JP7467211B2 - IMAGE PROCESSING APPARATUS, IMAGE PROCESSING METHOD AND PROGRAM FOR IMAGE PROCESSING APPARATUS - Google Patents

Description

The present invention relates to an image processing device, an image processing method for an image processing device, and a program.

Large-format printers used in fields such as graphic arts use particularly large paper sizes, and when a print job is submitted, it can be difficult to print in high-quality mode. In particular, when an extremely large image (high-resolution image) is embedded in a page of a print job, or when a large amount of graphic data is included, memory may run out midway through processing the page, making it impossible to continue processing. Generally, printer drivers and printer controllers are configured to process using set hardware resources (for example, there is a limit to the memory that can be allocated to a process), so some kind of countermeasure must be taken.

The methods of Patent Document 1 and Patent Document 3 are known as examples of measures to be taken when memory becomes insufficient during print job processing and processing cannot continue. Patent Document 1 discloses a method in which, when memory becomes insufficient, the processing program performs image formation (rendering) using internal data recorded in memory, thereby releasing the data stored up to that point and reducing the data size. In addition to these technologies, Patent Document 2 discloses a method in which lossless image compression processing (lossless compression) is used for large images.

JP 2011-61555 A JP 2008-78826 A Japanese Patent Application Laid-Open No. 6-261202

Image size can be reduced by compressing image data. However, even in this case, there is a limit to memory capacity, and there may be cases where memory capacity is insufficient and processing cannot continue.

The object of the present invention is to prevent a capacity shortage in the main storage device (main memory) and suppress a decrease in processing speed, even when the size of image data is large.

The image processing device of the present invention has a writing means for writing image data included in print data to an external storage device without compressing it in a first case, and a writing means for compressing image data included in the print data and writing the compressed image data to the external storage device in a second case, and an image forming means for reading the image data from the external storage device in the first case and forming an image for printing based on the image data, and for reading the compressed image data from the external storage device, decompressing the compressed image data, and forming an image for printing based on the decompressed image data in the second case, and a time for writing first image data to the external storage device without compressing it and a time for reading the first image data from the external storage device are calculated as a time for printing. In the first case, the result of adjusting the weight value is shorter than the total time of the time to compress the first image data, the time to write the compressed first image data to the external storage device, the time to read the compressed first image data from the external storage device, and the time to decompress the compressed first image data, and the second case is when the result of adjusting the weight value is longer than the total time of the time to compress the first image data, the time to write the compressed first image data to the external storage device, the time to read the compressed first image data from the external storage device, and the time to decompress the compressed first image data.

According to the present invention, even when the size of image data is large, it is possible to prevent a shortage of capacity in the main storage device (main memory) and suppress a decrease in processing speed.

FIG. 2 illustrates an example of a hardware configuration of an image processing apparatus. FIG. 2 is a block diagram illustrating an example of a functional configuration of the printing system. 5A and 5B are diagrams illustrating a compression and decompression process of print data and image data. FIG. 13 is a diagram showing an example of memory reduction through compression. 13 is a diagram showing internal data generated by an intermediate data generating unit; FIG. FIG. 2 is a diagram showing how images included in PDL data are stored. FIG. 4 is a diagram showing the structure of data referenced during image forming processing. 13 is a flowchart showing an initial process. 10 is a flowchart showing a PDL data analysis process. 4 is a flowchart showing an image forming process. FIG. 13 is a diagram showing a state of transfer of image data. 13 is a flowchart showing an initialization process. 4 is a flowchart showing an image forming process.

First Embodiment
1 is a diagram showing an example of a hardware configuration of an image processing apparatus 100 according to the first embodiment. The image processing apparatus 100 has a CPU 101, a RAM 102, a font ROM 103, a program ROM 104, a data ROM 105, a bus 106, and a keyboard controller (KBC) 107. The image processing apparatus 100 further has a CRT controller (CRTC) 108, a disk controller (DKC) 109, a printer controller (PRTC) 110, and a network controller (NC) 111.

The CPU 101 executes programs such as an OS and applications loaded from the program ROM 104 or the hard disk (HD) 114 to the RAM 102, and realizes the functions of the software and the processing of the flowcharts described below. The RAM 102 is a main storage device and functions as the main memory and work area of the CPU 101. The keyboard controller 107 controls key input from the keyboard (KB) 112 and a pointing device (not shown). The CRT controller 108 controls the display of the CRT display 113. The CRT display 113 may be a liquid crystal display. The disk controller 109 controls access to the hard disk 114 and flexible disk (FD) that store the boot program, various applications, font data, and user files. The hard disk 114 is an external storage device. The printer controller 110 controls the transmission and reception of signals to and from the connected printer. The network controller 111 is connected to a network and executes communication control processing with other devices connected to the network. Note that the functions of the image processing device 100 described below are described as being realized by software, but each function may be implemented in the image processing device 100 by dedicated hardware. Note that the CPU 101 is a multi-core CPU. The image processing device 100 may have multiple CPUs.

FIG. 2 is a block diagram showing an example of the functional configuration of a printing system according to the first embodiment. The printing system includes a computer 200 and an image processing device 100. The computer 200 includes a print data generation unit 201. The print data generation unit 201 generates print data 203 from data to be printed 202.

The image processing device 100 has an input unit 211, an analysis unit 212, a raster image processing unit 220, and an output unit 240. The input unit 211 inputs the print data 203 generated by the print data generation unit 201. The analysis unit 212 analyzes the print data 203 input by the input unit 211 and extracts drawing commands. The raster image processing unit 220 has an intermediate data generation unit 221 and a rendering unit 222. Before explaining the internal data 230 of the hard disk 114, we will first explain the issues that arise when the intermediate data generation unit 221 does not use the hard disk 114.

The intermediate data generation unit 221 extracts drawing information and images from the drawing commands extracted by the analysis unit 212, and generates intermediate data. When generating the intermediate data, the intermediate data generation unit 221 generates internal data for generating the intermediate data. The internal data is stored in the RAM 102 in the image processing device 100.

Figure 3(c) is an example of print data 203. In print data 203, image data is placed in the center of a page measuring 72,000 pixels wide by 51,000 pixels high, and the area within that that will actually be printed is set as the clip area (clip range). When print data 203 containing such image data is input, intermediate data generation unit 221 compresses the image data using lossless compression to reduce data size, as shown in Figure 3(a), and stores it in RAM 102. Thereafter, rendering unit 222 expands the compressed image at full size once, as shown in Figure 3(b), and clips only the necessary parts of the expanded image.

When the intermediate data generating unit 221 extracts image data at the stage of generating intermediate data to continue image processing, the unit reduces the area required to store the images by appropriately performing lossless compression on the images. However, if the intermediate data generating unit 221 repeatedly compresses images and the print data 203 contains more image data than expected, the memory area may be exceeded, resulting in a shortage of memory area.

Figure 4 is a graph showing an example of memory space shortage as a result of repeated compression processing. The vertical axis shows memory usage (GB), and the horizontal axis shows processing time (minutes). The maximum value on the vertical axis, 2 GB, is the maximum memory capacity. Image compression processing occurs and memory usage is reduced, but memory usage reaches nearly the maximum value of 2 GB, causing a memory shortage. In this way, even when compression processing is performed, there are cases where memory shortage occurs and it is difficult to continue processing.

To solve the above problem, the intermediate data generating unit 221 sequentially generates internal data 230 for generating intermediate data, and proceeds with processing while referring to the internal data 230. The internal data 230 includes edge information 231, composition information 232, and paint information 233. The intermediate data generating unit 221 stores the internal data 230 on the hard disk 114. The intermediate data generating unit 221 then uses the stored internal data 230 to generate intermediate data for each page. The rendering unit 222 renders the intermediate data generated by the intermediate data generating unit 221 to generate a raster image. The output unit 240 generates output data 250 based on the raster image generated by the rendering unit 222. The printer controller 110 outputs the output data 250 to the printer and prints the output data 250.

Figure 5 shows internal data 230 generated by the intermediate data generation unit 221. The internal data 230 includes edge information (boundary information) 231, composition information 232, and fill information 233.

Figure 6 shows how images included in PDL data (print data) 610 are stored as files on hard disk 114. PDL data 610 is a print job that includes high-definition images. Intermediate data generating unit 221 extracts four pieces of image data (1), (2), (3), and (4) from PDL data 610 and records them on hard disk 114. Image data (1), (2), (3), and (4) are extracted in order in the order of PDL data 610 (ascending order of addresses). Image data (1) to (4) are recorded together in files of 300 MB each. For example, image data (1) to (4) are saved in four files file1_raw.dat to file4_raw.dat. Image data (1) is recorded as 240 MB of data. Image data (2) is recorded as 160 MB of data. Image data (3) is recorded as 200 MB of data. Image data (4) is recorded as 500 MB of data. All image data (1)-(4) is recorded as uncompressed image data or compressed image data. The intermediate data generation unit 221 extracts image data (1)-(4) from the PDL data 610 and records storage information for each of the image data (1)-(4) in the image management table 620. The rendering unit 222 can read out the image data recorded on the hard disk 114 by referring to the image management table 620.

Figure 7 is a diagram for explaining the structure of data referenced during image formation processing by the rendering unit 222. When forming an image, the rendering unit 222 forms the image in units of tiles. For this purpose, the intermediate data generating unit 221 generates tile management information 710. As shown in Figure 7, the tile management information 710 is generated in an area within the band to be processed on the print page. The image forming process processes the tile management information 710 sequentially. The tile management information 710 references the image management table 620 referenced by each tile, and is configured to read out images as necessary.

Figure 8 is a flowchart showing the initial processing of the intermediate data generation unit 221. First, in step S801, the intermediate data generation unit 221 sets the compression processing time TC when unit image data (e.g., an image of 100 MB) is compressed and decompressed using lossless compression processing. The compression processing time TC is the total time of the time to compress the unit image data, the time to write the compressed unit image data to the hard disk 114, the time to read the compressed unit image data from the hard disk 114, and the time to decompress the compressed unit image data. Note that the compression processing time TC may be the total time of the time to compress the unit image data and the time to decompress the compressed unit image data. For example, the intermediate data generation unit 221 sets the compression processing time TC based on information actually measured in advance by measurement, etc.

Next, in step S802, the intermediate data generation unit 221 determines whether to use a default value or an actual measured value of the installed personal computer environment as the value to be set for the access time TP of the hard disk 114. For example, the intermediate data generation unit 221 makes the determination according to the user's settings, etc. If the intermediate data generation unit 221 uses the default value, the process proceeds to step S803, and if the intermediate data generation unit 221 uses the actual measured value of the personal computer environment, the process proceeds to step S808.

In step S803, the intermediate data generating unit 221 sets a default value for the access time TP of the hard disk 114, and proceeds to step S804. The access time TP of the hard disk 114 is made up of the time TP.W for writing unit image data to the hard disk 114 without compression, and the time TP.R for reading unit image data from the hard disk 114, and the value is set based on information actually measured in advance by measurement, etc.

In step S808, the intermediate data generating unit 221 measures the time it takes to write the unit image data in the actual personal computer environment to the hard disk 114 without compression, and sets this time to the writing time TP.W of the hard disk 114. Then, the process proceeds to step S809.

In step S809, the intermediate data generating unit 221 measures the time it takes to read unit image data from the hard disk 114 in an actual personal computer environment, sets that time as the read time TP.R of the hard disk 114, and proceeds to step S804.

In step S804, the intermediate data generation unit 221 sets the weight value WGT and proceeds to step S805. The weight value WGT is, for example, a value smaller than 1.

Next, in step S805, the intermediate data generating unit 221 compares the access time (TP.W+TP.R)×WGT with the compression processing time TC according to formula (1). The access time (TP.W+TP.R)×WGT is the result of multiplying the sum of the write time TP.W and the read time TP.R by the weight value WGT.
(TP.W+TP.R)×WGT＜TC (1)

If the access time (TP.W+TP.R)×WGT is shorter than the compression processing time TC, the intermediate data generation unit 221 determines that the compression processing speed is low and proceeds to step S806. If the access time (TP.W+TP.R)×WGT is longer than the compression processing time TC, the intermediate data generation unit 221 determines that the compression processing speed is high and proceeds to step S810.

In step S806, the intermediate data generation unit 221 sets the uncompressed mode so that the image data is written to the hard disk 114 without being compressed, and proceeds to step S807.

In step S810, the intermediate data generation unit 221 sets the compression mode to compress the image data and write it to the hard disk 114, and proceeds to step S807.

In step S807, the intermediate data generation unit 221 saves the non-compression mode or compression mode set in step S806 or S810 as configuration information.

Since the weight value WGT is less than 1, the uncompressed mode is prioritized. The reason for using such a weight value WGT is that when an image is written uncompressed, only the necessary parts of the image are read during the image read process described below, improving processing time.

Figure 9 is a flow chart showing the PDL data analysis process of the intermediate data generation unit 221, showing the flow when processing image data. The image processing method of the image processing device 100 will be described below. When print data (PDL data) is input to the input unit 211, the analysis unit (interpreter) 212 performs analysis processing of the PDL data and sequentially extracts drawing commands within the PDL data. The PDL data is print data written in a page description language.

In step S901, the analysis unit 212 extracts an image brush drawing command from the PDL data.

Next, in step S902, the analysis unit 212 determines whether the command operand of the image brush drawing command is normal. If the command operand is normal, the analysis unit 212 proceeds to step S904, and if the command operand is not normal, the analysis unit 212 proceeds to step S903.

In step S903, the analysis unit 212 performs SKIP processing and returns to step S1001.

In step 904, the intermediate data generation unit 221 puts the object (image data) contained in the PDL data specified by the image brush drawing command into the information queue.

Next, in step S905, the intermediate data generation unit 221 registers the image data contained in the PDL data as fill information (fill = image) for the drawing data of the page.

Next, in step S906, the intermediate data generation unit 221 determines whether or not color conversion (e.g., conversion from a CMYK image to an RGB image) is necessary for the image data. If color conversion is necessary, the intermediate data generation unit 221 proceeds to step S907, and if color conversion is not necessary, the intermediate data generation unit 221 proceeds to step S908.

In step S907, the intermediate data generation unit 221 performs color conversion on the image data and proceeds to step S908.

In step S908, the intermediate data generation unit 221 references the configuration information saved in step S807 of FIG. 8 and sets the non-compressed mode or compressed mode of the configuration information.

Next, in step S909, if the configuration information is in non-compression mode, the intermediate data generation unit 221 writes the image data included in the PDL data or the image data color converted in step S907 to the hard disk 114 without compressing it. Also, if the configuration information is in compression mode, the intermediate data generation unit 221 compresses the image data included in the PDL data or the image data color converted in step S907, and writes the compressed image data to the hard disk 114. As described above, the intermediate data generation unit 221 functions as a writing unit. At that time, the intermediate data generation unit 221 records the storage information of each image data in the image management table 620 of FIG. 6.

Figure 10 is a flowchart showing the image formation process of the rendering unit 222, and shows the process of reading image data.

First, in step S1001, the rendering unit 222 generates face information and declares (submits) that the generated face information will be processed.

Next, in step S1002, the rendering unit 222 determines whether or not processing is possible. If processing is possible, the rendering unit 222 proceeds to step S1004, and if processing is not possible, the rendering unit 222 proceeds to step S1003.

In step S1003, the rendering unit 222 waits and returns to step S1001.

In step S1004, the rendering unit 222 starts a render task. Next, in step S1021, the rendering unit 222 starts a thread that performs tile processing. The rendering unit 222 is configured to sequentially form an image for each tile.

Next, in step S1022, the rendering unit 222 sequentially scans the target tiles and checks the information within the target tiles. The information within the tiles is associated with the tile management information 710 in FIG. 7.

Next, in step S1023, the rendering unit 222 determines whether or not the target tile includes an image. If the target tile includes an image, the rendering unit 222 can read the image by referencing the image management table 620 from the tile management information 710 as shown in FIG. 7. If the target tile includes an image, the rendering unit 222 proceeds to step S1024, and if the target tile does not include an image, the rendering unit 222 proceeds to step S1027.

In step S1024, the rendering unit 222 sets the file handle. Next, in step S1025, the rendering unit 222 performs a seek process.

Next, in step S1026, if the configuration information is in non-compression mode, the rendering unit 222 reads image data of the clip area (print area) of the image data included in the target tile from the hard disk 114. If the configuration information is in compression mode, the rendering unit 222 reads compressed image data included in the target tile from the hard disk 114 and expands the compressed image data. Then, the rendering unit 222 obtains image data of the clip area (print area) of the expanded image data.

Next, in step S1027, the rendering unit 222 performs tile data processing. If the rendering unit 222 reads image data in step S1126, it processes the image data of the clip area as tile data.

Next, in step S1028, the rendering unit 222 functions as an image forming unit, and uses the tile data to form an image for printing (generate pixels), and then the process ends.

Figures 11(a) to (c) are diagrams showing how image data is transferred. As shown in Figure 11(c), the image data arranged in the center of the print page of the print data is clipped. In Figure 11(a), the intermediate data generating unit 221 writes the image data stored in the RAM 102 to the hard disk (HD) 114 in uncompressed mode. In Figure 11(b), the rendering unit 222 reads only the image data in the clip area (print area) of the uncompressed written image data based on the clip information. For example, when the image data is about 500 MB, the rendering unit 222 takes about 15 seconds to read all the image data. In contrast, when the clip area is about 30% of the entire area, the reading of the image data in the clip area is completed in about 5 seconds. When converted to a job that takes 75 seconds in a conventional processing system, the processing is completed in 65 seconds (about 13% faster).

Note that the access time (TP.W+TP.R)×WGT in FIG. 8 may be the total time of the time to write the unit image data to the hard disk 114 without compression and the time to read the image data of the clip area of the unit image data from the hard disk 114.

Second Embodiment
Next, the second embodiment will be described. In the second embodiment, in the case of non-compression mode, the intermediate data generating unit 221 does not write all the target image data (herein called full mode), but writes only odd-numbered bands for each specific band to the hard disk 114 (this is called half mode). Image data, which is a high-definition image, is generally large in size, so that writing half of the size to the hard disk 114 creates a large margin in the RAM 102, and it is not necessary to write more image data than necessary to the hard disk 114. In addition, writing to the hard disk 114 takes about 30 seconds in actual measurement, even for writing 500 MB, for example, which causes a decrease in performance. Therefore, in the second embodiment, in accordance with a predetermined condition, instead of writing all the image data to the hard disk 114, only image data of a size necessary to secure an area in the RAM 102 is written to the hard disk 114. For example, an image of half the size of the image data is written.

Figure 12 is a flowchart showing the initial processing of the intermediate data generation unit 221. First, in step S1201, the intermediate data generation unit 221 sets the compression processing time TC when a unit image data (e.g., an image of 100 MB) is compressed and decompressed using lossless compression processing.

Next, in step S1202, the intermediate data generation unit 221 determines whether to use a default value or an actual measured value of the installed personal computer environment as the value to be set for the access time TP of the hard disk 114. If the intermediate data generation unit 221 uses the default value, the process proceeds to step S1205, and if the actual measured value of the personal computer environment is used, the process proceeds to step S1203.

In step S1205, the intermediate data generating unit 221 sets the access time TP of the hard disk 114 to a default value, and proceeds to step S1206. The access time TP of the hard disk 114 consists of the time TP.W for writing the unit image data to the hard disk 114 without compression, and the time TP.R for reading the unit image data from the hard disk 114.

In step S1203, the intermediate data generating unit 221 measures the time it takes to write the unit image data to the hard disk 114 without compressing it in the actual personal computer environment, and sets this time to the writing time TP.W of the hard disk 114. Then, the process proceeds to step S1204.

In step S1204, the intermediate data generating unit 221 measures the time it takes to read unit image data from the hard disk 114 in an actual personal computer environment, and sets that time as the read time TP.R of the hard disk 114. Then, the process proceeds to step S1206.

In step S1206, the intermediate data generating unit 221 predicts the area size of the image to be clipped and predicts the clipping rate of the image to be clipped. The clipping rate is the ratio of the clipping area (printing area) of the image data included in the PDL data to the total area of the image data included in the PDL data.

Next, in step S1207, the intermediate data generation unit 221 sets the predicted clip rate to the clip rate CLP_RATE.

Next, in step S1210, the intermediate data generating unit 221 compares the access time TP.W+TP.R×CLP_RATE with the compression processing time TC according to formula (2). The access time TP.W+TP.R×CLP_RATE is the sum of the product of the read time TP.R and the clip rate CLP_RATE and the write time TP.W.
(TP.W+TP.R×CLP_RATE) < TC (2)

If the access time TP.W+TP.R×CLP_RATE is shorter than the compression processing time TC, the intermediate data generation unit 221 determines that the compression processing speed is low and proceeds to step S1211. If the access time TP.W+TP.R×CLP_RATE is longer than the compression processing time TC, the intermediate data generation unit 221 determines that the compression processing speed is high and proceeds to step S1214.

In step S1211, the intermediate data generation unit 221 sets the uncompressed mode to write the image data to the hard disk 114 without compressing it, and proceeds to step S1212.

In step S1212, the intermediate data generation unit 221 generates the write mode, bandwidth information, and selected band information as management information related to the image. Specifically, the intermediate data generation unit 221 generates management information related to an image in which the image write mode is the half mode, the bandwidth is 512 lines, and the selected band is an odd band, and proceeds to step S1213.

In step S1214, the intermediate data generation unit 221 sets the compression mode to compress the image data and write it to the hard disk 114, and proceeds to step S1213.

In step S1213, the intermediate data generation unit 221 saves the set non-compression mode and image-related management information or compression mode as configuration information.

Next, the PDL data analysis process of the intermediate data generation unit 221 will be described with reference to FIG. 9. The processes of steps S901 to S907 in FIG. 9 are the same as those in the first embodiment. Next, in step S908, the intermediate data generation unit 221 references the configuration information saved in step S1213 in FIG. 12, sets the non-compressed or compressed mode of the configuration information, and if the non-compressed mode is selected, sets management information related to the image.

Next, in step S909, if the configuration information is in the non-compression mode, the intermediate data generation unit 221 writes the image data included in the PDL data or the color-converted image data to the hard disk 114 without compressing it, according to the management information regarding the image. For example, the management information regarding the image is that the image write mode is the half mode, the bandwidth is 512 lines, and the selected band is an odd band. In this case, the intermediate data generation unit 221 writes only the odd bands for each 512 bandwidth to the hard disk 114 without compressing the image data included in the PDL data or the image data color-converted in step S907. That is, in this case, the intermediate data generation unit 221 writes a part of the image data included in the PDL data or the color-converted image data to the hard disk 114 without compressing it. Then, the intermediate data generation unit 221 stores the other image data of the image data included in the PDL print data or the color-converted image data in the RAM 102.

In addition, if the configuration information is in compression mode, the intermediate data generation unit 221 compresses the image data included in the PDL data or the image data color converted in step S907, and writes the compressed image data to the hard disk 114. At that time, the intermediate data generation unit 221 records the storage information of each image data in the image management table 620 in FIG. 6.

Figure 13 is a flowchart showing the image formation process of the rendering unit 222 according to the second embodiment, showing the process of reading image data.

First, in step S1301, the rendering unit 222 generates face information and declares (submits) that the generated face information will be processed.

Next, in step S1302, the rendering unit 222 determines whether or not processing is possible. If processing is possible, the rendering unit 222 proceeds to step S1304, and if processing is not possible, the rendering unit 222 proceeds to step S1303.

In step S1303, the rendering unit 222 waits and returns to step S1301.

In step S1304, the rendering unit 222 starts a render task. Next, in step S1310, the rendering unit 222 starts a thread that performs tile processing. The rendering unit 222 is configured to sequentially form an image for each tile.

Next, in step S1311, the rendering unit 222 sequentially scans the target tiles and checks the information within the target tiles. The information within the tiles is associated with the tile management information 710 in FIG. 7.

Next, in step S1312, the rendering unit 222 determines whether or not the target tile includes an image. If the target tile includes an image, the rendering unit 222 can read the image by referencing the image management table 620 from the tile management information 710 as shown in FIG. 7. If the target tile includes an image, the rendering unit 222 proceeds to step S1313, and if the target tile does not include an image, the rendering unit 222 proceeds to step S1318.

In step S1313, the rendering unit 222 refers to the image management table 620 and determines whether the image data has been written to the hard disk 114 and needs to be read. If the image data needs to be read, the rendering unit 222 proceeds to step S1314, and if the image data does not need to be read, the image data is stored in the RAM 102, so the rendering unit 222 proceeds to step S1317.

In step S1314, the rendering unit 222 sets the file handle. Next, in step S1315, the rendering unit 222 performs a seek process.

Next, in step S1316, if the configuration information is in uncompressed mode, the rendering unit 222 reads out image data of the odd bands included in the target tile from the hard disk 114. The rendering unit 222 then combines the read out image data of the odd bands with the image data of the even bands stored in the RAM 102. That is, in this case, the rendering unit 222 reads out a portion of the image data from the hard disk 114, and forms an image for printing based on the portion of the image data from the hard disk 114 and the other image data from the RAM 102.

If the configuration information is in compressed mode, the rendering unit 222 reads the compressed image data contained in the target tile from the hard disk 114 and expands the compressed image data. Then, the process proceeds to step S1318.

In step S1317, the rendering unit 222 sets the address in RAM 102 where the image data is stored, reads the image data stored in RAM 102, and proceeds to step S1318.

Next, in step S1318, the rendering unit 222 performs tile data processing. If the rendering unit 222 reads image data in step S1316 or S1317, the rendering unit 222 processes the read image data or the composite image data as tile data.

Next, in step S1319, the rendering unit 222 uses the tile data to form an image for printing (generate pixels), and then ends the process.

As described above, in the case of uncompressed mode, the intermediate data generation unit 221 does not write all of the target image data to the hard disk 114, but uses management information related to the image to write only the odd bands of the image data to the hard disk 114. This allows the intermediate data generation unit 221 to further reduce processing time. In addition, by predicting the clip rate CLP_RATE, the intermediate data generation unit 221 can set the uncompressed mode or compressed mode with higher accuracy than when a fixed weight value WGT is used.

Other Embodiments
The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) for implementing one or more of the functions.

The above embodiments are merely illustrative examples of how the present invention may be implemented, and the technical scope of the present invention should not be interpreted in a limiting manner based on these embodiments. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features.

211 Input section, 212 Analysis section, 221 Intermediate data generation section, 222 Rendering section, 240 Output section

Claims (11)

a write means for writing image data included in the print data to the external storage device without compressing the image data in the first case, and for compressing the image data included in the print data and writing the compressed image data to the external storage device in the second case;
an image forming means for reading the image data from the external storage device in the first case, and forming an image for printing based on the image data, and for reading the compressed image data from the external storage device in the second case, and for expanding the compressed image data, and forming an image for printing based on the expanded image data ;
In the first case, a result of adjusting a total time of a time for writing the first image data to the external storage device without compression and a time for reading the first image data from the external storage device using a weight value is shorter than a total time of a time for compressing the first image data, a time for writing the compressed first image data to the external storage device, a time for reading the compressed first image data from the external storage device, and a time for decompressing the compressed first image data,
The second case is a case where a result of adjusting a total time of a time for writing the first image data to the external storage device without compression and a time for reading the first image data from the external storage device using a weight value is longer than a total time of a time for compressing the first image data, a time for writing the compressed first image data to the external storage device, a time for reading the compressed first image data from the external storage device, and a time for expanding the compressed first image data.
13. An image processing device comprising: The image processing device according to claim 1, characterized in that in the first case, the image forming means reads out image data of the print area of the image data from the external storage device, and forms an image for printing based on the image data of the print area, and in the second case, reads out the compressed image data from the external storage device, expands the compressed image data, and forms an image for printing based on the image data of the print area of the expanded image data. the first case is a case where a result of multiplying a weight value by a total time of a time for writing the first image data to the external storage device without compression and a time for reading the first image data from the external storage device is shorter than a total time of a time for compressing the first image data, a time for writing the compressed first image data to the external storage device, a time for reading the compressed first image data from the external storage device, and a time for decompressing the compressed first image data,
3. The image processing device according to claim 1, wherein the second case is a case where a result of multiplying a weight value by the total time of a time to write the first image data to the external storage device without compression and a time to read the first image data from the external storage device is longer than the total time of a time to compress the first image data, a time to write the compressed first image data to the external storage device, a time to read the compressed first image data from the external storage device, and a time to expand the compressed first image data. 4. The image processing apparatus according to claim 3 , wherein the weight value is a value smaller than one. The image processing device according to any one of claims 1 to 4, characterized in that the writing means determines whether the first case or the second case occurs based on the time it takes to write the first image data to the external storage device without compressing it, the time it takes to read the first image data from the external storage device, the time it takes to compress the first image data, and the time it takes to expand the compressed first image data. The image processing device of any one of claims 1 to 5, characterized in that the writing means determines whether the first case or the second case exists based on the time it takes to write the first image data to the external storage device without compressing it, the time it takes to read the first image data from the external storage device, the time it takes to compress the first image data, the time it takes to write the compressed first image data to the external storage device, the time it takes to read the compressed first image data from the external storage device, and the time it takes to expand the compressed first image data. In the first case, the writing means writes a part of the image data included in the print data to the external storage device without compressing the part of the image data,
The image processing device according to any one of claims 1 to 6, characterized in that, in the first case, the image forming means reads out the portion of the image data from the external storage device and forms an image for printing based on the portion of the image data. In the first case, the writing means stores other image data of the image data included in the print data in a main storage device;
8. The image processing device according to claim 7, wherein the image forming means, in the first case, forms an image for printing based on the part of the image data in the external storage device and the other image data in the main storage device. 9. The image processing apparatus according to claim 1, wherein the print data is print data described in a page description language. a writing step of writing image data included in the print data to the external storage device without compressing the image data in the first case, and compressing the image data included in the print data and writing the compressed image data to the external storage device in the second case;
an image forming step of reading the image data from the external storage device in the first case, and forming an image for printing based on the image data, and an image forming step of reading the compressed image data from the external storage device in the second case, decompressing the compressed image data, and forming an image for printing based on the decompressed image data ;
In the first case, a result of adjusting a total time of a time for writing the first image data to the external storage device without compression and a time for reading the first image data from the external storage device using a weight value is shorter than a total time of a time for compressing the first image data, a time for writing the compressed first image data to the external storage device, a time for reading the compressed first image data from the external storage device, and a time for decompressing the compressed first image data,
The second case is a case where a result of adjusting a total time of a time for writing the first image data to the external storage device without compression and a time for reading the first image data from the external storage device using a weight value is longer than a total time of a time for compressing the first image data, a time for writing the compressed first image data to the external storage device, a time for reading the compressed first image data from the external storage device, and a time for expanding the compressed first image data.
23. An image processing method for an image processing apparatus comprising: A program for causing a computer to function as each of the means of the image processing device according to any one of claims 1 to 9 .

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