U.S. patent application number 10/035148 was filed with the patent office on 2002-07-11 for image forming device and image processing system.
Invention is credited to Nakamura, Toshiaki, Ohtsuji, Shinya.
Application Number | 20020090239 10/035148 |
Document ID | / |
Family ID | 18868937 |
Filed Date | 2002-07-11 |
United States Patent
Application |
20020090239 |
Kind Code |
A1 |
Ohtsuji, Shinya ; et
al. |
July 11, 2002 |
Image forming device and image processing system
Abstract
For obtaining a natural image with certainly providing
visibility upon printing, an image forming apparatus includes a
data buffer temporarily storing a printing data input through an
input terminal, a printing data converting portion active when the
description of a character is contained data temporarily stored in
the data buffer, for converting the printing data for enhancing
visibility of the character, an output terminal for externally
outputting the printing data after conversion and a process end
signal output terminal for externally outputting a signal when end
of printing data is detected by a data end judgment portion.
Inventors: |
Ohtsuji, Shinya;
(Tokai-mura, JP) ; Nakamura, Toshiaki;
(Hitachinaka, JP) |
Correspondence
Address: |
ANTONELLI TERRY STOUT AND KRAUS
SUITE 1800
1300 NORTH SEVENTEENTH STREET
ARLINGTON
VA
22209
|
Family ID: |
18868937 |
Appl. No.: |
10/035148 |
Filed: |
January 4, 2002 |
Current U.S.
Class: |
400/76 |
Current CPC
Class: |
G06K 2215/0011 20130101;
G06K 15/181 20130101; B41J 5/30 20130101 |
Class at
Publication: |
400/76 |
International
Class: |
B41J 011/44 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 4, 2001 |
JP |
2001-46 |
Claims
What is claimed is:
1. An image forming apparatus comprising: a data buffer storing an
input printing data; a judgment portion for making judgment whether
a define statement of a predetermined character is included in data
stored in said data buffer; and a line screen value converting
portion for converting a line screen definition for performing
halftone printing of said predetermined character when a define
statement of said predetermined character is contained in data
stored in said data buffer.
2. An image forming apparatus as set forth in claim 1, wherein said
line screen value converting portion comprises: a first information
input terminal for receiving input of a value of line screen to be
converted; a second information input terminal receiving an input
designating a font size to be conversion object; a font size
comparing portion active when a description of the font size in the
data in said data buffer, for comparing the font size with a font
size given from said second information input terminal; a line
screen conversion character string storage portion storing an
additional character string performing line screen conversion; and
a selector for switching output between input printing data and
said line screen conversion character string on the basis of result
of judgment in said character string judgment portion and
comparison in said font size comparing portion.
3. An image forming apparatus as set forth in claim 2, wherein said
line screen value converting portion comprises: a background color
information extracting portion for extracting information of a
background color from the printing data; and a line screen value
determining portion for determining a line screen value for
conversion with taking the extracted background color into
account.
4. An image forming apparatus comprising: a data buffer storing an
input printing data; a character string judgment portion for making
judgment whether a define statement of a predetermined character in
data stored in said data buffer; and a color information converting
portion for converting a color definition of the character to be
printed.
5. Am image forming apparatus as set forth in claim 4, wherein said
color information converting portion comprises: a color judgment
portion for extracting color information in the data in said data
buffer and making judgment whether degradation of visibility can be
caused upon gray scale conversion; a color conversion character
string storing portion storing the character string to perform
color conversion; and a selector for switching output between the
input printing data and the character string with converted color
definition on the basis of result of judgment in said character
string judgment portion and comparison in said font size comparing
portion.
6. An image forming apparatus as set forth in claim 5, wherein said
color information converting portion comprises: a background color
information extracting portion for extracting information of the
background color from the printing data; and a color information
determining portion for determining color information to be
converted on the basis of extracted background color
information.
7. An image forming apparatus comprising: a data buffer temporarily
storing a printing data input through an input terminal; a printing
data converting portion active when the description of a character
is contained data temporarily stored in said data buffer, for
converting said printing data for enhancing visibility of the
character; an output terminal for externally outputting the
printing data after conversion; and a process end signal output
terminal for externally outputting a signal when end of printing
data is detected by a data end judgment portion.
8. An image forming apparatus as set forth in claim 1, wherein said
printing data converting portion comprises: a first information
input terminal for receiving input of a value of line screen to be
converted; a second information input terminal receiving an input
designating a font size to be conversion object; a font size
comparing portion active when a description of the font size in the
data in said data buffer, for comparing the font size with a font
size given from said second information input terminal; a line
screen conversion character string storage portion storing an
additional character string performing line screen conversion; and
a selector for switching output between input printing data and
said line screen conversion character string on the basis of result
of judgment in said character string judgment portion and
comparison in said font size comparing portion.
9. An image forming apparatus as set forth in claim 8, wherein said
line screen value converting portion comprises: a background color
information extracting portion for extracting information of a
background color from the printing data; and a line screen value
determining portion for determining a line screen value for
conversion with taking the extracted background color into
account.
10. Am image forming apparatus as set forth in claim 4, wherein
said printing data converting portion comprises: a color judgment
portion for extracting color information in the data in said data
buffer and making judgment whether degradation of visibility can be
caused upon gray scale conversion; a color conversion character
string storing portion storing the character string to perform
color conversion; and a selector for switching output between the
input printing data and the character string with converted color
definition on the basis of result of judgment in said character
string judgment portion and comparison in said font size comparing
portion.
11. An image forming apparatus as set forth in claim 5, wherein
said color information converting portion comprises: a background
color information extracting portion for extracting information of
the background color from the printing data; and a color
information determining portion for determining color information
to be converted on the basis of extracted background color
information.
12. An image processing system comprising: a printer driver
converting input image data into a printing data; and a printer
apparatus performing data output using the converted image data,
said printer driver including at least said image forming apparatus
defined in any one of claims 1 to 11.
13. An image processing system comprising: a printer driver
converting input image data into a printing data; and a printer
apparatus performing data output using the converted image data,
said printer apparatus including at least said image forming
apparatus defined in any one of claims 1 to 11.
14. An image forming method comprising: parsing process for parsing
information of an input printing data; converting process for
converting the printing data based on said parsing process; and
output process for outputting on the basis of printing data process
through said conversion process.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to an image forming
apparatus for improving degradation of visibility of printing
product upon printing on a paper. More particularly, the invention
relates to an image forming apparatus useful for monochrome
printing of a color image or a gray scale image.
Description of the Related Art
[0002] Conventionally, in Japanese Patent Application Laid-Open No.
Heisei 5 (1993)-250113, there has been disclosed a technology for
obtaining conspicuous monochrome image upon monochrome printing of
an image, in which color image data and code data are mixedly
present by outlining an image around a portion where an image data
and a code data overlap.
[0003] When the image around the portion where the image data and
the code data overlap, is outlined, a gap to an original image
becomes large to be unnatural image.
SUMMARY OF THE INVENTION
[0004] It is therefore an object of the present invention to obtain
a natural image with certainly providing visibility, upon
printing.
[0005] According to the first aspect of the present invention, an
image forming apparatus comprises:
[0006] a data buffer storing an input printing data;
[0007] a judgment portion for making judgment whether a define
statement of a predetermined character is included in data stored
in the data buffer; and
[0008] a line screen value converting portion for converting a line
screen definition for performing halftone printing of the
predetermined character when a define statement of the
predetermined character is contained in data stored in the data
buffer.
[0009] In the preferred construction, the line screen value
converting portion may comprise:
[0010] a first information input terminal for receiving input of a
value of line screen to be converted;
[0011] a second information input terminal receiving an input
designating a font size to be conversion object;
[0012] a font size comparing portion active when a description of
the font size in the data in the data buffer, for comparing the
font size with a font size given from the second information input
terminal;
[0013] a line screen conversion character string storage portion
storing an additional character string performing line screen
conversion; and
[0014] a selector for switching output between input printing data
and the line screen conversion character string on the basis of
result of judgment in the character string judgment portion and
comparison in the font size comparing portion.
[0015] The line screen value converting portion may comprise:
[0016] a background color information extracting portion for
extracting information of a background color from the printing
data; and
[0017] a line screen value determining portion for determining a
line screen value for conversion with taking the extracted
background color into account.
[0018] According to the second aspect of the present invention an
image forming apparatus comprises:
[0019] a data buffer storing an input printing data;
[0020] a character string judgment portion for making judgment
whether a define statement of a predetermined character in data
stored in the data buffer; and
[0021] a color information converting portion for converting a
color definition of the character to be printed.
[0022] In the preferred construction, the color information
converting portion may comprise:
[0023] a color judgment portion for extracting color information in
the data in the data buffer and making judgment whether degradation
of visibility can be caused upon gray scale conversion;
[0024] a color conversion character string storing portion storing
the character string to perform color conversion; and
[0025] a selector for switching output between the input printing
data and the character string with converted color definition on
the basis of result of judgment in the character string judgment
portion and comparison in the font size comparing portion.
[0026] The color information converting portion may comprise:
[0027] a background color information extracting portion for
extracting information of the background color from the printing
data; and
[0028] a color information determining portion for determining
color information to be converted on the basis of extracted
background color information.
[0029] According to the third aspect of the present invention, an
image forming apparatus comprises:
[0030] a data buffer temporarily storing a printing data input
through an input terminal;
[0031] a printing data converting portion active when the
description of a character is contained data temporarily stored in
the data buffer, for converting the printing data for enhancing
visibility of the character;
[0032] an output terminal for externally outputting the printing
data after conversion; and
[0033] a process end signal output terminal for externally
outputting a signal when end of printing data is detected by a data
end judgment portion.
[0034] The printing data converting portion may comprise:
[0035] a first information input terminal for receiving input of a
value of line screen to be converted;
[0036] a second information input terminal receiving an input
designating a font size to be conversion object;
[0037] a font size comparing portion active when a description of
the font size in the data in the data buffer, for comparing the
font size with a font size given from the second information input
terminal;
[0038] a line screen conversion character string storage portion
storing an additional character string performing line screen
conversion; and
[0039] a selector for switching output between input printing data
and the line screen conversion character string on the basis of
result of judgment in the character string judgment portion and
comparison in the font size comparing portion.
[0040] In such case, the line screen value converting portion may
comprise:
[0041] a background color information extracting portion for
extracting information of a background color from the printing
data; and
[0042] a line screen value determining portion for determining a
line screen value for conversion with taking the extracted
background color into account.
[0043] In the alternative, the printing data converting portion may
comprise:
[0044] a color judgment portion for extracting color information in
the data in the data buffer and making judgment whether degradation
of visibility can be caused upon gray scale conversion;
[0045] a color conversion character string storing portion storing
the character string to perform color conversion; and
[0046] a selector for switching output between the input printing
data and the character string with converted color definition on
the basis of result of judgment in the character string judgment
portion and comparison in the font size comparing portion.
[0047] The color information converting portion may comprise:
[0048] a background color information extracting portion for
extracting information of the background color from the printing
data; and
[0049] a color information determining portion for determining
color information to be converted on the basis of extracted
background color information.
[0050] According to the fourth aspect of the present invention, an
image processing system comprises:
[0051] a printer driver converting input image data into a printing
data; and
[0052] a printer apparatus performing data output using the
converted image data,
[0053] the printer driver including at least the image forming
apparatus set forth above.
[0054] According to the fifth aspect of the present invention, an
image processing system comprises:
[0055] a printer driver converting input image data into a printing
data; and
[0056] a printer apparatus performing data output using the
converted image data,
[0057] the printer apparatus including at least the image forming
apparatus as set forth above.
[0058] According to the sixth aspect of the present invention, an
image forming method may comprise:
[0059] parsing process for parsing information of an input printing
data;
[0060] converting process for converting the printing data based on
the parsing process; and
[0061] output process for outputting on the basis of printing data
process through the conversion process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] The present invention will be understood more fully from the
detailed description given hereinafter and from the accompanying
drawings of the preferred embodiment of the present invention,
which, however, should not be taken to be imitative to the
invention, but are for explanation and understanding only.
[0063] In the drawings:
[0064] FIG. 1 is a block diagram showing a construction of the
first embodiment of an image forming apparatus according to the
present invention;
[0065] FIG. 2 is a block diagram showing a construction of a line
screen converting portion in the first embodiment of the image
forming apparatus according to the present invention;
[0066] FIGS. 3A, 3B and 3C are explanatory illustrations showing
examples of system construction of image processing system to be
employed in the image forming apparatus according to the present
invention;
[0067] FIG. 4 is an explanatory illustration showing a process
flowchart in accordance with the present invention;
[0068] FIG. 5 is a block diagram showing a construction of the
second embodiment of an image forming apparatus according to the
present invention;
[0069] FIG. 6 is an explanatory illustration showing an effect by
increasing of line screen in the present invention;
[0070] FIG. 7 is a block diagram showing a construction of a color
information converting portion in the second embodiment of the
image forming apparatus according to the present invention; and
[0071] FIG. 8 is a block diagram showing a construction of the
third embodiment of an image forming apparatus according to the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0072] The present invention will be discussed hereinafter in
detail in terms of the preferred embodiments of image forming
apparatus and image processing system according to the present
invention with reference to the accompanying drawings. In the
following description, numerous specific details are set forth in
order to provide a thorough understanding of the present invention.
It will be obvious, however, to those skilled in the art that the
present invention may be practiced without these specific details.
In other instance, well-known structure are not shown in detail in
order to avoid unnecessary obscurity of the present invention.
[0073] Upon outputting data containing color information by a
monochrome printer, a conversion process for converting the color
information into a gray scale is performed. Particularly, among
color information for each pixel, brightness information is
extracted to convert into a gray scale level between
white.about.gray.about.black on the basis of the extracted
brightness information. Upon practically outputting a gray scale
image by the monochrome printer, the gray scale level has to be
expressed by a binary value of white and black. For this reason,
halftone dot called as halftone cell is employed to realize pseudo
gray scale expression. For example, when a size of one halftone
cell is sixteen dot square and when output resolution of printing
output is 2400 dpi, a hundred-fifty halftone cells are aligned in
one inch. Number of the halftone cells will be hereinafter referred
to as line screen which represents number of lines of dots
appearing per linear inch. Once the line screen and resolution are
determined, size of the halftone cell is determined. On the other
hand, depending upon size of the halftone cell, capability of
gradation expression is determined. A ratio of white dots and black
dots in the halftone cell expresses gray scale level of the
halftone dot determines number of gradation levels in gray scale
expression to be expressed by the halftone cell. For example, when
the size of one halftone cell is constructed by sixteen dots
square, two-hundreds fifty-six gradation levels can be expressed.
In general, a relationship of
Number of gradation levels=(resolution(dpi))/(line
screen(lpi)).sup.-2)
[0074] is established. Due to the foregoing relationship between
the line screen, the resolution and number of gradation levels,
smaller value of line screen achieves greater number of gradation
levels to be expressed. A monochrome expression to be expressed
through the foregoing conversion process for an original color
image can be converted into expression to cause degradation of
visibility in some objective original image. The present invention
has been worked out for solving the problem set forth above.
[0075] On the other hand, in general, when the image data such as
photographic image is to be printed, greater number of gradation
levels achieved higher expression ability of the gray scale to
achieve more natural feeling. On the other hand, upon printing data
containing monotone data, such as character, greater line screen
increases clarity of expression in detailed portion, such as edge
or the like to be more conspicuous. However, upon practically
printing by the printer, the resolution, the line screen are
constant at fixed value in the image data to be printing object.
Therefore, number of gradation levels naturally becomes constant.
When the line screen is set small with giving higher preference for
the image data, visibility of the color character data,
particularly small character is sacrificed. Conversely, when the
line screen is set large with giving higher preference for the
character data, number of gradation levels of the image expression
is reduced to make the printed image expressionlessly crushed as a
whole. The present invention has been worked out for presenting
solution for the problems set forth above.
[0076] On the other hand, it should be noted that the object of the
present invention should not be limited to the monochrome printer
but is also applicable for color printer output for providing
solution for degradation of visibility to be caused by coloration
of the background color and graphic pattern and/or character. The
present invention has been worked out with focusing the drawbacks
set forth above and thus to provide means for optimally setting
printing characteristics for objective image data and character
data by converting only portions possibly causing degradation of
visibility with inserting a predetermined setting character string
in a printing data. Hereinafter, the preferred embodiments of the
present invention will be discussed hereinafter.
[0077] (First Embodiment)
[0078] FIG. 1 is a schematic block diagram of the first embodiment
of an image forming apparatus according to the present invention,
which can perform resolution conversion. The shown embodiment of
the image forming apparatus generally comprises the following
components 1 to 7. The reference numeral 1 denotes an input
terminal, through which a printing data is to be input. In the
shown embodiment, a postscript data described in a printer
description language is an input objective data. The reference
numeral 2 denotes a data buffer accumulating input printing data
per one line. The data buffer stores the input data with shifting
per one line. The reference numeral 3 denotes a data end judgment
portion for making judgment whether the data in the data buffer 2
is the end data among data stored in the data buffer 2. Namely, the
data end judgment portion 3 typically detects the end of stored
data by detecting "EOF" indicative end of the file. The reference
numeral 4 denotes a character judgment portion which makes judgment
whether a define statement of a particular character. The reference
numeral 5 denotes a line screen value converting portion for
converting a line screen definition for converting a character into
halftone data to be printed when a description of the character is
contained in the stored data in the data buffer 2. The reference
numeral 6 denotes an output terminal for externally outputting the
printing data after performing line screen conversion. The
reference numeral 7 denotes a process end signal output terminal
for externally outputting a signal upon detection of end of fine by
the data end judgment portion 3.
[0079] FIG. 2 shows a particular embodiment of the line screen
value converting portion 5. The reference numeral 21 denotes an
information input terminal for inputting a value of line screen to
be converted. The reference numeral 22 denotes an information input
terminal designating a font size to be conversion object. The
reference numeral 23 denotes a font size comparing portion for
comparing the font size given from the information input terminal
21. The reference numeral 24 denotes a line screen conversion
character string storage portion storing an additional character
string for performing line screen conversion. The reference numeral
25 denotes a selector for selectively switching the input data and
the line screen conversion character string to output on the basis
of the result of the character string judgment portion 4 and the
font size comparing portion 23.
[0080] The first embodiment of the image forming apparatus takes
the printing data as input. The image forming apparatus for
improving visibility of printing output by parsing information of
the printing data, comprises the input terminal for inputting the
printing data, the data buffer 2 accumulating the printing data per
one line, the data end judgment portion 3 for making judgment
whether the data in the data buffer is end of the printing data,
the character judgment portion 4 for making judgment whether the
define statement of the predetermined character is contained in
data in the data buffer 2, the line screen value converting portion
5 for converting line screen definition for converting the
character to be printed into halftone data, the output terminal 6
for externally output the printing data after conversion and the
process end signal output terminal 7 for externally outputting the
signal upon detection of end of the file by the data end judgment
portion 3. The line screen value converting portion 5 comprises the
first information input terminal 21 for inputting the value of the
line screen to be converted, the second information input terminal
22 designating the font size to be the conversion object, the font
size comparing portion 23 comparing the font size with the font
size given from the information input terminal, the line screen
conversion character string storage portion 24 for storing
additional character string for performing line screen conversion,
and the selector 25 selectively switching between the input
printing data and the output of the line screen converting
character string to output depending upon the result of judgment in
the character string judgment portion 4 and comparison in the font
size comparing portion 23.
[0081] FIG. 3 shows an example of construction of an image
processing system to be employed in the image forming apparatus
according to the present invention.
[0082] In FIGS. 3A, 3B and 3C, the reference numeral 31 denotes the
image processing system typically represented by a personal
computer. It is not required that the image processing system is
not specified to be the personal computer but can be arithmetic
processor, data accumulator or the like having terminal for
outputting the printing data. The reference numeral 32 denotes the
image forming apparatus shown in FIG. 1. The reference numeral 33
denotes the image output device, such as the printer, for
outputting data on the paper on the basis of the printing data. In
the shown embodiment, the image processing system 31 is desirably a
monochrome output postscript printer which can parse and print the
printer description language post script language.
[0083] In FIG. 3A, the image forming apparatus 32 is incorporated
in the image processing system 31 for operation. In FIG. 3B, the
image forming apparatus is incorporated in the image output device
33. In FIG. 3C, the image forming apparatus 32 is not incorporated
neither in the image processing system 31 nor the image output
device 33 and is located therebetween to permit independent
operation. The image processing system shown in FIG. 3 is used as a
printing system, for example.
[0084] It should be noted that the function of the image forming
apparatus 32 may be realized by hardware or by software.
Accordingly, the function of the image forming apparatus may be
realized by the software as program to be executed on the image
processing system 31 or the image output device 33.
[0085] FIG. 4 is one embodiment of a process flowchart of the
present invention. It should be noted that the shown embodiment is
premised to the postscript data as the input data, the present
invention is applicable for printing other type printing data.
[0086] At first, a printing data 400 obtained from the input
terminal 1 of FIG. 1 is stored in the data buffer 2 per one line
(step 401). In the character judgment portion 4, judgment is made
whether the printing object contains a character string as the
character data (step 402). The printing data in postscript
description frequently differentiate definition of the character
string per application. When define statement of the character
string indicative of the character data is "MF", and when this
character string is expressed in one line of the character data, it
indicates that character information, such as font size, fond kind
and so forth is described in the line. Therefore, the character
judgment portion 4 may be set for detecting this character string
"MF". When the character string is detected (YES in step 402),
judgment is made that the printing object is the character data to
extract the font size of the character to print from the relevant
line in the fond size comparing portion 23. Position of the
description of the font size is fixed by the software as source of
generation of the character data, and thus can be easily
extracted.
[0087] For example, in the shown embodiment, when the font
definition character string in the printing data is [300 0 0-300 0
0]/AATT11E17C23A8-0 MF, it is premised that the numerical value
"300" is the value determining the font size, and the character
string "/AATT11E17C23A8-0" expresses the kind of font.
[0088] Comparison is made between the extracted font size and the
font size input from the information input terminal 21 (step 403).
When the font size of the character to print is smaller (YES in
step 403), a command is output to the selector for outputting the
character string in the line screen conversion character string
storage portion 24. In practice, a description to increase line
screen is added (step 404). In the selector 25, the data in the
data buffer 2 is normally output. However, when judgment is made in
the character judgment portion 4 and the font size comparing
portion 23 that the line screen conversion character string is to
be output, outputting of data of the data buffer 2 is temporarily
stopped to switch the data path for outputting the character string
in the line screen conversion character string storage portion 24.
As a result, data produced by inserting the line screen conversion
character string to the input printing data can be output from the
output terminal 6.
[0089] When the operation is repeated per one line of the input
data and when the character string indicative of the end of data is
detected in the data buffer 2 in the data end judgment portion 3
(YES in step 405), the shown process goes END to externally output
a signal indicative of end of process from the output terminal 7.
In response to this, new printing data 406 is prepared. As
alternative method of data end judgment other than that detecting
the character string indicative of the end of data as set forth
above, it is possible to make judgment of data end when data amount
of the input data reaches a predetermined amount. In the further
alternative, it is possible to make judgment when a predetermined
period is elapsed after input. In short, any method which may
detect possible data end, may be used.
[0090] The character string in the line screen conversion character
string storage portion 24 may be formed in accordance with
description of the postscript. The following is one example of the
character string:
1 /freq X def /HProc {dup mul exch dup mul add I exch sub} def freq
45 /HProc load setscreen
[0091] In the character string, X is line screen value to be
converted and is replaced with a line screen designation parameter
obtained from the information. Greater value of X may improve
visibility of the character.
[0092] FIGS. 6A and 6B are imaginary illustrations showing the
effect of improvement of visibility by increasing of the line
screen. In FIGS. 6A and 6B, each circle represents dot to be
printed. One inch length is assumed as shown in FIGS. 6A and 6B,
the resolution of the shown figure becomes 20 dpi. FIG. 6A shows
the character expressed by a halftone cell of 2.times.2 dots. In
this case, gradation level is 4, and line screen is 10 lpi. On the
other hand, in FIG. 6B, the halftone cell is formed by single dot.
Therefore, the gradation level is 2 and the line screen is 20 lpi.
If the original character is colored, the gradation expression of
the character is done by halftone expression. In these Figures,
there is shown an example of expression of gradation by making two
dots in the four dot halftone cell in FIG. 6A. On the other hand,
in the example of FIG. 6B, since only two tone expression is
possible, the cells located in the character portion is expressed
by black irrespective of the original color. From comparison of
FIGS. 6A and 6B, it should be clear that visibility of FIG. 6B
having greater line screen is much higher than that of FIG. 6A.
[0093] (Second Embodiment)
[0094] FIG. 7 is a schematic block diagram showing a construction
of the second embodiment of the image forming apparatus performing
resolution conversion according to the present invention. The shown
embodiment of the image forming apparatus is constructed with the
following components identified by the reference numerals 1 to 7
and 70. The components identified by the reference numerals 1 to 7
are the same as those discussed in connection with the first
embodiment. The reference numeral 70 denotes a color information
converting portion converting color definition for printing the
character when data in the data buffer 2 contains description of
the character.
[0095] FIG. 5 shows an alternative embodiment of particular example
for realizing the color information converting portion 70. The
reference numeral 51 denotes a color judgment portion for
extracting color information in the data stored in the data buffer
4 and making judgment whether degradation of visibility can be
caused upon conversion into gray scale image. The reference numeral
52 denotes a color conversion character string storage portion
storing the character string to perform color conversion. The
reference numeral 53 denotes a selector for switching output
between the input printing data and the color conversion character
string depending upon the result of judgment in the character
string judgment portion 4 and the font size comparing portion 23. A
system construction is similar to FIG. 3.
[0096] At first, the printing data obtained from the input terminal
1 of FIG. 1 is temporarily stored in the data buffer 2 per one
line. In the character string judgment portion 4, judgment is made
whether a character string indicative of the character data is
contained in the printing object or not. When the character string
is detected and thus judgment is made that the printing object is
the character data, color information of the character is extracted
in the color judgment portion 51. If judgment is made that the
color of the character is light as converted into gray scale, a
command is output to the selected so that the character string in
the color conversion character string storage portion 52 is out. In
the selector 53, data in the data buffer 2 is normally output.
However, when judgment is made that outputting of the color
conversion character string is necessary, in the character judgment
portion 4 and the color judgment portion 51, the selector is
switched for interrupting outputting of the data in the data buffer
2 as done in normal state, and outputting the character string in
the color conversion character string storage portion 52. As a
result, from the output terminal 6, the color information from the
input printing data can be converted into the color information
having high visibility. When the operation is repeated per one line
of the input data and when the character string indicative of the
end of data is detected in the data buffer 2 in the data end
judgment portion 3, the shown process goes END to externally output
a signal indicative of end of process from the output terminal
7.
[0097] The character string of the color conversion character
string storage portion 24 can improve visibility of the character
by describing to make the character to be expressed in black,
uniformly.
[0098] (Third Embodiment)
[0099] In the present invention, in the preferred embodiment, line
screen value conversion and/or color conversion may be performed
with taking the background color of the original into
consideration. FIG. 8 is a schematic block diagram showing the
third embodiment of the image forming apparatus according to the
present invention permitting printing in consideration of the
background color of the original.
[0100] In FIG. 8, the components identified by the reference
numerals 1 to 7, 21, 23 to 25 are similar to those discussed in
connection with the first embodiment. The reference numeral 80
denotes a background color information extracting portion
extracting a background color information in the printing data
description stored in the data buffer. The reference numeral 81
denotes a line screen value determining portion for determining a
line screen for converting in consideration of the extracted
background color. While the second embodiment determines the line
screen value derived by external input, the shown embodiment
determines the line screen value in consideration of the background
color of the printing data in the background color information
extracting portion 80 and the line screen value determining portion
81. Other operations are the same as those in the first embodiment.
Also, the shown embodiment may be modified by adding the similar
function to the color information converting portion 70n in the
second embodiment, color information to convert is determined.
[0101] As set forth above, in the preferred embodiments of the
present invention, by inserting setting character string in
arbitrary portion in the printing data, means for setting of
optical printing characteristics for the objective image data and
the character data can be provided. Namely, the image forming
apparatus receiving input of the printing data and improving
visibility of the printing output with parsing information of the
printing data includes the input terminal receiving the printing
data as input, the data buffer storing the printing data per one
line, the data end judgment portion for making judgment whether the
data in the data buffer is end data in the printing data, the
character string judgment portion for making judgment whether the
define statement of the predetermined character in the data in the
data buffer, the printing data converting portion converting the
printing data for improving visibility of the character when the
description of the character is contained in the data buffer, the
output terminal for externally outputting the printing data after
conversion, and the process end signal output terminal for
externally outputting the signal when end of file is detected by
the data end judgment portion. By adding or converting the
character string for improving visibility of the character font
smaller than or equal to a designated character size, expression of
the detail portion, such as edge of the character image can be made
clear. As set forth above, by adding the character string improving
visibility of the character font smaller than or equal to the
character size, expression of the detail portion, such as edge of
the character image can be made clear.
[0102] Although the present invention has been illustrated and
described with respect to exemplary embodiment thereof, it should
be understood by those skilled in the art that the foregoing and
various other changes, omission and additions may be made therein
and thereto, without departing from the spirit and scope of the
present invention. Therefore, the present invention should not be
understood as limited to the specific embodiment set out above but
to include all possible embodiments which can be embodied within a
scope encompassed and equivalent thereof with respect to the
feature set out in the appended claims.
[0103] For instance, while the embodiments have been discussed in
terms of printing output of the color original by a monochrome
printer, the present invention should not be limited to this.
Namely, the present invention is applicable for the case where the
color original is output by a color printer.
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