JPH11259243A - Printing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quicken a whole processing time by reducing the processing of a host computer, reducing the RAM capacity of a print controller, and selecting a further efficient compressing method. SOLUTION: A printer driver 3' outputs picture data converted for each band according to an instruction to print a picture to be printed on a host computer 1. A compressing method is decided under the consideration of the characteristics of the compressor of a print controller 2. Picture data received by a host I/F 4 are stored in an RAM 7. The picture data are developed into image data, compressed by the compressor designated by the printer driver 3', and stored in the RAM 7 by each band unit so that the picture data can be printed by a printer engine 10. A print activating instruction is outputted to the printer engine 10 after the end of the development for one page, and the image data are outputted from the RAM 7 by a video DAM controller 8'. Then, an extender corresponding to the compressing method of each band is selected, and the image data are extended and outputted through an engine I/F 9 to the printer engine 10, and a printing operation is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing system comprising a host computer, a printing apparatus for performing printing of an image including a color image formed thereon, and a printing control apparatus connected therebetween. In particular, the present invention relates to a printing system that determines a compression method from the type of image data divided into a plurality of bands and performs compression processing efficiently.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 9-1 discloses a printing control apparatus which recognizes an image to be printed by a conventional method and selects a compression method for each band from a plurality of compression methods.
There is a technology described in Japanese Patent No. 47093, and these technologies will be described below.

FIG. 13 is a block diagram showing a schematic configuration of a conventional print control apparatus. In FIG. 13, 1 is a host computer, 2 is a print control device (printer controller), 3 is a printer driver, 4 is a host interface (host I / F), 5 is a CPU, 6 is a ROM,
Reference numeral 7 denotes a RAM, 8 denotes a video DMA controller, 9 denotes an engine interface (engine I / F), and 10 denotes a printer engine.

A user creates an image to be printed by the host computer 1, designates a printer for performing print output, and outputs a print command of the created image. When the print command is output, the host computer 1 outputs a printer driver 3 which is a program adapted to the connected printer.
Thus, the image data is converted into image data of a command code system that can be interpreted by the print control device 2. Then, the host computer 1 outputs the image data converted by the printer driver 3 to the host I / F 4 of the connected printer. In the print control device 2, when reception of image data to be printed by the host I / F 4 is started, the CPU 5 having the transmitted image data in the print control device 2 according to the code information written in the ROM 6. It is developed and rendered as image data in the RAM 7 in the print control device 2.

[0005] Normally, as a method of developing and drawing into image data in the print control device 2, a full bitmap method of storing one page of image data as it is, and
There is a partial bitmap method that divides the image data area of a page into a fence (band). For example, FIG.
When storing the image data as shown in FIG.
In the case of the full bitmap method, one page of image data is directly stored from the drawing start address to the drawing end address as in the address map of FIG. However, the actual address map is code data of one byte at a time, and has a configuration in which image data is serially arranged from the head address of an image.

In the case of the partial bitmap method, an image to be printed is divided into a plurality of bands of the same width in the sub-scanning direction as shown in FIG.
Although the band is divided into two bands, the number of bands is not limited.) As shown in FIG.
An image is drawn by allocating a free area in M that can accommodate the band to the band. By using the partial bitmap method as described above, it is possible to develop the image data even if it is not always possible to secure a continuous free area for one page on the work RAM.

Next, after the CPU 5 has developed the image data into the RAM 7, the CPU 5 issues a print start command to the printer engine 10 to start printing, and the developed image data is transmitted via the engine I / F 9. Is output to the printer engine 10 to execute printing. However, normally, when image data is output to the printer engine 10 (video output), an enormous amount of data must be transferred in a short period of time. It is trying to make it.

In the case of the partial bitmap method, a DMA start address of a band to be printed and the number of transfers are designated to the video DMA controller 8, and the DMA operation for the set number of transfers is performed. In addition, video DM
When the DMA transfer is completed, the A controller 8
Issues an interrupt request to U5 indicating that the DMA transfer has been completed,
Signal the end. The CPU 5 sets the DMA parameters of the next succeeding band in the video DMA controller 8 again, and completes the output to the printer engine 10 by performing the same DMA operation.

Here, the printer driver 3 performs compression processing of the image data to be transferred in order to reduce the transfer time required for transferring the image data from the host computer 1 to the print control device 2. At this time,
According to the description of Japanese Patent No. 147093, the printer driver 3 shown in FIG. 13 of the related art has a plurality of compression processing methods, and the most efficient compression method is selected according to the content of image data included in a band to be printed. Then, the compressed image data and code information indicating what compression method is employed are transmitted to the print control device 2. Further, the print control device 2 has decompressors corresponding to the compression methods of the printer driver 3, and the decompressors corresponding to the compression processing methods of the respective bands specified by the printer driver 3. After the selection and decompression, the code information of the image data is recognized, the image data is stored in the RAM 7 in the print control device 2 and expanded, and then transferred to the printer engine 10 to execute printing.

By performing the above operations, when printing an image created by a user, the image data is divided into a plurality of bands, and the most efficient compression method is determined from the contents of the image data in each band. By making the selection, it is possible to perform the printing process in which the time related to the image transfer from the host computer 1 to the print control device 2 is reduced.

Further, with the development of laser printers and printer engines, machines which handle high-speed, high-resolution images have increased, and laser printers capable of performing color processing have been developed. Therefore, a large-capacity RAM is required. Along with this, a printing control device is configured with less RAM by using a compression technique, and a high-speed CPU is being employed in the printing control device to improve processing speed.

[0012]

However, in a print control system using a print control device according to the above-described prior art method, compression processing is performed to reduce the transfer time when transferring data from the host computer to the print control device. However, since the image data is expanded after being decompressed on the print control device side, if the image data to be printed is small, there is a problem that the printing time is rather delayed.

Further, since the image data must be expanded after being expanded, it is necessary to have a page buffer which secures a RAM area for one page. In order to reduce the RAM capacity, the print control apparatus needs to have a page buffer. However, there is also a problem that a compressor is required and the cost is increased.

Further, since the compression processing is performed on the host computer side, the processing load on the CPU on the host computer side increases, and when the processing capacity of the host computer is slow, the transfer waiting time on the printing control apparatus side. Happened
There is also a problem that the entire printing time is delayed, and even if a high-speed CPU is used in the printing control device, a transfer waiting time similarly occurs, and the processing time remains unchanged. . Along with that, there is a problem that the user has to introduce a host computer having a high processing capability.

Further, since the band width for dividing the image data has a predetermined size, even if it is compared using a plurality of compression methods, only the same compression ratio can be obtained. Depending on the number of types of data, there is a problem that the compression efficiency deteriorates and the transfer time increases.

The present invention is directed to solving the above-mentioned problems of the prior art, and reduces the processing of the host computer, reduces the capacity of the RAM of the print control device, and selects an efficient compression method. It is an object of the present invention to provide a print control system that shortens the entire processing time.

[0017]

In order to achieve this object, a printing system according to the present invention converts a created image desired to be printed into image data in a language system that can be interpreted by a print control device. A host computer provided with printer driver means for dividing image data into a plurality of bands in the sub-scanning direction, recognizing the type of image data in each band, determining a compression method, and transmitting the image data and the compression method. Interface means connected to a host computer for data transfer, compression processing means for compressing received image data according to a compression method determined by the printer driver means, decompression processing means for performing decompression processing corresponding to the compression method, compression Decompression processing means for decompressing and compressing image data by adopting a method, and decompressing and compressing image data by decompression processing means. A print control device having transfer processing means for performing decompression processing to the lint engine means and transferring the image data; and a printing device having print engine means for printing out image data transferred from the transfer processing means. I do.

Also, the created print-desired image is converted into image data in a language system that can be interpreted by the print control device, and the image data is divided into a plurality of bands in the sub-scanning direction. Printer driver means for recognizing the type of data, selecting and determining a compression method from at least two or more compression methods, and transmitting the image data and the compression method.

Also, the created print desired image is converted into image data of a language system that can be interpreted by the print control device, and the image data is divided into a plurality of bands in the sub-scanning direction. A printer driver for recognizing the type of the text image or the image image, selecting a compression method from at least two compression methods, and transmitting the image data and the compression method. .

Further, the created print desired image is converted into image data of a language system that can be interpreted by the print control device, and the image data is divided into a plurality of bands in the sub-scanning direction and included in each band. Printer driver means for recognizing a type determined from a ratio occupied by different types of image data, selecting a compression method from at least two compression methods, and transmitting the image data and the compression method is provided. It is characterized by the following.

Also, the created print desired image is converted into image data of a language system that can be interpreted by the print control device, and the image data is divided into a plurality of bands in the sub-scanning direction and included in each band. When the image data is of a different type, the bandwidth is changed so as to be one type, the type is recognized, a compression method is selected and determined from at least two or more compression methods, and the image data and the compression method are determined. A printer driver means for transmitting is provided.

Also, after converting the created color image desired to be printed into image data in a language system that can be interpreted by the print control device, and converting the image data represented by RGB data into CMYK data, Each component is divided into bands in the sub-scanning direction, the type of image data in each band is recognized, a compression method is determined, and printer driver means for transmitting the image data and the compression method is provided. It is.

According to the above arrangement, the printer driver means determines a compression method for reducing the amount of RAM for storing image data for each band, and the actual compression is performed by the print control device. RAM in the control device
Can be reduced, and the processing of the host computer can be reduced to reduce the transmission waiting time.

Further, by having a plurality of compression and decompression processes, efficient compression and decompression processes suitable for various types of image data can be performed.

Further, when performing the compression processing of the image data, the compression ratio can be increased by performing the exclusive compression and decompression processing of the text image and the image image.

When the compression method for each band is determined, the compression method with higher compression efficiency can be selected by determining the compression method based on the ratio according to the type of image data included in the band.

By changing the bandwidth so that the type of image data included in each band is one, efficient compression can be performed.

In the case of color printing, RGB data is converted into CMYK data, then divided into bands, and a compression process designated when image data is expanded is performed, so that efficient compression can be performed even in color printing. It can be carried out.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of a print control device of a print control system according to an embodiment of the present invention. Here, components having substantially the same functions and corresponding to the components described in FIG. 13 showing the conventional example are denoted by the same reference numerals. In FIG. 1, 1 is a host computer, 2 is a print control device, 3 'is a printer driver, and 4 is a host I / O.
F, 5 are a CPU, 6 is a ROM, 7 is a RAM, 8 'is a video DMA controller, 9 is an engine I / F, 10 is a printer engine, 11a, 11b and 11c are compressors, 1
2a, 12b and 12c are decompressors.

In the present embodiment, a user creates an image desired to be printed using an application program running on the host computer 1. At this time, there are various types of images created by the user, such as an image extending over a plurality of pages and an image created as a color image. Upon completion of the creation of the image, the user is connected to the host computer 1 and issues a print command by selecting a printer to be printed from among the printers capable of printing. At this time, the print command from the user includes designation of the number of copies, designation of color / monochrome, designation of enlargement / reduction ratio, designation of paper size,
Various print modes are designated, such as designation of whether or not to perform centralized printing for printing a plurality of pages collectively on a sheet of paper.

Thereafter, when a print command is issued by the user, a program called a printer driver 3 'stored in the host computer 1 is used to satisfy various print modes specified by the user. , And converts it into code information that can be decoded by the connected print control device 2, and further outputs image data divided into a plurality of bands in the sub-scanning direction. At this time, the compression method used for each band is determined in consideration of the characteristics of the compressors 11a to 11c inside the print control device 2.

In the print control device 2, reception of image data from the host computer 1 is started by the host I / F 4 for connection to a network or various interfaces. When the host I / F4 starts receiving image data, C
An interrupt is generated to the PU 5 to notify that the print command has been issued, and the received image data is buffered in the RAM 7 and temporarily stored.
The CPU 5 develops the received and buffered image data into image data so that the printer engine 10 can print the image data. That is, image data received as code information is converted into bitmap information and stored. At this time, the CPU 5 develops a portion divided into a plurality of bands in the sub-operation direction and stored in the RAM 7 and developed into image data, and a plurality of compressors 11a.
11c using a compressor designated by the printer driver 3 '. However, in this example, there are three types of compressors, but any number of compression methods may be used. Further, compression may be performed only by a program. Expanded and compressed image data is RA
It is stored in M7. Thereafter, the type of compression method used for each band is stored in a table as shown in FIG.

When such operations are repeated and the development of the image data for one page is completed, the state of the printer engine 10 is detected. Is output and the printing operation is executed.

When printing is performed, a dedicated video DM
The A controller 8 'directly outputs the data from the RAM 7 to the printer engine 10 (generally, data output to the printer engine must be handled as an image, and a large amount of data must be transferred in a short period of time. If the decompression process is performed by the CPU, a print overrun occurs due to a difference in processing time, so a dedicated decompressor is used when performing DMA transfer.) At the time of the processing, the expanders 12a to 12c which correspond to the method of compressing each band are selected according to the information in the table shown in FIG. The print operation is executed by outputting to the printer engine 10 through F9.

As a compression method, in the case of a text image, since the same color component frequently occurs as a continuous dot, a run-length compression method such as MH code, MR code, and MMR code is high. This is adopted because there is a characteristic that results in a compression ratio. In the case of an image image, halftone image data is often generated continuously with a small change amount. Therefore, a two-dimensional compression method such as JPEG has a characteristic that a high compression ratio is obtained. Adopt this. Further, when the image to be printed is a color image, many printer engines 10 can express halftone image data with one pixel, so that a high compression ratio is obtained when compressing multi-valued data. It is conceivable to employ a compression method that is used.

In the case where various compression methods exist as described above, depending on the selected compression method, for example, when an image is compressed using run-length compression, an image having an even larger size than the original image can be obtained. Since it becomes an image, it is understood that it is better to select and use a different compression method at least for an image image.

When an image to be printed is a color image, a color correction process for converting RGB data into CMYK data is usually required. From this,
If the compression method is determined at the time of the RGB data, the image data after the color correction processing is changed,
As a result, there is a possibility that a compression method with a low compression ratio may be adopted. Therefore, the printer driver 3 ′ determines the compression method processing after converting the data into CMYK data by color correction processing. Good compression methods can be employed.

In the case where the image data to be printed is as shown in FIG. 3, when the image data is divided into bands as shown in FIG. , By re-dividing the bandwidth as shown in FIG.
It is possible to select a compression method with a better compression ratio by selecting one of the data types of images contained in one band as much as possible and selecting a compression method suitable for each characteristic. It becomes possible.

[0039]

FIG. 6 is a block diagram showing an embodiment of a printing control system according to the present invention, which is a schematic configuration of a color printing control apparatus. In FIG. 6, 1 is a host computer,
2 is a print control device, 3 'is a printer driver, 4 is a host I / F, 5 is a CPU, 6 is a ROM, 7 is a RAM, 8 "
Is a video DMA controller, 9 is an engine I / F, 1
0 is a printer engine, 13 is a text compressor, 14
Is an image compressor, 15 is a text decompressor, and 16 is an image decompressor. Further, in this embodiment, the image data as shown in FIG. 7 is printed out in color, and FIG. 8 is a flowchart showing the processing of the printer driver, and FIG. 9 is the processing of the printing control device. The flowchart will be described with reference to these flowcharts.

First, the image created by the user (S1) is sent from the host computer 1 to the host I / F 4 inside the print control device 2 (S2). At this time, in the host computer 1, the print data is converted into a language format that can be interpreted by the print control device 2 connected by the printer driver 3 'and output. At this time, when outputting the image data, the image of one page is divided into a plurality of bands in the sub-scanning direction as viewed from the printer engine 10 as shown in FIG. 10 (S3). Next, the language format is sequentially changed from the first band. Prior to this, the image data represented by the RGB data is subjected to color correction processing and converted into CMYK data (in this example, the RGB data is 8 bits (25
6) Although expressed as gradations, any gradation may be used) (S4). The compression method of the image data converted into the CMYK data is determined for each band (S5), and the image data is transmitted to the print control device 2 (S6).

However, in the band 3 shown in FIG. 10, an image image and a text image are mixed, and in such a situation, the same type of image is changed by changing the band width as shown in FIG. The band is included in one band (however, if a plurality of types of images are mixed even if the band width is changed, it is determined based on the area ratio of the existing image). Thus, the printer driver 3 '
Depending on the type of image data, if the image existing in the band is text, specify the text compressor,
If it is an image, specify it for the image.

Next, on the print control device 2 side, the host I / O
The image data received (S10) by F4 is temporarily stored in the RAM.
7 (S11). At the same time as the reception, an interrupt request is generated in the CPU 5 to notify the reception and the CPU 5
In step 5, development into image data is started. At the time of development into image data, since the data has been input in a band unit from the printer driver 3 'in advance, the data is developed from band 0 into image data (S12).
After the image is expanded into image data, in this example, since a compression method for text is specified for band 0, compression is performed using the text compressor 13 (S13).
At the same time, the compression method for each band is registered in a table provided in another area in the RAM 7 as shown in FIG. 12 (S14). Such operations are repeated to develop all bands for one page into image data (S15).

When the one page development process is completed, the state of the printer engine 10 is detected, and if there is no error or the like and the printer engine 10 is ready for printing, the printer engine 10 starts printing. A command is output to start printing (S16). At the same time, CPU
5 designates which compression method is adopted for the band to be printed from band 0 according to the table of FIG.
The designation of the start address of the AM 7 and the designation of the number of transfers are set in the video DMA controller 8 ″. When the DMA parameters are set and the DMA is started, the video DMA controller 8 ″ sequentially reads data from the start address on the RAM 7, After the read image data is selected and decompressed by a decompressor (text decompressor 15 and image decompressor 16) compatible with the specified compression method, the image data is output to the engine I / F 9 (S17).

Similarly, by performing this operation for all the bands, it becomes possible to print color image data that has been efficiently compressed by a plurality of compression methods.

[0045]

As described above, according to the present invention,
By the printer driver that configures the print control system,
The compression method for reducing the RAM for each band is determined, and the actual compression is performed by the print control device, thereby reducing the RAM capacity of the print control device and further reducing the processing of the host computer. Thus, the transmission waiting time can be reduced, and the transmission waiting time of the image data and the entire processing time can be shortened.

Further, by having a plurality of compression and decompression processes, various types of image data can be efficiently compressed, so that the print processing time can be further shortened.

Further, when performing a plurality of compression processes, dedicated compression and decompression processes are performed on text images and image images to increase the compression ratio, thereby reducing the RAM capacity and cost. it can.

When the compression method for each band is determined, the compression method having higher compression efficiency can be selected by determining the compression method based on the ratio of the types included in the image data included in the band. Thus, the processing can be sped up.

Further, by changing the bandwidth in accordance with the content of the image data of each band, efficient compression is performed, so that the capacity of the RAM can be further reduced and the cost can be reduced.

In color printing, the printer driver converts the RGB data into CMYK data, divides the data into bands, expands the bands, and performs the specified compression processing. This makes it possible to reduce the capacity of the RAM and improve the function.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a print control device of a print control system according to an embodiment of the present invention.

FIG. 2 is a table showing the types of compression methods used in each band according to the embodiment of the present invention.

FIG. 3 is a diagram showing image data desired to be printed according to the embodiment of the present invention;

FIG. 4 is a diagram showing contents of image data divided into bands according to the embodiment of the present invention;

FIG. 5 is a diagram showing re-partitioning of the bandwidth in the embodiment of the present invention.

FIG. 6 is a block diagram illustrating a schematic configuration of a color print control apparatus according to an embodiment of the present invention;

FIG. 7 is a diagram showing color image data desired to be printed in the embodiment of the present invention.

FIG. 8 is a flowchart illustrating processing of a printer driver according to the embodiment of the present invention.

FIG. 9 is a flowchart illustrating processing of the print control apparatus according to the embodiment of the present invention.

FIG. 10 is a diagram showing a state in which an image of one page is divided into a plurality of bands according to the embodiment of the present invention.

FIG. 11 is a diagram showing a case where the bandwidth is changed according to the embodiment of the present invention;
Image of the same type of image in one band

FIG. 12 is a diagram showing a table for registering a compression method for each band in the embodiment.

FIG. 13 is a block diagram illustrating a schematic configuration of a conventional print control device.

FIG. 14 is a diagram showing an example of image data.

15 is a diagram showing an address map of the image data shown in FIG.

FIG. 16 is a diagram showing a state in which image data is divided into a plurality of bands having the same width.

FIG. 17 is a diagram showing a state in which an empty area for a band is secured on the work RAM;

[Explanation of symbols]

 Reference Signs List 1 host computer 2 print control device (printer controller) 3, 3 'printer driver 4 host I / F 5 CPU 6 ROM 7 RAM 8, 8', 8 "video DMA controller 9 engine I / F 10 printer engine 11a, 11b, 11c Compressor 12a, 12b, 12c Decompressor 13 Text Compressor 14 Image Compressor 15 Text Decompressor 16 Image Decompressor

Claims (6)

[Claims] 1. A method according to claim 1, wherein the printing control unit converts the created image to be printed into image data in a language system that can be interpreted by a print control device, divides the image data into a plurality of bands in the sub-scanning direction, A host computer provided with a printer driver for transmitting the image data and the compression method by recognizing the type of data and determining a compression method; an interface connected to the host computer for transmitting and receiving data; Compression processing means for performing compression processing on the image data according to the compression method determined by the printer driver means; decompression processing means for performing expansion processing corresponding to the compression method; and decompression and expansion of the image data using the compression method Expansion processing means for expanding image data expanded and compressed by the expansion processing means to the print engine means. A printing control apparatus having a transfer processing means for transferring the image data transferred from the printing apparatus, and a printing apparatus having a print engine means for printing out the image data transferred from the transfer processing means. 2. A printing control apparatus according to claim 1, wherein the printing control apparatus converts the generated printing desired image into image data in a language system that can be interpreted by a print control apparatus, divides the image data into a plurality of bands in a sub-scanning direction, and forms an image inside each band. A host computer having printer driver means for recognizing the type of data, selecting and determining a compression method from at least two compression methods, and transmitting the image data and the compression method; Interface means for exchanging received data, compression processing means for performing compression processing on the received image data by a compression method determined by the printer driver means, decompression processing means for performing decompression processing corresponding to the compression method, and the compression method Expansion processing means for expanding and compressing the image data by employing the image processing apparatus, and an image expanded and compressed by the expansion processing means A print control device provided with a transfer processing unit for transferring data by performing decompression processing to the print engine unit, and a printing device provided with a print engine unit for printing out image data transferred from the transfer processing unit. A printing system characterized by the following. 3. A print control apparatus converts a created image desired to be printed into image data in a language system that can be interpreted by a print control device, divides the image data into a plurality of bands in the sub-scanning direction, A host computer provided with printer driver means for recognizing the type of data text image or image image, selecting and determining a compression method from at least two or more compression methods, and transmitting the image data and the compression method Interface means connected to the host computer for exchanging data, compression processing means for compressing the received image data according to the compression method determined by the printer driver means, and performing decompression processing corresponding to the compression method Expansion processing means, expansion processing means for expanding and compressing the image data by employing the compression method, and expansion processing A print control unit having a transfer processing unit for transferring image data decompressed and expanded by the unit to the print engine unit by performing decompression processing, and a print engine unit for printing out the image data transferred from the transfer processing unit. And a printing device provided. 4. A printing control apparatus converts the created print desired image into image data of a language system that can be interpreted by a print control device, divides the image data into a plurality of bands in the sub-scanning direction, and includes the image data inside each band. Printer driver means for recognizing a type determined from a ratio occupied by different types of image data, selecting a compression method from at least two or more compression methods, and transmitting the image data and the compression method A host computer provided with a host computer, interface means connected to the host computer for transmitting and receiving data, compression processing means for performing compression processing on the received image data by a compression method determined by the printer driver means, and corresponding to the compression method. Expansion processing means for performing expansion processing, and expansion processing for expanding and compressing the image data by employing the compression method Means, a print control device having a transfer processing means for transferring image data decompressed and compressed by the decompression processing means to the print engine means by performing decompression processing, and print-outputting the image data transferred from the transfer processing means A printing apparatus provided with print engine means for performing printing. 5. A method according to claim 1, wherein the printing control device converts the created image to be printed into image data in a language system that can be interpreted by the print control device, divides the image data into a plurality of bands in the sub-scanning direction, and includes the image data inside each band. When the image data to be processed is of a different type, the bandwidth is changed so as to be one type, the type is recognized, a compression method is selected and determined from at least two or more compression methods, and the image data and the A host computer provided with printer driver means for transmitting a compression method, an interface means connected to the host computer for transmitting and receiving data, and compression for compressing the received image data by a compression method determined by the printer driver means Processing means, decompression processing means for performing decompression processing corresponding to the compression method, A print control device comprising: expansion processing means for expanding and compressing; transfer processing means for expanding and transferring image data expanded and compressed by the expansion processing means to the print engine means; and transfer from the transfer processing means. And a printing device provided with a print engine means for printing out the image data. 6. After converting the created color image desired to be printed into image data in a language system that can be interpreted by a print control device, and converting the image data expressed in RGB data into CMYK data, A host provided with printer driver means for dividing each color component into bands in the sub-scanning direction, recognizing the type of image data in each band, determining a compression method, and transmitting the image data and the compression method A computer, and interface means connected to the host computer for transmitting and receiving data;
Compression processing means for performing compression processing on the received image data by a compression method determined by the printer driver means;
Decompression processing means for performing decompression processing corresponding to the compression method,
A print processing unit that expands and compresses the image data by adopting the compression method, and a transfer processing unit that expands and compresses the image data expanded and compressed by the expansion processing unit to a print engine unit and transfers the image data. A printing system, comprising: a control device; and a printing device provided with a print engine for printing out the image data transferred from the transfer processing unit.