JP2009119859A - Concentration calculation device, concentration setting device, concentration calculation program, and concentration setting program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concentration calculation device, a concentration setting device, a concentration calculation program, and a concentration setting program capable of suppressing the generation of waste paper, and adjusting the printing concentration of coloring materials with ease by needing no skilled technology. <P>SOLUTION: The concentration calculation device comprises an image data obtaining section for obtaining printing image data, a concentration obtaining section for obtaining the printing concentration in a second printing system, a position specifying section for specifying positions on the printing image shown by printing image data, a first color estimating section for estimating the printing colors in a first printing system, a second color estimating section for estimating the printing colors in a second printing system, a target color obtaining section for obtaining the printing colors at specified positions as target colors relative to the colors in the positions in the first printing system, and a concentration calculation section for calculating respective printing concentrations of coloring materials of a plurality of colors in the first printing system so that the target colors are attained at set positions on printing images by the first printing system. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a density calculation device, a density calculation program for calculating a printing density of a color material when printing an image in a printing system, a density setting device for setting a printing density of a color material, and a density setting program.

  Conventionally, in the field of printing, an image is edited using a personal computer, a film original is created based on the edited image, a printing plate is created based on the film original, and the printing plate is mounted on a printing press. Ink is then applied, and a printed image is generated through a series of processes in which the applied ink is transferred onto printing paper. In recent years, a digital printing machine has been developed in which a CTP (Computer To Plate) for printing an image directly on a printing plate is incorporated in a printing machine, and a plate making process and the like that require skilled techniques are automated. Demand is growing as a printing machine for small lots and many types of products that produces many types of printed materials with a smaller number of copies than a printing machine.

  By the way, a series of operations for printing on paper is a large-scale operation in which the number of printing units is several hundred copies, and processing time and cost are increased. Therefore, it is easier than a printing press before performing an actual printing operation. A proof image in which a print image is reproduced by a simple printer or the like is created, and the proof image is used to check the finished print image in advance. Furthermore, in recent years, proof images have also been displayed on calibrated monitors, making it possible to more efficiently check the image of the printed image in each printing step, eliminating waste of paper more efficiently. Is becoming possible.

  However, in advance confirmation using a proof image, it is possible to grasp the pattern of the print image and the overall composition image, but for the color and finish of the print image including the thickness of the ink, the image is printed on the printing press. It has been confirmed by printing. Actually, the preferred ink thickness varies depending on the printing media such as newspapers, advertisements, posters, magazines, etc., so when printing images are created, the desired color can be obtained by driving the printing press and repeatedly performing test printing. Until the above is obtained, the user manually adjusts the printing density of the ink of the printing press. For this reason, there is a problem that a skillful technique for adjusting the printing density of the ink is required, or a large amount of damaged paper is eventually generated. In addition, the amount of waste paper generated until the final ink print density is determined is almost constant regardless of the number of printed copies. Therefore, the smaller the number of printed copies, the higher the percentage of lost paper. become. For this reason, in a digital printer for a small lot and a wide variety, it is important to reduce the cost by increasing the time until the ink printing density is determined and suppressing the occurrence of waste paper.

In this regard, Patent Document 1 generates a predicted image in which a print image is predicted based on the opening value of the ink key for adjusting the print density of the ink and the pixel value of the image data, and the user selects the predicted image. A technique for manually adjusting the print density of ink with reference is described, and Patent Document 2 sets and adjusts the color of a color sample printed on a reference printing machine that has been subjected to color adjustment as a target color. A technique for automatically adjusting the print density of ink so that the color of a print image printed by a target printing machine approaches a target color is described. In the technique described in Patent Document 1, since it is possible to roughly check the color of a printed image before printing, it is possible to reduce the processing time until the printing density of ink is determined. With this technology, the ink print density can be easily adjusted so that the color of the color sample printed by the reference printer can be reproduced by another printer.
JP 2001-347645 A JP 2004-106523 A

  However, in the technique described in Patent Document 1, in order to improve the prediction accuracy of a print image, it is necessary to finely associate the opening value of the ink key and the pixel value of the image data. End up. In addition, although the predicted image of the printed image can be confirmed, the work of determining the print density of the ink necessary for correcting the color of the predicted image to a desired color requires skillful technology and experience. There is also a problem that it is difficult for few users to adjust the printing density of ink.

  Further, in the technique described in Patent Document 2, since the print density of the ink is adjusted little by little while actually performing the test printing until the color reproduction characteristics in the reference printing machine are realized in the printing machine to be adjusted, If the initial state is not properly set, it takes time until the printing density of the ink is stabilized, resulting in a problem that a large amount of paper is lost.

  In view of the above circumstances, the present invention is a density calculation device, a density setting device, a density calculation program, which can easily adjust the printing density of a color material without suppressing generation of waste paper and without requiring a skilled technique. And it aims at providing a concentration setting program.

The density calculation apparatus of the present invention that achieves the above object is a first printing system that sets the print density of each of a plurality of color materials and prints an image based on image data using the color material at the print density. An image data acquisition unit for acquiring print image data representing a print image to be printed;
The print density of each of the color materials of a plurality of colors is set, and the print density in a second print system different from the first print system that prints an image based on the image data using the color material at the print density. A concentration acquisition unit to acquire;
A location designation unit for designating a location on the print image represented by the print image data acquired by the image data acquisition unit;
A first color estimation unit that estimates a print color in the first printing system based on the print density and image data of each of a plurality of color materials;
A second color estimation unit that estimates a print color in the second printing system based on the print density and image data of each of the color materials of the plurality of colors;
The print image data acquired by the image data acquisition unit and the print density acquired by the density acquisition unit are given to the second color estimation unit, and the print color at the location specified by the location specification unit is set to the first print A target color acquisition unit that acquires the target color for the color of the location in the system;
The first color estimation unit determines the print density of each of the color materials of the plurality of colors so that the target color acquired by the target color acquisition unit is realized at the location by the first printing system based on the print image data. And a concentration calculation unit that calculates the density using the calculation unit.

  Here, the “location” in the present invention may be one point, a region, or a point group composed of a plurality of points.

  The color material print density referred to in the present invention indicates the density of a print image set by adjusting the supply amount of the color material by opening / closing the ink key or the like.

  According to the density calculation apparatus of the present invention, based on the print density and print image data of each of the color materials set in the second print system, the specified location on the print image in the second print system is determined. The print color is estimated and acquired as a target color, and the print density of each of the color materials is calculated so that the target color is realized at a specified location on the print image output in the first printing system. Is done. For this reason, even if it does not have a skilled technique, the printing density of a color material can be set easily and the printing color in a 2nd printing system can be reproduced with a 1st printing system. In addition, with the calculated print density of the color material as an initial value, a plurality of color materials are used so that the target color is realized at a specified location on the print image while the print image is actually printed in the first printing system. By finely adjusting each print density, the color reproduction characteristics in the second printing system can be accurately realized in the first printing system, and the time until the printing density of the color material is stabilized is shortened. And the generation of waste paper can be suppressed. Furthermore, in the density calculation apparatus of the present invention, the target color in the desired color can be obtained by transmitting the print density of the second printing system using the Internet line or the like. Even if there is no printed color sample, the printing color in the second printing system can be easily realized in other printing systems.

Further, in the concentration calculation apparatus of the present invention, the location designating unit designates a plurality of locations with different priorities as the locations,
The target color acquisition unit acquires each target color for each of a plurality of locations.
The density calculation unit has a common print density at which the target colors of each of the plurality of locations are realized by the printing system, and has a relatively low priority for realizing the accuracy of the plurality of locations where the priority is relatively high. It is preferable that the calculation is performed with more emphasis on the realization accuracy at the location.

  Usually, in a printing system, colors are often expressed by a combination of C, M, Y, and K color materials, and a target color at each of a plurality of locations can be obtained only by combining the print densities of these four color materials. It is difficult to realize these simultaneously. According to the preferable concentration calculation device, since the realization accuracy at a location having a relatively high priority among the plurality of locations is calculated with more importance than the realization accuracy at a location having a relatively low priority, for example, a company Important colors such as logo colors can be realized with high accuracy.

  In the density calculation apparatus of the present invention, the location designation unit displays a print image based on the print image data, and designates the location according to a selection operation for selecting the location on the displayed print image. Is preferred.

  The user can easily specify a location where the target color is realized simply by selecting an important color on the displayed print image.

Further, in the density calculation apparatus of the present invention, the location specifying unit specifies an area on the print image,
Preferably, the target color acquisition unit acquires a target color for the average color in the region.

  Colors such as skin color, green color, sky blue color, and gray color are important factors that determine the impression of printed matter, and are treated as important colors in the field of printing. According to the density calculation apparatus of the present invention, it is possible to easily obtain a visually preferable print image by roughly specifying a region having an important color such as green or skin color on the print image.

Further, in the density calculation apparatus of the present invention, the location specifying unit specifies an area on the print image,
Preferably, the target color acquisition unit acquires a target color for a color that appears most frequently in the region.

  According to this preferred density calculation device, even if important colors are dispersed on the printed image, it is only necessary to specify an area containing a lot of important colors. An actual printed image can be obtained.

In the density calculation apparatus of the present invention, the print image data is a set of color data representing the color of each point on the print image,
Preferably, the location designating unit designates, as the location, one or more point sets selected from the point set having a larger number of points among the set of points on the print image having the same color data. is there.

  According to this preferable density calculation device, it is possible to save the user from selecting an important color and generate a print image in which an important color having a high appearance frequency is expressed by a target color.

In the density calculation apparatus of the present invention, the print image data is a set of color data representing the color of each point on the print image,
It is preferable that the location designating unit designates each point on the print image in which the color is represented by the same color data as the color data representing a predetermined important color as the location.

  By storing a company logo color or the like as an important color in advance, it is possible to easily obtain a printed image in which the important color is expressed by a target color.

  In the concentration calculation apparatus of the present invention, it is preferable that the location designation unit assigns a higher priority to each of a plurality of locations in descending order of the area of the location.

  The important colors on the printed image often occupy a large area, and according to this preferable density calculation device, it is possible to easily generate a printed matter in which the important colors are expressed by the target color.

  In the density calculation apparatus of the present invention, at least one of the first color estimation unit and the second color estimation unit is configured to output the second color based on chart image data representing a chart image in which patches of a plurality of colors are arranged. Correspondence between the color of each patch and the print density obtained when the printing system prints the chart image at each print density while changing the print density to a series of print densities for each color of a plurality of colors. And, based on the temporary print density designated for each of the color materials of a plurality of colors, it is preferable that the print color at the above location is estimated based on the print image data and the temporary print density. .

  The applicant of the present invention determines the print color of a print image when the print density of the color material is generated based on print image data in which the halftone value of each of the plurality of colors is 100%. The standard print density that becomes the standard color and the change print in which the print density is changed from the standard print density to the optical density ± 0.1, ± 0.2, etc. for each color material of multiple colors Print a chart image in which patches of multiple colors are arranged with each density set, and predict the print color at the desired print density using the colorimetric results of the patches on each generated chart image A printing color prediction method is proposed. According to this print color prediction method, the color of the print image can be accurately confirmed before the image is actually printed. According to the preferred density calculation device, each of the color materials of a plurality of colors such that the target color is realized at a specified position on the print image printed by the first printing system by the reverse calculation of the print color prediction method described above. The print density is calculated. For this reason, it is possible to easily set the print density without requiring a skilled technique.

  Further, in the density calculation apparatus of the present invention, an expected image of a print image obtained by printing by the first printing system based on the print density and print image data of each of the color materials calculated by the density calculation unit It is preferable that a display unit for displaying is provided.

  By displaying the predicted image, it is possible to confirm the quantitative accuracy of the print density and the finished print image without actually performing printing.

In the concentration calculation apparatus of the present invention,
Obtained by printing the chart image with the print density of the first printing system set to the standard print density when the print color of the image printed based on the predetermined image data becomes the predetermined standard color Obtained by printing the chart image with the print density of the first printing system set to a series of print densities that change from the standard print density for each of the reference colors of each patch and each color material of a plurality of colors A storage unit for storing the correspondence between the color difference of each patch color with respect to the reference color and the density difference of the print density with respect to the standard print density;
The first color estimation unit receives a provisional print density of each of the color materials of a plurality of colors and the designation of the above part, acquires a relation part corresponding to the part out of the correspondence relation stored in the storage part, It is preferable that the printing color at that location is estimated by interpolation processing using the reference color of each patch and the related portion.

  For example, when the print density of each color material of C, M, Y, and K is changed by 13 steps, 28561 print densities are created by combining them, and the print color is predicted in all of them. When trying to save the correspondence, a huge amount of memory is required. According to this preferred density calculation device, the reference color of each patch and the correspondence between the color difference of the patch color with respect to the reference color and the density difference of the print density with respect to the standard print density are stored, and depending on the designated location Only the related portion is acquired, and the print color of the designated place in the state where the temporary print density is set is estimated. For this reason, it is possible to estimate the print color while suppressing increases in memory capacity and processing time.

In the concentration calculation apparatus of the present invention,
The density calculation unit calculates a determinant Ax = y (where A is a matrix, x is a vector representing a density difference, and y is a vector representing a print color difference) corresponding to the correspondence stored in the storage unit. A general inverse matrix A ′ for the matrix A that uniquely gives a solution x ′ satisfying the norm minimum and least squares solution to the exact solution solved for x by the determinant x ′ = A′y, and the determinant x ′ = Substitute the difference between the color of the above location and the target color into y of A'y to obtain a solution of the density difference, and use the density shifted from the standard density by the obtained density difference as the starting point of the temporary print density. By repeating the designation of the temporary print density for one color estimation unit and the acquisition of the print color estimated by the first color estimation unit, the print density at which the target color is realized as the print color at the location is searched. The application form that it is a thing is suitable.

For example, when printing an image using four color materials of C, M, Y, and K, x is four-dimensional, and the color of the image is measured by a colorimeter and the measured values L *, a *, and b are measured. When * is obtained, since y is three-dimensional, there is no inverse matrix A ⁻ for matrix A, but by giving a condition that the norm minimum and least squares solutions are satisfied, a solution x ′ approximated to an exact solution The general inverse matrix A ′ for uniquely determining can be determined. According to this preferred density calculation device, the print density close to the print density that realizes the target color is calculated by the general inverse matrix, and the print density that actually realizes the target color is searched from the calculated print density as a starting point. Therefore, it is possible to reduce the problem of being addicted to the local solution and to calculate the print density at high speed.

In the concentration calculation apparatus of the present invention,
When the target color acquisition unit acquires a plurality of target colors for each of a plurality of locations, the density calculation unit calculates the color of each location and the target color for that location in y of the determinant x ′ = A′y. By substituting the difference, a simultaneous equation is created, and by solving the simultaneous equation, a solution for the density difference common to multiple target colors is obtained, and the density shifted from the standard density by the obtained density difference As a starting point, it is more preferable to search for a print density at which a plurality of target colors are realized as print colors at a plurality of locations.

  Multiple target colors are set by creating simultaneous equations that show the correspondences between multiple target colors and calculating the print density common to multiple target colors using a general inverse matrix that satisfies the simultaneous equations. Even in this case, it is possible to efficiently calculate the print density that realizes these target colors.

In addition, the density setting device of the present invention that achieves the above object is the first printing that sets the print density of each of the color materials of a plurality of colors and uses the color material at the print density to print an image based on the image data. An image data acquisition unit for acquiring print image data representing a print image to be printed by the system;
The print density of each of the color materials of a plurality of colors is set, and the print density in a second print system different from the first print system that prints an image based on the image data using the color material at the print density. A concentration acquisition unit to acquire;
A location designation unit for designating a location on the print image represented by the print image data acquired by the image data acquisition unit;
A first color estimation unit that estimates a print color in the first printing system based on the print density and image data of each of a plurality of color materials;
A second color estimation unit that estimates a print color in the second printing system based on the print density and image data of each of the color materials of the plurality of colors;
The print image data acquired by the image data acquisition unit and the print density acquired by the density acquisition unit are given to the second color estimation unit, and the print color at the location specified by the location specification unit is set to the first print A target color acquisition unit that acquires a target color for the color of the above-mentioned part in the system;
The first color estimation unit determines the print density of each of the color materials of a plurality of colors so that the target color acquired by the target color acquisition unit is realized at the location by the first printing system based on the print image data. A concentration calculation unit for calculating using
A density setting unit configured to set the print density of each of the color materials calculated by the density calculation unit in the first printing system.

  According to the density setting device of the present invention, it is possible to suppress the occurrence of waste paper and easily adjust the printing density of the color material without requiring skilled techniques.

  Note that the density setting device is only shown here for its basic form, but this is merely to avoid duplication, and the density setting apparatus according to the present invention is not limited to the above basic form, Various forms corresponding to each form of the above-described concentration calculation apparatus are included.

Further, the concentration calculation program of the present invention that achieves the above object is executed in a computer, and on the computer,
Print image data representing a print image printed by the first printing system that prints an image based on the image data by setting the print density of each of the color materials of a plurality of colors and using the color material at the print density is acquired. An image data acquisition unit to perform,
The print density of each of the color materials of a plurality of colors is set, and the print density in a second print system different from the first print system that prints an image based on the image data using the color material at the print density. A concentration acquisition unit to acquire;
A location designation unit for designating a location on the print image represented by the print image data acquired by the image data acquisition unit;
A first color estimation unit that estimates a print color in the first printing system based on the print density and image data of each of a plurality of color materials;
A second color estimation unit that estimates a print color in the second printing system based on the print density and image data of each of the color materials of the plurality of colors;
The print image data acquired by the image data acquisition unit and the print density acquired by the density acquisition unit are given to the second color estimation unit, and the print color at the location specified by the location specification unit is set to the first print A target color acquisition unit that acquires the target color for the color of the location in the system;
The first color estimation unit determines the print density of each of the color materials of a plurality of colors so that the target color acquired by the target color acquisition unit is realized at the location by the first printing system based on the print image data. And a concentration calculation unit that calculates using the above.

  Note that the concentration calculation program also shows only those basic forms here, but this is merely to avoid duplication, and the concentration calculation program according to the present invention is not limited to the above basic form. Various forms corresponding to each form of the above-described concentration calculation apparatus are included.

  Further, the element such as an image data acquisition unit constructed on the computer system by the density calculation program of the present invention may be one element constructed by one program part, and a plurality of elements are one program. It may be constructed by parts. In addition, these elements may be constructed so as to execute such actions by themselves, or constructed by giving instructions to other programs and program components incorporated in the computer system. May be.

In addition, the concentration setting program of the present invention that achieves the above object is executed in a computer, and on the computer,
Print image data representing a print image printed by the first printing system that prints an image based on the image data by setting the print density of each of the color materials of a plurality of colors and using the color material at the print density is acquired. An image data acquisition unit to perform,
The print density of each of the color materials of a plurality of colors is set, and the print density in a second print system different from the first print system that prints an image based on the image data using the color material at the print density. A concentration acquisition unit to acquire;
A location designation unit for designating a location on the print image represented by the print image data acquired by the image data acquisition unit;
A first color estimation unit that estimates a print color in the first printing system based on the print density and image data of each of a plurality of color materials;
A second color estimation unit that estimates a print color in the second printing system based on the print density and image data of each of the color materials of the plurality of colors;
The print image data acquired by the image data acquisition unit and the print density acquired by the density acquisition unit are given to the second color estimation unit, and the print color at the location specified by the location specification unit is set to the first print A target color acquisition unit that acquires the target color for the color of the location in the system;
The first color estimation unit determines the print density of each of the color materials of the plurality of colors so that the target color acquired by the target color acquisition unit is realized at the location by the first printing system based on the print image data. A concentration calculation unit to calculate using,
And a density setting unit configured to set the print density of each of the color materials calculated by the density calculation unit in the first printing system.

  The density setting program is only shown here for its basic form, but this is merely to avoid duplication, and the density setting program according to the present invention is not limited to the above basic form. Various forms corresponding to each form of the above-described concentration calculation apparatus are included.

  Furthermore, the elements such as the image data acquisition unit constructed on the computer system by the density setting program of the present invention may be constructed by one program part, and a plurality of elements may be constructed by one program. It may be constructed by parts. In addition, these elements may be constructed so as to execute such actions by themselves, or constructed by giving instructions to other programs and program components incorporated in the computer system. May be.

  According to the present invention, it is possible to easily adjust the printing density of a color material without generating a waste paper and without requiring a skilled technique.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a printing system in which an embodiment of the present invention is incorporated.

  A printing system 1 shown in FIG. 1 mainly generates a printing image 20 representing a printing image by editing a printing machine 20 that creates a printing image using inks of C, M, Y, and K colors. The system includes a workstation 30, a control device 10 that controls the printing density of each of the C, M, Y, and K inks in the printing machine 20, and a colorimeter 11 that measures a printed image. In practice, the printing system 1 is connected to a color scanner that reads an original image, a printer that prints out an image based on the image data, and the like. Is not shown here. The printing system 1 corresponds to an example of a first printing system according to the present invention, and the reference printing machine corresponds to an example of a second printing system according to the present invention.

The workstation 30 includes R, G, and B color separation image data obtained by reading a document with a color scanner (not shown), and C, M, Y, and K four colors created using a personal computer or the like. Separation image data, color separation image data of L ^* , a ^* , and b ^* three colors obtained by photographing a subject with a digital camera are input. In the workstation 30, electronic plate collection based on the input color separation image data is performed by an operator, and print image data representing a page of an image for printing is generated. The printing machine 20 expresses an image with a set of pixels, and the print image data represents an image with a set of pixels having any half-% value from 0% to 100%. , M, Y, K color plate halftone data is used. The generated print image data is sent to the printing machine 20.

  The printing press 20 has a CTP (not shown) that generates printing plates for C, M, Y, and K colors, and a printing plate for printing and is coated with ink so that C, Image forming units 21Y, 21M, 21C, and 21K that form color plate images of M, Y, and K colors are provided, and printing formed on a sheet on the downstream side of the image forming units 21Y, 21M, 21C, and 21K. A colorimeter 11 for measuring an image is provided. When the printing image data is transmitted to the printing machine 20, printing plates for C, M, Y, and K colors are generated based on the printing image data, and printing plates for these C, M, Y, and K colors are generated. Mounted on the image forming units 21Y, 21M, 21C, and 21K. In the image forming units 21Y, 21M, 21C, and 21K, the ink having the printing density controlled by the control device 10 is applied to the printing plate, and the ink is sequentially transferred onto the paper so C, M, Y, and K color plate images are formed and sequentially overlaid to generate a print image.

  Here, since the degree of light reflection on the surface of the paper varies depending on the type of printing media such as newspapers, advertisements, magazines, etc., even if the same amount of ink of the same color is supplied, the color impression of the finished printed image Will change. However, corporate logo colors and the like must always be stably expressed in the same color. For important colors on the print image, the color of the print image generated by the printing machine 20 can be adjusted in advance. It is required to match the color of the print image generated by the applied standard printing press. In the present embodiment, the printing system 1 is connected to the reference printer via the Internet line, and the reference printing machine transmits the print density of each color of C, M, Y, and K after color adjustment. The workstation 30 estimates the color on the print image printed by the reference printing machine (hereinafter, the estimated color is referred to as a target color), and C, M that realizes the target color in the printing machine 20. The initial print density of each color ink is calculated. The calculated initial print density is transmitted to the control device 10, and the control device 10 adjusts the opening / closing states of the ink fountains of the image generating units 21Y, 21M, 21C, and 21K, so that the print density of each color ink is the initial print density. Set to

  When the initial print density of the ink is set, the image generators 21Y, 21M, 21C, and 21K perform test printing, the colorimeter 11 measures the color of the printed image, and the control device 10 measures the color in the colorimeter 11. The print density of the ink is finely adjusted so that the measured value approaches the target color, and the test printing is repeated. When the colorimetric value reaches the target color and the ink printing density is stabilized, the start of printing is transmitted from the workstation 30 to the control device 10, and actual printing is performed instead of the trial printing. In this embodiment, by setting a value close to the target print density for realizing the target color as the initial print density of the ink, the time until the print density of the ink is stabilized is increased, and the waste paper Occurrence is suppressed.

  Here, in the following, details of processing executed in the workstation 30 will be described.

  As shown in FIG. 1, the workstation 30 is a large-sized personal computer. As shown in FIG. 1, the work station 30 has a main body device 31 and an image display device 32 that displays an image on a display screen 32a in accordance with an instruction from the main body device 31. By specifying an arbitrary position on the display screen 32a by inputting a keyboard 33 for inputting various types of information according to key operations to the main unit 31, an instruction corresponding to an icon or the like displayed at that position is input. A mouse 34 is provided.

  FIG. 2 is a hardware configuration diagram of the workstation.

  Inside the main unit 31 of the workstation 30, as shown in FIG. 2, a main memory that is loaded with a CPU 301 for executing various programs and a program stored in the hard disk device 303 is read and executed for execution by the CPU 301. 302, the hard disk device 303 in which various programs and data are stored, the FD 41 are loaded, the FD drive 304 that accesses the FD 41, the CD-ROM drive 305 that accesses the CD-ROM 42, and the image data from the management server 20 The I / O interface 306 for sending various instruction data to the management server 20 is built in, and these various elements, and the image display device 32, keyboard 33, and mouse 34 shown in FIG. Are connected to each other.

  Here, the CD-ROM 42 stores a print density adjustment program 100 (see FIG. 3) which is an embodiment of each of the density calculation program and the density setting program of the present invention.

  FIG. 3 is a conceptual diagram showing the CD-ROM 42.

  As shown in FIG. 3, the print density adjustment program 100 stored in the CD-ROM 42 includes an image acquisition unit 110, a target color setting unit 120, a density acquisition unit 130, a target color acquisition unit 140, a color prediction unit 150, and density calculation. The display unit 160 includes a unit 160, a density adjustment unit 170, an operation unit 180, and an image display unit 190.

  The CD-ROM 42 is loaded in the CD-ROM drive 305 of the workstation 30, and the print density adjustment program 100 stored in the CD-ROM 42 is uploaded to the workstation 30 and stored in the hard disk device 303. When the print density adjustment program 100 is activated and executed, the print density adjustment apparatus 200 (see FIG. 4), which is an embodiment of the density calculation apparatus and density setting apparatus of the present invention, is provided in the workstation 30. Is built.

  In the above description, the CD-ROM 42 is exemplified as a storage medium for storing the print density adjustment program 100. However, the storage medium for storing the print density adjustment program 100 is not limited to the CD-ROM. It may be a storage medium such as an optical disk, MO, FD, or magnetic tape. Further, the print density adjustment program 100 may be directly supplied to the workstation 30 via the I / O interface 306 without using a storage medium.

  Details of each part of the print density adjustment program 100 will be described together with the operation of each part of the print density adjustment apparatus 200.

  FIG. 4 is a functional block diagram of the print density adjusting apparatus 200.

  The print density adjustment apparatus 200 includes an image acquisition unit 210, a target color setting unit 220, a density acquisition unit 230, a target color acquisition unit 240, a color prediction unit 250, a density calculation unit 260, and a density adjustment unit 270. , An operation unit 280, an image display unit 290, and a storage unit 201.

  An image acquisition unit 210, a target color setting unit 220, a density acquisition unit 230, a target color acquisition unit 240, a color prediction unit 250, a density calculation unit 260, and a density adjustment unit that constitute the print density adjustment apparatus 200. The image acquisition unit 110, the attention color setting unit 120, the density acquisition unit 130, the target color acquisition unit 140, and the color prediction are included in the print density adjustment program 100 of FIG. Corresponds to the unit 150, the density calculation unit 160, the density adjustment unit 170, the operation unit 180, and the image display unit 190, respectively.

  4 is composed of a combination of computer hardware and an OS or application program executed on the computer, whereas each element of the print density adjustment program 100 shown in FIG. The difference is that it is configured only by the application program.

  FIG. 5 is a flowchart showing a flow of a series of processes until the print density of ink of the printing machine 20 is set in the print density adjusting apparatus 200 shown in FIG.

  Hereinafter, the operation of each element of the print density adjustment apparatus 200 shown in FIG. 4 will be described according to the flowchart of FIG. 5, and the elements of the print density adjustment program 100 shown in FIG.

  Prior to printing, information for calculating a target color of a print image in the printing machine 20 is transmitted from the reference printing machine to the workstation 30.

  In the reference printing machine, when the print density of the ink of each color of C, M, Y, K is generated based on the print image data in which the halftone value of each color of C, M, Y, K is 100% The print color of the print image is set to a standard print density that becomes a predetermined standard color. Hereinafter, a state where the ink printing density is set to the standard printing density is referred to as a standard state.

  A standard printing press set to the standard state prints a chart image in which multiple patches with different colors (half-tone values) are arranged based on the chart image data prepared in advance, and uses a colorimeter. To measure each patch.

  In addition, the above-described chart in a state where the print density of each of the CMYK inks is changed independently to the standard print density and the optical density is −0.2, −0.1, +0.1, +0.2. A chart image is printed based on the image data. Hereinafter, a state in which the ink printing density is changed from the standard printing density is referred to as a changed state. In this example, each color of CMYK is set to a change state of “standard printing density−0.2”, “standard printing density−0.1”, “standard printing density + 0.1”, and “standard printing density + 0.2”. Thus, a total of 16 chart images are printed. Each patch on the generated chart image is also measured.

  In the present embodiment, the ink printing density of each of the 16 chart images in total, the halftone value of the patch on each chart image, and the colorimetric value are transmitted from the reference printer to the workstation 30.

  The color predicting unit 250 uses the ink print density, the patch dot% value, and the patch colorimetric value of each chart image transmitted from the reference printer, and the dot% value of the input data in the reference printer. And the correspondence between the print density of the ink and the predicted print color are calculated, and the calculated correspondence is stored in the storage unit 201. A detailed method for calculating the predicted print color will be described later.

  Similarly to the reference printing machine, the printing machine 20 prints the chart image with the printing density of the CMYK inks set to the standard printing density, and measures each patch on the chart image. , CMYK ink density is changed to "standard printing density -0.2", "standard printing density -0.1", "standard printing density +0.1", "standard printing density +0.2" A total of 16 chart images are set and printed, and each patch on the generated chart image is measured. Further, the color prediction unit 250 uses the print density of the ink of each chart image in the printing machine 20, the halftone value of the patch, and the colorimetric value of the patch image to determine the halftone value of the input data in the printing machine 20. The correspondence relationship between the ink print density and the predicted print color is calculated, and the calculated correspondence relationship is also stored in the storage unit 201.

  The printing preparation process as described above is performed.

  When the printing image is actually generated in the printing machine 20, the printing density of the reference inks of C, M, Y, and K colors after color matching is transmitted from the reference printing machine to the workstation 30. It is done. The print density of the reference ink transmitted from the reference printer is acquired by the density acquisition unit 230 of FIG. 4 via the I / O interface 306 of FIG. 2 (step S1 of FIG. 5). The density acquisition unit 230 corresponds to an example of the density acquisition unit referred to in the present invention.

  Subsequently, print image data is acquired by the image acquisition unit 210 of FIG. 4 (step S2 of FIG. 5). As described above, in the present embodiment, as the print image data, halftone C, M, Y, and K color plates representing an image with a set of pixels having any halftone value from 0% to 100%. % Data is acquired. The image acquisition unit 210 corresponds to an example of the image data acquisition unit referred to in the present invention. The acquired print image data is transmitted to the target color setting unit 220 and the image display unit 290.

  The image display unit 290 displays a notice color setting screen for setting an important notice color among colors of pixels in the print image represented by the print image data (that is, a location in the print image) as shown in FIG. Display above.

  FIG. 6 is a diagram illustrating an example of an attention color setting screen.

  The attention color setting screen 500 shown in FIG. 6 includes a reference information display unit 500A for displaying various types of information on the reference printing press, and a target printing press information display unit 500B for displaying various types of information on the printing press 20 shown in FIG. The reference information display unit 500A and the target printing press information display unit 500B have print images 510A and 510B represented by the print image data and the target color set using the target color setting screen 500. Color information display sections 520A and 520B indicating information, density manual adjustment sections 530A and 530B for manually adjusting the printing density of ink, add buttons 541A and 541B for adding a target color, and deleting a target color Delete buttons 542A and 542B for automatic adjustment and automatic adjustment buttons 543A and 54 for starting calculation of the initial print density of ink And B, execution button 544A to perform the configuration of the ink printing density to the printing machine 20, and the 544B are provided.

  In the example shown in FIG. 6, the printing machine 20 shown in FIG. 4 is configured so that the printing color of the reference printing machine is realized by switching between the printing machine to be adjusted for the printing density of the ink and the target printing machine. Adjustment in the positive direction for adjusting the printing density of the ink in the negative direction and adjustment in the negative direction for adjusting the printing density of the ink in the reference printing machine so as to realize the printing color in the printing machine 20 shown in FIG. Can do. Hereinafter, the adjustment in the positive direction for adjusting the printing density of the ink of the printing machine 20 shown in FIG. 4 will be described.

  When the user selects the add button 541B using the mouse 34 or the like, a designation method selection screen for selecting the designation method of the target color is displayed on the display screen 32a of FIG.

  FIG. 7 is a diagram illustrating an example of the designation method selection screen.

  On the designation method selection screen 600, various radio buttons for manually designating a target color, various radio buttons for automatically designating a target color, and a next button for displaying information on the specified target color 621 and a cancel button 622 for canceling the setting. As a radio button for manually specifying the target color, a point selection radio button 611 for specifying the color of the point as the target color by selecting a point on the print image 510B shown in FIG. By selecting an area on the print image 510B shown in FIG. 6, an area radio button 612 is provided for designating the average value or mode value of the colors in the area as the attention color. As a radio button for designating, a frequency analysis radio button 613 that uses a color having a high appearance frequency in the print image 510B as a target color, and an important color stored in advance in the storage unit 201 of FIG. A DB collation radio button 614 to be designated is prepared.

  When the user selects the point selection radio button 611 or the area radio button 612 using the mouse 34 or the like and further selects the next button 621, the attention color setting screen 500 shown in FIG. 6 is displayed again.

  When a point of interest on the print image 510B of the target color setting screen 500 is selected with the point selection radio button 611 selected, position information of the target point is transmitted from the operation unit 280 of FIG. 4 to the target color setting unit 220. It is done. Attention color setting section 220 acquires a halftone value representing a noticeable location indicated by position information transmitted from operation section 280 on print image 510B, and the color represented by the halftone value is temporarily set as a noticeable color. .

  Further, when an area including an important color is selected on the print image 510B of the attention color setting screen 500 in a state where the area radio button 612 is selected, the position information of the area is displayed from the operation unit 280 of FIG. This is transmitted to the setting unit 220. The attention color setting unit 220 acquires the halftone value in the area indicated by the position information transmitted from the operation unit 280 on the print image 510B, and temporarily sets the average color represented by the halftone value as the attention color. Is done.

  When the target color is temporarily set, the target color setting unit 220 instructs the image display unit 290 to display the set color information screen for displaying the target color information, and the set color information screen is displayed on the display screen 32a. .

  FIG. 8 is a diagram illustrating an example of the setting color information screen.

  Part (A) of FIG. 8 shows an example of a temporarily set color information screen 630 for displaying information on a target color manually specified using the target color setting screen 500. In the temporary setting color information screen 630, a color value display unit 631 for displaying the halftone value of each color of CMYK of the temporarily set target color, and a priority setting unit for setting the priority of the target color 632, a reselect button 633 for reselecting the target color by returning to the target color setting screen 500, a cancel button 635 for setting the target color, a target color, and a target color for the target color. A next button 634 is set for setting the.

  The color value display unit 631 displays the halftone value of the target color temporarily set by the target color setting unit 220, but the user can finely adjust the halftone value manually. In this example, the priority set in the priority setting unit 632 has five levels from “1” to “5”, and the higher the numerical value, the higher the priority.

  As described above, the target color is manually set.

  Further, when the user selects a frequency analysis radio button 613 or a DB collation radio button 614 that is a radio button for automatically designating a target color on the designation method selection screen 600 of FIG. 7, and further selects the next button 621. The selected content is transmitted from the operation unit 280 to the target color setting unit 220.

  When the frequency analysis radio button 613 is selected, the target color setting unit 220 analyzes a plurality of halftone values representing all the pixels on the print image constituting the print image data, and the halftone values are the same. The total number of pixels is calculated. Furthermore, a predetermined number (two in this example) of halftone values having a large calculated total number is selected, and the color represented by the selected halftone value is temporarily set as a target color.

  When the DB collation radio button 614 is selected, the attention color setting unit 220 obtains important color information stored in advance in the storage unit 201 and temporarily sets the important color as the attention color. Important colors include the skin color that determines the impression of printed matter, gray, and the company logo color, corporate color, and product color.

  When the attention color is set, the attention color setting unit 220 instructs the image display unit 290 to display the setting color information screen for displaying the attention color information, and the setting color information screen is displayed on the display screen 32a.

  Part (B) of FIG. 8 shows an example of an automatically set color information screen 640 for displaying information of a color of interest that is temporarily set automatically using the color of interest setting screen 500. On the automatic setting color information screen 640, the halftone value of the set target color is displayed, and the priority setting unit 642 for setting the priority of the target color and the addition as the target color are determined. There are provided a check box 641 for canceling, a cancel button 644 for setting the target color, and a next button 633 for setting a target color for the target color.

  As described above, the target color is automatically set.

  When the user selects the next button 634 or 643 shown in FIG. 8 using the mouse 34 or the like, the setting contents on the temporary setting color information screen 630 or the automatic setting color information screen 640 are transferred from the operation unit 280 to the attention color setting unit 220. Reportedly. The attention color setting unit 220 sets the color represented by the final halftone value included in the transmitted setting contents as the attention color (step S3 in FIG. 5). A combination of the operation unit 280 and the target color setting unit 220 corresponds to an example of a location designation unit according to the present invention. The set halftone value of the target color is transmitted to the target color acquisition unit 240 and the density calculation unit 260.

  When the halftone value of the target color is transmitted, the target color acquisition unit 240 transmits an instruction to predict the target color print color in the reference printing machine to the color prediction unit 250.

  In the color prediction unit 250, the printing color of the target color in the reference printing machine is calculated (step S4 in FIG. 5).

  Here, the description of the flowchart of FIG. 5 is temporarily interrupted, and a printing color prediction method will be described.

  As described above, in this embodiment, the printing densities of the CMYK inks in the reference printing machine are “standard printing density−0.2”, “standard printing density−0.1”, and “standard printing density + 0.1”. ”,“ Standard printing density + 0.2 ”, the total 16 chart images are printed, and each patch on the generated chart image is colorimetrically measured.

Here, the print color R of the patch when the print density of each of the CMYK inks is changed by a desired fluctuation amount with respect to the standard print density is the color measurement of the patch printed by the standard printing machine set to the standard state. The value is R _(std) , the difference between the colorimetric value of the patch when the print density of the ink of only C color is changed and the colorimetric value of the patch printed at the standard print density is R _ΔC , and the ink of only M color R _{ΔM is} the difference between the colorimetric value of the patch when the print density is changed and the colorimetric value of the patch printed at the standard print density, and the colorimetry of the patch when the print density of only Y-color ink is changed The difference between the measured value and the color measurement value of the patch printed at the standard print density is R _ΔY , and the patch color measurement value and the measurement of the patch printed at the standard print density when the print density of only the K color ink is changed If the amount of color value difference is _RΔK ,
R = R _(std) + _RΔC + _RΔM + _RΔY + _RΔK (1)
Can be obtained approximately. By substituting the colorimetric values obtained by measuring the colors of the chart image printed in the standard state and the patches of each of the 16 chart images in the changed state into Equation (1), the print density of the ink is determined for each patch. Correspondence between (standard printing density ± variation) and patch printing color R is obtained. That is, the print color of the patch can be predicted from the halftone value of the patch and the print density of the ink. In addition, by executing the interpolation process for the ink print density, the print color R corresponding to the print density of the fine variation ink is also calculated, and further, the interpolation process is executed for the halftone value of the patch. The print color R for a large number of input data (half-% values) is also calculated.

  In the color prediction unit 250, the correspondence relationship between the halftone value of the input data, the print density of the ink, and the predicted print color in the reference printer is calculated in advance as described above. Is stored in the storage unit 201.

  In step S4 of FIG. 5, the reference of the reference printing press acquired in step S1 of FIG. 5 based on the correspondence relationship of the reference printing press stored in the storage unit 201 in the color prediction unit 250 shown in FIG. The predicted print color associated with the print density of the ink and the halftone value of the target color transmitted from the target color acquisition unit 240 is acquired. The predicted print color is predicted to be the color of interest in the print image when the print image is printed based on the print image data on the reference printing machine that has been color-matched using the color sample. Is.

  In the present embodiment, once the correspondence relationship of the reference printer is generated and saved, when printing is actually performed, it is only necessary to obtain the print density of the reference ink from the reference printer. It is possible to obtain the printing color of the reference printing machine in a desired color while suppressing the amount of data transmitted from the printing machine. The color prediction unit 250 corresponds to an example of a second color estimation unit according to the present invention. The acquired print color for each target color is transmitted to the target color acquisition unit 240.

  In the target color acquisition unit 240, the print color transmitted from the color prediction unit 250 is acquired as a temporary target color for each target color.

  When the provisional target color is acquired, the target color determination screen is displayed on the display screen 32a.

  FIG. 9 is a diagram illustrating an example of the target color determination screen.

  On the target color determination screen 650, the halftone value of the target color is displayed, radio buttons 651 and 652 for selecting the target color for determining the target color, and an execution button 657 for instructing determination of the target color, all. An end button 658 for informing that the target color of the target color has been acquired, a cancel button 659 for instructing stop of target color determination, and a target color display unit 656 for displaying the temporarily determined target color are provided.

  When the target color is confirmed for all the target colors displayed on the target color selection screen 650 and the user selects the end button 658 using the mouse 34 or the like, the target color acquisition unit 240 temporarily determines the target. The color is determined as the final target color (step S4 in FIG. 5). The target color acquisition unit 240 corresponds to an example of the target color acquisition unit referred to in the present invention. The determined target color is transmitted to the density calculation unit 260.

  When the target color is determined, the attention color setting screen 500 shown in FIG. 6 is displayed again on the display screen 32a shown in FIG. When the user selects the automatic adjustment button 543 with the mouse 34 or the like, the calculation of the initial print density of ink is started. First, a determination selection screen for selecting a determination condition for determining that the print color in the target color is adjusted to the target color in the target color when the print image is generated based on the print image data in the printing machine 20 Is displayed.

  FIG. 10 is a diagram illustrating an example of the determination selection screen.

  The determination selection screen 700 includes a color difference input unit 714 for inputting a color difference determination criterion for determining that the print color has been adjusted to the target color, and an average color difference radio for performing determination using the average color difference of each target color. The determination is performed using the button 711, the weighted average color difference radio button 712 for performing determination using the average color difference weighted according to the priority for each target color, and the largest color difference among the color differences of each target color. There are provided a maximum color difference radio button 713, an OK button 715 for confirming the setting contents, and a cancel button 716 for canceling the setting.

  When the user uses the mouse 34 or the like to select the color difference of the determination criterion and the type of color difference to be used and selects the OK button 715, the selection content is transmitted from the operation unit 280 to the density calculation unit 260.

  In the density calculation unit 260, calculation of the initial print density of the ink is started.

  First, the density calculation unit 260 determines a temporary ink printing density common to each target color, and the printing machine 20 in which the temporary ink printing density is set generates a print image based on the print image data. At this time, the print color of the target color is predicted (step S5 in FIG. 5).

  As described above, as in the case of the reference printing machine, the printing machine 20 also prints the chart image prior to actual printing, and each patch on the chart image is colorimetrically measured.

  Further, the color predicting unit 250 assigns the colorimetric values obtained by measuring the respective patches to the equation (1), whereby the correspondence between the ink printing density and the patch printing color R is determined for each patch. Further, the correspondence relationship between the halftone value of the input data, the printing density of the ink, and the predicted printing color in the printing machine 20 is calculated by interpolation calculation. The correspondence relationship between the halftone value of the input data, the ink print density, and the predicted print color in the printing machine 20 is also stored in the storage unit 201 in advance prior to printing.

  In the color prediction unit 250, based on the correspondence relationship of the printing machine 20 stored in the storage unit 201, printing for each target color corresponding to the temporary ink printing density and the halftone value of each target color. The color is acquired. The color prediction unit 250 corresponds to an example of a first color estimation unit according to the present invention. The acquired printing colors of the printing press 20 for each target color are transmitted to the density calculation unit 260.

  In the density calculation unit 260, when the target color of the target color is acquired from the target color acquisition unit 240 and the print color of the target color in the printing press 20 is acquired from the color prediction unit 250, the color difference between the print color and the target color. Is larger than the reference color difference (step S6 in FIG. 5). When only one target color is set, the color difference between the target color and the print color is determined as the determination target color difference. When a plurality of target colors are set, and the average color difference radio button 711 is selected on the determination selection screen 700 shown in FIG. 10, the average value of the color differences between the print color and the target color in each of the plurality of target colors. Is determined as the color difference to be determined, and the weighted average color difference radio button 712 is selected, the higher the priority of each target color with respect to the color difference between the print color and the target color in each of the plurality of target colors, When the average value is calculated with a large weight, the calculated weighted average value is determined as the color difference to be determined, and the maximum color difference radio button 713 is selected, the print color and the target color for each of the plurality of target colors The largest color difference is determined as the determination target color difference. Further, it is determined whether the color difference to be determined is larger than the reference color difference input by the color difference input unit 714.

  When the color difference to be determined is larger than the reference color difference (step S6 in FIG. 5: Yes), the print density of ink is changed by a predetermined value (step S7 in FIG. 5), and the print color in step S5 is changed to the color prediction unit 250. Let's run the prediction again. Further, the color difference between the target color and the target color at the new ink printing density is determined. A specific method for changing the printing density of the ink will be described later.

  A series of processes for changing the printing density of ink (step S7 in FIG. 5), printing color prediction (step S5 in FIG. 5), and color difference determination (step S6 in FIG. 5), the color difference to be determined is less than the reference color difference. The process is repeated until convergence (step S6 in FIG. 5: No) or until a predetermined maximum number of repetitions (eg, 3000) is reached. When the change of the ink print density is completed, the ink print density at the end of the change is provisionally determined as the initial print density. The density calculator 260 corresponds to an example of the density calculator according to the present invention.

  As a method of changing the print density of ink so that the color difference to be judged converges to the reference color difference or less, the print density adjustment amount of each color of C, M, Y, K is finely adjusted within a predetermined adjustment range. In this method, the color difference is calculated by brute force by predicting the print color in all print density combinations (when using the print density of 13 steps for C, M, Y, K4 colors, 28561 ways Print color and color difference are calculated while changing the print density adjustment amount of each color of C, M, Y, and K in a coarse adjustment step within a predetermined adjustment range. Only when the calculated color difference is smaller than the color difference calculated so far, a method of adjusting the print density adjustment amount by a fine adjustment step can be applied. In the present embodiment, specifically, (1) printing color and color difference are calculated while changing in a coarse adjustment step (0.05) within a predetermined adjustment width (from −0.15 to +0.15). (2) When the new color difference is smaller than the color difference calculated so far, each color of C, M, Y, K is changed in a fine adjustment step (0.025) in the plus direction and the minus direction, respectively. The printed colors and color differences of the eight patterns are calculated. (3) Further, using the print density adjustment amount in the direction in which the smallest color difference among the calculated 8 color differences is calculated, the process returns to the process (2) to calculate the print color and the color difference. In this way, the process of determining the initial print density by first changing the print density adjustment amount in the coarse adjustment step, determining the adjustment direction of the print density adjustment amount, and then changing the print density adjustment amount in the fine adjustment step. Time can be increased.

  When the initial print density is provisionally determined, the density calculation unit 260 transmits an instruction to display the calculation result display screen to the image display unit 290, and the calculation result display screen is displayed on the display screen 32a.

  FIG. 11 is a diagram illustrating an example of a calculation result display screen.

  Part (A) of FIG. 11 shows a calculation result display screen 720 displayed when the initial print density converges. Part (B) of FIG. 11 shows that the initial print density does not converge. A calculation result display screen 730 displayed when the maximum number of iterations is reached is shown.

  The calculation result display screens 720 and 730 include result display units 721 and 731 on which initial print densities of C, M, Y, and K colors and a color difference between the target color and the print color are displayed, and a result display unit 721. An OK button 722, 733 for confirming the initial print density displayed in 731 and a cancel button 723, 734 for canceling the setting of the initial print density are displayed. The calculation result shown in Part (B) of FIG. On the display screen 730, a warning message 732 “Color difference determination condition is not satisfied” is also displayed.

  When the user selects an OK button 722 or 733 with the mouse 34 or the like, the initial print density is transmitted from the density calculation unit 260 shown in FIG. 4 to the density adjustment unit 270.

  The density adjustment unit 270 generates an expected image of a print image to be printed in the printing system 1 based on the print density and print image data of each of the CMYK inks transmitted from the color prediction unit 250. Further, the density adjustment unit 270 notifies the image display unit 290 of an expected image and instructs the update of the attention color setting screen 500 shown in FIG.

  The image display unit 290 replaces the print image 510 on the target color setting screen 500 shown in FIG. 6 with an expected image, and the color information display unit 520 displays the halftone value, target color, priority of each target color already set. The predicted print color, the color difference between the target color and the print color are displayed, and the calculated initial print density of the ink is displayed in the density manual adjustment unit 530. When the user finely adjusts the initial print density of the ink manually, the user changes the value on the density manual adjustment unit 530 using the mouse 34 or the like. The image display unit 290 corresponds to an example of the display unit referred to in the present invention.

  When the user selects the execution button 544 with the mouse 34 or the like, the initial print density of ink is transmitted from the density adjustment unit 270 in FIG. 4 to the control device 10, and the control device 10 prints the ink on the printing machine 20. The density is set to the initial print density (step S8 in FIG. 5). The density adjustment unit 270 corresponds to an example of a density setting unit according to the present invention.

  When the initial printing density of the ink is set, the trial printing is repeated while finely adjusting the printing density of the ink in the control device 10, and the colorimetric value obtained by the colorimeter 11 reaches the target color and printing of the ink is performed. When the density is stabilized, the start of printing is transmitted from the workstation 30 to the control device 10 and actual printing is performed. In this embodiment, since the initial print density of the ink close to the target print density for realizing the target color is set, the time until the ink print density is stabilized can be increased, and Occurrence can be suppressed. In addition, once color matching of the reference printer is performed, in another printer, if the ink printing density of the reference printer is acquired via the Internet line, the standard without using skilled techniques is required. The printing color of the printing press can be easily reproduced.

  Above, description of 1st Embodiment of this invention is complete | finished and 2nd Embodiment of this invention is described. The second embodiment of the present invention has the same configuration as that of the first embodiment shown in FIG. 4, but only the method of setting a target color in the target color setting unit 220 is different from the first embodiment. Therefore, FIGS. 4, 6 and 7 are also used in the description of the present embodiment, and only differences from the first embodiment will be described.

  Also in this embodiment, when the area radio button 612 shown in FIG. 6 is selected and an area including an important color is selected on the print images 510A and 510B on the target color setting screen 500, the position information of the area is displayed. 4 to the target color setting unit 220. In the attention color setting unit 220 of the present embodiment, a plurality of halftone values representing all the pixels in the area indicated by the position information transmitted from the operation unit 280 in the print images 510A and 510B are analyzed, and the halftone% is displayed. The total number of pixels with the same value is calculated. Furthermore, a predetermined number (two in this example) of halftone values having a large total number is selected, and the color represented by the selected halftone value is set as the target color. By setting the color with high appearance frequency in the area as the attention color, the user can easily set the important color as the attention color even when the important colors are dispersed in the area. Can do.

  In the attention color setting unit 220, the plurality of set attention colors are given higher priority in descending order of the area of the image portion having the attention color on the print images 510A and 510B. Usually, important colors often occupy a large area on a printed image, and priorities are automatically assigned according to the area of each color, so even if you do not have skilled knowledge about printing It is possible to obtain a print image that is visually appealing in which important colors are expressed by target colors.

  Above, description of 2nd Embodiment of this invention is complete | finished and 3rd Embodiment of this invention is described. The third embodiment of the present invention has the same configuration as that of the first embodiment shown in FIG. 4, but the processes in the color prediction unit 250 and the density calculation unit 260 are different from those in the first embodiment. Therefore, FIG. 4 and FIG. 5 are also used in the description of the present embodiment, and only differences from the first embodiment will be described.

  Also in this embodiment, prior to printing, the chart image is printed with the ink printing density of the reference printing machine set to the standard printing density, and the printing density of each of the CMYK inks with respect to the standard printing density. A total of 16 chart images are printed in a state where each is changed to −0.2, −0.1, +0.1, +0.2 in terms of optical density. Further, the printing density of each of the 16 chart images, the halftone value of the patch on each chart image, and the colorimetric value are transmitted from the reference printing machine to the workstation 30, and the corresponding relationship is stored in the storage unit 201. Saved in.

  Subsequently, the printing machine 20 also prints the chart image with the standard print density set, and the CMYK colors are “standard print density−0.2”, “standard print density−0.1”, A total of 16 chart images are printed with the changed state of “standard printing density + 0.1” and “standard printing density + 0.2”. Further, each patch on each chart image is measured by a colorimeter, and in addition to the color of each patch at the standard print density (hereinafter referred to as a reference color), the change in the print density after the change to the standard print density The correspondence relationship between the amount and the difference between the color of each patch and the reference color at the changed print density is stored in the storage unit 201. In the present embodiment, the density conversion values X, Y, and Z of the colorimetric values of the patches at the standard print densities C, M, Y, and K are associated with the input network% values C, M, Y, and K of the patches. The standard profiles, the print density fluctuations Dc, Dm, Dy, Dk, the print color differences ΔX, ΔY, ΔZ for each patch and the input network% values C, M, Y, K for each patch. The saved difference profile is saved. Thus, by storing only the correspondence obtained by actually measuring the color of the patch, the required memory capacity can be reduced.

  When printing is actually performed, as in the first embodiment, the density acquisition unit 230 acquires the print density of the reference ink transmitted from the reference printer (step S1 in FIG. 5), and the image acquisition unit 210 performs printing. Image data is acquired (step S2 in FIG. 5), and the target color in the print image represented by the print image data is set (step S3 in FIG. 5). Subsequently, the printing color of the target color in the reference printer is determined using the correspondence between the halftone value of each patch and the colorimetric value stored in the storage unit 201 and the above-described equation (1). The predicted and predicted print color is set as the target color of the target color in the printing machine 20 (step S4 in FIG. 5), the printing density of the temporary ink of the printing machine 20 is determined, and the printing of the temporary ink is performed. The print color of the target color in the density is predicted (step S5 in FIG. 5), and the color difference between the predicted print color and the target color is determined (step S6 in FIG. 5). Until the color difference to be determined converges below the reference color difference (step S6 in FIG. 5: No), the temporary ink printing density of the printing press 20 is changed (step S7 in FIG. 5), and the new temporary ink printing density. The printing color prediction of the target color in (Step S5 in FIG. 5) and the color difference determination (Step S6 in FIG. 5) are repeated. In this embodiment, the ink print density of the printing machine 20 that realizes the target color is calculated, and the print density is set to the temporary ink print density in the initial state, so that the color difference converges below the reference color difference. Speeding up the processing time is being measured.

  FIG. 12 is a diagram showing a flow of a series of processes for calculating the printing density of ink.

  First, in the color prediction unit 250, the input C of the target color in which the input network% values C, M, Y, and K of the patch are set out of the standard profile and the difference profile of the printing press 20 stored in the storage unit 201. Only corresponding parts close to the M, Y, K values are extracted. Subsequently, by executing interpolation processing, a table showing the correspondence between the print density fluctuation amounts Dc, Dm, Dy, Dk in the target color and the print color differences ΔX, ΔY, ΔZ with respect to the reference color is created. (Step S11 in FIG. 12).

  FIG. 13 is a conceptual diagram of the created table.

  The axis shown in FIG. 13 indicates the amount of variation in the print density of each color of C, M, Y, and K with respect to the standard print density. The center point plotted with a black circle indicates the standard print density, and the value of the center point indicates the print color (reference color) of the target color when the ink print density is set to the standard print density. Also, each point plotted with a white circle indicates the printing density when the printing density of each color ink of CMYK is independently changed with respect to the standard printing density, and the value of each point is the printing density of the ink Indicates the difference between the print color of the target color and the standard color in a state where the print density indicated by each point is set. For example, the print color of the target color at the print density of the ink indicated by the dots plotted with hatched circles can be calculated by substituting the values of the points plotted with black circles and white circles into the above equation (1). it can. In addition, when the print density intervals when the ink density of each of the CMYK inks is changed independently of the standard print density are rough, the interpolation process is executed for the ink print density as in the first embodiment. By doing so, the amount of variation in the printing density of the ink may be made fine to create the table.

Here, in the above-described equation (1), the difference between the two predicted printing colors R1 and R2 is the measurement of the patch at the standard printing density with respect to the variation in printing density of the inks of C, M, Y, and K colors. It is represented by the sum of the difference between the color value and the colorimetric value of the patch at the ink printing density after the change,
R1-R2 = Σ (R1 _Color -R2 _Color ) (1_1)
It becomes. When the colorimetric values (L *, a *, b *) are represented by the colorimetric density values (-log (X), -log (Y), -log (Z)), the standard printing shown in the table of FIG. Difference Δc-log of the print colorimetric density of the target color in the print density of the ink after the change with respect to the print colorimetric density of the target color at the standard print density and the variation amount Dc, Dm, Dy, Dk The correspondence relationship with (X), Δ-log (Y), and Δ-log (Z) is expressed by the following determinant (2).

Also, Equation (2) is
X = JD Formula (2_1)
Δ−log (X), Δ−log (Y), Δ−log (Z) between the print colorimetric density of the target color in the actual standard print density and the colorimetric density value of the target color in the target color ) Is substituted for the left side X, the solution D is the density difference between the ink print density and the standard print density for realizing the target color. However, D is 3-dimensional, X is because it is four-dimensional, D = J - ^X become inverse matrix obtaining a unique solution J ^- is absent. Therefore, the general inverse matrix J ⁺ is obtained by adding the following two conditions,
D ′ = J ⁺ X Expression (2_2)
The approximate solution D ′ close to the exact solution D is uniquely determined by the determinant.

(Condition 1) Since the approximate solution D ′ is different from the exact solution D, JD ′ ≠ X and an error e (= JD′−X) is generated. A variation D ′ of the print density that minimizes the square of the error e is calculated. (Least squares solution)
(Condition 2) Since the fluctuation amount D of the printing density is a difference from the standard printing density, the smaller the fluctuation amount D is, the better the stability of the adjusted printing press is. For this reason, the fluctuation amount D ′ having the smallest absolute value is calculated. (Minimum norm solution)
Also, the spectral density distributions of C, M, and Y colors and the color matching functions of X, Y, and Z colors are mainly associated with C and X, M and Y, and Y and Z. For example, a determinant (2) Although there is a relationship that Δ-logX changes greatly when Dc in FIG. 4 changes, all the colorimetric density values X, Y, and Z change when the print density of K color is changed. For this reason, even when only the print density Dk of the K ink is originally changed, the solution D ′ calculated under the above-mentioned norm minimum condition prints the C, M, and Y color inks. The density Dc, Dm, Dy is changed, and the K color does not change much.

  The determinant (3) is a determinant obtained by transposing the Dk component indicating the variation amount of the K color to the left side in the determinant (2).

  The Dk component relating to the K color in the determinant (2) is separated, and first the Dk component is set to “0”. By calculating the approximate solution D ′ under the condition that only the C, M, and Y colors are changed, and then adjusting the K color individually, the accuracy of the solution can be improved.

  Further, when a plurality of target colors and target colors for each of the plurality of target colors are set, the expression (2_1) can be expressed as Xn “print colorimetric density of target color_n at standard print density” for each of the plurality of target colors. And the target color_n is a difference_n between the measured color density value of the target color_n ”, but since the print density of ink set in one printing is one, the calculated solution D ′“ target color n ” The density difference between the ink print density n and the standard print density for realizing the above is one regardless of the target color and the target color. If the weight added to each Xn is Wn,

A plurality of simultaneous equations shown in Expression (4) are created. The weight Wn of each color is a diagonal matrix having the same diagonal component. When Expression (4) is expressed by a determinant,

It becomes. Create simultaneous equations showing the correspondence between multiple target colors, and calculate the print density common to multiple target colors, even when multiple target colors are set, realize those target colors The print density can be calculated efficiently.

The Moore-Penrose type general inverse matrix J ⁺ is calculated under the above conditions, and an approximate solution D ′ of the solution D indicating the variation amount of the print density of the ink for realizing the target color with respect to the standard print density. Is obtained (step S12 in FIG. 12).

  Subsequently, the approximate solution D ′ calculated by the equation (2_2) is substituted into the solution D of the equation (2_1), so that the ink printing density is changed by the variation amount D ′ from the standard printing density. A printing color X ′ when the color is printed is calculated. The calculated print color X ′ is transmitted to the density calculation unit 260.

  In the density calculation unit 260, the difference between the print color X ′ and the target color X is calculated (step S13 in FIG. 12), and an average color difference between them is obtained.

  At this time, when the calculated average color difference is smaller than the currently stored average color difference, the variation D ′ (Dk, Dc, Dm, Dy) and the average color difference are held (step of FIG. 12). S14). In the present embodiment, an example is shown in which the variation amount D ′ when the average color difference is minimized, but the evaluation condition in step S14 is the variation amount D when the maximum color difference of the target color is minimized. It may hold '.

  Subsequently, the K color variation amount Dk is changed (step S15 in FIG. 12), the print color X ′ is calculated, the difference between the print color X ′ and the target color X is calculated (step S13 in FIG. 12), and the average color difference is calculated. Is calculated, and the variation D ′ (Dk, Dc, Dm, Dy) and the average color difference are held (step S14 in FIG. 12). In the present embodiment, the variation amount K of the K color is changed by “0.025” steps from “−0.15 to +0.15”, and the processing from step S13 to step S15 is repeated. It is.

  When the processing in all steps is completed (step S15 in FIG. 12: Yes), the fluctuation amount D ′ (Dk, Dc, Dm, Dy) held at the present time is set as an initial solution (step S16 in FIG. 12). .

In addition, until the predetermined specified number of times is reached (step S17 in FIG. 12), the variation D ′ (Dk, Dc, Dm, Dy) set as the initial solution is substituted into the expression 2_1, and a new general matrix J ⁺ Is calculated (step S12 in FIG. 12), and further, the processes from step S13 to step S16 are executed, whereby the update of the initial solution is repeated.

  When the predetermined specified number of times is reached (step S17 in FIG. 12: Yes), the initial solution set at that time is determined as the temporary ink printing density in step S6 in FIG. 5 (step S18 in FIG. 12). .

  Subsequently, the printing density when the target color is realized is searched while changing the printing density of each of the plurality of inks, starting from the determined printing density of the temporary ink.

  FIG. 14 is a diagram illustrating the relationship between the printing density of temporary ink and the search direction.

  In the present embodiment, the search is performed by changing the print density of each of the C, M, Y, and K colors by 0.025 starting from the print density of the temporary ink indicated by the black circle.

  FIG. 15 is a diagram showing a flow of a series of processes for searching for the print density when the target color is realized, starting from the print density of the temporary ink.

  First, starting from the printing density of the temporary ink (step S31 in FIG. 15), all eight printing densities are set by changing the C, M, Y, and K colors by 0.025 for each color. Subsequently, the difference between each print density and the standard print density is substituted into Equation 2_1 to obtain the print color of the target color at each print density, and the average color difference between the print color and the target color is calculated. (Step S32 in FIG. 15).

  When the calculated average color difference is smaller than the average color difference in the printing density of the temporary ink (step S33: No in FIG. 15), the minimum average color difference is obtained by adding the variation amount to the printing density of the temporary ink. Is set to a new ink printing density (step S34 in FIG. 15). Furthermore, when the minimum average color difference at the current time is smaller than the preset allowable color difference (step S35 in FIG. 15: Yes), the final print density of the temporary ink at the current time is realized as the target color. It is determined as the printing density of ink (step S37 in FIG. 15).

  If the current minimum average color difference is equal to or greater than the allowable color difference (step S35: No in FIG. 15), whether the predetermined number of times is reached (step S36 in FIG. 15), or the average color difference is the allowable color difference. 15 (step S35 in FIG. 15), the average color difference between the print color and the target color at the peripheral print density starting from the print density of the new temporary ink is calculated (step S32 in FIG. 15). The comparison of the average color difference (step S33 in FIG. 15) and the update of the printing density of the temporary ink (step S34 in FIG. 15) are repeated.

  FIG. 15 also shows an example of searching for a print density that minimizes the average color difference between the print color and the target color as the print density when the target color is realized. You may search for the minimum print density.

As described above, by using the general inverse matrix J ⁺ , the print density of the ink that realizes the target color is calculated, and the final print density is searched from the print density as a starting point. It is possible to reduce the trouble that gets stuck and to speed up the processing time.

  Here, the example of setting the print density of each of the CMYK four color inks has been described above. However, the present invention sets, for example, the print density of each of the special color inks in addition to the CMYK four colors. It may be.

  In the above, an example in which ink is used as a color material has been described. However, the color material referred to in the present invention may be, for example, a toner for an electrophotographic printer.

1 is an overall configuration diagram of a printing system in which an embodiment of the present invention is incorporated. It is a hardware block diagram of a workstation. It is a conceptual diagram which shows CD-ROM. It is a functional block diagram of a printing density adjusting device. It is a flowchart figure which shows the flow of a series of processes until the printing density of ink is set. It is a figure which shows an example of an attention color setting screen. It is a figure which shows an example of the designation | designated method selection screen. It is a figure which shows an example of a setting color information screen. It is a figure which shows an example of a target color determination screen. It is a figure which shows an example of the determination selection screen. It is a figure which shows an example of a calculation result display screen. It is a figure which shows the flow of a series of processes which calculate the printing density of ink. It is a conceptual diagram of the created table. It is a figure which shows the relationship between the printing density of temporary ink, and a search direction. It is a figure which shows the flow of a series of processes which search printing density when a target color is implement | achieved from the printing density of temporary ink.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing system 10 Control apparatus 20 Printing machine 30 Workstation 31 Main body apparatus 32 Image display apparatus 33 Keyboard 34 Mouse 301 CPU
302 Main Memory 303 Hard Disk Device 304 FD Drive 305 CD-ROM Drive 306 I / O Interface 100 Print Density Adjustment Program 110 Image Acquisition Unit 120 Focus Color Setting Unit 130 Density Acquisition Unit 140 Target Color Acquisition Unit 150 Color Prediction Unit 160 Density Calculation Unit 170 Density Adjustment Unit 180 Operation Unit 190 Image Display Unit 200 Print Density Adjustment Device 210 Image Acquisition Unit 220 Attention Color Setting Unit 230 Density Acquisition Unit 240 Target Color Acquisition Unit 250 Color Prediction Unit 260 Density Calculation Unit 270 Density Adjustment Unit 280 Operation Unit 290 Image display

Claims (16)

Print image data representing a print image to be printed by the first printing system in which the print density of each of the color materials of a plurality of colors is set and the color material is used at the print density and an image based on the image data is printed. An image data acquisition unit to acquire;
In a second printing system different from the first printing system, wherein the printing density of each of the color materials of the plurality of colors is set and the color material is used at the printing density to print an image based on image data A density acquisition unit for acquiring the print density;
A location designating unit for designating a location on the print image represented by the print image data obtained by the image data obtaining unit;
A first color estimation unit that estimates a printing color in the first printing system based on a printing density and image data of each of the color materials of the plurality of colors;
A second color estimation unit that estimates a printing color in the second printing system based on a printing density and image data of each of the color materials of the plurality of colors;
The second color estimation unit is provided with the print image data acquired by the image data acquisition unit and the print density acquired by the density acquisition unit, and the print color of the location specified by the location specification unit is A target color acquisition unit that acquires a target color for the color of the portion in the first printing system;
The print density of each of the color materials of the plurality of colors is set to the first color so that the target color acquired by the target color acquisition unit is realized at the location by the first printing system based on the print image data. A density calculation apparatus comprising: a density calculation unit that calculates using a color estimation unit. The location designation unit designates a plurality of locations with different priorities as the location,
The target color acquisition unit acquires each target color for each of the plurality of locations,
The density calculation unit has a common print density at which the target colors of the plurality of locations are realized by the printing system, an implementation accuracy at a location having a relatively high priority among the plurality of locations, The concentration calculation apparatus according to claim 1, wherein the concentration calculation is performed with an emphasis on realization accuracy at a relatively low location.   The location designation unit displays the print image based on the print image data, and designates the location according to a selection operation for selecting the location on the displayed print image. Item 3. The concentration calculation apparatus according to Item 1 or 2. The location designating unit designates an area on the print image;
The density calculation apparatus according to claim 1, wherein the target color acquisition unit acquires a target color with respect to an average color in the region. The location designating unit designates an area on the print image;
The density calculation apparatus according to claim 1, wherein the target color acquisition unit acquires a target color for a color that appears most frequently in the region. The print image data is a set of color data representing the color of each point on the print image,
The location designating unit designates, as the location, one or more point sets selected from those having a larger number of points among a set of points on the print image having the same color data. The concentration calculation apparatus according to claim 1, wherein: The print image data is a set of color data representing the color of each point on the print image,
3. The location designation unit designates each point on the print image in which a color is represented by the same color data as color data representing a predetermined important color as the location. The concentration calculation apparatus described.   The concentration calculation apparatus according to claim 2, wherein the location specifying unit assigns a high priority to each of the plurality of locations in descending order of area.   At least one of the first color estimator and the second color estimator is configured so that the second printing system uses the chart image data representing a chart image in which patches of a plurality of colors are arranged. The correspondence between the color of each patch and the print density obtained by printing at each print density while changing the print density to a series of print densities for each color material of the plurality of colors, The print color at the location based on the print image data and the temporary print density is estimated based on the temporary print density designated for each color material. The density | concentration calculation apparatus of any one of 1-8.   A display unit for displaying an expected image of a print image obtained by printing by the first printing system based on the print density of each of the color materials calculated by the density calculation unit and the print image data; The concentration calculation apparatus according to claim 1, wherein the concentration calculation apparatus is provided. Obtained by printing the chart image with the print density of the first printing system set to a standard print density when the print color of an image printed based on predetermined image data is a predetermined standard color. The chart image is printed by setting the print density of the first printing system to a series of print densities that change from the standard print density for each of the reference colors of each of the patches and the color materials of the plurality of colors. A storage unit that stores the correspondence between the color difference of each patch color obtained with respect to the reference color and the density difference of the print density with respect to the standard print density;
The first color estimation unit receives a provisional print density of each of the color materials of the plurality of colors and designation of the location, and obtains a related portion corresponding to the location from the correspondence stored in the storage unit The print color at the location is estimated by an interpolation process using the reference color of each patch and the related portion. Concentration calculator.   The density calculation unit has a determinant Ax = y corresponding to the correspondence relationship stored in the storage unit (where A is a matrix, x is a vector representing a density difference, and y is a vector representing a difference in print color). ) For the exact solution obtained by solving for x, a solution x ′ satisfying the norm minimum and least squares solution is uniquely given by the determinant x ′ = A′y. Substituting the difference between the color of the part and the target color into y of x ′ = A′y to obtain a solution of the density difference, and the density shifted from the standard density by the obtained density difference is the temporary print density As the starting point, by repeating the designation of the temporary print density for the first color estimation unit and the acquisition of the print color estimated by the first color estimation unit, the target color is set as the print color at the location. 12. A search for a print density to be realized. Concentration calculating device.   When the target color acquisition unit acquires a plurality of target colors for each of a plurality of locations, the density calculation unit determines the color of each location and the target color for the location in y of the determinant x ′ = A′y. The simultaneous equation is created by substituting the difference between and a solution of the density difference common to the plurality of target colors by solving the simultaneous equation, and a density shifted from the standard density by the obtained density difference is obtained. 13. The density calculation apparatus according to claim 12, wherein the plurality of target colors are searched for a print density that is realized as a print color at each of the plurality of locations as a starting point of the temporary print density. Print image data representing a print image to be printed by the first printing system in which the print density of each of the color materials of a plurality of colors is set and the color material is used at the print density and an image based on the image data is printed. An image data acquisition unit to acquire;
In a second printing system different from the first printing system, wherein the printing density of each of the color materials of the plurality of colors is set and the color material is used at the printing density to print an image based on image data A density acquisition unit for acquiring the print density;
A location designating unit for designating a location on the print image represented by the print image data obtained by the image data obtaining unit;
A first color estimation unit that estimates a printing color in the first printing system based on a printing density and image data of each of the color materials of the plurality of colors;
A second color estimation unit that estimates a printing color in the second printing system based on a printing density and image data of each of the color materials of the plurality of colors;
The second color estimation unit is provided with the print image data acquired by the image data acquisition unit and the print density acquired by the density acquisition unit, and the print color of the location specified by the location specification unit is A target color acquisition unit that acquires a target color for the color of the portion in the first printing system;
The print density of each of the color materials of the plurality of colors is set to the first color so that the target color acquired by the target color acquisition unit is realized at the location by the first printing system based on the print image data. A density calculation unit that calculates using a color estimation unit of
A density setting device comprising: a density setting unit configured to set, in the first printing system, the printing density of each of the color materials calculated by the density calculation unit. Executed in a computer, on the computer,
Print image data representing a print image to be printed by the first printing system in which the print density of each of the color materials of a plurality of colors is set and the color material is used at the print density and an image based on the image data is printed. An image data acquisition unit to acquire;
In a second printing system different from the first printing system, wherein the printing density of each of the color materials of the plurality of colors is set and the color material is used at the printing density to print an image based on image data A density acquisition unit for acquiring the print density;
A location designating unit for designating a location on the print image represented by the print image data obtained by the image data obtaining unit;
A first color estimation unit that estimates a printing color in the first printing system based on a printing density and image data of each of the color materials of the plurality of colors;
A second color estimation unit that estimates a printing color in the second printing system based on a printing density and image data of each of the color materials of the plurality of colors;
The second color estimation unit is provided with the print image data acquired by the image data acquisition unit and the print density acquired by the density acquisition unit, and the print color of the location specified by the location specification unit is A target color acquisition unit that acquires a target color for the color of the portion in the first printing system;
The print density of each of the color materials of the plurality of colors is set to the first color so that the target color acquired by the target color acquisition unit is realized at the location by the first printing system based on the print image data. A density calculation program that constructs a density calculation unit that calculates using a color estimation unit. Executed in a computer, on the computer,
Print image data representing a print image to be printed by the first printing system in which the print density of each of the color materials of a plurality of colors is set and the color material is used at the print density and an image based on the image data is printed. An image data acquisition unit to acquire;
In a second printing system different from the first printing system, wherein the printing density of each of the color materials of the plurality of colors is set and the color material is used at the printing density to print an image based on image data A density acquisition unit for acquiring the print density;
A location designating unit for designating a location on the print image represented by the print image data obtained by the image data obtaining unit;
A first color estimation unit that estimates a printing color in the first printing system based on a printing density and image data of each of the color materials of the plurality of colors;
A second color estimation unit that estimates a printing color in the second printing system based on a printing density and image data of each of the color materials of the plurality of colors;
The second color estimation unit is provided with the print image data acquired by the image data acquisition unit and the print density acquired by the density acquisition unit, and the print color of the location specified by the location specification unit is A target color acquisition unit that acquires a target color for the color of the portion in the first printing system;
The print density of each of the color materials of the plurality of colors is set to the first color so that the target color acquired by the target color acquisition unit is realized at the location by the first printing system based on the print image data. A density calculation unit that calculates using a color estimation unit of
A density setting program that constructs a density setting unit that sets, in the first printing system, the printing density of each of the color materials calculated by the density calculation unit.

Images