U.S. patent application number 09/050468 was filed with the patent office on 2001-08-16 for image processing apparatus and system.
Invention is credited to HIRASAWA, MASAHIDE, NAGASAWA, KENICHI.
Application Number | 20010013944 09/050468 |
Document ID | / |
Family ID | 13812947 |
Filed Date | 2001-08-16 |
United States Patent
Application |
20010013944 |
Kind Code |
A1 |
NAGASAWA, KENICHI ; et
al. |
August 16, 2001 |
IMAGE PROCESSING APPARATUS AND SYSTEM
Abstract
In order to provide an image processing apparatus and system,
which can effectively use the functions of an interface and can
fully use an image forming apparatus, an image processing apparatus
of this invention, which is connected to a plurality of image
forming apparatuses via an interface, includes an image output
means for transmitting the image to be formed via the interface, an
input means for inputting the image forming conditions, and a mode
designation means for designating the image communication mode of
the interface in accordance with the image forming conditions input
by the input means.
Inventors: |
NAGASAWA, KENICHI;
(KAWASAKI-SHI, JP) ; HIRASAWA, MASAHIDE;
(SAGAMIHARA-SHI, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Family ID: |
13812947 |
Appl. No.: |
09/050468 |
Filed: |
March 31, 1998 |
Current U.S.
Class: |
358/1.14 |
Current CPC
Class: |
H04L 12/40058 20130101;
H04N 2201/33364 20130101; H04N 2201/33357 20130101; H04L 12/40123
20130101; H04N 2201/33328 20130101; H04N 2201/0084 20130101; H04N
1/33307 20130101; G06F 3/1236 20130101; H04N 1/32561 20130101; H04N
1/00204 20130101; G06F 3/1211 20130101; G06F 3/1285 20130101; H04N
2201/33321 20130101; H04L 12/40117 20130101; H04N 2201/33378
20130101; H04N 2201/0082 20130101 |
Class at
Publication: |
358/1.14 |
International
Class: |
B41B 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 2, 1997 |
JP |
9-083807 |
Claims
What is claimed is:
1. An image processing apparatus connected to a plurality of image
forming apparatuses via an interface, comprising: image output
means for transmitting an image to be formed via said interface;
input means for inputting an image forming condition; and mode
designation means for designating an image communication mode in
said interface in accordance with the image forming condition input
by said input means.
2. An apparatus according to claim 1, wherein said input means can
input the number of images to be formed for an identical image, and
said mode designation means designates the image communication mode
of said interface in accordance with the number.
3. An apparatus according to claim 2, wherein, said mode
designation means designates a first mode of said interface in
which said plurality of image forming apparatuses can
simultaneously receive an image when the number is not less than a
predetermined value, and designates a second mode in which only a
designated one of said plurality of image forming apparatus can
receive an image when the number is less than the predetermined
value.
4. An apparatus according to claim 3, wherein the first mode is a
synchronous mode for transferring a predetermined volume of data at
predetermined periods, and the second mode is an asynchronous mode
for transferring data in an idle time of said interface.
5. An apparatus according to claim 3, wherein said input means can
input information indicating whether the image to be formed is a
color image or monochrome image, and said mode designation means
can designate the first mode of said interface only when the image
to be formed is a color image.
6. An apparatus according to claim 3, wherein said input means can
input information indicating whether the image to be formed is a
color image or monochrome image, and said mode designation means
sets a small value as the predetermined value when the image to be
formed is a color image and sets a large value as the predetermined
value when the image to be formed is a monochrome image.
7. An apparatus according to claim 3, wherein said input means can
input a size of the image to be formed, and said mode designation
means sets the predetermined value in accordance with the size.
8. An apparatus according to claim 3, wherein said input means can
input resolution of the image to be formed, and said mode
designation means can designate the first mode of said interface in
accordance with the resolution.
9. An apparatus according to claim 8, further comprising means for
encoding the image to be formed by high-efficiency coding, and
wherein operation of said high-efficiency coding means is
controlled in accordance with the resolution.
10. An apparatus according to claim 3, wherein said input means can
input resolution of the image to be formed, and said mode
designation means sets the predetermined value in accordance with
the resolution.
11. An apparatus according to claim 10, further comprising means
for encoding the image to be formed by high-efficiency coding, and
wherein operation of said high-efficiency coding means is
controlled in accordance with the resolution.
12. An apparatus according to claim 3, wherein said mode
designation means can control the number of apparatuses that
actually perform image formation among said plurality of image
forming apparatuses using the second mode upon designating the
first mode of said interface.
13. An apparatus according to claim 12, wherein when said mode
designation means sets said interface in the first mode, said
designation means can designate one of a highest-speed mode for
forming images using all of said plurality of image forming means
irrespective of the number of images to be formed, and a sort mode
for making the number of images to be formed match the number of
image forming apparatuses actually used in image formation among
said plurality of image forming apparatuses.
14. An apparatus according to claim 1, wherein said input means
comprises means for receiving a command from a computer via said
interface.
15. An apparatus according to claim 1, further comprising a memory
for storing the image to be formed for at least one frame.
16. An apparatus according to claim 1, wherein said interface
connects said image processing apparatus to said plurality of image
forming apparatuses via a serial bus.
17. An apparatus according to claim 16, wherein said interface
comprises an IEEE 1394 serial bus.
18. An image processing system comprising: an image supply
apparatus for supplying an image; a plurality of image forming
apparatuses; a common interface for connecting said image supply
apparatus and said plurality of image forming apparatuses; input
means for inputting an image forming condition; and control means
for controlling an image communication mode of said interface in
accordance with the image forming condition input by said input
means.
19. A system according to claim 18, wherein said image supply
apparatus outputs, an image generated by another apparatus
connected to said interface, via said interface.
20. A system according to claim 19, wherein said other apparatus
comprises an electronic camera.
21. A system according to claim 20, wherein said electronic camera
comprises said input means.
22. A system according to claim 19, wherein said other apparatus
comprises a personal computer.
23. A system according to claim 22, wherein said personal computer
comprises said input means.
24. A system according to claim 18, wherein said image supply
apparatus comprises a memory for storing an image to be formed for
at least one frame.
25. A system according to claim 18, wherein said interface connects
said image supply apparatus to said plurality of image forming
apparatuses via a serial bus.
26. A system according to claim 25, wherein said interface
comprises an IEEE 1394 serial bus.
27. An image processing apparatus connected to an image forming
apparatus via an interface, which has at least a synchronous mode
for transferring a predetermined volume of data at predetermined
periods, and an asynchronous mode for transferring data in an idle
time of data transmission in the synchronous mode, comprising:
image output means for transmitting an image to be formed via said
interface; input means for inputting an image forming condition;
and mode designation means for selecting one of the synchronous and
asynchronous modes of said interface in accordance with the image
forming condition input by said input means.
28. An apparatus according to claim 27, wherein said input means
can input the number of images to be formed for an identical image,
and said mode designation means selects a communication mode in
said interface in accordance with the number.
29. An apparatus according to claim 27, wherein said input means
can input whether the image to be formed is a color image or
monochrome image, and said mode designation means selects a
communication mode of said interface depending on whether the image
to be formed is a color image or monochrome image.
30. An apparatus according to claim 27, wherein said input means
can input a size of the image to be formed, and said mode
designation means selects a communication mode of said interface in
accordance with the size.
31. An apparatus according to claim 27, wherein said input means
can input resolution of the image to be formed, and said mode
designation means selects a communication mode of said interface in
accordance with the resolution.
32. An apparatus according to claim 27, wherein said input means
comprises means for receiving a command from a computer via said
interface.
33. An apparatus according to claim 27, further comprising a memory
for storing the image to be formed for at least one frame.
34. An apparatus according to claim 27, wherein said interface
connects said image processing apparatus to said plurality of image
forming apparatuses via a serial bus.
35. An apparatus according to claim 34, wherein said interface
comprises an IEEE 1394 serial bus.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image processing
apparatus and system and, more particularly, to an image processing
apparatus and system, which can transfer an image to be formed to
an image forming apparatus via a digital interface.
[0003] 2. Related Background Art
[0004] In recent years, higher-speed digital interfaces have been
developed, and for example, a universal serial bus (USB) and faster
IEEE1394-1995 (High Performance serial bus) (to be referred to as a
1394 serial bus hereinafter) are known.
[0005] Such serial buses have been developed to transfer a large
volume of data such as audio data, video data, and the like in real
time among a home digital VTR, electronic camera, and PC (personal
computer).
[0006] On the other hand, as color scanners, color copying
machines, color printers, and the like have gained higher
performance, these apparatuses are often connected to the PC.
Hence, if these apparatuses are connected to the PC via the 1394
serial bus, a color image can be printed out, e.g., a color image
captured using a video camera can be printed out via the 1394
serial bus.
[0007] The 1394 serial bus has an asynchronous transfer mode
(asynchronous transfer) and synchronous transfer mode (isochronous
transfer). More specifically, asynchronous transfer is a one-to-one
transfer mode for transmitting data from a source node to a
destination node during an idle time of isochronous transfer (to be
described below, and is used for transferring data with a small
information volume, e.g., text data, commands, still image data,
and the like.
[0008] On the other hand, isochronous transfer is a characteristic
mode of the 1394 serial bus, and is especially suitable for
transferring data that requires real-time transfer such as video
data, audio data, and the like. Also, asynchronous transfer is a
one-to-one transfer mode, but isochronous transfer can transfer
data from one node to all other nodes by a broadcast function.
These two modes can use a bus time-divisionally, and the 1394
serial bus is characterized by having these two modes.
[0009] However, asynchronous transfer alone may not fully use the
functions of a printer since recent printers have multiple
functions and higher resolutions. More specifically, when the
printer for printing out an image is designated and high-resolution
color images are successively printed out in the asynchronous
transfer mode, the transfer time may become larger than the time
required for printouts.
[0010] Also, asynchronous transfer designates a specific node
connected to the 1394 serial bus. For this reason, even when a
plurality of printers are connected to the 1394 serial bus, if a
plurality of identical color images are to be printed out, the
transfer time is likely to be much larger than the time required
for printouts.
[0011] If printouts are always executed in the isochronous transfer
mode, the print data requires a considerably large band occupation
time of the 1394 serial bus, and disturbs transfer of real-time
data among apparatuses such as a video camera that requires
temporary continuous data transfer.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to solve the
above-mentioned problems.
[0013] It is another object of the present invention to provide an
image processing apparatus and system, which can effectively use
the functions of an interface, and can fully use the functions of
an image forming apparatus.
[0014] In order to achieve the above objects, according to one
aspect of the present invention, an image processing apparatus
connected to a plurality of image forming apparatuses via an
interface, comprises image output means for transmitting an image
to be formed via the interface, input means for inputting an image
forming condition, and mode designation means for designating an
image communication mode in the interface in accordance with the
image forming condition input by the input means.
[0015] With this arrangement, the performance of the plurality of
image forming apparatuses can be effectively used without lowering
the performance of the interface itself.
[0016] According to another aspect of the present invention, an
image processing apparatus connected to an image forming apparatus
via an interface, which has at least a synchronous mode for
transferring a predetermined volume of data at predetermined
periods, and an asynchronous mode for transferring data in an idle
time of data transmission in the synchronous mode, comprises image
output means for transmitting an image to be formed via the
interface, input means for inputting an image forming condition,
and mode designation means for selecting one of the synchronous and
asynchronous modes of the interface in accordance with the image
forming condition input by the input means.
[0017] According to the image processing apparatus with the above
arrangement, since the synchronous and asynchronous modes can be
appropriately selectively used, the performance of the image
forming apparatus and, hence, the functions of the interface can be
effectively used.
[0018] Other objects and features of the present invention will
become apparent from the following detailed description of the
preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a block diagram showing a system according to the
present invention, e.g., a system to which a plurality of nodes
including a plurality of image forming apparatuses are connected
via a serial bus;
[0020] FIG. 2 is a block diagram showing the arrangement of a
personal computer (PC) 1 and controller 2 in FIG. 1 in detail;
[0021] FIG. 3 comprised of FIGS. 3A and 3B is a flow chart for
explaining the operation of the personal computer and controller in
the system shown in FIGS. 1 and 2;
[0022] FIG. 4 is a chart showing progress of asynchronous transfer
in the serial bus shown in FIG. 1 along with passage of time;
[0023] FIG. 5 shows an example of the packet format in asynchronous
transfer in the serial bus shown in FIG. 1;
[0024] FIG. 6 comprised of FIGS. 6A and 6B is a flow chart showing
the operation of the personal computer, a video camera, and
printers in the system shown in FIGS. 1 and 2;
[0025] FIG. 7 shows a display example on a monitor shown in FIG.
1;
[0026] FIG. 8 is a chart showing progress of isochronous transfer
in the serial bus shown in FIG. 1 along with passage of time;
[0027] FIG. 9 shows an example of the packet format in isochronous
transfer in the serial bus shown in FIG. 1;
[0028] FIG. 10 is a chart showing progress of both isochronous
transfer and asynchronous transfer in the serial bus shown in FIG.
1 along with passage of time;
[0029] FIG. 11 shows the display state of a screen used for setting
the print conditions and the like on the monitor; and
[0030] FIG. 12 is a table showing the relationship between the
print conditions and transfer modes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The preferred embodiments of the present invention will be
explained in detail hereinafter with reference to the accompanying
drawings.
[0032] FIG. 1 shows a system according to the present invention,
e.g., a system to which a plurality of nodes including a plurality
of image forming apparatuses are connected via a serial bus.
[0033] The system shown in FIG. 1 comprises a personal computer
(PC) 1, an image processing apparatus (controller) 2 corresponding
to an embodiment of the present invention, a video camera 3 which
can output a digital color still image signal, and color printers
4, 5, 6, and 7, which respectively form nodes of a 1394 serial bus.
These nodes respectively have 1394 serial bus interfaces
(1394-I/Fs) 1a, 2a, 3a, 4a, 5a, 6a, and 7a.
[0034] As is well known, in the 1394 serial bus, when bus reset is
produced by a connection event of a new node or a power-ON event
while a plurality of nodes are connected, a root node is
determined, and serial bus access requests are issued to that root
node, which must perform bus arbitration. It is assumed, in this
specification, that bus reset has already been produced in the
state shown in FIG. 1, for the sake of simplicity. Also, one of the
nodes 1 to 7 shown in FIG. 1 has a root node function.
[0035] FIG. 2 is a block diagram showing the arrangement of the PC
1 and controller 2 in FIG. 1 in detail. In FIG. 2, the PC 1
comprises a central processing unit (CPU) 11, and a hard disk drive
(HDD) 12 serving as a storage device. The PC 1 also comprises a
monitor 13, and a manual operation unit 14 including a keyboard and
mouse. Using the monitor 13 and manual operation unit 14, various
commands can be input, as will be described later.
[0036] The PC 1 further comprises an optical disk drive 15 which
can load and access an optical disk 16 that stores printer drive
software (to be described later), a color processing unit 17
including a color processing board set in advance in the PC 1, a
codec 18 including a codec board set in advance in the PC 1, and
the above-mentioned 1394-I/F 1a. These units are connected to each
other via an internal bus B1 of the PC 1. The color processing unit
17 has a function of converting a color image signal input from an
input apparatus into color image data independent from that input
apparatus, and converting a color image signal independent from the
input apparatus into a color image signal matching the
characteristics of an output apparatus. The codec 18 has a function
of compressing and encoding a non-compressed color image signal by
a standard high-compression coding scheme such as JPEG, a function
of decoding a color image signal compressed in the video camera,
and the like.
[0037] The controller 2 comprises a page memory 21 which can store
at least non-compressed data of a color image having a maximum
size, and comprises, e.g., an SDRAM or the like. The controller 2
also comprises a CPU 22, and a color processing unit 23 which can
perform the same processing as that of the color processing unit 17
for only limited input apparatuses and printers.
[0038] The controller 2 further comprises codecs A 24, B 25, and C
26. The codec A 24 can decode color image data which is
high-compression-encoded by the video camera 3, and can also
implement the same high-compression coding (e.g., compression
according to a DVC format) as in the video camera 3. The codec B 25
can implement compression, e.g., lossless compression that can be
decoded by the printers 4 to 7. The codec C 26 can decode color
image data encoded by a high-compression coding scheme such as JPEG
as a standard scheme in the PC 1, and can encode data by that
high-compression coding scheme.
[0039] FIGS. 3A and 3B are flow charts for explaining the operation
of this embodiment shown in FIGS. 1 and 2, i.e., the system
connected via the 1394 serial bus. In FIGS. 3A and 3B, the left
flow chart shows the operation of the PC 1, and the right flow
chart shows the operation of the controller 2. The operation of
this embodiment will be explained below with reference to the flow
charts in FIGS. 3A and 3B.
[0040] In the PC 1, when the printer drive software is read from
the optical disk drive 15, and is opened (step S102), the PC 1
sends a start-up command to the controller 2 using the
above-mentioned asynchronous transfer.
[0041] FIG. 4 shows progress in asynchronous transfer along with
passage of time. In FIG. 4, a subaction gap at the left end
indicates a bus idle state. When this idle time has reached a given
value, the PC 1 determines that the bus can be used, and executes
arbitration for managing bus access.
[0042] Note that the arbitration is a process for arbitrating
access to the bus among nodes prior to data transport since one and
only node can transmit at a certain time in the 1394 serial bus.
More specifically, when arbitration starts, more than one nodes
issue bus access requests to the root node, and the root node
permits only a given node to access the bus, by arbitration.
[0043] When the PC 1 is permitted to access the bus as a result of
the arbitration, it executes data transfer including the start-up
command as data in the packet format. Upon completion of data
transfer, the controller 2 responds by sending back a reception
acknowledgement send-back code (ack) for the transferred data
(start-up command) after a short gap called an ack gap or sends a
response packet to complete the transfer. The code ack consists of
4-bit information and 4-bit check sum and includes information
indicating that data transfer is successful, busy, or pending. The
code ack is sent back to the source node. However, since such
send-back and response processes do not directly pertain to the
present invention, these processes are not shown in FIGS. 3A and
3B, and a detailed description thereof will be omitted.
[0044] FIG. 5 shows an example of the packet format in asynchronous
transfer. Each packet has a header field in addition to a data
field and error correction data CRC, and the header field contains
an objective node ID, source node ID, transfer data length, various
codes, and the like to transfer the packet, as shown in FIG. 5.
More specifically, in this case, the objective node ID indicates
the controller 2, and the source node ID indicates the PC 1.
Therefore, in step S102, the start-up command is transferred while
being contained in a command transfer portion in the data field
shown in FIG. 5. Since transfer in step S102 does not include any
image data, the data field is short, and does not include any
compressed image data in FIG. 5.
[0045] Asynchronous transfer is a one-to-one communication from the
own node to the destination node. The packet transferred from the
source node is transferred to all the nodes in the network, but
each node ignores a packet with an address other than its own
address, and only one destination node (controller 2 in this case)
can read the packet.
[0046] Referring back to FIGS. 3A and 3B, the dotted line arrows in
FIGS. 3A and 3B indicate transfer of data, commands, and the like
in the asynchronous transfer mode, and the broken line arrows
indicate transfer of data, commands, and the like in the
isochronous transfer mode. Note that the one-dashed chain line
arrows indicate transfer in either the asynchronous or isochronous
transfer mode.
[0047] Upon reception of the start-up command (step S201), the
controller 2 starts up the apparatus by, e.g., turning on the power
supply of the main body (step S202), and waits for the next command
(step S203). The PC 1 similarly issues a start-up command of the
video camera 3 by asynchronous transfer after the start-up command
of the controller (step S101).
[0048] FIGS. 6A and 6B are flow charts for explaining the operation
of the system of this embodiment. In FIGS. 6A and 6B, the left flow
chart shows the operation of the PC 1, the upper right flow chart
shows the operation of the video camera 3, and the lower right flow
chart shows the operation of one of the printers 4 to 7.
[0049] After the start-up command of the video camera, the PC 1
opens an image retrieve program included in the printer drive
software, and displays a screen shown in FIG. 7 on the screen of
the monitor 13 (step S104). At the same time, the PC 1 transfers a
retrieve command to the video camera in the asynchronous transfer
mode. Upon receiving the retrieve command, the video camera 3
retrieves a portion where a still image is recorded from a magnetic
tape stored therein, and reproduces a still image (step S302). The
video camera 3 transfers the reproduced still image to the PC 1
also in the asynchronous transfer mode. Note that color image data
recorded on the magnetic tape has undergone predetermined
high-compression coding, and the video camera 3 transfers the
compressed image data together with attribution data such as the
photographing date, the number of pixels, and the like in the data
format shown in FIG. 5 to the PC 1 via the 1394-I/F 3a. The
transfer data format at that time is as shown in FIG. 5.
[0050] An image display unit 32 in FIG. 7 displays a color image
obtained by decoding the compressed image signal transferred from
the video camera by the codec 18. The attribution data transferred
together with the compressed image data are displayed within a
frame 33. The user of the PC 1 checks if the color image displayed
on a display unit 32 is to be printed. If a print is required, the
user clicks a print button 37 with the mouse, and designates that
image as the one to be printed (step S106). If the image need not
be printed, the user clicks a next image button 34 or previous
image button 35 with the mouse in step S106. In response to
clicking on the next image button 34 or previous image button 35,
the PC 1 transfers a re-retrieve command to the video camera 3 in
the asynchronous transfer mode. In step S302, the video camera 3
retrieves and reproduces a still image recorded immediately before
or after the still image currently displayed on the display unit
32, and transfers the retrieved still image data to the PC 1 again
as a compressed image signal in the asynchronous transfer mode.
[0051] When the image to be printed is designated upon clicking the
print button 37, the PC 1 sends data indicating the designated
image and an output command of that image to the video camera 3
(step S107). When the user does not designate any images to be
printed, he or she can end processing by clicking a completion
button 36 in FIG. 7. However, since this processing is not directly
related to the present invention, a description thereof is omitted
from the flow charts in FIGS. 3A, 3B and 6A, 6B. In response to the
image output command (step S303), the video camera 3 decodes the
compressed image data recorded on the magnetic tape, and transfers
the non-compressed image signal to the controller 2 (step S304). At
this time, since a non-compressed color image signal always
requires a very large information volume, this transfer is done by
isochronous transfer.
[0052] FIG. 8 shows progress in isochronous transfer along with
passage of time. The isochronous transfer is executed at
predetermined time intervals on the bus. This time interval is
called an isochronous cycle. The isochronous cycle time is 125
.mu.s. A cycle start packet indicates the start time of each cycle,
and has a role of performing time adjustment of the individual
nodes. A node called a cycle master transmits the cycle start
packet. The cycle master transmits the cycle start packet
indicating the start of the current cycle a predetermined idle
period (subaction gap) after the completion of transfer in the
previous cycle. The transmission time interval of cycle start
packets is normally 125 .mu.s.
[0053] As indicated by channels A, B, and C in FIG. 8, a plurality
of different packets with different channel IDs can be separately
transferred within one cycle. With this transfer, a plurality of
nodes can attain real-time transfer at the same time, and the
receiving node fetches only data with a desired channel ID. The
channel ID does not represent any destination address but merely
assigns a logical number to data. Hence, a certain packet is
transferred from one source node to all other nodes in so-called
broadcast communications.
[0054] Prior to packet transfer in the isochronous transfer mode,
arbitration is made as in the asynchronous transfer mode. However,
since the isochronous transfer mode is not a one-to-one
communication mode unlike in the asynchronous transfer mode, no ack
(reception acknowledgement send-back code) is present in the
isochronous transfer mode. An isochronous gap (iso gap) shown in
FIG. 8 represents an idle period required for recognizing the idle
state of the bus before the isochronous transfer. After an elapse
of the predetermined idle period, the node which wants to start
isochronous transfer determines that the bus is idle, and can
perform arbitration before the transfer.
[0055] FIG. 9 shows an example of the packet format of isochronous
transfer. Each of various types of packets assigned to the
individual channels has a header field in addition to a data field
and error correction data CRC. The header field contains the
transfer data length, channel No., various codes, error correction
header CRC, and the like, as shown in FIG. 9. In case of this
embodiment, non-compressed image data is written in a portion
indicated by "image data" in the data field.
[0056] FIG. 10 shows progress of both isochronous transfer and
asynchronous transfer within one cycle along with passage of
time.
[0057] The PC 1 that has issues the image output command to the
video camera 3 in step S107 then outputs an image getting command
to the controller 2 (step S108). The image getting command is
transferred in the asynchronous transfer mode, and includes data
that defines the channel from which data is to be got. Upon
reception of the image getting command (step S203), the controller
2 converts non-compressed image data transferred from the video
camera in the isochronous transfer mode, e.g., R (red), G (green),
and B (green) image data, into Y (yellow), M (magenta), C (cyan),
and K (black), four-color component data by the color processing
unit 23, and stores them in the page memory 21. Upon completion of
getting, the controller 2 transfers a getting completion report as
report data to the PC 1 in the asynchronous transfer mode (step
S205).
[0058] Upon reception of the getting completion command (step
S109), the PC 1 displays a screen shown in FIG. 11 on the screen of
the monitor 13 so as to set the print conditions and the like. In
FIG. 11, a display screen 41 of the monitor 13 displays a window 42
for setting the number of prints, a window 43 for setting the print
size, a window 44 for setting the resolution, and a window 45 for
selecting a color/monochrome print mode. The user sets the number
of prints, print size, resolution, color/monochrome print mode, and
the like by operating the keyboard or mouse of the manual operation
unit 14. A panel 47 is used for designating the print mode in this
embodiment, and the type of connected printer is displayed within a
window 48.
[0059] The print conditions set on this screen 41 are transferred
to the controller 2 in the asynchronous transfer mode in step S110.
The controller 2 checks the transferred print conditions, and
determines the transfer method of the non-compressed color image
signal stored in the page memory 21 to the printers 4, 5, 6, and 7.
FIG. 12 shows the relationship between the print conditions and
transfer modes.
[0060] As can be seen from FIG. 12, when a monochrome image is
transferred, the asynchronous transfer mode is selected
independently of the number of prints, resolution, size, and the
like, and black (K) data for one page of color image data stored in
the page memory is transferred to the printers 4 to 7 as
non-compressed image data. More specifically, in case of monochrome
data or when even color data has low resolution, e.g., a print at
200 dpi is to be instructed, the asynchronous transfer mode is
used. In such case, since image data for one page can be
transferred in the asynchronous transfer mode sufficiently within
the page print time of the printer (the printer displayed within
the window 48 in FIG. 11) without being compressed, the
non-compressed data is transferred. In the system shown in FIG. 1,
since the four printers 4, 5, 6, and 7 are connected to the 1394
serial bus, a maximum of four images can be simultaneously printed.
In this case, it is determined that non-compressed data for four
pages, i.e., four non-compressed image data for one page, can be
transferred sufficiently within the page print time of each printer
even in the asynchronous transfer mode.
[0061] On the other hand, when the color image to be transferred
has middle resolution (e.g., 400 dpi), if a plurality of identical
images are to be simultaneously printed, color image data for one
page cannot often be transferred within the page print time of the
printer in correspondence with the required number of prints.
Although such transfer also depends on the print size, it is
confirmed in this embodiment that non-compressed color image data
having middle resolution can be surely transferred twice within the
page print time of each printer in the asynchronous transfer mode
if it has a print size of B4 or larger (B4 or A3), and can be
transferred a maximum of five times if it has a print size of A4 or
smaller (A4 or B5). In the system shown in FIG. 1, however, since
the number of printers connected to the 1394 serial bus is four,
all data having an A4 size or smaller are transferred in the
asynchronous transfer mode in practice upon printing. As for
printouts of data having a B4 size or larger, when three or more
images are simultaneously printed, isochronous transfer is
used.
[0062] Likewise, when the color image to be transferred has high
resolution (e.g., 800 dpi), since the data volume of an image
signal for one page is still larger, the number of times of
asynchronous transfer of color image data for one page within the
page print time of the printer is further reduced. Hence, in this
embodiment, data undergoes lossless compression coding with a low
compression ratio (e.g., about 1/2) using the codec B 25 of the
controller 2, and the compressed data is transferred to the
printers 4, 5, 6, and 7. In this embodiment, it is confirmed that
high-resolution color image data which is encoded by lossless
compression coding can be surely transferred once within the page
print time of each printer in the asynchronous transfer mode if it
has a print size of B4 or larger (B4 or A3), and can be transferred
a maximum of three times if it has a print size of A4 or smaller
(A4 or B5). More specifically, isochronous transfer is used when
two images or more are to be simultaneously printed upon printing
out data having a size of B4 or larger, or when four or more images
are to be simultaneously printed upon printing data having a size
of A4 or smaller.
[0063] When the isochronous transfer is used, all the printers can
simultaneously print using the transferred color image data. In
this case, upon printing a plurality of pages, color image data for
the second page can be transferred in the isochronous transfer mode
before a plurality of images for the first page are printed out.
Hence, a plurality of color image data for a plurality of pages can
be printed using ready printers in turn. A mode for printing using
ready printers in turn in such manner is called a highest-speed
print mode in this embodiment. Also, a mode for printing using only
printers corresponding to the number of color images to be printed
for each page for the purpose of user's convenience is called a
high-speed sort mode.
[0064] One of these modes is designated by, e.g., the mouse in the
window 48 in the screen 41, and isochronous transfer is done by
writing data indicating the designated printer in the data field in
FIG. 9 in accordance with the designated mode. When a printer
designated mode is designated in the window 48, asynchronous
transfer is unconditionally done.
[0065] As described above, when the controller 2 transfers image
data according to the determined mode (step S206), each printer
receives the print command and image data (step S401), prints (step
S402), and transfers a print completion report upon completion of
printout for one page in the asynchronous transfer mode (step
S403). Upon reception of the print completion report, the
controller 2 checks if all the print jobs are completed (step
S209). If the print jobs are not completed, the controller 2 issues
the next print command, and transfers the next image data if
necessary (steps S208 and S207). After the controller 2 has
received a print completion report for that command, it confirms
that all the print jobs are completed (step S209), and transfers an
all print completion report to the PC 1 in the asynchronous
transfer mode (step S210). Upon reception of the all print
completion report (step S111), the PC 1 can close the printer drive
software (step S112).
[0066] According to the arrangement of the system of the above
embodiment, since the isochronous and asynchronous transfer modes
of the 1394 serial sub can be selectively used in consideration of
the print conditions, highest-speed, high-quality printouts can be
obtained by fully using the functions of the printers and 1394
serial bus.
[0067] Note that the criterion for selectively using the
isochronous and asynchronous transfer modes should be appropriately
set in correspondence with the printers used, and is not limited to
a specific example shown in FIG. 12. In the above embodiment, the
1394 serial bus is used. However, the present invention can also be
applied to interfaces having equivalent functions.
[0068] As described above, according to the image processing
apparatus and system of the present invention, the function of the
interface can be effectively used, and the functions of the image
forming apparatus can be fully used.
[0069] Many widely different embodiments of the present invention
may be constructed without departing from the spirit and scope of
the present invention. It should be understood that the present
invention is not limited to the specific embodiments described in
the specification, except as defined in the appended claims.
* * * * *