JP2016192623A - Image processing apparatus and method, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus and method, and a recording medium for color conversion of an image at high speed while suppressing the amount of usage of memory.SOLUTION: The method generates a development table corresponding to the color distribution of an image included in print data and imparts it to the image. Thereafter, when performing color conversion, the method develops a corresponding area of a color conversion LUT in memory on the basis of the development table and refers to a developed LUT component, thereby generating a color-converted image. In accordance with the priority order of the print data and a load on a calculator, the method switches between use and no use of the development table.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image processing method in a printing system that prints print data consisting of a plurality of pages at a high speed by parallel processing.

  Conventionally, analog printing machines such as offset printing and gravure printing have been used in the commercial printing field for printing commercial printed matter such as books and brochures. However, due to changes in the market needs for printing a wide variety of products with a small number of copies, the introduction of ink-jet and laser-type digital printers is in progress. At the same time, as required in analog printing, high-speed printing processing is also required in digital printing.

  The printing process of digital printing is generally performed according to the following flow. First, when digital print data created using a computer such as a personal computer is input to the print server, the print server checks whether the print data is complete with information necessary for subsequent print processing (pre-scan). ). If the required information is available as a result of the inspection, the print data described in Page Description Language (PDL) is analyzed, and the image data in the print data is converted to a color that can be reproduced by the printing press. Convert. After the print data including the color-converted image data is decomposed into multi-value data for each plate such as cyan, magenta, yellow, and black (CMYK), the decomposed multi-value data is transferred to a printing machine. A printed matter is completed when the printing machine transfers the transferred multi-value data to printing paper.

  In the image color conversion process in the above printing process, mapping is performed to associate the pixel values of the image described in the sRGB color space (the international standard of the color space established by the IEC (International Electrotechnical Commission)) with the color signal values of the printing press. Processing is performed. In the mapping process, the RGB axes of the sRGB color space are divided by a predetermined number of divisions such as 8 divisions or 16 divisions, and the space is divided into a grid. Then, an output value corresponding to the input value of each grid point is calculated, and this correspondence table is created as a Look-Up Table (LUT). When a pixel value of an input image, that is, an input value is input, an output value corresponding to the input value is calculated with reference to the LUT. If the input value matches the grid point, the output value at that grid point is the output value corresponding to the input value. If the input value does not match the grid point, the grid point containing the input value The output value must be calculated by interpolation.

  For this interpolation calculation, various interpolation methods such as cube interpolation and tetrahedral interpolation have been proposed according to the grid points used for the interpolation. The processing in the interpolation calculation will be described by taking tetrahedral interpolation with high interpolation accuracy as an example. When an input value is input, first, a lattice to which the input value belongs is searched, and among the six tetrahedrons in the lattice, inside / outside determination is made as to which tetrahedron the input value exists, and the input value is determined. Specify the tetrahedron to be included. Next, the output value corresponding to the input value from the internal ratio of the distance from the origin to the point of the input value and the length from the origin to the other three vertices, with one vertex of the specified tetrahedron as the origin Is calculated. By performing the above processing, it is possible to interpolate the output value corresponding to the input value, but for the interpolation calculation, search of the lattice to which the input value belongs, determination of the inside / outside of the input value for the tetrahedron in the lattice, and Since calculation of the internal ratio is required, there is a problem that the calculation speed is slow. In addition, since the interpolation calculation interpolates points between grid points, if the color change between the actual grid points is non-linear, the interpolation accuracy decreases.

  Output values (hereinafter referred to as overall LUTs) for all input values are calculated without thinning out the color conversion LUTs in a grid pattern, and output values can be obtained without interpolation by using the overall LUTs.

  However, if the paper size of the print data is A4 and 400 dpi, a working memory of at least 44 MB (210 mm x 297 mm x (400 / 25.4) ^ 2 x 3 = 44 MB (^ symbol represents a power)) is required. . On the other hand, since this entire LUT has all output values for all input values, for example, when each channel is a 3-channel LUT with 8-bit color depth, the data capacity is 48 MB (256 ^ 3 × 3 = 48MB). For this reason, if print data is processed by a parallel computer using this entire LUT, the memory capacity is compressed by the entire LUT, so even a computer equipped with multiple arithmetic devices cannot increase the degree of parallelism and print. The processing speed cannot be increased.

  Accordingly, the following prior application techniques have been disclosed as techniques for reducing the memory usage by the LUT.

The technique disclosed in Patent Document 1 is a technique for limiting the LUT component held according to the maximum luminance of an input image in an LUT in a YC _{b Cr} color space (a color space defined by luminance and chromaticity). For example, when the maximum luminance Y _max of the input image is 50, the LUT data capacity is reduced by not retaining the LUT component exceeding Y _max (see FIG. 6 of Patent Document 1).

  The technique disclosed in Patent Document 2 divides the LUT into coarse areas, approximates each divided area with a linear line, calculates an error value between the original LUT component value and the approximate value, and calculates the divided area. The coefficient and error value of the linear straight line are held in (see FIGS. 1 to 3 of Patent Document 2). This reduces the data capacity of the LUT. The output value corresponding to the input value is calculated from the coefficient and error value of the primary line.

JP 2008-245029 Japanese Patent No.4411230

  However, in the case of the technique disclosed in Patent Document 1, even if the color distribution of 99% of pixels is biased, if the remaining 1% of pixels are out of the bias, most of the LUTs are not compressed. Memory usage cannot be reduced. In the case of the technique disclosed in Patent Document 2, approximate lines and error values are calculated even for an input range having a very low appearance probability in the input image, and the coefficients and error values of all approximate lines are stored. For this reason, when an input image with a biased color distribution is input, memory is consumed for data that is not used. In the prior application technique, when calculating the output value, the LUT grid points are calculated using the approximate straight line coefficient and error value, and then the interpolation operation is performed. Therefore, the processing speed is higher than the normal interpolation operation. Becomes slower.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide an image processing apparatus and method, and a recording medium, which perform high-speed color conversion of images with a minimum memory usage. To do.

  In order to achieve the above object, the image processing apparatus of the present invention generates in advance a development table that describes the color area of the LUT to be developed in the memory for each image, and stores the minimum necessary amount on the memory based on the development table. The color conversion is performed by expanding the LUT.

  According to the present invention, it is possible to perform color conversion at high speed while reducing the amount of memory used during color conversion of an image in print processing.

Diagram showing examples of images included in print data and their color distribution in RGB space The figure which shows the example of the expansion table in this invention The figure which shows the logical structure of the printing system in this invention The figure which shows the example of the process of the printing system which concerns on a 1st Example, and the flow of a process of a compression means. The figure which shows the example of the flow of a process of the expansion | deployment table production | generation means based on a 1st Example, and a compression means. The figure which shows the example of the logical structure of the system which concerns on a 2nd Example. The figure which shows the example of the flow of a process of the image processing apparatus which concerns on a 2nd Example. The figure which shows the example of UI which concerns on a 2nd Example

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[First embodiment]
Prior to the description of the examples, the knowledge based on the present invention will be described first.

  FIGS. 1A to 1C show examples (sample images) of images included in print data assumed by the present invention. 1A is a graphics image created by spreadsheet software or document creation software, FIG. 1B is a portrait image of a person as a subject, and FIG. 1C is an image of autumn leaves.

  FIG. 1D shows the color distribution of each sample image in the sRGB color space. In FIG. 1 (d), reference numerals 1001 (circular mark distribution), 1002 (positive mark distribution), and 1003 (square mark distribution) are the color distributions of the sample images. Looking at the distributions 1001, 1002, and 1003, it can be clearly seen that the distribution is different from the color distribution of other images. Also, looking at the grid usage rate of each sample image (ratio of grid used by each image when each RGB axis in the sRGB color space is divided into 32), FIG. 1 (a) is 1.7%, 1 (b) is 2.6% and FIG. 1 (c) is 8.9%.

  From the above two points, it can be seen that the color distribution of a general image is biased and the grid usage rate is low. In other words, since the color distribution of the image is biased, even if all the LUT components are expanded on the memory for speeding up, it can be said that only a small part of the LUT is actually used.

  Therefore, in the present invention, a development table is generated according to the color distribution of the image, the LUT component is developed on the memory using the development table, and color conversion is performed with reference to the developed LUT component. In this way, color conversion can be performed at high speed with the minimum necessary memory usage.

  Further, in the present invention, a 1-bit flag (development flag) sequence (development table) is generated in order to specify a grid that must be expanded on a memory at the time of color conversion with a small amount of calculation. FIG. 2 shows an example of an expansion table when each axis of the LUT is divided into eight. By using this expansion table, the lattice to be expanded on the memory can be specified by bit shift and logical product operation, so that the LUT component can be expanded on the memory at high speed.

  FIG. 3 shows a logical configuration of the printing system assumed in this embodiment. In FIG. 3, 1 is a printing system that prints print data, 10 is a print server that converts print data into data (RIP (Raster Image Processing) data) that can be printed by a printing press, 11 is print data creation, The client PCs 12 for transferring the print data to the print server are printers that transfer the color material to the print paper based on the input RIP data.

  101 is an input profile describing the input / output characteristics of the image input device, an output profile describing the input / output characteristics of the image output device, and colors such as image observation conditions on the image input device side and image observation conditions on the image output side Profile holding means for holding conversion conditions, 102 is an input value generating means for generating an input value for generating a color conversion LUT, 103 is a second color from the color value of the first color space. Color conversion means for converting to color values in space, 104 is a compression means for compressing the color conversion LUT converted by the color conversion means for each predetermined grid, and 105 is a color conversion LUT (compression LUT) compressed by the compression means ) Is a compressed LUT holding means.

  106 is print data to be printed, 107 is pre-scanning means for checking whether or not the print data 106 transferred from the client PC 11 to the server 10 holds information necessary for printing, and 108 is described in PDL PDL interpretation means for interpreting the printed data, 109 is a development table generation means for generating a development table according to the color distribution of the image included in the PDL-interpreted print data and assigning it to the image, 110 is the development table PDL data holding means 111 for holding PDL data including an image to which is assigned PDL data input means for acquiring PDL data from the PDL data holding means.

  112 obtains a compressed LUT corresponding to the color conversion condition of the image data included in the PDL data acquired by the PDL data input means from the compressed LUT holding means, and compresses the compressed LUT on the memory based on the expansion table attached to the image data. An expansion unit 113 expands the LUT component of the image by referring to the LUT component expanded on the memory by the expansion unit, so that the pixel value of the image is changed from the color value of the first color space to the second color space value. An image conversion means 114 for converting the color value into a RIP means 114 for converting PDL data including the image converted by the image conversion means into a raster image, and 115 for printing the RIP data generated by the RIP means A printing unit 116 is a printed matter printed by the printing unit.

  Examples of hardware configurations of the print server 10 and the client PC 11 are shown below. CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), VRAM (Video RAM), keyboard controller, magnetic storage medium, optical storage medium. Further, a network controller, an input / output controller, and the like. These are connected to the bus. Since the details of the server are not the main requirements in the present invention, a detailed description is omitted.

  The print server 10, the client PC 11, and the printer 12 are connected to each other via a network. In the embodiment, it is assumed that they are connected via the Internet. The network according to the present invention may be connected using any technique and means as long as data exchange is possible between connected devices.

  Next, the processing flow of the printing system in this embodiment will be described.

<Processing in the printing system>
Hereinafter, an example of the flow of processing of the printing system assumed in this embodiment will be described in detail with reference to FIG.

  In step S101, the input value generation means 102 generates all combinations of input values (entire LUT).

  In step S102, the color conversion unit 103 converts the input value stored in the entire LUT from the color value of the first color space to the color value of the second color space based on the input profile, the output profile, and the color conversion condition. To do.

  In step S103, the compression unit 104 compresses the entire LUT converted in step S102 for each predetermined lattice.

  In step S104, the prescan unit 107 receives print data input from the client PC and performs prescan.

  In step S105, the PDL interpretation unit 108 interprets the print data.

  In step S106, the development table generation unit 109 generates a development table according to the color distribution of the image included in the print data, adds the development table to the image data, and stores the PDL data in the PDL data holding unit.

  In step S107, the PDL data input unit 111 acquires the PDL data stored in the PDL data holding unit.

  In step S108, the expansion unit 112 acquires a compression LUT corresponding to the color conversion condition of the image included in the PDL data from the compression LUT holding unit 105, and calculates the LUT component of the compression LUT based on the expansion table attached to the image. Expand on memory.

  In step S109, the image conversion unit 113 converts the pixel value of the image with reference to the LUT component on the memory.

  In step S110, the RIP unit 114 RIPs the PDL data including the image subjected to color conversion in step S109.

  In step S111, the printing unit 115 prints the RIP data that has been RIPed in step S110.

<Processing in compression means 104>
FIG. 4B is a flowchart showing an example of processing in the compression unit 104.

  In step S201, the compression unit 104 calculates a difference value between adjacent components in the lattice.

  In step S202, the compression means 104 stores the output value of the starting point component of the grid in the correspondence table.

  In step S203, the compression means 104 assigns a code according to the appearance probability of the difference value. Specifically, a short code is assigned to a difference value having a high appearance probability, and a long code is assigned to a difference value having a low appearance probability.

  In step S204, the compression unit 104 stores the correspondence table and the code table in the compression LUT holding unit 309.

<Processing in Expansion Table Generating Unit 109>
First, the expansion table used in the present embodiment will be described in detail with reference to FIG.

  According to the present invention, output values for all combinations of input values are partially expanded in a memory according to the type of image, and color conversion is performed using the expanded output values, thereby reducing memory usage and color conversion. Increase speed. In the present invention, since the LUT is partially expanded in the memory, it is necessary to determine whether or not the output value corresponding to the input value is expanded in the memory. In the present invention, determination is performed at high speed by using a bit string described below.

  Hereinafter, in order to simplify the description, a one-dimensional description will be given. FIG. 2 (a) shows a decimal notation and a binary notation of boundary values (grid boundary values) of each lattice when a one-dimensional axis is divided into eight, a binary notation of the upper 3 bits, a decimal notation, and The expansion flag indicating the expansion status of each grid is shown. When the axis is divided into eight lattices with the lattice boundary values shown in the first column of FIG. 2A, the binary representation of the lattice boundary values can be represented by the values in the second column of FIG. Further, if the upper 3 bits of the grid boundary value in binary notation are taken out, it can be expressed by the value in the third column of FIG. 3, and if expressed in decimal notation, it can be expressed by the value in the second column of FIG. it can. Whether each grid should be expanded in a memory and whether it is expanded or not can be expressed by 8 binary values as shown in the fifth column of FIG. In other words, this expansion / non-expansion information (expansion flag) can be expressed on a memory by using an 8-bit bit string. FIG. 2B shows an example of a bit string for storing the expansion flag.

  In the figure, 2001 represents an expansion flag composed of an 8-bit bit string, and 2002 to 2009 represent expansion flags for the 1st to 8th lattices, respectively.

  Hereinafter, as a specific example, a method for acquiring a development flag when the input value is 35 will be described with reference to FIG. First, the input value 35 (first column in FIG. 2 (f)) is converted into binary notation (second column in FIG. 2 (f)). Next, the upper 3 bits of the input value in binary notation are acquired (FIG. 2 (f), third column). The acquired upper 3 bits are converted into decimal notation (FIG. 2 (f), fourth column). The bit string of the expansion flag is right-shifted by the value obtained by the conversion (in this case, the number of shifts is 1). As a result, since the expansion flag of the lattice to which the input value belongs to the least significant bit of the bit string is stored, the expansion flag stored in the least significant bit can be acquired by performing a logical product with 0000 0001.

  The above is the method for acquiring the expansion flag of the lattice to which the input value 35 belongs. This is generalized as follows. The number of divisions for each axis of all LUTs

The bit depth of the image

Then the number of shifts of the input value

Can be expressed as:

  The expansion flag of the lattice to which the input value belongs can be acquired by the above calculation, and it can be determined whether or not the lattice is expanded in the memory by referring to the value of the expansion flag.

  Next, with reference to FIG. 5A, the expansion table generation processing in the present embodiment will be described in detail. FIG. 5A is a flowchart showing an example of processing in the expansion table generating unit 109.

  In step S301, the expansion table generating unit 109 initializes each bit of the expansion table with 0. Here, 0 indicates that the lattice does not need to be expanded in the memory or is not expanded. On the other hand, 1 indicates that it is necessary to expand in the memory or that it is expanded.

  In step S302, the development table generation unit 109 determines whether all pixels of the image have been processed.

  In step S303, the expansion table generating unit 109 sets 1 to the corresponding bit of the expansion table corresponding to the grid that includes the pixel values of the image.

  In step S304, the expansion table generating unit 109 determines whether the processing has been completed for all pixels. If the process has not ended, the process returns to step S302 to repeat the process. If the process has been completed, the process proceeds to step S304.

  In step S305, the expansion table generating unit 109 associates the expansion table with the image data.

<Processing in Expansion Unit 112>
FIG. 5B is a flowchart showing an example of processing in the expansion means 112.

  In step S401, the expansion unit 112 acquires the starting point component of the compression LUT stored in the correspondence table.

  In step S402, the expansion unit 112 writes the starting point component in the memory.

  In step S403, the decompressing unit 112 determines whether processing has been performed for all components of the compression LUT.

  In step S404, the decompressing means 112 acquires a symbol corresponding to the code of the code table from the compression LUT.

  In step S405, the expansion unit 112 writes the value obtained by adding the symbol value to the previous component to the memory as the current component value.

  In step S406, the decompressing unit 112 determines whether the processing has been completed for all components of the compression LUT. If the process has not ended, the process returns to step S403 to repeat the process. If the process has been completed, the process proceeds to step S407.

  As described above, according to the technique described above, a development table is generated in advance according to the color distribution of the image data included in the print data, and the LUT component of the compression LUT is developed on the memory using the development table at the time of color conversion. And refer to the expanded LUT component. In this way, color conversion can be performed at high speed while reducing the amount of memory used.

[Second Example]
A second embodiment to which the present invention is applied will be described below.

  In the printing system assumed in the present invention, there is a demand for performing a specific print job at high speed according to the priority of the print job. In order to respond to such a request, the second embodiment has a configuration capable of processing a print job at a high speed even when a large amount of memory is consumed when there is a sufficient memory space.

  In other words, the print speed for the print job is switched according to the contents of the express flag set in advance for the print job and the free capacity of the memory of the printing system. FIG. 6 shows a logical configuration in the present embodiment, and FIG. 7 shows an example of a processing flow.

  Hereinafter, the system configuration in the present embodiment will be described with reference to FIG. The same components are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 6, 2 is a printing system in this embodiment, 20 is a print server in this embodiment, 201 is free information acquisition means for acquiring the free space of the memory, and 202 is all according to the free space of the memory. All expansion determination means 203 for determining whether or not to expand the LUT components in the memory, 203 is all expansion means for expanding all the LUT components in the memory.

<Processing in printing system 2>
Hereinafter, the flow of processing in the printing system 2 will be described in detail with reference to FIG.

  FIG. 7 is a flowchart illustrating an example of processing in the printing system 2.

  In step S501, the all development determination unit 202 refers to the express flag described in the header of the print job, and determines whether the print job is an express job. When the value of the express flag is 1, the process proceeds to step S503, and when the value of the flag is 0, the process proceeds to step S502.

  In step S502, the free information acquisition unit 201 acquires the free capacity of the system memory.

In step S503, the total expansion determination unit 202 determines whether the free capacity of the memory is larger than the necessary capacity. When the entire LUT is c channel and 1 component n bits, the required capacity r can be calculated by r = c × 2 ⁿ . If the available memory capacity is larger than the required capacity, the process proceeds to step S504. On the other hand, when the free space of the memory is smaller than the required amount, the process proceeds to step S108.

  In step S504, the all expansion means 203 expands all LUT components in the memory using all correspondence tables and code tables.

  The all expansion determination process of this embodiment can be automatically determined based on the free memory capacity. Further, a UI including a check box for setting the memory usage status and the priority of the print job as shown in FIG. 8 is presented to the user so that the user can specify whether to process the print job with priority. Also good.

  In FIG. 8, 30 is a UI for receiving user input, 301 is an input profile input unit for inputting an input profile file name, 302 is an output profile input unit for inputting an output profile file name, and 303 is print data. A printing condition designating unit for designating a printing condition for printing the image, 304 a matching method selecting unit for selecting a matching method for color conversion of the image included in the print data, and 305 for the color conversion of the image The black point correction specification unit 306 for specifying whether to map the black point (color where R = G = B = 0) to the color signal value of the black point of the printing press, 306 indicates the memory usage status of the post-processing server in time series Memory usage status display section to be displayed, 307 is a print job priority specifying section for specifying whether to process the print job preferentially, and 308 is an OK button for reflecting the conditions set in each item of UI40 in post-processing , Reference numeral 309 denotes a cancel button for canceling the conditions set in each item of the UI 40.

  By presenting such a UI, it is possible to print a designated print job at a high speed according to the judgment of the operator.

  As described above, according to the technology described above, it is possible to print a high-priority print job at high speed by controlling the LUT component developed in the memory in accordance with the priority of the print job and the availability of the memory.

[Other embodiments]
In the above embodiment, the input values to be generated are all combinations of the input values. However, the input values are not limited to “all combinations”, and the input values may be generated every predetermined number of points. good. For example, an input value may be generated every other suitable number of points such as every other point. In this case, in order to obtain an output value for an input value that has not been generated, the output value may be an average value or a weighted average value of output values corresponding to grid points surrounding the input value.

  In the above embodiment, the color space of the image is the sRGB color space. However, the color space is not limited to this, and may be another color space such as an AdobeRGB color space.

  In the embodiment, the generation means such as the expansion table generation means and the input value generation means generate the expansion table and the input value. However, the expansion table and the input value prepared in advance are acquired and used. Needless to say, it may be done.

  In the above embodiment, the timing for generating the expansion table is after the print data is transferred to the print server, but is not limited to this. For example, when the user saves the print data on the client PC An expansion table may be generated. Furthermore, after the print data is saved on the client PC, it may be generated in the background when the CPU load on the client PC is low, and the expansion table only needs to be generated before the PDL interpretation is executed.

  In this embodiment, the development table is generated for each image. However, the present invention is not limited to this. For example, when a plurality of images are included in the print data, all the images are integrated. Then, a development table for the integrated image may be generated and attached to the print data. By doing so, it is only necessary to hold one development table for one print data, and therefore the amount of memory used to hold the development table can be reduced. At the same time, since the decompression process of the compression LUT can be reduced once per print data, the processing speed can be improved.

<Storage medium>
Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer), and a device (for example, a copying machine and a facsimile device) including a single device You may apply to.

  Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  In addition, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code. It goes without saying that a part of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

  Further, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

1 printing system, 10 printing server, 11 client PC, 12 printing,
101 profile holding means, 102 input value generating means, 103 color conversion means, 104 compression means,
105 compressed LUT holding means, 106 print data, 107 prescan means, 108 PDL interpretation means,
109 expansion table generation means, 110 PDL data holding means, 111 PDL data input means,
112 developing means, 113 image converting means, 114 RIP means, 115 printing means, 116 printed matter,
2 printing systems, 20 print servers, 201 vacancy information acquisition means, 202 full deployment determination means,
203 All deployment means, 30 UI, 301 input profile input section,
302 Output profile input section, 303 Print condition specification section, 304 Matching method selection section,
305 Black point correction specification part, 306 Memory usage display part, 307 Print job priority specification part,
308 OK button, 309 Cancel button, 1001 Cumulative appearance probability in Fig. 1 (a),
1002 Cumulative appearance probability in FIG. 1 (b), 1003 Cumulative appearance probability in FIG. 1 (c), 2001 unfolding flag,
1st bit of 2002 expansion flag, 2nd bit of 2003 expansion flag,
3rd bit of 2004 expansion flag, 4th bit of 2005 expansion flag,
5th bit of 2006 expansion flag, 6th bit of 2007 expansion flag,
7th bit of 2008 expansion flag, 8th bit of 2009 expansion flag

Claims (3)

A printing system for processing multiple print jobs,
An expansion table generating means for generating an expansion table that describes a region of the color conversion LUT to be expanded on the memory based on the color distribution of the image included in the print data and attaching the expansion table to the image;
An input means for generating a color conversion LUT, an output profile, and an input means for acquiring color conversion conditions;
Input value generation means for generating a combination of input values for generating the color conversion LUT;
Color conversion means for color-converting the input value from a first color space to a color space value of a second color space based on the input profile, output profile, and color conversion conditions;
Compression means for generating a compression LUT in which a color conversion LUT (overall LUT) storing an output value corresponding to an input value converted by the color conversion means is compressed for each part;
Expansion means for expanding the LUT component of the compression LUT on a memory based on the expansion table;
Image conversion means for converting the pixel value of the input image from the first color space to the color space value of the second color space using the LUT component expanded by the expansion means;
An image processing method comprising: The development table generation means divides the color distribution of the input image in a predetermined color space into a plurality of areas, and generates a plurality of development flags indicating whether or not each area is developed on a memory. The image processing method according to claim 1. The image processing method according to claim 1, further comprising: an all expansion determination unit that determines whether or not to use an expansion table for expansion of the compression LUT according to the priority of the print data and the load on the computer.