedure is being called by the showpage operator. A block 502
then calls the EndPage procedure, which consumes the reason code
and PageCount operands and returns a boolean result that specifies
the disposition of the current page in the raster memory 452.
During normal operation, the EndPage procedure returns true during
execution of the showpage or copypage operators (causing a physical
page to be produced) and returns false during device deactivation.
A decision-making block 504 determines whether the result returned
from the EndPage procedure is true or false.
[0203] If the EndPage procedure returns "true", a block 506
transmits the contents of the raster memory 452 to the demand
printer 84 for rendering. A block 508 then clears the raster memory
452 by executing a procedure similar to a Postscript.RTM. erasepage
operator. Under normal operation, the EndPage procedure returns
true if it is called by the showpage or copypage operator. Thus,
the showpage and copypage operators cause the contents of the
raster memory 452 to be transmitted to the demand printer 84 for
rendering.
[0204] If the EndPage procedure returns a "false", the showpage
operator does not perform either of the functions of the blocks 506
and 508 (i.e., no page is rendered), but skips to a block 510. The
block 510 executes a procedure similar to a PostScript.RTM.
initgraphics operator which resets the [CTM], the clipping path,
and other graphics parameters to the default values for the current
demand printer 84, thus setting up the graphics state for composing
the next page. The clipping path defines the rendering area for the
current page stored in the raster memory 452.
[0205] A block 512 then increments the Pagecount operand by one and
a block 514 calls the BeginPage procedure with Pagecount as an
operand. The BeginPage procedure marks the beginning of the next
page in the merged PostScript.RTM. file 450 to be interpreted by
the RIP 82.
[0206] The standard operation of the level 2 showpage operator
illustrated in FIG. 20 may be represented by the following
Postscript.RTM. pseudo code:
10 /showpage { /reason 0 def % reason = 0 for % showpage pagecount
reason EndPage % call EndPage % procedure { transmit contents of %
do these lines raster memory to % only demand printer % {close
oversize brace} if Endpage erasepage } if % returns true
initgraphics % set default graphics % state /pagecount pagecount 1
add def % increment % pagecount pagecount BeginPage % call
BeginPage % procedure } def
[0207] The Imposition-on-the-Fly Procedures
[0208] The imposition-on-the-fly procedures of the present
invention create a layer on top of the demand printer, called a
"virtual device." The desired position (scale, orientation and
size) of a page to be printed by the demand printer is specified by
a procedure (called "setvirtualdevice") which establishes the
virtual device for that page. Thus, from the standpoint of the
Postscript.RTM. program, the [CTM] is the same as the system
default matrix and every page begins with a [CTM] mapping user
space coordinates to the lower left corner of the output device.
The [CTM] can be explicitly manipulated as if each PostScript.RTM.
page were imaged on a distinct, but identical, physical page.
[0209] Thus, when imposing and rendering a selected page from the
merged Postscript.RTM. file 450, the current output device (i.e.
the demand printer 84) is defined as the virtual device. In
general, the virtual device for a selected page is the same size as
the page and is positioned at the place on the flat 456 where the
page is to be rendered.
[0210] The virtual device is established by setting the current
transformation matrix ([CTM]) to properly position the page. A
clipping path, which defines the rendering area in the raster
memory 452, is then created around the border of the page. Thus,
the RIP 82 "sees" the position where the page is to be rendered as
the current output device.
[0211] For pages in the merged Postscript.RTM. file 450 that will
not be rendered on the current flat 456 (i.e. are not included in
the current book), the current output device (the demand printer
84) is defined as a scaled-down virtual device for the next page to
be imposed and rendered on the flat. The scaled-down virtual device
allows any intervening pages not to be imposed on the flat to be
quickly interpreted by the RIP 82.
[0212] The imposition-on-the fly procedures include the
setvirtualdevice procedure, which establishes the virtual device
for the next page to rendered on the flat 456 and an
EnableVirtualDevice procedure which sets up the showpage operator
to support virtual devices. The EndPage and BeginPage procedures
that are invoked by the showpage operator are also redefined. These
procedures will be described in detail below.
[0213] The Imposition-on-the-Fly Instruction Set:
[0214] Preferably, the instruction set for implementing
imposition-on-the-fly by creating the virtual device for pages to
be rendered on the flat are input to the RIP 82 in the
below-described format. However, the present invention may be
modified to properly impose different instruction set formats.
[0215] The imposition-on-the-fly instruction set contains the
name(s) of the merged PostScript.RTM. file(s) 450 that will be
interpreted by the RIP 82 and rendered by the demand printer 84.
These file names are associated with entry lists (stored in arrays)
containing one or more entries, wherein each entry contains the
following information:
[0216] 1) A first user procedure--The user procedure may contain
various instructions, including comments, printer's marks (such as
barcodes or watermarks) or other information. (The user procedure
may also be null and is not essential to the imposition-on-the-fly
procedures of the present invention).
[0217] 2) A page number--The page number is the sequential number
of the page description in the merged Postscript.RTM. file 450 of
the page to be rendered on the flat 456. The merged PostScript.RTM.
file 450 is assumed to contain page descriptions in sequential
order, wherein the first page description is page "0."
[0218] 3) Operands to the setvirtualdevice procedure--As explained
in detail below, the setvirtualdevice procedure establishes the
appropriate virtual device as the current output device for a
particular page. The setvirtualdevice procedure requires the
following three operands, which are included in each entry in the
entry list:
[0219] i) the scaling, translation and rotation factors which will
be used to generate a "virtual [CTM]" which will properly position
the selected page on the flat 456. These factors are listed as
follows: [scale_x scale_y translate-x translate_y rotate];
[0220] ii) the user space coordinates of the lower-left and
upper-right corners of the actual rendering area of the next page
to be rendered on the flat 456. These corner coordinates will be
used to generate a clipping path around the border of the page in
the raster memory 452. The corner coordinates are listed as
follows: [ClipllX ClipllY ClipurX ClipurY]; and
[0221] iii) the size (width and length) of the page to be rendered
on the flat. The page size is listed as follows: [PageX PageY].
(The page size is not necessarily equivalent to the clipping path
defining the rendering area of the page, as many demand printers
are unable to place marks at the extreme edges of the page).
[0222] 4) A second user procedure ("offsets"): Like the first user
procedure, the second user procedure may contain comments,
printer's marks (barcodes, watermarks, etc.) or other information
or may be null. In a preferred embodiment, however, for the first
page on the flat, the second user procedure is used to "offset" the
program to the next page to be rendered on the flat.
[0223] For example, the merged PostScript.RTM. file generally
contains many, many pages because it includes separate page
descriptions for each variable page. Assume a simple four page book
with three master pages and only one variable page. The book may be
sent to 1,000 different people, with different variable information
for each person. Thus, the merged PostScript.RTM. file contains
1,003 page descriptions-3 master pages and 1,000 variable pages.
Imposition-on-the-fly with offsets allows for quick printing of the
books because it "skips over" (i.e. does not RIP) the 999 variable
pages that will not be included in each book.
[0224] For imposition-on-the-fly with offsets, the second user
procedure for the first entry in the instruction set contains a
file object, an offset position and the PostScript.RTM.
setfileposition operator. The offset position points to the next
page description in the file that is to be included on the flat.
(The offset positions were calculated and saved by the block 364 of
FIG. 13.) The setfileposition operator reopens the current merged
Postscript.RTM. file 450 to that offset position.
[0225] Thus, the Postscript.RTM. instruction set format for
imposition-on-the-fly imposition of the present invention is as
follows:
11 [ (FileName) [ { user procedure 1 } page# { operands to
setvirtualdevice } { FileObject offset setfileposition } ] [ { user
procedure 1} page# { operands to setvirtualdevice } { user
procedure 2 - barcodes, watermarks, etc. } ] ]
[0226] A sample imposition-on-the-fly with offsets instruction set
is attached as Appendix I. The Appendix I instruction set also
includes code in certain second user procedures to print a
barcode.
[0227] Explanation of Variables:
[0228] The variables used by the imposition-on-the-fly procedures
may be conveniently defined and stored in a user dictionary
(called, for example, "impositiondict"). These variables
include:
[0229] 1) PageOffset--the cumulative number of pages from any
previous Postscript.RTM. files that have been interpreted in
accordance with the imposition-on-the-fly procedures of the present
invention. Initially, PageOffset is set to -1 (no previous files
(or pages) have been interpreted).
[0230] 2) CurrentPage--the number of the next page in the current
merged Postscript.RTM. file 450 that is to be rendered on the
current flat 456. CurrentPage is initially set to 0.
[0231] 3) LastPage--the number of the last page in the current
merged PostScript.RTM. file 450 that is to be rendered on the
current flat, which is equal to the page number in the last entry
of the entry list. LastPage is initially set to 1 and is used to
determine how many page descriptions in the merged Postscript.RTM.
file must be interpreted in order to properly render all of the
selected pages on the current flat.
[0232] 4) PageCount--the number of times that the showpage operator
has been executed (initially 0). In level 2 PostScript.RTM.
implementations, PageCount is stored and incremented internally by
the RIP 82 through the showpage operator. However, in level 1
PostScript.RTM. implementations, the PageCount variable must be
explicitly defined and incremented to emulate the operation of the
level 2 showpage operator.
[0233] 5) PageList--the list of entries (page numbers and
imposition procedures) contained in the entry list.
[0234] 6) CurrentIndex--an index into the PageList.
[0235] 7) LastIndex--the number of entries in the entry list.
[0236] 8) DefaultMatrix--used to store the value of the [CTM]
describing the virtual device (the "virtual [CTM]"). The scaling,
translation and rotation components of the virtual [CTM] are
supplied as operands to the setvirtualdevice procedure.
[0237] 9) PageX and PageY--the width and height respectively of the
page to be rendered on the flat 456. The values of PageX and PageY
are provided in each entry of the entry list as operands to the
setvirtualdevice procedure.
[0238] 10) DefaultPageX and DefaultPageY--the default values of the
page width and height, respectively. Their values are initially set
to 8{fraction (1/2)}" (612) and 11" (792), respectively.
[0239] 11) ClipllX, ClipllY, ClipurX and ClipurY--the user space
coordinates of the lower-left and upper-right corners,
respectively, of the clipping path defining the border of the
virtual device. The values of these variables are also included as
operands to the setvirtualdevice procedure.
[0240] 12) Portrait--a boolean variable used to describe the page
orientation of the current page. If Portrait is true, the current
page has a portrait orientation (page width<page height). If
Portrait is false, the current page has a landscape orientation
(page width>page height).
[0241] 13) DefaultPortrait--the default value for the page
orientation, which is initially set to true (portrait
orientation).
[0242] 14) VirtualDeviceEnabled--a boolean variable used to
determine whether a procedure called, for example,
"EnableVirtualDevice," has been executed. As explained in detail
below, the EnableVirtualDevice procedure sets up the standard
PostScript.RTM. showpage operator to support virtual devices.
[0243] 15) ImageDone--a boolean variable used to specify when the
current flat 456 has been completed. ImageDone is initially and
normally set to false, indicating that the current flat 456 has not
been completed.
[0244] A further description of the variables used is included in
the following PostScript.RTM. code, which creates the
impositiondict dictionary and initializes the variables:
12 /impositiondict 200 dict def % create dictionary %
impositiondict begin /Identity matrix def % used as input to
setmatrix /Matrix matrix def % dummy matrix for temp storage
/Matrix2 matrix def % dummy matrix for temp storage /Matrix3 matrix
def % dummy matrix for temp storage /Matrix4 matrix def % dummy
matrix for temp storage /DefaultPageX 612 def % default page width
(X) and /DefaultPageY 792 def % page length (Y) (8 1/2" .times. %
11") /DefaultPortrait true def % assume page orient = % portrait
/PageOffset -1 def % first file - no previous % pages /CurrentPage
0 def % initial value of page to % impose /CurrentIndex 0 def %
initial value of page to % impose /LastPage 2147483647 def %
initial value is highest % number /PageCount 0 def % used in level
1 only /DefaultMatrix matrix % the "default" matrix for the
currentmatrix def % current virtual device /VirtualDeviceEnabled
false def % allow normal % operation /ImageDone false def % not
done with current media % Set initial job defaults /Portrait
DefaultPortrait def % default to portrait % mode /PageX
DefaultPageX def % initial page size /PageY DefaultPageY def %
/ClipllX 0 def % initial lower left /ClipllY 0 def % and upper
right /ClipurX DefaultPageX def % corners of /ClipurY DefaultPageY
def % clipping path
[0245] The Redefined PostScript.RTM. Operators:
[0246] Also, before executing the imposition-on-the-fly procedures
of the present invention, several Postscript.RTM. operators must be
redefined for compatibility with the EnableVirtualDevice and
setvirtualdevice procedures, which will be described in detail
below. The virtual device, in effect, "shields" the PostScript.RTM.
program and RIP from where the pages are being painted into the
raster memory 452 through the [CTM]. Thus, in general, the
PostScript.RTM. operators that affect the [CTM] must be redefined
to also "shield" the Postscript.RTM. program and RIP from the final
mapping of the page description from user space to device space
coordinates. The PostScript.RTM. operators which must be redefined
include:
13 initmatrix transform initclip itransform setmatrix dtransform
currentmatrix idtransform erasepage nulldevice initgraphics
copypage
[0247] The standard operation of these, and all other
PostScript.RTM. operators, is fully described in the
PostScript.RTM. Language Reference Manual, Second Edition (1990),
from Adobe Systems, Inc., which was previously incorporated by
reference.
[0248] The first step in redefining the above-listed
PostScript.RTM. operators is to rename the standard operator, for
example, "systemdict_operator," because its definition is stored in
the systemdict dictionary. This may be implemented by the following
code:
14 /systemdict_initmatrix systemdict /initmatrix get def
/systemdict_initclip systemdict /initclip get def
/systemdict_setmatrix systemdict /setmatrix get def
/systemdict_erasepage systemdict /erasepage get def
/systemdict_initgraphics systemdict /initgraphics get def
/systemdict_currentmatrix systemdict /currentmatrix get def
/systemdict_transform systemdict /transform get def
/systemdict_itransform systemdict /itransform get def
/systemdict_dtransform systemdict_/dtransform get def
/systemdict_idtransform systemdict /idtransform get def
[0249] As explained below, the standard nulldevice and copypage
operators are not renamed because their standard operation will
never be used in connection with the present invention. The new
definitions of the operators, described below, are then loaded into
the userdict dictionary.
[0250] The Redefined Initmatrix Operator:
[0251] The standard PostScript.RTM. initmatrix operator sets the
[CTM] to the system default matrix for the current device. The
initmatrix operator is redefined to set the [CTM] equal to the
virtual [CTM] which defines the virtual device.
[0252] The virtual [CTM] may be stored in the variable
DefaultMatrix.
[0253] The PostScript.RTM. initmatrix operator may be redefined by
the following code:
15 /initmatrix { impositiondict begin DefaultMatrix
systemdict_setmatrix end } bind def
[0254] The Redefined Initclip Operator:
[0255] The clipping path normally corresponds to the boundary of
the maximum imageable area for the current output device (the
demand printer 84). The standard PostScript.RTM. initclip operator
replaces the current clipping path in the graphics state with the
default clipping path for the current demand printer. The initclip
operator is redefined to replace the current clipping path in the
graphics state with a clipping path defining the border of the
virtual device page.
[0256] The flowchart of FIG. 21 illustrates the program steps
implemented by the redefined initclip operator. A decision-making
block 520 determines whether a current path exists by checking for
the existence of a currentpoint. If no currentpoint is defined, a
block 522 stores an empty path in a variable called, for example,
"p1." Alternatively, if a currentpoint is defined, a block 524
invokes a previously defined utility routine called, for example,
"MakePath," that creates a path description from the current path.
The block 524 then saves the current path description in the
variable p1. The MakePath procedure, which may be stored in the
impositiondict dictionary, is similar to the level 2
Postscript.RTM. upath operator and may be implemented by the
following code:
16 /MakePath { [ {/moveto cvx} {/lineto cvx} {/curveto cvx}
{/closepath cvx} pathforall ] cvx } bind def
[0257] Next, a black 526 saves the current [CTM] and a block 528
sets the [CTM] to the virtual [CTM]. A block 530 then creates a
clipping path between the corners of the virtual device, which were
specified by the values of the ClipllX, ClipllY, ClipurX and
ClipurY variables provided as operands to the setvirtualdevice
procedure. A block 532 then restores the [CTM] which was saved by
the block 526 and the current path saved in the variable p1.
[0258] The Postscript.RTM. initclip operator may be redefined by
the following code:
17 /initclip impositiondict begin { currentpoint } stopped { /p1 {
} def } % p1 = empty path { pop pop /p1 MakePath def} % p1 =
current % path ifelse matrix systemdict_currentmatrix init matrix
systemdict_initclip newpath ClipllX ClipllY moveto % create
clippath ClipurX ClipllY lineto ClipurX ClipurY lineto ClipllX
ClipurY lineto closepath clip newpath systemdict_setmatrix p1 %
restore current end % path } bind def
[0259] The Redefined setmatrix Operator:
[0260] The standard PostScript.RTM. setmatrix operator replaces the
current [CTM] in the graphics state with a matrix that is supplied
on the Operands stack. The matrix supplied on the Operands stack
("the operand matrix") can be considered the result of the
concatenation of the system default matrix with an operations
matrix.
[0261] The setmatrix operator is redefined to calculate the
operations matrix by concatenating the operand matrix with the
inverse of the system default matrix. Thus,
[0262] [operand matrix]=[operations matrix] [system default
matrix], and
[0263] [operations matrix]=[operand matrix] [system default
matrix].sup.-1.
[0264] Once the operations matrix is calculated, it is concatenated
with the virtual [CTM] (stored in DefaultMatrix) and saved as the
new [CTM]. Thus,
[0265] new [CTM]=[operations matrix] [virtual CTM].
[0266] The Postscript.RTM. setmatrix operator may be redefined by
the following code:
18 /setmatrix { impositiondict begin Matrix defaultmatrix Matrix2
invertmatrix Matrix3 concatmatrix DefaultMatrix Matrix4
concatmatrix systemdict_setmatrix end } bind def
[0267] The Redefined currentmatrix Operator:
[0268] The standard currentmatrix operator replaces the matrix
supplied on the Operands stack with the current [CTM] in the
graphics state.
[0269] The current [CTM] can be considered the result of
concatenating the virtual [CTM] (saved in DefaultMatrix) with an
operations matrix. The redefined currentmatrix operator calculates
the operations matrix by concatenating the current [CTM] with the
inverse of the virtual [CTM] as set forth below:
[0270] [current CTM]=[operations matrix] [virtual CTM], and
[0271] [operations matrix]=[current CTM] [virtual CTM].sup.-1.
[0272] The [operations matrix] is then concatenated with the system
default matrix and the resultant matrix is stored in the matrix on
the Operands stack.
[0273] The Postscript.RTM. currentmatrix operator may be redefined
by the following code:
19 /currentmatrix { impositiondict begin Matrix
systemdict_currentmatrix DefaultMatrix Matrix2 invertmatrix Matrix3
concatmatrix Matrix4 defaultmatrix 3 -1 roll concatmatrix end }
bind def
[0274] The Redefined erasepage Operator:
[0275] The standard erasepage operator erases the entire current
page stored in raster memory by painting the page white. The
erasepage operator is redefined to erase only the virtual device
page, which is the area defined by the next page to be rendered on
the current flat.
[0276] The erasepage operator is redefined by calling the redefined
initclip operator, described above, which establishes a clipping
path around the border of the virtual device page. The area inside
the clipping path is then painted white. The standard
PostScript.RTM. gsave operator (described in detail in connection
with the optional imposition-on-the-fly procedures of the
invention) is called immediately before the redefined initclip
operator to save the current graphics state, including the current
clipping path, gray level, etc. Also, after the virtual device page
has been painted white, the standard PostScript.RTM. grestore
operator (also described in detail in connection with the optional
procedures) is called to restore the current graphics state.
[0277] The Postscript.RTM. erasepage operator may be redefined by
the following code:
20 /erasepage { impositiondict begin gsave % systemdict_gsave for
optional procs initclip clippath 1 setgray fill grestore %
systemdict_grestore for optional % procs end } bind def
[0278] (In the optional imposition-on-the-fly procedures, the
standard PostScript.RTM. gsave and grestore operators are
redefined. Thus, in the optional procedures, the erasepage operator
is redefined by calling the systemdict_gsave and
systemdict_grestore operators, as specified above.)
[0279] The Redefined initgraphics Operator:
[0280] The standard PostScript.RTM. initgraphics operator resets
several values in the graphics state, including the [CTM], the
current path and the clipping path, to their default values. The
standard initgraphics operator is equivalent to the following
PostScript.RTM. language sequence:
21 initmatrix newpath initclip 1 setlinewidth 0 setlinecap 0
setlinejoin [ ] 0 setdash 0 setgray 10 setmiterlimit
[0281] The initgraphics operator is redefined to perform the above
listed sequence. However, the redefined initgraphics calls the
redefined initmatrix and initclip operators, which were described
above. Thus, the redefined initgraphics operator resets the [CTM]
and the clipping path to their default values for the virtual
device.
[0282] The PostScript.RTM. initgraphics operator may be redefined
by the following code:
22 /initgraphics { initmatrix newpath initclip 1 setlinewidth 0
setlinecap 0 setlinejoin [ ] 0 setdash 0 setgray 10 setmiterlimit }
bind def
[0283] The Redefined "transform" Operators:
[0284] The standard Postscript.RTM. transform operator transforms a
supplied user space coordinate (x,y) to the corresponding device
space coordinate (x',y') as specified by the [CTM]. Since the [CTM]
is altered during the imposition process, the transform operator is
redefined to perform the transformation as if the [CTM] had not
been altered.
[0285] If a matrix operand is supplied to the standard transform
operator, the transformation from user to device space is performed
according to the supplied matrix. Thus, if a matrix operand is
supplied, the transform operator is also redefined to perform the
transformation according to the supplied matrix.
[0286] The PostScript.RTM. language includes three other
"transform" operators (dtransform, itransform and idtransform)
which are redefined in the same manner as the transform
operator.
[0287] The standard PostScript.RTM. dtransform operator specifies a
"distance" transformation of a coordinate from user to device space
according to the [CTM] or a supplied matrix operand. In a distance
transformation, the translation components (tx and ty) of the [CTM]
are not used.
[0288] The standard PostScript.RTM. itransform operator specifies a
transformation of a coordinate in device space (x',y') to user
space (x,y) according to the inverse of the [CTM] or a supplied
matrix operand. The standard idtransform operator specifies a
distance transformation from device space to user space according
to the inverse of the [CTM] or a supplied matrix operand.
[0289] FIG. 22 illustrates the program steps implemented by the
redefined transform operator. The other transform operators are
redefined in the same way. A decision-making block 534 first
determines whether a matrix operand was supplied to the transform
operator. If a matrix operand was supplied, a block 536 simply
calls the standard transform operator (now renamed
"systemdict_transform") to perform the transformation according to
the supplied matrix. (For the other transform operators, the block
536 calls systemdict_dtransform, systemdict_itransform or
systemdict_idtransform).
[0290] Alternatively, if the block 534 determines that a matrix
operand was not supplied, a block 538 first saves a copy of the
current [CTM] in the graphics state on the Operands Stack.
[0291] As explained previously, the current [CTM] can be considered
the result of the concatenating the virtual [CTM] (saved in
DefaultMatrix) with an operations matrix. A block 540 thus
calculates the operations matrix by concatenating the current [CTM]
with the inverse of the virtual [CTM].
[0292] Next, a block 542 sets a new [CTM] equal to the operations
matrix concatenated with the system default matrix. The new [CTM]
is now equal to what the [CTM] would have been if the
setvirtualdevice and imposition procedures were not
implemented.
[0293] A block 544 then calls the standard transform operator to
perform the transformation from user to device space according to
the new [CTM]. (Again, for the other transform operators, the block
544 calls the standard dtransform, itransform, or idtransform
operator).
[0294] Lastly, a block 546 resets the [CTM] equal to the current
[CTM] saved on the Operands Stack by the block 538.
[0295] The Postscript.RTM. transform operators may be redefined by
the following code:
23 /transform { impositiondict begin dup type /arraytype eq {
systemdict_transform % or systmdict_dtransform % or %
systemdict_itransform % or systemdict_idtransform } { Matrix
systemdict_currentmatrix dup 4 1 roll DefaultMatrix Matrix2
invertmatrix Matrix3 concatmatrix Matrix2 defaultmatrix Matrix4
concatmatrix systemdict_setmatrix systemdict_transform % or - %
systemdict_dtransform % or systemdict_itransform % or
systemdict_idtransform 3 -1 roll systemdict_setmatrix } ifelse end
} bind def
[0296] The Redefined nulldevice Operator:
[0297] The standard Postscript.RTM. nulldevice operator installs a
"null device" as the current output device. The standard
PostScript.RTM. nulldevice operator produces no physical output and
has no associated raster memory. However, any graphics or font
operations executed will be saved in the current graphics state.
The Postscript.RTM. nulldevice operator also sets the [CTM] to an
identity matrix ([1 0 0 1 0 0]) and establishes the clipping path
as a single point at the origin.
[0298] The standard Postscript.RTM. nulldevice operator, however,
is not suitable for use with this invention because is not a page
device operator and, therefore, has no EndPage and BeginPage
procedures associated with it. Thus, the nulldevice operator is
redefined to set the [CTM] to the identity matrix and establish a
one point clipping path without altering the current page
device.
[0299] The Postscript.RTM. nulldevice operator may be redefined by
the following code:
24 /nulldevice { impositiondict /Identity get systemdict_setmatrix
newpath clip } bind def
[0300] The Redefined copypage Operator:
[0301] Under normal operation, the standard PostScript.RTM.
copypage operator transmits one copy of the current page to the
demand printer without erasing the current page or changing the
graphics state. Like the showpage operator, the operation of the
copypage operator depends on the EndPage and BeginPage procedures,
which are redefined by the present invention. In the present
invention, the EndPage and BeginPage procedures are redefined so
that the copypage operator has no affect. The EndPage and BeginPage
procedures could be redefined to check for the copypage operator
(by comparing the reason code to one). Alternatively, the operation
of the copypage operator can simply be nulled by the following
code:
25 /copypage { } def
[0302] The EnableVirtualDevice Procedure:
[0303] The EnableVirtualDevice procedure, which is called by the
ImposeJob procedure at the end of the instruction set, sets up the
showpage operator to support virtual devices. FIG. 23 is a
flowchart illustrating the program steps implemented by the
EnableVirtualDevice procedure. A block 550 first determines whether
the RIP 82 implements level 1 or level 2 PostScript.RTM. by
determining whether the PostScript.RTM. setpagedevice operator is
defined in the systemdict dictionary. If the RIP 82 implements the
level 2 Postscript.RTM. language, a block 552 loads the redefined
EndPage and BeginPage procedures into the current graphics state
for the demand printer 84 by calling the setpagedevice operator. As
described in detail below, the EndPage and BeginPage procedures are
redefined to define the current output device as a virtual device
for pages to be rendered or as a scaled-down virtual device for
non-rendered pages.
[0304] The blocks 550 and 552 of the EnableVirtualDevice procedure
may be implemented by the following code:
26 /EnableVirtualDevice { /setpagedevice where { % level 2 pop 2
dict begin /EndPage impositiondict /EndPage get def /BeginPage
impositiondict /BeginPage get def currentdict end setpagedevice
}
[0305] Alternatively, if the block 550 determines that the RIP 82
implements level 1 PostScript.RTM., a block 554 renames the
standard level 1 showpage operator and a block 556 redefines the
showpage operator to emulate the operation of the level 2 showpage
operator as illustrated in FIG. 20. Next, a block 558 executes the
BeginPage procedure for the first page (page "0") in the merged
PostScript.RTM. file 450. (This was done automatically in the level
2 implementation by the block 552 by calling the setpagedevice
operator).
[0306] The blocks 554-558 may be implemented by the following
code:
27 { impositiondict /systemdict_showpage % rename systemdict
/showpage get put % showpage /showpage { % emulate impositiondict
begin % level 2 PageCount 0 EndPage systemdict_showpage } if
systemdict_initgraphics /PageCount PageCount 1 add def PageCount
/BeginPage load end exec } def 0 impositiondict /BeginPage get exec
} ifelse
[0307] Next, a block 560 invokes a procedure (called, for example,
"DisablePageDevice") which was previously stored in the
impositiondict dictionary. The DisablePageDevice procedure
redefines the Postscript.RTM. setpagedevice operator and all other
compatibility operators that call the setpagedevice operator.
Disabling these operators ensures that the raster memory 452 (which
may contain the raster descriptions of previously processed pages
to be rendered on the flat 456) is not erased by the setpagedevice
operator. The DisablePageDevice procedure is described in detail
below in connection with FIG. 24.
[0308] After the block 560 invokes the DisablePageDevice procedure
described above, a block 562 sets the boolean variable called
"VirtualDeviceEnabled" to true to indicate that the procedure has
been completed and the showpage operator is set up to support
virtual devices.
[0309] The blocks 560 and 562 of the EnableVirtualDevice procedure
may be implemented by the following code:
28 impositiondict /DisablePageDevice get exec impositiondict
/VirtualDeviceEnabled true put } bind def
[0310] The DisablePageDevice Procedure:
[0311] FIG. 24 is a flowchart illustrating the program steps
implemented by the DisablePageDevice procedure, which is invoked by
the block 560 of the EnableVirtualDevice procedure. Because
setpagedevice is a level 2 operator, a block 570 determines whether
the RIP 82 implements the level 1 or the level 2 PostScript.RTM.
language by determining whether the setpagedevice operator is
defined in the systemdict dictionary. If the RIP 82 implements the
level 2 PostScript.RTM. language, blocks 572-580 redefine the
setpagedevice operator to correct the page orientation of the
output device, if necessary.
[0312] During normal level 2 operation, a dictionary operand
containing input media selection entries is provided to the
Postscript.RTM. setpagedevice operator and the setpagedevice
operator establishes the current output device according to the
information contained in the current graphics state and the
dictionary operand. The dictionary operand may contain, for
example, an entry for PageSize, which is an array of two numbers
indicating the width and height of the current page. Thus, a call
to the setpagedevice operator may alter the page size, which is
critical in setting up the virtual device.
[0313] The block 572 of the redefined setpagedevice operator first
determines whether an entry for PageSize was included in the
dictionary operand to the setpagedevice operator. If so, the block
574 then determines whether the PageSize specified in the entry is
portrait or landscape orientation by comparing the page width to
the page height supplied in the PageSize entry. (As explained
above, for purposes of the invention, if the page width is less
than the page height, the orientation is referred to as portrait
and the variable Portrait is set to true. If the page width is
greater than the page height, the orientation is referred to as
landscape and the variable Portrait is set to false).
[0314] A block 576 then compares the page orientation of the
PageSize entry (determined by block 574) to the page orientation of
the virtual device (stored in the variable Portrait). If they are
not the same, a block 578 invokes a procedure called, for example,
"SetPortrait," which changes the orientation of the virtual device
from portrait to landscape, or vice versa. (The SetPortrait
Procedure is described in detail below). Next, for consistency with
the normal operation of the setpagedevice operator, a block 580
calls the redefined initgraphics and erasepage operators.
Alternatively, if the block 576 determines that the page
orientation of the PageSize entry is the same as the virtual
device, or if the block 572 determines that PageSize was not
included in the dictionary operand to the setpagedevice operator,
the program skips directly to the block 580, which completes the
redefinition of the setpagedevice operator.
[0315] The blocks 570-580 of the DisablePageDevice procedure may be
implemented by the following code:
29 /DisablePageDevice { /setpagedevice where { pop userdict
/setpagedevice { dup /PageSize known { /PageSize get impositiondict
begin aload pop lt Portrait ne { SetPortrait } if end } { pop }
ifelse initgraphics erasepage } put } if
[0316] After the block 580 calls the redefined initgraphics and
erasepage operators, or if the block 570 determines that the RIP 82
implements level 1 PostScript.RTM., a block 582 redefines the
compatibility operators, which are defined in either the statusdict
dictionary or the userdict dictionary, which call the setpagedevice
operator or perform similar level 1 operations.
[0317] For compatibility operators that change the page
orientation, the block 582 redefines the operator to set the
orientation of the virtual device equal to the orientation of the
page specified by the operator and to initialize the virtual
device. These operators may be redefined by a utility routine
called, for example, "SetPageSize," which is similar to the blocks
576-580 described above. The SetPageSize routine may be implemented
by the following code:
30 /SetPageSize { lt Portrait ne { % correct orientation of virtual
SetPortrait % device, if necessary } if initgraphics % initialize
virtual device erasepage % (emulate setpagedevice) } bind def
[0318] For compatibility operators that do not affect the page
orientation, the block 582 simply disables or nulls the operators.
The block 582 of the DisablePageDevice procedure, which redefines
or disables the compatibility operators, may be implemented by the
following code:
31 statusdict begin % operators in statusdict /a3tray
{impositiondict begin 842 792 SetPagesize end} def /a4tray
{impositiondict begin 595 842 SetPageSize end} def /ledgertray
{impositiondict begin 1224 792 SetPageSize end} def /setpage {pop
pop pop} def /setpagestackorder {pop} def /settumble {pop} def
/11x17tray {impositiondict begin 792 1224 SetPagesize end} def
/b5tray {impositiondict begin 516 729 SetPagesize end} def
/legaltray {impositiondict begin 612 1008 SetPageSize end} def
/setdefaulttimeouts {pop} def /setduplexmode {pop} def /setmargins
{pop pop} def /setpagemargin {pop} def /lettertray {impositiondict
begin 612 792 SetPageSize end} def /setmirrorprint {pop} def
/setpageparams {pop pop pop pop} def /setresolution {pop} def end %
operators in userdict /a3 {impositiondict begin 842 1191
SetPageSize end} def /b5 {impositiondict begin 516 729 SetPageSize
end} def /letter {impositiondict begin 612 792 SetPageSize end} def
/lettersmall {impositiondict begin 612 792 SetPageSize end} def
/legal {impositiondict begin 612 1008 SetPagesize end} def /ledger
{impositiondict begin 1224 792 SetPageSize end} def /11x17
{impositiondict begin 792 1224 SetPageSize end} def /a4
{impositiondict begin 595 842 SetPageSize end} def /a4small
{impositiondict begin 595 842 SetPageSize end} def /note { }
def
[0319] The SetPortrait Procedure:
[0320] The SetPortrait procedure, which is invoked by the block 578
of the DisablePageDevice procedure, changes the orientation of the
virtual device from portrait to landscape or vice versa. FIG. 25
illustrates the program steps implemented by the SetPortrait
procedure. A block 590 first determines whether the variable
Portrait is true (indicating the page is portrait) or false
(indicating the page is landscape).
[0321] If Portrait is true, the orientation of the device must be
converted from portrait to landscape. As illustrated in FIG. 26A, a
portrait-orientated page 592 is represented in a cartesian
coordinate system with an origin at point O.sub.P. The
portrait-orientated page 592 has a width PageX and a height PageY.
The rendering area on the page 592 is bordered by a clipping path
594, which may be defined by the coordinates of its lower-left
corner (llx, lly) and the coordinates of its upper-right corner
(urx, ury).
[0322] The portrait-oriented page 592 is converted to a
landscape-oriented page 596 by translating the origin O.sub.P of
the page 592 in the positive x-direction and then rotating the
coordinate system 90 degrees counterclockwise, resulting in the
landscape-orientated coordinate system of the page 596 with an
origin O.sub.L. Although the device space coordinates of the
clipping path 594 are unchanged, the clipping path 594 must be
redefined with respect to the new landscape coordinate system.
[0323] Referring again to FIG. 25, after the block 590 determines
that the orientation of the device must be converted from portrait
to landscape, a block 600 redefines the corner coordinate variables
as follows:
32 Portrait Coordinate Landscape Coordinate ClipllX ClipllY ClipllY
Pagex - ClipurX ClipurX ClipurY ClipurY PageX - ClipllY
[0324] Next, blocks 602 and 604 create matrices which will
translate the origin O.sub.P by the page width (PageX) in the
positive x-direction and then rotate the portrait coordinate system
90 degrees counterclockwise about the origin O.sub.P. A block 606
then concatenates the matrices with the current virtual [CTM] to
create the new virtual [CTM], which specifies the device in
landscape orientation.
[0325] The blocks 590 and 600-606 of the SetPortrait procedure may
be implemented by the following code:
33 /SetPortrait { Portrait { /tmp ClipllX def /ClipllY PageX
ClipurX sub def /ClipurX ClipurY def /ClipurY PageX tmp sub def 90
Matrix rotate PageX 0 Matrix2 translate DefaultMatrix Matrix3
concatmatrix DefaultMatrix concatmatrix pop }
[0326] If the block 590 determines that the variable Portrait is
false, the orientation of the device must be converted from
landscape to portrait. Referring also to FIG. 26B, a
landscape-oriented page 608 is specified in a Cartesian coordinate
system with an origin O.sub.L. The rendered area on the page 608 is
bordered by a clipping path 610 defined by the coordinates of its
lower-left and upper-right corners. The landscape-oriented page 608
is converted to a portrait-oriented page 612 by translating the
origin O.sub.L in the positive y-direction and then rotating the
coordinate system 90 degrees clockwise about the origin O.sub.L.
This generates a portrait-oriented coordinate system with an origin
O.sub.P.
[0327] Similar to the above-described portrait to landscape
procedure, a block 614 first redefines the corner coordinates of
the clipping path as follows:
34 Landscape Coordinate Portrait Coordinate ClipllY ClipllX ClipllX
PageY - ClipurY ClipurY ClipurX ClipurX PageY - ClipllY
[0328] Next, blocks 616 and 618 create matrices to translate the
origin O.sub.L in the positive y-direction and then rotate the
origin O.sub.L 90 degrees clockwise. A block 620 then concatenates
the matrices with the current virtual [CTM] to generate the new
virtual [CTM], which specifies the device in a portrait coordinate
system.
[0329] The blocks 614-620 of the SetPortrait procedure, which
convert from landscape to portrait orientation, may be implemented
by the following code:
35 /tmp ClipllY def /ClipllY ClipllX def /ClipllX PageY ClipurY sub
def /ClipurY ClipurX def /ClipurX PageY tmp sub def -90 Matrix
rotate 0 PageY Matrix2 translate DefaultMatrix Matrix3 concatmatrix
DefaultMatrix concatmatrix pop } ifelse
[0330] the new virtual [CTM] is generated, a block 622 exchanges
the values of PageX and PageY. Thus, for example, when converting
from portrait to landscape, the portrait page width becomes the
landscape page height and the portrait page height becomes the
landscape page width. Lastly, a block 624 changes the value of the
variable Portrait. Thus, if Portrait was initially true (indicating
portrait orientation), it is set to false to indicate that the
device is now in landscape orientation. Conversely, if Portrait was
initially false (indicating landscape orientation), it is set to
true to indicate that the device is now in portrait
orientation.
[0331] The blocks 622-624 may be implemented by the following
code:
36 /tmp PageX def /PageX PageY def /PageY tmp def /Portrait
Portrait not def } bind def
[0332] The SetPortrait procedure described above comprises an
optional part of the present invention and is not necessary for use
with Postscript.RTM. applications which do not alter the page
orientation.
[0333] The setvirtualdevice Procedure:
[0334] The setvirtualdevice procedure establishes the current
transformation matrix ([CTM]), the clipping path, and the page size
such that the current output device is specified as a virtual
device. The virtual device is defined to be the size of the next
page to be rendered, with the origin and page boundary at the
position on the flat 456 where the page is to be rendered.
[0335] The setvirtualdevice procedure requires the following three
"operands," which are provided in the instruction set list:
[0336] 1) the imposition procedure, which includes the scaling,
translation and rotation factors--[scale_x scale_y translate_x
translate_y rotate];
[0337] 2) the user space coordinates of the lower-left and
upper-right corners of the rendering area of the page to be
imposed, which will be used to generate a clipping path around the
border of the virtual page in the raster memory 22--[clip_ll_x
clip_ll_y clip_ur-x clip_ur_y]; and
[0338] 3) the page width and page length--[page size_x page
size_y].
[0339] FIG. 27 illustrates the program steps implemented by the
setvirtualdevice procedure. A block 630 first determines whether
the variable VirtualDeviceEnabled is set to true, indicating that
the EnableVirtualDevice procedure has been executed and the
showpage operator is set up to support virtual devices. If the
block 630 determines that VirtualDeviceEnabled is false, a block
633 invokes the EnableVirtualDevice procedure. (A block 6333, which
is implemented only in connection with the optional
imposition-on-the-fly-procedures, will be described below.)
[0340] Next, a block 634 defines the variables PageX and PageY as
the width and height of the virtual device, respectively.
Similarly, a block 636 defines the variables ClipllX and ClipllY as
the x and y coordinates of the lower-left corner of the virtual
device and the variables ClipurX and ClipurY as the x and y
coordinates of the upper-right corner of the virtual device.
[0341] A block 638 then calls the standard PostScript.RTM.
initmatrix operator (renamed "systemdict_initmatrix"), which sets
the [CTM] to the system default matrix for the current output
device. A block 640 then executes the scale, translate and rotate
operators with the operands to the setvirtualdevice procedure.
These scale, translate and rotate operations alter the system
default matrix to specify the virtual [CTM]. A block 642 saves the
resultant virtual [CTM] in the variable DefaultMatrix. The virtual
[CTM] specifies that the origin of the virtual device is at_the
position on the flat where the next page is to be rendered on the
flat 456.
[0342] A decision-making block 644 then compares the page width
(PageX) to the page height (PageY). If PageX is less than PageY, a
block 646 sets the variable Portrait to true (indicating portrait
orientation). Alternatively, if PageX is greater than PageY, a
block 648 sets the variable Portrait to false (indicating landscape
orientation).
[0343] Next, a block 650 calls the redefined initclip operator to
set the clipping path around the border of the virtual page. (See
FIG. 21).
[0344] The setvirtualdevice procedure may be implemented by the
following code:
37 /setvirtualdevice { impositiondict begin VirtualDeviceEnabled
not { EnableVirtualDevice } if aload pop /PageY exch def % set page
size /PageX exch def aload pop pop /ClipurY exch def % set clipping
path corners /ClipurX exch def /ClipllY exch def /ClipllX exch def
systemdict_initmatrix aload pop 5 -2 roll scale % execute scale,
translate 3 -2 roll translate % and rotate rotate DefaultMatrix
systemdict_currentmatrix pop % set % [CTM] /Portrait Pagex PageY lt
def initclip % set clipping path end } bind def
[0345] The ImposeJob Procedure:
[0346] The ImposeJob procedure is invoked after references to the
merged Postscript.RTM. files 450 and the instruction set have been
placed on the Operands stack. Further, the above-described
procedures and variables have been loaded into the impositiondict
dictionary.
[0347] FIG. 28 is a flowchart illustrating the program steps
implemented by the ImposeJob procedure according to the
imposition-on-the-fly procedures of the present invention. A block
652 invokes the EnableVirtualDevice procedure, described above in
connection with FIG. 23, to set up the showpage operator to support
virtual devices.
[0348] A block 654 then retrieves the first file/list pair
(containing the name of the merged PostScript.RTM. file and the
corresponding entry list with the user procedures, page numbers and
operands for the setvirtualdevice procedures for the current flat
456) from the instruction set. The file/list pair is stored in an
array that was placed on the Operands Stack prior to calling the
ImposeJob procedure.
[0349] For each file/list pair, a block 656 invokes the ImposeFile
procedure, described below, which retrieves each entry from the
entry list and determines which pages described in the merged
PostScript.RTM. file 450 should be rendered on the flat 456.
Assuming more than one file/list pair is contained in the array,
the blocks 654 656 are implemented in a loop which individually
retrieves each file/list pair from the array and invokes the
ImposeFile procedure to process each file/list pair.
[0350] After every file/list pair from the instruction set has been
processed by the ImposeFile procedure, a block 658 sets the boolean
variable ImageDone to true. ImageDone will be used to instruct the
RIP 82 that the imposition job is complete and the flat 456 can be
ejected. The value of ImageDone at this point could be determined
by a global variable. ImageDone could also be set to true in the
user procedure in the last entry of the last instruction set
list.
[0351] Next, a block 660 determines whether the showpage operator
was redefined to emulate level 2. If so, a block 662 executes the
standard level 1 showpage operator (renamed "systemdict_showpage")
in order to transmit the contents of the raster memory 452 to the
demand printer 84 for physical rendering of the flat 456. In the
level 2 implementation, the flat 456 is automatically rendered by
the showpage operator when the redefined EndPage procedure returns
a "true." (See FIG. 20). If the showpage operator was not
redefined, a block 664 ends the program.
[0352] The blocks 652-662 of the ImposeJob procedure may be
implemented by the following code:
38 /ImposeJob % Impose pages from each input file { impositiondict
/EnableVirtualDevice get exec { % Call ImposeFile for aload pop pop
% each file in instruction % set impositiondict /ImposeFile get
exec } forall impositiondict /ImageDone true put impositiondict
/systemdict_showpage known { % Did we redefine showpage
impositiondict /systemdict_showpage get exec %If yes, execute it. }
if } def
[0353] (Blocks 653 and 657 of the ImposeJob procedure, which are
implemented only in connection with the optional
imposition-on-the-fly of the invention, will be described
below.)
[0354] The ImposeFile Procedure:
[0355] FIG. 29 illustrates the program steps implemented by the
ImposeFile procedure of the imposition-on-the-fly procedures of the
invention. When the ImposeFile procedure is invoked, the ImposeJob
procedure has placed a file/list pair from the instruction set on
the Operands stack. The file/list pair contains a list of entries
(the "PageList"), wherein each entry specifies:
[0356] 1) a first user procedure;
[0357] 2) the number of the page to rendered on the flat 456;
[0358] 3) the operands to the setvirtualdevice procedure (which
generates the virtual [CTM] for properly positioning the page on
the flat 456); and
[0359] 4) a second user procedure (specifying offsets).
[0360] A block 670 sets the variable
PageOffset=CurrentPage+PageOffset+1. CurrentPage (representing the
number of the next page in the current merged Postscript.RTM. file
450 that is to be rendered on the flat 456) is initially 0 and
Pageoffset (representing the cumulative number of pages from
previous files processed) is initially -1. Therefore, on the first
pass of the ImposeFile procedure, PageOffset is equal to 0
(indicating that no previous files have been processed). A block
672 then uses the pointer CurrentIndex to retrieve the first entry
from the entry list received from the ImposeJob procedure. A block
673 then retrieves the page number from the entry and sets
CurrentPage equal to its value. Thus, CurrentPage now specifies the
number of the first page in the current merged postscript.RTM. file
that should be rendered on the flat.
[0361] Next, a decision-making block 674 determines whether the
first page in the current Postscript.RTM. file (page number 0)
should be rendered on the flat by comparing CurrentPage to 0. If
CurrentPage is equal to 0, the first page in the merged
PostScript.RTM. file 450 should be imposed and rendered on the
flat, and a block 675 executes the first user procedure contained
in the current entry retrieved by the block 672. Alternatively, if
the block 674 determines that the first page is not on the flat, a
block 676 pops the first user procedure from the retrieved entry
from the stack.
[0362] After the block 675 has executed the user procedure or after
the block 676 pops the user procedure, a block 678 executes the
setvirtualdevice procedure, which was described in detail above in
connection with FIG. 25. The setvirtualdevice procedure sets the
virtual [CTM] and the clipping path according to the operands
included in the retrieved entry.
[0363] The blocks 670-678 of the ImposeFile procedure may be
implemented by the following code:
39 /ImposeFile { impositiondict begin /PageOffset CurrentPage
PageOffset add 1 add def /PageList exch def /CurrentIndex 0 def
PageList CurrentIndex get % get entry aload pop pop 5 -2 roll dup
/CurrentPage exch def % get page number for 1st % page 0 eq { % if
1st page is on flat exec % execute user procedure } { pop % if 1st
page is not on % flat } ifelse % pop user procedure
setvirtualdevice % call setvirtualdevice
[0364] Next, a decision-making block 680 determines whether the
first page in the current Postscript.RTM. file (page number 0)
should be rendered on the flat by comparing CurrentPage to 0. If
CurrentPage is not equal to zero (i.e. the first page should not be
rendered on the flat), a block 682 invokes a procedure called, for
example, "MakeNull." The MakeNull procedure, which is described in
detail below in connection with FIG. 30, creates a scaled-down
version of the virtual device for the next page to be rendered on
the flat. The MakeNull procedure will be used to quickly interpret
pages included in the merged Postscript.RTM. file 450 that will not
be rendered on the current flat 456. The block 682 also calls the
redefined initclip operator (see FIG. 21).
[0365] After the block 682 executes the MakeNull procedure, or,
alternatively, if the block 680 determines that CurrentPage is
equal to zero (i.e. the first page should be rendered on the flat),
a block 684 sets the variable LastPage equal to the page number of
the last page in the PostScript.RTM. file to be rendered on the
flat. The last page is determined by defining LastIndex as the
number of entries in the instruction set minus one. The entries are
indexed starting with zero (i.e., 0, 1, 2, 3,) such that the last
of four entries will be entry number 3). LastIndex is then used to
retrieve the page number from the last entry in the entry list,
which is stored in the variable LastPage. The block 684 thus
determines the number of page descriptions in the current merged
Postscript.RTM. file 450 that need to be interpreted in order to
properly render all of the selected pages on the flat 456.
[0366] The blocks 680-684 of the ImposeFile procedure may be
implemented by the following code:
40 /CurrentPage 0 ne { % if page is not on flat MakeNull % execute
MakeNull % procedure initclip } if /LastIndex PageList length 1 sub
def /LastPage PageList LastIndex get 1 get def
[0367] A block 686 then opens the current merged PostScript.RTM.
file 450, if necessary, and defines a file object (i.e. "TheFile")
to access the current merged Postscript.RTM. file 450. The block
686 then interprets the current merged Postscript.RTM. file 450,
which contains various page descriptions, including the selected
pages to be rendered on the current flat 456. Each page description
includes the showpage operator, which will invoke the redefined
EndPage and BeginPage procedures of the present invention.
[0368] Preferably, the block 686 executes the merged
PostScript.RTM. file 450 in stopped mode, which dictates that the
execution will stop once the last page that needs to be processed
for the flat 456 is executed (determined by the value of LastPage).
Once execution is complete, a block 688 flushes and closes the
current PostScript.RTM. file and a block 690 returns to the block
654 of the ImposeJob procedure (FIG. 26) to retrieve the next
file/list pair from the instruction set.
[0369] The blocks 686-690 of the ImposeFile procedure may be
implemented by the following code:
41 dup type 1 string type eq { (r) file } if dup /TheFile exch def
cvx end stopped { count 0 eq dup not { pop dup (done with current
file) ne } if { stop } { pop } ifelse impositiondict /TheFile get
dup flushfile closefile } bind def
[0370] The MakeNull Procedure:
[0371] The MakeNull Procedure is invoked by the block 682 of the
ImposeFile procedure before processing pages that will not be
rendered on the current flat 456. The MakeNull Procedure creates a
low resolution (scaled-down) replica of the virtual device for the
next page to be rendered on the flat. This low resolution virtual
device allows for fast processing of the non-rendered pages. The
non-rendered pages are processed using a low resolution replica of
the virtual device for the next page to be rendered on the flat to
ensure that any marks generated by the processing do not overwrite
a portion of the flat 456 that is already imaged.
[0372] The MakeNull procedure creates a low resolution replica of
the virtual device by scaling the components of the virtual [CTM].
Further, the MakeNull procedure positions the scaled-down virtual
device in the middle of the original virtual device. This ensures
that the scaled-down virtual device will be completely contained
within the clipping path defining the original virtual device.
[0373] As explained earlier, by definition, the virtual [CTM]
contains the components [a b c d t.sub.x t.sub.y] and specifies a
transformation of the coordinates (x, y) in user space to the
coordinates (x', y') in device space as follows:
x'=ax+cy+t.sub.x
y'=bx+dy+t.sub.y
[0374] The Postscript.RTM. language includes a scale operator which
creates a temporary matrix from supplied x and y scale factors and
concatenates the temporary matrix with the current [CTM]. The scale
operator then replaces the current [CTM] with the resultant
matrix.
[0375] Invoking the Postscript.RTM. scale operator with x and y
scale factors (s.sub.x and s.sub.y) as operands, the scaled
[CTM]=[s.sub.xa s.sub.xb s.sub.yc s.sub.yd t.sub.x t.sub.y]. Thus,
the new transformation from user to device space specified by the
scaled [CTM] is given by:
x'=s.sub.xax+s.sub.ycy+t.sub.x (1)
y'=s.sub.xbx+s.sub.ydy+t.sub.y. (2)
[0376] The exact scale factors s.sub.x and s.sub.y may vary
according to the type of Postscript.TM. RIP 82 used. However, a 1
to 1 ratio between user and device space coordinates leads to
significantly faster processing of pages over normal processing on
a high resolution device. Also, the Postscript.RTM. nulldevice
operator installs a [CTM] with a 1 to 1 ratio of user to device
coordinates. Therefore, although the scale factors could be tuned
for optimal performance on a given PostScript.RTM. RIP 82, it is
assumed that a 1 to 1 ratio between user and device space
coordinates will run with reasonable efficiency on any
PostScript.RTM. RIP 82. Thus, the scale factors s.sub.x and s.sub.y
used by the MakeNull procedure are preferably calculated to achieve
a 1 to 1 ratio between user and device space as follows.
[0377] To achieve a 1 to 1 ratio between user and device space
coordinates with only the scale factors, the unit vector in user
space from coordinate points (0,0) to (1,0) and from (0,0) to (0,1)
must have unit length in device space. Therefore,
.vertline.(x'(1,0), y'(1,0))-(x'(0,0), y'(0,0)).vertline.=1 (3)
[0378] and
.vertline.(x'(0,1), y'(0,1))-(x'(0,0), y'(0,0)).vertline.=1.
(4)
[0379] From equations (1) and (3),
[0380] .vertline.(s.sub.xa+t.sub.x, s.sub.xb+t.sub.y)-(t.sub.x,
t.sub.y).vertline.=1
[0381] .vertline.(s.sub.xa, s.sub.xb).vertline.=1
[0382] ((s.sub.xa).sup.2+(s.sub.xb).sup.2).sup.1/2=1
[0383] Thus, s.sub.x=1/(a.sup.2+b.sup.2).sup.1/2.
[0384] Similarly, s.sub.y=1/(c.sup.2+d.sup.2).sup.1/2.
[0385] FIG. 30 illustrates the program steps implemented by the
MakeNull procedure. A block 698 first determines and saves the
device space coordinates of the midpoint of the virtual clipping
path. The midpoint (mpx, mpy) is determined by first retrieving the
corner coordinates of the virtual clipping path, which are stored
in the variables ClipllX, ClipurX, ClipllY, and ClipurY. The x-axis
midpoint (mpx) is calculated by adding the lower left and upper
right x-axis corner coordinates (ClipllX and ClipurX) and dividing
by two. Similarly, the y-axis midpoint (mpy) is calculated by
adding the y-axis corner coordinates (ClipllY and ClipurY) and
dividing by two. After the midpoint is calculated, the standard
PostScript.RTM. transform operator (renamed "systemdict_transform")
is executed to convert the user space coordinates to device space
coordinates.
[0386] Next, a block 700 gets the virtual [CTM] which is stored in
the variable DefaultMatrix. A block 702 then calculates the scale
factors, s.sub.x and s.sub.y, as specified above and a block 704
applies the scale factors to the virtual [CTM]. A block 706 then
saves the scaled virtual [CTM] as the new virtual [CTM] in the
variable DefaultMatrix.
[0387] A block 708 then sets the midpoint of the scaled clipping
path (specified by the new virtual [CTM]) to correspond with the
coordinates of the midpoint of the original clipping path (saved by
the block 698). The block 708 determines the difference between the
saved midpoint coordinates and the new midpoint coordinates and
then translates the new coordinates by that difference.
[0388] The MakeNull procedure may be implemented by the following
code:
42 /MakeNull { impositiondict begin ClipllX ClipurX add 2 div
ClillY ClipurY add 2 div systemdict_transform /mpy exch def %
calculate /mpx exch def % midpoint DefaultMatrix dup dup dup dup 0
get dup mul % compute a.sup.2 exch 1 get dup mul % compute b.sup.2
add 1 exch div sqrt dup 1.0 gt % compute s.sub.x { pop 1.0 } if
exch dup 2 get dup mul % compute c.sup.2 exch 3 get dup mul %
compute d.sup.2 add 1 exch div sqrt dup 1.0 gt % compute s.sub.y {
pop 1.0 } if Matrix scale % scale matrix exch Matrix2 concatmatrix
% save as the new systemdict_setmatrix % virtual default % matrix
ClipllX ClipurX add 2 div ClipllY ClipurY add 2 div
systemdict_transform /mpy exch mpy sub neg def % translate /mpx
exch mpx sub neg def % midpoint mpx mpy systemdict_idtransform
translate systemdict_currentmatrix pop end } bind def
[0389] The Redefined EndPage Procedure:
[0390] The page descriptions contained in the merged
PostScript.RTM. file 450 all include the showpage operator, which
will invoke the redefined EndPage and BeginPage procedures.
[0391] The redefined EndPage procedure updates the CurrentPage
variable, which represents the number of the next page in the
merged Postscript.RTM. file 450 that should be imposed and rendered
on the flat. The redefined EndPage procedure also calls the
setvirtualdevice and MakeNull procedures for the pages to be
interpreted.
[0392] FIG. 31 is a flowchart illustrating the program steps
implemented by the redefined EndPage procedure. A block 710
determines whether the EndPage procedure was called by the showpage
operator by determining whether the reason code is 0. A block 712
compares CurrentPage plus PageOffset to PageCount to determine
whether the current page in the Postscript.RTM. file should be
imposed and rendered on the flat 456.
[0393] Assuming both of the blocks 710 and 7122 are true, a block
713 set ups the default environment by calling the standard
initgraphics operator (now renamed "systemdict_initgraphics"). The
block 713 then retrieves and executes the second user procedure
(containing, for example, the offset instructions) from the current
entry. If the second user procedure contains offset instructions,
the PostScript.RTM. file will be repositioned to the start of the
next page to be included in the book, thereby skipping processing
of any irrelevant pages. If the second user procedure contains
other instructions (such as barcodes, watermarks, etc.), they will
also be executed.
[0394] Next, a block 714 increments the pointer CurrentIndex, which
will be used to retrieve the next entry from the entry list
(PageList). The decision-making block 716 then determines whether
there is another entry in the instruction set by comparing
CurrentIndex to LastIndex.
[0395] If CurrentIndex is less than or equal to LastIndex, a block
718 resets the graphics state to its system default value by
calling the standard Postscript.RTM. initgraphics operator (now
renamed "systemdict_initgraphics"). A block 720 then uses
CurrentIndex to retrieve the next entry in the entry list to place
the operands for the setvirtualdevice procedure on the Operands
stack and a block 722 invokes the setvirtualdevice procedure.
[0396] A block 724 then sets CurrentPage equal to the number of the
page from the retrieved entry. CurrentPage is now updated to
contain the number of the next page from the merged PostScript.RTM.
file 450 that should be imposed and rendered on the flat 456.
[0397] Next, a block 726 invokes the MakeNull procedure to set up
the low resolution virtual device for processing of non-rendered
pages. The MakeNull procedure is called because it is assumed that
the next page in the merged PostScript.RTM. file 450 will not be
rendered on the flat 456. (If the next page should be rendered on
the flat, the redefined BeginPage procedure, described in detail
below, will establish the virtual device for that page). A block
728 then removes the user procedure (which is contained in the
retrieved entry) from the Operands Stack.
[0398] If any of the blocks 710, 712 or 716 are false, or after the
block 728 pops the user procedure, a block 730 places the value of
the variable ImageDone on the stack. If ImageDone has the value of
true, indicating that the flat is completed, the calling of the
EndPage procedure (i.e., by the showpage operator or for new device
activation) will automatically transfer the contents of the raster
memory 452 to the demand printer 84 to physically render the
selected pages on the flat 456. (See FIG. 19).
[0399] A block 732 then resets ImageDone to false to specify that
the flat is not completed and the contents of the raster memory 452
will not yet be transferred to the demand printer 84 for physical
rendering.
[0400] The redefined EndPage procedure may be implemented by the
following code:
43 /EndPage { impositiondict begin 0 eq exch CurrentPage PageOffset
add eq and { systemdict_initgraphics PageList CurrentIndex get 5
get exec /CurrentIndex CurrentIndex 1 add def CurrentIndex
LastIndex le { systemdict_initgraphics PageList CurrentIndex get
aload pop setvirtualdevice /CurrentPage exch def MakeNull pop } if
} if ImageDone /ImageDone false def end } bind def
[0401] The Redefined BeginPage Procedure:
[0402] FIG. 32 is a flowchart illustrating the program steps
implemented by the redefined BeginPage procedure. A block 740 first
calls the redefined initmatrix operator to set the virtual
[CTM].
[0403] Referring also to FIG. 20, the BeginPage procedure receives
PageCount as an operand from the showpage operator. A
decision-making block 742 compares CurrentPage (which was updated
by the block 724 of the redefined EndPage procedure of FIG. 31) to
PageCount. CurrentPage contains the number of the next page in the
Postscript.RTM. file to be rendered on the flat 456. Thus, if
CurrentPage and PageCount are equal, the current page in the merged
PostScript.RTM. file 450 should be imposed and rendered on the flat
456 and a block 744 retrieves the next entry (containing the user
procedures, page number and setvirtualdevice operands) from the
entry list.
[0404] A block 745 then executes the user procedure from the
retrieved entry and a block 746 invokes the setvirtualdevice
procedure to set up the virtual [CTM] and clipping path for the
virtual device (see FIG. 27). A block 748 then pops the page number
from the retrieved entry.
[0405] Next, a block 750 "blanks out" the virtual page by coloring
the area inside of the clipping path white. This is necessary to
erase any stray marks that may have been placed on the page when
the non-rendered pages were processed using the MakeNull
procedure.
[0406] Alternatively, if the block 742 determines that the next
page in the merged PostScript.RTM. file 450 should not be rendered
on the flat (i.e. CurrentPage is not equal to PageCount), a
decision-making block 752 compares PageCount to LastPage plus
Pageoffset. If PageCount is greater than LastPage plus PageOffset,
subsequent pages in the PostScript.RTM. file do not need to be
interpreted because they are beyond the last page that should be
rendered on the flat 456. Thus, a block 754 stops the execution of
the merged PostScript.RTM. file 450. As explained earlier, the
ImposeFile procedure executes the merged PostScript.RTM. file 450
in stopped context. In order to distinguish between the expected
stop in the block 754 and an unexpected stop caused, for example,
by a PostScript.RTM. error, the string "done with current file" is
generated by the block 754 of the redefined BeginPage procedure.
Referring also to FIG. 27, the block 386 of the ImposeFile
procedure checks for the "done with current file" string to
determine when to proceed to the block 688 to flush and close the
merged Postscript.RTM. file 450.
[0407] Alternatively, if the block 752 determines that PageCount is
less than or equal to LastPage plus PageOffset (i.e. the current
page is before the last page to be rendered on the flat), a block
756 calls the redefined initclip operator to reset the virtual
clipping path. (See FIG. 20).
[0408] The redefined BeginPage procedure may be implemented by the
following code:
44 /BeginPage { initmatrix impositiondict begin dup CurrentPage
PageOffset add eq { % page on flat pop % pop PageCount PageList
CurrentIndex get % get entry aload pop 5 -1 roll exec % execute
user procedure setvirtualdevice pop % pop the page number clippath
1 setgray fill % blank out virtual % page 0 setgray newpath } bind
{ % page not on % flat LastPage PageOffset add gt { end (done with
current file) stop } if initclip } ifelse end } bind def
[0409] The ImageDone Variable:
[0410] As explained earlier, the variable ImageDone is a boolean
variable used to indicate when all the pages for the current flat
456 have been interpreted and painted into the raster memory 452
such that the flat 456 can be physically rendered by the demand
printer 84. ImageDone is initially and normally set to false,
indicating that the current flat 456 has not yet been completed.
However, referring to FIG. 26, after all the file/list pairs from
the instruction set have been processed ty the ImposeJob procedure,
the block 658 sets ImageDone to true to indicate that the flat is
completed. Also, the user procedure contained in the last entry in
a file/list pair in the instruction set could include an
instruction to set ImageDone to true to specify that the current
flat is completed.
[0411] The ImageDone variable is used by the redefined EndPage
procedure. Referring to FIGS. 20 and 31, the block 730 of the
redefined EndPage procedure returns the value of ImageDone to the
block 502 of the showpage operator. If ImageDone is true, the block
504 transmits the contents of the raster memory to the demand
printer to render the current flat.
[0412] The ImageDone variable may be utilized to allow for multiple
flats to be rendered by a single file/list pair in the instruction
set (see Appendix I sample instruction set).
[0413] The Showdevice Procedure:
[0414] The imposition-on-the-fly procedures may include an
additional procedure, called, for example, "showdevice," which uses
the ImageDone variable to allow a user to render the flat at any
time. The showdevice procedure sets ImageDone to true and then
calls the showpage operator, which will invoke the redefined
EndPage procedure and render the current flat, as described
above.
[0415] The showdevice procedure may be implemented by the following
code:
45 /showdevice { impositiondict /ImageDone true put showpage }
def
[0416] The showdevice procedure will normally be used when a user
implements the setvirtualdevice (and related) procedures in a
non-imposition application in which the ImposeJob and ImposeFile
procedures are eliminated. For example, the showdevice procedure
could be implemented to render any selected page(s) contained in
the merged Postscript.RTM. file 450. Optional Imposition-on-the-Fly
Procedures:
[0417] Optionally, additional procedures may be included in the
imposition-on-the-fly procedures which will allow the proper
imposition of page descriptions using the PostScript.RTM. save and
restore operators.
[0418] The Postscript.RTM. save operator takes a "snapshot" of the
state of virtual memory, which stores all values of composite
objects, such as strings and arrays. Many of the variables used by
the imposition-on-the-fly procedures of the present invention are
stored in virtual memory. The save operator also saves the current
graphics state by pushing a copy of the current graphics state onto
the Graphics State Stack. The postScript.RTM. restore operator
restores the virtual memory and the current graphics state to the
state at the time the corresponding save operator was executed.
[0419] The Postscript.RTM. gsave operator pushes a copy of the
current graphics state onto the Graphics State Stack and the
PostScript.RTM. grestore operator pops the saved graphics state
from the Graphics State Stack and restores it as the current
graphics state. The Postscript.RTM. grestoreall operator restores
either the bottom-most graphics state stored on the Graphics State
Stack or the first graphics state that was stored by the save
operator (as opposed to the gsave operator). The elements of the
current graphics state affected by these operators includes the
current [CTM], clipping path and, current path. However, they do
not affect the contents of the raster memory 452.
[0420] The Postscript.RTM. save and restore operators may adversely
affect the imposition-on-the-fly procedures of the present
invention, as well as on other imposition methods. The problem
arises if a page description in the merged PostScript.RTM. file 450
invokes a save operator, which will save the [CTM] that specifies
the desired position for that page on the device. If a subsequent
page description invokes a restore operator, the [CTM] for the
prior page will replace the [CTM] for the subsequent page. Thus,
the subsequent page will be incorrectly positioned on the flat
456.
[0421] To overcome this problem, two new procedures (Vsave and
Vrestore) are used in connection with the above-described
procedures. The Vsave and Vrestore procedures will be used to
redefine the PostScript.RTM. save and restore operators such that
they do not interfere with the other imposition-on-the-fly
procedures of the present invention.
[0422] The Vsave Procedure:
[0423] Generally, the Vsave procedure appends the page size
components (PageX and PageY) and the virtual [CTM] components
(which define the virtual device) to the current path, which will
be saved by the Postscript.RTM. save operator. Later, the Vrestore
procedure will retrieve these components, remove them from the
current path, and use them to generate the correct clipping path,
page orientation and [CTM] for the restored page.
[0424] FIG. 33 is a flowchart illustrating the program steps
implemented by the optional Vsave procedure. A block 800 saves a
copy of the current [CTM] and then a block 801 sets the [CTM] equal
to an identity matrix ([1 0 0 1 0 0]).
[0425] The identity matrix is used because all points used to
describe the current path are specified in user space coordinates.
However, at the time a PostScript.RTM. program enters a point into
the current path, each coordinate is transformed into device space
according to the [CTM]. Thus, the identity matrix will be used when
adding the components to the current path to avoid any round off
errors that may occur in this conversion from user space to device
space.
[0426] A decision-making block 802 then determines whether a
currentpoint is defined. If a currentpoint is defined, a block 804
sets the variable p1 equal to the current path. This may be
accomplished by invoking the previously defined MakePath procedure,
which creates a description of the current path in the current
coordinate system. (The MakePath procedure was described above in
connection with the block 524 of the redefined initclip operator of
FIG. 20).
[0427] A block 806 then defines a variable called, for example,
"firstop" to be the PostScript.RTM. lineto operator. By definition,
the Postscript.RTM. lineto operator adds a straight line segment to
the current path by connecting the previous current point to the
new one.
[0428] Alternatively, if the block 802 determines that no
currentpoint exists, a block 808 sets p1 equal to an empty path. A
block 810 then defines firstop to be the Postscript.RTM. moveto
operator, which establishes a new currentpoint.
[0429] After firstop is defined by either the block 806 or the
block 810, a block 812 creates an "unlimited" bounding box for the
current path. A bounding box, which is normally established by the
PostScript.RTM. setbbox operator, defines the area in which the
current path coordinates must fall. The operands to the setbbox
operator are the user space coordinates of the lower-left
upper-right corners of the bounding box. Since the page size and
[CTM] components will be added to the current path during the Vsave
procedure, the bounding box must be set large enough to encompass
the "points" defined by those components. Thus, a previously
defined procedure called, for example, "SetBigBBox," may be invoked
to set the bounding box to be the largest possible. The SetBigBBox
procedure may be implemented by the following code:
46 /SetBigBBox /setbbox where { pop { -2147483648 -2147483648
2147483648 2147483648 setbbox } bind def } { { } def } ifelse
[0430] After the large bounding box is set, a: block 814 invokes
the firstop operator (defined by the block 806 or the block 810) to
append the page size components (PageX and PageY) to the current
path. Next, a block 818 appends the virtual [CTM] components
(stored in the variable DefaultMatrix) to the current-path. A block
820 then replaces the identity [CTM] with the [CTM] that was saved
by the block 800.
[0431] The Vsave procedure may be implemented by the following
code:
47 /Vsave { Matrix systemdict_currentmatrix dup Identity
systemdict_setmatrix % [CTM] = % identity { currentpoint} stopped {
% no current % point /p1 { } def % define empty % path /firstop {
moveto } def } { % current point pop pop % create real % path /p1
MakePath def /firstop { lineto } def } ifelse SetBigBBox PageX
PageY firstop % append page % size DefaultMatrix aload pop lineto %
append [CTM] lineto lineto systemdict_setmatrix } bind def
[0432] The Vrestore Procedure:
[0433] The Vrestore procedure retrieves the page size and virtual
[CTM] components (which defined the virtual device) appended to the
current path by the Vsave procedure and uses them to generate the
correct clipping path, page orientation and virtual [CTM] for the
restored page.
[0434] FIG. 34 is a flowchart illustrating the program steps
implemented by the Vrestore procedure. A block 830 saves the
current [CTM] and a block 832 then sets the [CTM] to an identity
matrix. As in the Vsave procedure, the use of the identity [CTM]
will avoid any round off errors when transforming coordinates from
user space to device space in the current path.
[0435] A block 834 then retrieves the elements of the current path
by calling the PostScript.RTM. pathforall operator, which pushes
the user space coordinates of each path element onto the Operands
stack. The retrieved elements will include the page size and
virtual [CTM] components that were appended to the path by the
Vsave procedure. A block 836 then performs various stack
manipulation operations to place the page size and virtual [CTM]
components on top of the stack. The block 836 then stores the
components in variables called, for example, "ResDefaultMatrix,"
"ResPageX" and "ResPageY," which represent the page size and
virtual [CTM] at the time that the Postscript.RTM. save operator
was called.
[0436] Next, a decision-making block 838 compares the
ResDefaultMatrix (at time of save) to the current virtual [CTM] (at
time of restore), which is saved in the variable DefaultMatrix. The
equivalency of the matrices may be easily determined by using a
previously defined utility routine, called, for example,
"EqualMatrix," which performs a component-by-component comparison
of the two matrices, allowing for a slight floating point round-off
error. If the two matrices are equivalent, the EqualMatrix routine
returns a true on the stack; if they are not equivalent, the
EqualMatrix routine returns a false. The EqualMatrix routine may be
implemented by the following code:
48 /EqualMatrix { true impositiondict begin /Count 0 def 6 { 1
index Count get 3 index Count get eq sub abs .0001 lt and /Count
Count 1 add def } repeat 3 1 roll pop pop end } bind def
[0437] If the block 838 determines that the restored [CTM] and
current [CTM] are not equivalent, it is assumed that the save
operator was called during interpretation of one page and the
restore operator was called during interpretation of another page.
A block 840 then sets the [CTM] back to the value saved by the
block 830. Next, a block 842 calls p1, which contains the current
path at the time the save operator was called. The block 842 then
removes the page size and [CTM] components that were added to the
current path and sets p1 equal to the remaining path elements.
[0438] The blocks 830-842 of the Vrestore procedure may be
implemented by the following code:
49 /Vrestore { Matrix systemdict_currentmatri- x Identity
systemdict_setmatrix mark { } { } { } { } pathforall 6 2 roll 4 2
roll mark 7 1 roll ] /ResDefaultMatrix exch def /ResPageY exch def
/ResPageX exch def cleartomark DefaultMatrix ResDefaultMatrix
EqualMatrix not { systemdict_setmatrix /p1 mark MakePath aload pop
pop pop pop pop pop pop pop pop pop pop pop pop ] cvx def
[0439] Next, a decision-making block 844 determines the orientation
of the restored page by comparing ResPageX to ResPageY. If ResPageX
is greater than ResPageY, a variable called ResPortrait is set to
false to indicate a landscape orientation. Alternatively, if
ResPageX is less than ResPageY, the variable ResPortrait is set to
true to indicate a portrait orientation. The block 844 then
compares ResPortrait (the restored page orientation) to Portrait
(the saved page orientation). If the page orientation has changed
(ResPortrait and Portrait are not equal), a block 846 calls the
SetPortrait procedure to change the orientation of the device. (See
FIGS. 25 and 26A & B).
[0440] The blocks 844 and 846 of the Vrestore procedure may be
implemented by the following code:
50 ResPageX ResPageY gt { /ResPortrait false def } { /ResPortrait
true def } ifelse ResPortrait Portrait ne { SetPortrait } if
[0441] If the block 844 determines that the orientation is the
same, or after the block 846 corrects the orientation, a block 848
saves the procedures for generating the current clipping path in a
variable called, for example, "c1," by calling the MakePath
procedure.
[0442] A block 850 then calculates the new [CTM] by determining the
accumulation of operations applied on the restored virtual [CTM]
and applying those operations on the current virtual [CTM]. The
block 850 calculates the new [CTM] by first getting the current
[CTM], which may be considered the result of the restored virtual
[CTM] (i.e., the virtual [CTM] restored from the save operator)
concatenated with an operations matrix. The block 850 then
calculates the operations matrix by concatenating the current [CTM]
with the inverse of the restored virtual [CTM]. The operations
matrix is then concatenated with the current virtual [CTM] to
generate the new [CTM]. Thus, the block 850 assumes that:
[0443] [current CTM]=[operations] [restored virtual CTM]. Further,
the block 850 performs the following operations:
[0444] [operations]=[current CTM] [restored virtual CTM].sup.-1;
and
[0445] [new CTM]=[operations] [current virtual CTM].
[0446] The blocks 848 and 850 of the Vrestore procedure may be
implemented by the following code:
51 clippath % generate clip path procedures /c1 MakePath def Matrix
systemdict_currentmatrix % calculate new ResDefaultMatrix % [CTM]
Matrix2 invertmatrix Matrix3 concatmatrix DefaultMatrix Matrix4
concatmatrix systemdict_setmatrix
[0447] A block 852 then regenerates the clipping path (saved in c1)
and a block 854 regenerates the current path (saved in p1) in the
new coordinate system specified by the new [CTM]. The blocks 852
and 854 may be implemented by the following code:
52 systemdict_initclip newpath c1 clip newpath p1 }
[0448] Alternatively, if the block 838 determines that the restored
virtual [CTM] is equivalent to the current virtual [CTM] (i.e., the
save and restore operators were called on the same page), a block
856 simply removes the page size and virtual [CTM] components from
the current path. A block 858 then restores the current path and a
block 860 sets the [CTM] back to the value saved by the block
830.
[0449] The blocks 856-860 may be implemented by the following
code:
53 { /p1 mark MakePath aload pop pop pop pop pop pop pop pop pop
pop pop pop pop ] cvx def newpath p1 systemdict_setmatrix } ifelse
} bind def
[0450] The Redefined PostScript.RTM. Save Operators:
[0451] The Postscript.RTM. save operators (which include save and
gsave) are redefined to invoke the Vsave procedure. Before the
operators are redefined, however, they are renamed
("systemdict_operator," for example) because their normal operation
is defined in the systemdict dictionary. The save operators may be
renamed by the following code:
54 /systemdict_save systemdict /save get def /systemdict_gsave
systemdict /gsave get def
[0452] The PostScript.RTM. save and gsave operators are then
redefined. FIG. 35 is a flowchart illustrating the program steps
implemented to redefine to PostScript.RTM. save operators. A block
872 first invokes the Vsave procedure, which was described above in
connection with FIG. 33. The Vsave procedure saves the current path
in p1 and then appends the page size and virtual [CTM] components
to the current path.
[0453] A block 874 then invokes the standard PostScript.RTM. save
(or gsave) operator (now renamed "systemdict_save" or
"systemdict_gsave"). The save operator performs its standard
function of saving the current state of virtual memory and the
current graphics state, including the current path (which now
includes the page size and virtual [CTM] components). The gsave
operator performs its standard function of saving the current
graphics state.
[0454] Next, a block 876 sets the [CTM] to an identity matrix. As
before, this will eliminate any round off errors in the current
path. A block 878 then restores the current path to the path stored
in p1 (the path without the added page size and virtual [CTM]
components) and a block 880 restores the [CTM] back to the virtual
[CTM].
[0455] The blocks 870-880 for redefining the Postscript.RTM. save
operator may be implemented by the following code:
55 /save { impositiondict begin Vsave systemdict_save Identity
systemdict_setmatrix newpath p1 exch systemdict_setmatrix end }
bind def
[0456] Similarly, the Postscript.RTM. gsave operator may be
redefined by implementing the following code:
56 /gsave { impositiondict begin Vsave systemdict_gsave Identity
systemdict_setmatrix newpath p1 systemdict_setmatrix end } bind
def
[0457] The Redefined Postscript.RTM. Restore Operators:
[0458] The PostScript.RTM. restore operator must also be renamed
and redefined to invoke the Vrestore procedure. Like the save
operators, the restore operator is renamed, for example,
"systemdict_restore," by the following code:
57 /systemdict_restore systemdict /restore get def
[0459] Because the PostScript.RTM. save and restore operators
affect the contents of virtual memory and the graphics state, the
values of many variables used during the imposition and
setvirtualdevice procedures may be inadvertently altered by the use
of these operators. However, simple values stored on the Operands
Stack are not affected. Therefore, the Postscript.RTM. restore
operator is redefined to protect the values of the variables stored
in virtual memory by saving them on the Operands Stack before
calling the standard PostScript.RTM. restore operator.
[0460] FIG. 36 is a flowchart illustrating the program steps
implemented by the redefined restore operator. A block 892 places
the values of all the imposition variables stored in virtual memory
on the Operands stack so their values are not overwritten by the
restore operator. Then, a block 894 calls the standard restore
operator (now renamed "systemdict_restore"). A block 896 then puts
the values of the variables on the Operands stack back to their
pre-restore values. Lastly, a block 898 invokes the Vrestore
procedure.
[0461] The blocks 892-898 of the redefined restore operator may be
implemented by the following code:
58 /restore { impositiondict begin ImageDone % put variables on
stack CurrentIndex CurrentPage PageCount Portrait PageX PageY
ClipllX ClipllY ClipurX ClipurY mark DefaultMatrix % put [CTM]
components on aload pop % stack 19 -1 roll systemdict_restore %
call standard restore operator ] /DefaultMatrix exch def % replace
variables with /ClipurY exch def % pre-restore values /ClipurX exch
def /ClipllY exch def /ClipllX exch def /PageY exch def /PageX exch
def /Portrait exch def /PageCount exch def /CurrentPage exch def
/CurrentIndex exch def /ImageDone exch def Vrestore % invoke
Vrestore procedure end } bind def
[0462] The Redefined Postscript.RTM. grestore Operators:
[0463] The standard Postscript.RTM. grestore or grestoreall
operators, are renamed, for example, "systemdict_operator." This
may be implemented by the following code:
[0464] /systemdict_grestore systemdict/grestore get def
[0465] /systemdict_grestoreall systemdict/grestoreall get def
[0466] Because the PostScript.RTM. grestore and grestoreall
operators affect only the graphics state, it is not necessary to
protect the values of any variable stored in virtual memory. Thus,
the grestore or grestoreall operators are more simply
redefined.
[0467] FIG. 37 is a flowchart illustrating the program steps
implemented by the redefined Postscript.RTM. grestore and
grestoreall operators. A block 902 invokes the renamed standard
grestore or grestoreall operator and then a block 904 invokes the
Vrestore procedure, which will calculate the correct [CTM] and
correct the page orientation and clipping path.
[0468] The blocks 902-904 for redefining the Postscript.RTM.
grestore operator may be implemented by the following code:
59 /grestore { impositiondict begin systemdict_grestore Vrestore
end } bind def
[0469] Similarly, the grestoreall operator may be redefined by
implementing by the following code:
60 /grestoreall { impositiondict begin systemdict_grestoreall
Vrestore end } bind def
[0470] The Postscript.RTM. Level 2 Gstate Operators:
[0471] Level 2 PostScript.RTM. implementations support the
following three additional operators that affect the current
graphics state (and therefore the [CTM]) and that may interfere
with the imposition procedures of the present invention: gstate,
currentgstate and setgstate. The PostScript.RTM. gstate operator
creates a new graphics state object (whose initial value is the
current graphic state) and pushes it on the Operand stack. The
PostScript.RTM. currentgstate operator replaces the value of the
gstate object with the current graphics state. The PostScript.RTM.
setgstate operator replaces the current graphics state with the
value of the gstate object.
[0472] Similarly to the gsave and grestore operators described
above, the gstate operators are renamed and redefined to invoke the
Vsave the Vrestore procedures. The gstate operators may be renamed
by the following code:
61 /gstate where { % is this level 2? pop /systemdict_gstate
systemdict /gstate get def /systemdict_setgstate systemdict
/setgstate get def /systemdict_currentgstate systemdict
/currentgstate get def } if
[0473] Similar to the redefined gsave operator described above in
connection with FIG. 35, the gstate and currentgstate operators are
redefined to first invoke the Vsave procedure and then to call the
renamed standard gstate or currentgstate operator. The redefined
operators then restore the current path without the page size and
[CTM] components and reset the virtual [CTM].
[0474] Also, like the redefined grestore operator described above
in connection with FIG. 37, the setgstate operator is redefined to
first call the renamed setgstate operator and then to invoke the
Vrestore procedure.
[0475] The PostScript.RTM. level 2 gstate operators may be
redefined by the following code:
62 /gstate where { % is this level 2? pop /gstate { % redefine
gstate operator impositiondict begin % (like gsave operator) Vsave
systemdict_gstate Identity systemdict_setmatrix newpath p1 exch
systemdict_setmatrix end } bind def /currentgstate { % redefine
currengstate operator impositiondict begin % (like gsave %
operator) Vsave systemdict_currentgstate Identity
systemdict_setmatrix newpath p1 exch systemdict_setmatrix end }
bind def /setgstate { % redefine setgstate operator impositiondict
begin % (like grestore % operator) systemdict_setgstate Vrestore
end } bind def } if
[0476] These optional procedures are used when it is anticipated
that the page descriptions in the merged Postscript.RTM. file 450
may include a save operator in one page description and a restore
operator in a subsequent page description. If the optional
procedures are used, a slight modification should be made to the
setvirtualdevice procedure, described above in connection with FIG.
27. Referring to FIG. 27, an additional block 633 invokes the
redefined save operator and then pops the save object from the
Operands Stack after the block 6322 invokes the EnableVirtualDevice
procedure. This is necessary because the grestore and grestoreall
operators can be called without a corresponding save or gsave
operator. If grestore is called without a gsave operator, it
restores the graphics state from the top of the graphics state
stack. If grestoreall is called without a gsave or save operator,
it restores either the graphics state from the bottom of the
graphics state stack or the graphics state saved by the last save
operator. If the topmost save object was created prior to the
redefinition of the save operator, the saved current path will not
include the additions of the page size and [CTM] components and,
therefore, will not operate properly with the redefined grestore
and grestorall operators. Thus, invoking the redefined save
operator at the block 633 of the setvirtualdevice procedure ensures
that the grestore and grestoreall operators will always restore a
saved graphics state compatible with the present invention.
[0477] The blocks 630-633 of the setvirtualdevice procedure for the
third embodiment of the invention may be implemented by the
following code:
[0478] VirtualDeviceEnabled not {EnableVirtualDevice save pop}
[0479] if
[0480] Also, in some Postscript.RTM. applications, interpreting
different Postscript.RTM. files consecutively may interfere with
the operation of the invention. For example, two different
Postscript.RTM. files may use the same name for variables with
different definitions. If the second Postscript.RTM. file
interpreted does not explicitly initialize the variable, the
definition of the variable from the first PostScript.RTM. file will
be used, interfering with proper interpretation of the second
PostScript.RTM. file. To overcome this problem, the ImposeJob
procedure (FIG. 28) may be altered.
[0481] Referring to FIG. 28, blocks 653 and 657 are added to the
ImposeJob procedure to save the state of virtual memory (which
includes many variable definitions) before retrieving a file/list
pair from the instruction set and restoring that saved state before
retrieving the next file/list pair. Specifically, the block 653
executes the redefined save operator and stores the saved state in
a variable called, for example, "SavedState." The blocks 654 and
656 then retrieve a file/list pair from the instruction set and
invoke the ImposeFile procedure to process the file/list pair, as
described above. However, after the ImposeFile procedure finishes
processing each entry in the file/list pair, the block 657
retrieves the saved state stored in the variable SavedState and
executes the redefined restore operator to restore that state. The
block 657 thus initializes the virtual memory before the block 654
retrieves the next file/list pair from the instruction set.
[0482] The blocks 650-662 of the ImposeJob procedure incorporating
the blocks 653 and 657 may be implemented by the following
code:
63 /ImposeJob % Impose pages from each input % file {
impositiondict /EnableVirtualDevice get exec { aload pop pop
impositiondict /SavedState save put % save state impositiondict
/ImposeFile get % call ImposeFile for each exec % file in
instruction set % cleardictstack clear impositiondict /SavedState
get restore % restore saved state } forall impositiondict
/ImageDone true put impositiondict /systemdict_showpage known { %
Did we redefine showpage impositiondict /systemdict_showpage get
exec % If yes, execute it. } if } def
[0483] Further, as explained earlier, for compatibility with the
optional procedures, the PostScript.RTM. erasepage operator is
redefined by calling the systemdict_gsave and grestore operators.
All of the remaining imposition-on-the-fly procedures are
compatible with the optional procedures.
[0484] Numerous modifications and alternative embodiments of the
invention will be apparent to those skilled in the art in view of
the foregoing description. Accordingly, this description is to be
construed as illustrative only and is for the purpose of teaching
those skilled in the art the best mode of carrying out the
invention. The details may be varied substantially without
departing from the spirit of the invention, and the exclusive use
of all modifications which are within the scope of the appended
claims is reserved.
* * * * *