Color conversion apparatus and method, color conversion table creation apparatus, and storage medium

Abstract

The invention discloses a color conversion apparatus and method, a color conversion table creation apparatus, and a storage medium. The processor converts a signal value of a first color space representing an image into a signal value of a second color space including a YMCK signal corresponding to a usage amount of a pigment of a YMCK color and a special color signal corresponding to a usage amount of a pigment of a special color other than the YMCK color. A special color conversion ratio, which is a ratio at which the signal value of the first color space is converted into the special color signal, is set in accordance with a property of an image printed using the signal value of the second color space.

Description

Technical Field

[0001] The invention relates to a color conversion device, a color conversion table creation device, a color conversion method and a computer readable medium. Background Art

[0002] Japanese Patent Application Laid-Open No. 2012-205166 discloses a color conversion device that converts an input image signal into a device color signal corresponding to printing, using a GCR conversion table that replaces a plurality of color colorants, namely, C ink, M ink, and Y ink, with K ink. In the color conversion device, the color reproduction characteristics based on the GCR conversion table are evaluated, and an image for visualizing the evaluation result is created.

[0003] Japanese Patent Application Laid-Open No. 2008-263579 discloses a print control device that selects a color material set to be used for printing according to requirements for printing performance and creates a conversion profile for converting image data from a first color space into a second color space represented by the usage amount of each color material constituting the color material set. Summary of the invention

[0004] When a signal value of a first color space representing an image is converted into a signal value of a second color space including a signal value of YMCK colors, i.e., a YMCK signal, and a signal value of a special color other than YMCK colors, i.e., a special color signal, and an image is printed using the signal value of the second color space, the properties of the printed image differ depending on the conversion ratio of the signal value of the first color space into the special color signal in the signal value of the second color space. Furthermore, when a signal value of a first color space representing an image is converted into a signal value of a second color space, if the conversion ratio of the signal value of the first color space into the special color signal in the signal value of the second color space is set to be uniformly the same, the properties of the printed image may not be the properties desired by the user.

[0005] An object of the present invention is to make it easier to obtain an image having properties desired by a user, compared with a case where the conversion ratio of a special color signal in converting a signal value in a first color space into a signal value in a second color space is set to be uniform.

[0006] According to a first aspect of the present invention, there is provided a color conversion device, characterized in that it comprises a processor, which, when converting a signal value of a first color space representing an image into a signal value of a second color space including a YMCK signal corresponding to the usage amount of a YMCK color colorant and a special color signal corresponding to the usage amount of a colorant of a color other than the YMCK color, i.e., a special color, sets a ratio, i.e., a special color conversion ratio, for converting the signal value of the first color space into the special color signal according to the nature of an image printed using the signal value of the second color space.

[0007] According to the second aspect of the present invention, in the color conversion device based on the first aspect, the processor sets the ratio of converting the signal value of the first color space into the K color signal, that is, the K color conversion ratio and the special color conversion ratio according to the properties of the image printed using the signal value of the second color space.

[0008] According to a third aspect of the present invention, in the color conversion device based on the second aspect, the processor sets the special color conversion ratio in conjunction with the K color conversion ratio according to properties of an image printed using signal values ​​of the second color space.

[0009] According to the fourth aspect of the present invention, in the color conversion device based on the third aspect, the processor changes the K color conversion ratio in a manner that increases the usage of the K color colorant while changing the special color conversion ratio in a manner that reduces the usage of the special color colorant compared to a predetermined baseline value.

[0010] According to the fifth aspect of the present invention, in the color conversion device based on the third or fourth aspect, the processor does not change the K color conversion ratio when changing the special color conversion ratio in a manner that increases the usage of the special color colorant compared to a predetermined baseline value.

[0011] According to the sixth aspect of the present invention, in the color conversion device based on any one of the first to fifth aspects, when the processor converts the signal value of the first color space into the signal value of the second color space including the YMCK signal and a plurality of special color signals corresponding to the usage amounts of colorants of a plurality of special colors, the processor individually sets the ratios for converting the signal value of the first color space into each of the special color signals, i.e., a plurality of special color conversion ratios, according to the properties of an image printed using the signal value of the second color space.

[0012] According to the seventh aspect of the present invention, in the color conversion device based on any one of the first to sixth aspects, the processor causes the display unit that displays information to display a display image representing the correspondence between the usage of the colorant of the special color and the properties of the image printed using the signal value of the second color space.

[0013] According to the eighth aspect of the present invention, in the color conversion device based on the seventh aspect, the processor obtains information related to the usage of the special color colorant according to the operation of the displayed image, and sets the special color conversion ratio based on the usage of the special color colorant.

[0014] According to the ninth aspect of the present invention, in the color conversion device based on the eighth aspect, after the processor sets the usage of the K color material in conjunction with the usage of the special color color material obtained according to the operation on the displayed image, it individually sets the usage of the special color color material or the usage of the K color color material according to the operation on the displayed image, sets the special color conversion ratio based on the usage of the special color color material, and sets the ratio for converting the signal value of the first color space into the K color signal, i.e., the K color conversion ratio, based on the usage of the K color color material.

[0015] According to the tenth aspect of the present invention, in the color conversion device based on any one of the first to ninth aspects, the processor sets the special color conversion ratio for converting the signal value of the first color space representing the specific area that meets predetermined conditions in the image printed using the signal value of the second color space into the special color signal.

[0016] According to the eleventh aspect of the present invention, there is provided a color conversion table creation device, characterized in that it comprises a processor, wherein the processor creates a color conversion table, wherein the color conversion table converts the signal value of the first color space representing an image into the signal value of the second color space including a YMCK signal corresponding to the usage amount of the YMCK color colorant and a special color signal corresponding to the usage amount of the colorant of a color other than the YMCK color, i.e., a special color, and sets the ratio of converting the signal value of the first color space into the special color signal, i.e., the special color conversion ratio, according to the nature of the image printed using the signal value of the second color space.

[0017] According to a twelfth aspect of the present invention, there is provided a computer-readable medium storing a program for causing a computer to execute processing, wherein the processing is as follows: when converting a signal value of a first color space representing an image into a signal value of a second color space including a YMCK signal corresponding to the usage amount of a YMCK color colorant and a special color signal corresponding to the usage amount of a colorant of a color other than the YMCK color, i.e., a special color conversion ratio, a ratio for converting the signal value of the first color space into the special color signal is set according to the nature of an image printed using the signal value of the second color space.

[0018] According to the thirteenth aspect of the present invention, there is provided a color conversion method, characterized in that, when converting a signal value of a first color space representing an image into a signal value of a second color space including a YMCK signal corresponding to the usage amount of a YMCK color colorant and a special color signal corresponding to the usage amount of a colorant of a color other than the YMCK color, i.e., a special color conversion ratio, a ratio for converting the signal value of the first color space into the special color signal is set according to the nature of an image printed using the signal value of the second color space.

[0019] (Effect)

[0020] According to the first aspect, an image having properties desired by the user can be easily obtained compared to a case where the conversion ratio of the special color signal in converting the signal value of the first color space into the signal value of the second color space is uniformly set to the same.

[0021] According to the second aspect, an image having properties desired by the user can be easily obtained compared to a case where the conversion ratio of the K color signal in converting the signal value of the first color space into the signal value of the second color space is uniformly set to the same.

[0022] According to the third aspect, compared with the case where the special color conversion ratio and the K color conversion ratio are set independently of each other, an image having the properties desired by the user can be obtained by a simpler operation.

[0023] According to the fourth aspect, compared with the case where the K color conversion ratio is changed in a manner that reduces the usage amount of the K color material when the special color conversion ratio is changed in a manner that reduces the usage amount of the special color color material compared to the reference value, it is easy to make the light fastness of the image as the properties of the image and the cost required for printing the image good.

[0024] According to the fifth aspect, compared with the case where the K color conversion ratio is changed in a manner that increases the usage amount of the K color material when the special color conversion ratio is changed in a manner that increases the usage amount of the special color color material compared to the reference value, it is easy to make the granularity of the image, which is a property of the image, good.

[0025] According to the sixth aspect, compared with a case where a plurality of special color conversion ratios are uniformly set to be the same, an image having a property desired by the user can be easily obtained.

[0026] According to the seventh aspect, the user can easily understand the difference in image properties caused by changing the amount of special color material used, compared with a case where the display unit does not display the correspondence between the amount of special color material used and the image properties.

[0027] According to the eighth aspect, the user can set the usage amount of the special color material by operating the displayed image while confirming the correspondence between the usage amount of the special color material and the property of the image on the display unit.

[0028] According to the ninth aspect, compared with a case where information on the usage amount of the special color material or the usage amount of the K color material is not acquired individually, an image having properties desired by the user can be easily obtained.

[0029] According to the tenth aspect, an image having properties desired by a user can be easily obtained compared to a case where a special color conversion ratio for converting a signal value of a first color space representing a specific area into a special color signal is not set according to the properties of the specific area.

[0030] According to the eleventh aspect, an image having properties desired by the user can be easily obtained compared to a case where the conversion ratio of the special color signal in converting the signal value of the first color space into the signal value of the second color space is set to be uniform.

[0031] According to the twelfth aspect, a computer-readable medium storing a program is provided, which can easily obtain an image with the properties desired by the user, compared with the case where the conversion ratio of the special color signal in the signal value of the first color space into the signal value of the second color space is set to be the same.

[0032] According to the thirteenth aspect, compared with the case where the conversion ratio of the special color signal in converting the signal value of the first color space into the signal value of the second color space is set to be uniform, an image having the properties desired by the user can be easily obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a diagram illustrating the structure of a printing system to which this embodiment is applied;

[0034] Figure 2 is a functional block diagram of a color conversion device;

[0035] Figure 3is a diagram showing an example of a selection screen displayed on an operation display unit by a profile generating unit of a color conversion device;

[0036] Figure 4 is a diagram showing the relationship between the special color toner amount and the K color toner amount selected in conjunction with an operation on the toner amount selection section;

[0037] Figure 5 The knob of the toner amount selection portion is adjusted by the user's operation. Figure 3 Figure 14: A diagram of the selection screen after the state shown has been moved to the left;

[0038] Figure 6 This is a flowchart showing an example of a process of generating a color conversion profile by the profile generating unit. DETAILED DESCRIPTION

[0039] Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0040] Figure 1 This is a diagram for explaining the configuration of a printing system 100 to which this embodiment is applied.

[0041] The printing system 100 shown in the figure includes an input device 10, a printing device 20, and a color conversion device 30. The input device 10, the printing device 20, and the color conversion device 30 are connected to each other so as to be communicable.

[0042] The network connecting the input device 10, the printing device 20, and the color conversion device 30 uses, for example, a LAN (Local Area Network) or the Internet. Of course, the network may be a composite structure of a LAN and the Internet.

[0043] The input device 10 is constituted by a computer device and inputs image data for printing in the printing device 20 to the color conversion device 30 .

[0044] The printing device 20 prints an image on a sheet of paper as an example of a recording medium based on image data inputted from the input device 10 and subjected to color conversion processing by the color conversion device 30. The printing device 20 includes a printing unit 21 that performs a printing operation and a print control unit 22 that controls the operation of the printing unit 21 based on the image data generated by the color conversion device 30.

[0045] The printing unit 21 prints an image on a sheet of paper, for example, by means of an electrophotographic method. The printing unit 21 of the present embodiment uses toners of yellow (Y), magenta (M), cyan (C), and black (K) (hereinafter, these colors are sometimes referred to as normal colors) and toners of special colors different from the normal colors to print an image on a sheet of paper. A toner is an example of a colorant used to form an image. Here, a special color refers to a color different from the normal color, for example, a color that is difficult to achieve using toners of the normal colors of yellow, magenta, cyan, and black. As such a special color, in addition to fluorescent pink, fluorescent yellow, white, bright cyan, orange, purple, green, etc., metallic colors such as gold or silver colored with metallic pigments can also be cited, but are not limited to these. In the present embodiment, the case where the printing unit 21 forms an image using a toner of fluorescent pink (P) as a special color in addition to the normal colors is described as an example.

[0046] In addition, the printing unit 21 forms an image on paper using colorants of common colors, i.e., yellow (Y), magenta (M), cyan (C), and black (K) and one or more special colorants, and the printing form and the type of colorants are not particularly limited. The printing unit 21 may print an image on paper by inkjet printing, thermal transfer printing, offset printing, etc., in addition to the above-mentioned electrophotography.

[0047] In the following description, the normal colors of yellow (Y), magenta (M), cyan (C), and black (K) are sometimes referred to as YMCK colors. In addition, the YMCK colors used for printing in the printer 20 and the special color fluorescent pink (P) are sometimes referred to as YMCKP colors.

[0048] The color conversion device 30 is an example of a color conversion device or a color conversion table creation device, and is composed of a computer device. The color conversion device 30 may be physically a single computer, or may be implemented by distributed processing performed by multiple computers. In addition, the color conversion device 30 may be configured as a shared server that provides a so-called cloud service, or may be configured as a pre-installed server.

[0049] Alternatively, the color conversion device 30 may be built into the printing device 20 as a part of the printing device 20 .

[0050] Here, in the printing system 100 of the present embodiment, image data represented by signal values ​​in the RGB color space is input from the input device 10 to the color conversion device 30. The color conversion device 30 converts the input signal values ​​in the RGB color space into signal values ​​in the YMCKP color space used by the printing device 20. Then, the color conversion device 30 outputs the image data represented by the signal values ​​in the YMCKP color space to the printing device 20. In the printing device 20, based on the image data acquired from the color conversion device 30, an image is formed on paper using toners of Y, M, C, K, and P colors.

[0051] The signal value of the YMCKP color space includes a signal value of the YMCK color corresponding to the amount of toner used for the YMCK color and a signal value of the P color corresponding to the amount of toner used for the P color, which is a special color. The signal value of the YMCK color is an example of a YMCK color signal, and the signal value of the P color is an example of a special color signal. The signal value of each color in the YMCKP color space is associated with the amount of toner used for each color in the printing unit 21 of the printing device 20. The signal value of each color in the YMCKP color space is represented by a numerical value from 0% to 100%, for example.

[0052] Figure 2 is a functional block diagram of the color conversion device 30 .

[0053] The color conversion device 30 includes a color conversion unit 31 that performs color conversion processing on image data input from the input device 10, a profile generation unit 40 that generates a color conversion profile used in the color conversion processing performed by the color conversion unit 31, a profile storage unit 33 that stores the color conversion profile generated by the profile generation unit 40, and an operation display unit 35 that displays information to the user and receives input of information through the user's operation. The operation display unit 35 is an example of a display unit.

[0054] Here, each function of the color conversion unit 31 and the profile generation unit 40 in the color conversion device 30 is realized by a CPU 30A as an example of a processor. The CPU 30A reads a program stored in a ROM (Read Only Memory) 30B and executes the program using a RAM (Random Access Memory) 30C as a work area. The program executed by the CPU 30A can be provided to the color conversion device 30 in a state stored in a computer-readable recording medium such as a magnetic recording medium (a magnetic tape, a magnetic disk, etc.), an optical recording medium (an optical disk, etc.), an optical magnetic recording medium, a semiconductor memory, etc. In addition, the program executed by the CPU 30A can also be downloaded to the color conversion device 30 using a communication means such as the Internet.

[0055] In the present embodiment, the functions of the color conversion unit 31 and the profile generation unit 40 in the color conversion device 30 are implemented by software, but the present invention is not limited thereto and may be implemented by, for example, an ASIC (Application Specific IC).

[0056] The profile generating unit 40 generates a color conversion profile for converting signal values ​​in the RGB color space representing image data input from the input device 10 into signal values ​​in the YMCKP color space that can be reproduced by the printing device 20. The color conversion profile generated by the profile generating unit 40 is an example of a color conversion table that converts signal values ​​in a first color space representing an image into signal values ​​in a second color space including a YMCK signal corresponding to the amount of color material used for YMCK colors and a special color signal corresponding to the amount of color material used for colors other than YMCK colors, i.e., special colors.

[0057] The profile generating unit 40 includes a first conversion unit 41 that converts the signal value of the RGB color space into a signal value of a color space that is independent of the input device 10 and the printing device 20. The first conversion unit 41 of this embodiment converts the signal value of the RGB color space into a color space that is independent of the device, i.e., L * a * b * Signal value in color space. L * a * b * Color space for lightness L * 、Chroma a * and chromaticity b * The rectangular coordinate color space representation of the axis. RGB color space or L * a * b * The color space is an example of a first color space.

[0058] The profile generating section 40 also includes a color gamut compressing section 42 that converts the L converted by the first converting section 41 into a color gamut. * a * b * The signal values ​​of the color space are compressed into the same L * a * b * The signal value of the color gamut of the printing device 20 in the color space.

[0059] The profile generating section 40 also includes a second converting section 43 that converts the L compressed by the color gamut compressing section 42 into * a * b *The signal value of the color space is converted into a signal value of the YMCKP color space which can be reproduced by the printing device 20. The YMCKP color space is an example of the second color space.

[0060] The second conversion section 43 determines the signal value of K color in the signal value of the YMCKP color space based on the conversion ratio to the signal value of K color set by the K color setting section 45 described later. In addition, the second conversion section 43 determines the signal value of P color in the signal value of the YMCKP color space based on the conversion ratio to the signal value of P color set by the special color setting section 46 described later.

[0061] The profile generating section 40 also includes a K color setting section 45 for setting the L * a * b * The conversion ratio of the signal value of the color space to the signal value of the K color when converting the signal value of the YMCKP color space. * a * b * The conversion ratio to the signal value of K color when the signal value of the color space is converted into the signal value of the YMCKP color space is expressed as K color conversion ratio.

[0062] Here, in the printing device 20 that prints an image using color materials including YMCK colors, a part of the YMC color materials used for printing can be replaced with K color materials. * a * b * When the signal value of the color space is converted into the signal value of the YMCKP color space, the signal value of the YMC color is replaced with the signal value of the K color.

[0063] In this embodiment, the K color conversion ratio is represented by a numerical value between 0% and 100%, for example. A K color conversion ratio of 0% means that the signal value of K color is the lowest among the signal values ​​of the YMCKP color space for reproducing a certain color. In addition, a K color conversion ratio of 100% means that the signal value of K color is the highest among the signal values ​​of the YMCKP color space for reproducing a certain color.

[0064] In addition, the profile generating unit 40 includes a special color setting unit 46, which sets L * a * b * The conversion ratio of the signal value of the special color when the signal value of the color space is converted into the signal value of the YMCKP color space. * a * b *The conversion ratio of the signal value of the P color when the signal value of the color space is converted into the signal value of the YMCKP color space is used as the conversion ratio of the signal value of the special color. * a * b * The conversion ratio to the signal value of the special color when the signal value of the color space is converted into the signal value of the YMCKP color space is expressed as a special color conversion ratio.

[0065] Here, in the printing device 20 that prints an image using a color material of a special color P in addition to the normal colors YMCK, a part of the color material of the YMCK color can be replaced with the color material of the P color. * a * b * When the signal value of the color space is converted into the signal value of the YMCKP color space, the ratio of replacing the signal value of the YMCK color with the signal value of the P color. In addition, in the printing device 20, even if the amount of the colorant of the YMCK color replaced with the colorant of the P color is different, it is possible to reproduce an image of the same color by adjusting the usage amount of the colorants of the YMCK color and the P color.

[0066] In this embodiment, the special color conversion ratio is represented by a numerical value between 0% and 100%. When the special color conversion ratio is 0%, it means that the signal value of the P color is the lowest among the signal values ​​of the YMCKP color space for reproducing a certain color. In addition, when the special color conversion ratio is 100%, it means that the signal value of the P color is the highest among the signal values ​​of the YMCKP color space for reproducing a certain color.

[0067] The K color setting unit 45 and the special color setting unit 46 display a selection screen 90 (see below) for selecting the amount of K color material used and the amount of special color material used on the operation display unit 35 of the color conversion device 30. Figure 3 ).

[0068] Then, the K color setting unit 45 acquires information related to the usage amount of the K color material according to the user's operation on the selection screen 90. In the present embodiment, the K color setting unit 45 acquires information related to the amount of the K color material as an example of information related to the usage amount of the K color material. Then, the K color setting unit 45 sets the K color conversion ratio based on the acquired information related to the amount of the K color material.

[0069] In addition, the special color setting unit 46 acquires information related to the usage amount of the special color color material according to the user's operation on the selection screen 90. In the present embodiment, the special color setting unit 46 acquires information related to the P color color material usage amount as an example of information related to the usage amount of the special color color material. Then, the special color setting unit 46 sets the special color conversion ratio based on the acquired information related to the P color color material usage amount.

[0070] However, in the printing device 20 that prints an image using the color materials of the YMCK colors as normal colors and the color materials of the special colors, as described above, it is possible to reproduce an image of the same color even when the usage amounts of the color materials of the special colors are different. * a * b * Even when the special color conversion ratios when converting the signal values ​​in the color space into the signal values ​​in the YMCKP color space are different, the printing device 20 can reproduce an image of the same color.

[0071] In addition, in the printing device 20, as described above, even when the amount of the YMC color material replaced by the K color material is different, an image of the same color can be reproduced. * a * b * Even when the K color conversion ratio is different when the signal value of the color space is converted into the signal value of the YMCKP color space, the printing device 20 can reproduce an image of the same color.

[0072] In the present embodiment, the same color of the image printed by the printing device 20 means that the signal values ​​obtained when the image is color-measured by a colorimetric device (not shown) are the same.

[0073] Here, even when the reproduced colors are the same, the image printed by the printing device 20 may have different properties depending on the size of the special color conversion ratio or the K color conversion ratio in the color conversion device 30. Incidentally, the amount of each color material of YMCK or the P color material used for printing the image in the printing device 20, the total amount of color materials used for printing the image, etc. may differ depending on the size of the special color conversion ratio or the K color conversion ratio. As a result, the image printed by the printing device 20 may have different properties.

[0074] As a property of an image that changes due to the size of the special color conversion ratio or the K color conversion ratio, the light resistance of the image can be cited. The light resistance of an image refers to the degree to which degradation caused by exposure to light is unlikely to occur. Generally speaking, compared with the colorants of the YMCK colors that are normal colors, the colorants of the P color that are special colors are more susceptible to degradation such as fading due to exposure to light. In addition, when the colorant of the YMC color is replaced with the colorant of the K color, the total amount of colorant used in the image is reduced, and degradation such as fading due to exposure to light is less likely to become conspicuous. Therefore, there is a trend that the lower the special color conversion ratio, the better the light resistance of the image. In addition, there is a trend that the higher the K color conversion ratio, the better the light resistance of the image.

[0075] In addition, as a property of an image that changes due to the size of a special color conversion ratio or a K color conversion ratio, the cost required for printing the image can be cited. Generally speaking, there is a tendency that the unit price of special color colorants is high compared to the colorants of YMCK colors, which are normal colors. Therefore, the more special color colorants are used, the more likely the cost required for printing the image will be higher. In addition, when the YMC color colorant is replaced with the K color colorant, the total amount of colorant used for the image is reduced, and therefore, the cost required for printing the image is likely to be lower. Therefore, there is a tendency that the lower the special color conversion ratio, the lower the cost required for printing the image. In addition, there is a tendency that the higher the K color conversion ratio, the more the cost required for printing the image is reduced.

[0076] In addition, as a property of an image that changes due to the size of the special color conversion ratio or the K color conversion ratio, the grayscale of the image can be cited. The grayscale of an image refers to the smoothness of the change in the shade of the image. The grayscale of an image is improved by preventing the amount of each colorant of the YMCK color as the normal color and the P color as the special color from changing sharply. Therefore, there is a tendency that the grayscale of the image is better as the special color conversion ratio and the K color conversion ratio are higher.

[0077] In addition, as a property of an image that changes due to the size of the special color conversion ratio or the K color conversion ratio, the illumination dependence of the image can be cited. In the case of an image printed by the printing device 20, the visually recognizable color sometimes differs depending on the illumination of the environment in which the image is placed. The illumination dependence of an image refers to the degree to which the color is difficult to change due to differences in illumination. Incidentally, the better the illumination dependence of an image, the less likely it is that the color of the visually recognizable image will differ even when the illumination is different. There is a tendency that special color colorants or K color colorants are less likely to produce differences in color due to differences in illumination than YMC colorants. Therefore, there is a tendency that the higher the special color conversion ratio, the better the illumination dependence of the image. In addition, there is a tendency that the higher the K color conversion ratio, the better the illumination dependence of the image.

[0078] In addition, as a property of an image that changes due to the size of the special color conversion ratio or the K color conversion ratio, the granularity of the image can be cited. Depending on different printing methods, the printing device 20 may form an image by applying colorant in the form of dots on paper. The granularity of an image refers to the degree to which the dots of colorant constituting the image are difficult to be conspicuous. Incidentally, the better the granularity of the image, the less conspicuous the dots of colorant are, and the easier it is to present a smooth image. For example, in the case where the image represents human skin or the sky, it is preferred that the granularity of the image is good. There is a tendency that the higher the special color conversion ratio is, the better the granularity of the image becomes. In addition, there is a tendency that the lower the K color conversion ratio is, the better the granularity of the image becomes.

[0079] Thus, the properties of the image printed by the printing device 20 differ depending on the special color conversion ratio and the K color conversion ratio when converting the signal value of the image data input to the color conversion device 30 into the signal value of the YMCKP color space. Furthermore, when converting the signal value of the image data input to the color conversion device 30 into the signal value of the YMCKP color space, for example, if the special color conversion ratio is set to be the same, the properties of the image printed by the printing device 20 may not be the properties desired by the user.

[0080] In contrast, the color conversion device 30 of the present embodiment sets the special color conversion ratio according to the properties of the image to be printed by the printing device 20. More specifically, the color conversion device 30 of the present embodiment acquires information related to the usage amount of the special color material used in the printing of the image by the printing device 20 according to the properties of the image desired by the user, etc. Then, the color conversion device 30 sets the special color conversion ratio based on the acquired information related to the usage amount of the special color material, and generates a color conversion profile. Furthermore, the color conversion device 30 performs color conversion processing on the image data input from the input device 10 using the generated color conversion profile, and outputs the image data after the color conversion processing to the printing device 20.

[0081] Figure 3 1 is a diagram showing an example of a selection screen 90 displayed on the operation display unit 35 by the profile generating unit 40 of the color conversion device 30 . Figure 3 The selection screen 90 shown is for the user to select the usage amount of the special color toner and the usage amount of the K color toner in the image printed by the printing device 20. In the following description, the usage amount of the special color toner in the image printed by the printing device 20 is expressed as the special color toner amount. In addition, the usage amount of the K color toner in the image printed by the printing device 20 is expressed as the K color toner amount. The special color toner amount is an example of the usage amount of the special color color material, and the K color toner amount is an example of the usage amount of the K color color material.

[0082] like Figure 3 As shown in FIG. 1 , the selection screen 90 includes a toner amount selection section 91 for the user to select the toner amount of the special color. The toner amount selection section 91 is composed of a slider that can select the toner amount of the special color by moving the knob left and right. Incidentally, the user selects the toner amount of the special color by moving the knob of the toner amount selection section 91 left and right. Figure 3 In the toner amount selection portion 91, when the knob is moved to the left, the amount of the selected special color toner decreases, and when the knob is moved to the right, the amount of the selected special color toner increases.

[0083] Here, in the present embodiment, when the selected special color toner amount is changed by operating the toner amount selection unit 91, the selected K color toner amount is changed in conjunction with the special color toner amount. That is, in the selection screen 90 of the present embodiment, the special color toner amount and the K color toner amount can be selected together by operating the toner amount selection unit 91.

[0084] In this example, the state before the user operates the toner amount selection portion 91 (for example, Figure 3 In this manner, in a state where the knob of the toner amount selection portion 91 is located at the center, the special color toner amount and the K color toner amount selected by the toner amount selection portion 91 are set to preset reference values.

[0085] In addition, the toner amount selection unit 91 is not limited to Figure 3 The slider shown can be any slider as long as the user can select the special color toner amount. The toner amount selection unit 91 can be, for example, a method of directly inputting the special color toner amount or a method of selecting an option indicating a preset special color toner amount size (e.g., "more", "less", etc.).

[0086] The same applies to a special color toner amount selection section 95 and a K color toner amount selection section 96 to be described later.

[0087] Figure 4 1 and 2 are diagrams showing the relationship between the special color toner amount and the K color toner amount selected in conjunction with the operation of the toner amount selection unit 91 .

[0088] As described above, there is a tendency that the lower the special color conversion ratio is, the better the light resistance of the image and the cost required for printing the image, among the properties of the image printed by the printing device 20. In addition, there is a tendency that the higher the K color conversion ratio is, the better the light resistance of the image and the cost required for printing the image. Therefore, in this embodiment, when the knob of the toner amount selection unit 91 is moved to the left to reduce the special color toner amount relative to the reference value, the K color toner amount relative to the reference value is increased in conjunction with the special color toner amount.

[0089] In addition, as described above, there is a tendency that the higher the special color conversion ratio is, the better the grayscale, lighting dependency, and granularity of the image printed by the printing device 20 become. In addition, the higher the K color conversion ratio is, the better the grayscale and lighting dependency of the image become. On the other hand, when the K color conversion ratio is increased, the granularity of the image may deteriorate. That is, in the case of increasing the special color conversion ratio, when the K color conversion ratio is increased, there are properties of image quality that become better and properties of image quality that deteriorate. Therefore, in this embodiment, when the knob of the toner amount selection unit 91 is moved to the right so that the special color toner amount increases compared to the reference value, the K color toner amount is not changed from the reference value.

[0090] Thus, in the present embodiment, both the special color toner amount and the K color toner amount can be selected according to the properties of the image changed by the sizes of the special color toner amount and the K color toner amount by operating the toner amount selection section 91. Thus, for example, compared with the case where the special color toner amount and the K color toner amount are selected individually, the special color toner amount and the K color toner amount can be selected by a simple operation.

[0091] return Figure 3 The selection screen 90 includes a property display section 92, which indicates the correspondence between the special color toner amount selected by the toner amount selection section 91 and the property of the image printed by the printing device 20. The property display section 92 includes a first property display section 92A indicating the property of the image when the special color toner amount is increased and a second property display section 92B indicating the property of the image when the special color toner amount is decreased.

[0092] The first property display section 92A and the second property display section 92B of this embodiment indicate the properties of the image that become better when the special color toner amount is changed, as the correspondence between the special color toner amount and the properties of the image. More specifically, in the first property display section 92A, as an example of the properties of the image when the special color toner amount is increased, the words "grayscale / granularity / illumination dependence become better." are recorded. In addition, in the second property display section 92B, as an example of the properties of the image when the special color toner amount is reduced, the words "cost / light resistance become better." are recorded.

[0093] In this embodiment, the selection screen 90 includes the property display unit 92, so that the user can understand what properties the image printed by the printing device 20 has when the special color toner amount is changed. In addition, the user can select the special color toner amount through the toner amount selection unit 91 while referring to the properties of the image displayed on the property display unit 92.

[0094] This makes it easier to obtain an image having a property desired by the user, compared to, for example, a case where the selection screen 90 does not include the property display unit 92 .

[0095] Furthermore, the property display section 92 may display the property of the image that deteriorates when the special color toner amount is changed as the correspondence between the special color toner amount and the image property.

[0096] In addition, the selection screen 90 includes a property notification unit 93, and when the toner amount of the special color is excessively changed by the toner amount selection unit 91, the property notification unit 93 notifies the user that the property of the image is deteriorated. When the toner amount of the special color is excessively changed by the toner amount selection unit 91, the property notification unit 93 is displayed on the selection screen 90. When the toner amount selection unit 91 makes the toner amount of the special color less than a preset threshold, the property notification unit 93 of the present embodiment notifies that "the granularity may be deteriorated."

[0097] In the present embodiment, the selection screen 90 includes the property notification section 93, so that the user can understand that the quality of the image will deteriorate when the special color toner amount is excessively changed by the toner amount selection section 91. Thus, when the user does not want the quality of the image to deteriorate, the special color toner amount is excessively changed by the toner amount selection section 91. In addition, compared with the case where the selection screen 90 does not include the property notification section 93, for example, it is easier to obtain an image having the property desired by the user.

[0098] In addition, the selection screen 90 includes an individual selection section 94 for individually selecting the special color toner amount and the K color toner amount. The individual selection section 94 includes a check box 941 for the user to select when individually selecting the special color toner amount and the K color toner amount. In addition, the individual selection section 94 includes a special color toner amount selection section 95 for the user to individually select the special color toner amount. In addition, the individual selection section 94 includes a K color toner amount selection section 96 for the user to individually select the K color toner amount.

[0099] The special color toner amount selection section 95 is composed of a slider that can select the special color toner amount by moving the knob left and right. Similarly, the K color toner amount selection section 96 is composed of a slider that can select the K color toner amount by moving the knob left and right.

[0100] In the selection screen 90 of the present embodiment, when the check box 941 of the individual selection portion 94 is not selected, the knobs of the special color toner amount selection portion 95 and the K color toner amount selection portion 96 move according to the operation of the toner amount selection portion 91 .

[0101] Figure 5 The knob of the toner amount selection portion 91 is changed from Figure 3 The state shown is a diagram of the selection screen 90 after it has been moved to the left.

[0102] As described above, when the knob of the toner amount selection unit 91 is moved to the left, the selected special color toner amount becomes smaller than the reference value.

[0103] When the knob of the toner amount selection section 91 is moved to the left and the selected special color toner amount becomes less than the reference value, the selected K color toner amount becomes more than the reference value in conjunction with the special color toner amount. Then, the knob of the K color toner amount selection section 96 in the individual selection section 94 is moved from the center to the right.

[0104] In this way, in the selection screen 90 of the present embodiment, the knobs of the special color toner amount selection section 95 and the K color toner amount selection section 96 in the individual selection section 94 move according to the special color toner amount selected by the operation of the toner amount selection section 91. The user can understand the special color toner amount and the K color toner amount selected by the operation of the toner amount selection section 91 by checking the positions of the knobs of the special color toner amount selection section 95 and the K color toner amount selection section 96.

[0105] In addition, when the check box 941 of the individual selection portion 94 is selected in the selection screen 90, the special color toner amount can be individually selected by operating the special color toner amount selection portion 95. Similarly, when the check box 941 of the individual selection portion 94 is selected in the selection screen 90, the K color toner amount can be individually selected by operating the K color toner amount selection portion 96.

[0106] Incidentally, in the individual selection section 94, when the knob of the special color toner amount selection section 95 is moved to the left, the amount of the selected special color toner becomes smaller, and when the knob is moved to the right, the amount of the selected special color toner becomes larger. In addition, when the special color toner amount selection section 95 is operated to change the special color toner amount, the K color toner amount does not change.

[0107] Similarly, in the individual selection section 94, when the knob of the K color toner amount selection section 96 is moved to the left, the amount of the selected K color toner decreases, and when the knob is moved to the right, the amount of the selected K color toner increases. In addition, when the K color toner amount selection section 96 is operated to change the K color toner amount, the special color toner amount does not change.

[0108] return Figure 3 The selection screen 90 includes an area setting unit 97 for setting the special color toner amount in a specific area that meets a preset condition in the image to a value different from that in other areas.

[0109] There are cases where it is preferred that a specific area in an image has properties different from other areas. For example, as described above, in the case where the image represents human skin, etc., it is preferred that the granularity of the image, which is one of the properties of the image, is good. Moreover, there is a tendency that the granularity of the image becomes better as the amount of special color toner increases. In this embodiment, the amount of special color toner in the skin area representing human skin as an example of a specific area in the image that meets predetermined conditions can be increased by selecting the area setting unit 97. As a result, it is easier to obtain an image with the properties desired by the user than in the case where the selection screen 90 does not include the area setting unit 97.

[0110] In addition, the selection screen 90 includes an instruction section 98 for instructing the generation of a color conversion profile. When the user operates the instruction section 98, the profile generating section 40 causes the K color setting section 45 to acquire information on the amount of the K color toner selected on the selection screen 90, and the special color setting section 46 to acquire information on the amount of the special color toner selected on the selection screen 90. Then, the profile generating section 40 generates a color conversion profile based on the acquired information on the amount of the K color toner and the acquired information on the amount of the special color toner.

[0111] Here, in the present embodiment, the toner amount selection portion 91 , property display portion 92 , property notification portion 93 , individual selection portion 94 , area setting portion 97 , and instruction portion 98 included in the selection screen 90 are examples of display images displayed on the display portion.

[0112] Next, the color conversion profile generation process performed by the profile generation unit 40 will be described in detail.

[0113] Figure 6 1 is a flowchart showing an example of a process of generating a color conversion profile by the profile generating unit 40 .

[0114] In the profile generating section 40, the K color setting section 45 and the special color setting section 46 cause the operation display section 35 to display a selection screen 90 (see FIG. 1 ) for accepting selection of the special color toner amount and the K color toner amount. Figure 3 )(Step S101).

[0115] Next, the K color setting section 45 acquires information on the amount of K color toner selected on the selection screen 90 , and sets the K color conversion ratio based on the information (step S102 ).

[0116] Furthermore, the special color setting unit 46 acquires information on the special color toner amount selected on the selection screen 90 , and sets the special color conversion ratio based on the information (step S103 ).

[0117] Next, the first conversion unit 41 converts the signal value of the RGB color space representing the image data input from the input device 10 into an L color space that is independent of the input device 10 and the printing device 20. * a * b * The signal value of the color space (step S104).

[0118] Next, the color gamut compression unit 42 converts the L * a * b * The signal value gamut of the color space is compressed into the same L * a * b * The signal value of the color gamut of the printing device 20 in the color space (step S105).

[0119] Next, the second conversion unit 43 uses the K color conversion ratio set in step S102 and the special color conversion ratio set in step S103 to convert the L color after the color gamut compression in step S105 into the K color. * a * b *The signal value of the color space is converted into a signal value of the YMCKP color space that can be reproduced by the printing device 20 (step S106).

[0120] More specifically, the second conversion unit 43 determines the signal value of the K color in the YMCKP color space using the K color conversion ratio set in step S102. Next, the second conversion unit 43 determines the signal value of the P color, which is a special color in the YMCKP color space, using the special color conversion ratio set in step S103. Next, the second conversion unit 43 determines the signal value of the Y color, the signal value of the M color, and the signal value of the C color in the YMCKP color space.

[0121] The profile generating section 40 executes the processing from step S104 to step S106 for each grid point in the RGB color space.

[0122] Next, the profile generating unit 40 generates a color conversion profile for converting signal values ​​in the RGB color space into signal values ​​in the YMCKP color space used by the printing device 20 based on the results of the processing of steps S104 to S106 for each grid point in the RGB color space (step S107 ).

[0123] Then, the profile generating section 40 stores the color conversion profile generated in step S107 in the profile storing section 33 (step S108 ), and ends the series of processing.

[0124] In this way, the color conversion device 30 of the present embodiment generates a color conversion profile in which the special color conversion ratio and the K color conversion ratio are determined according to the properties of the image printed by the printing device 20 .

[0125] In addition, in the color conversion device 30, the color conversion section 31 performs color conversion processing of the image data input from the input device 10 using the color conversion profile stored in the profile storage section 33. Incidentally, the color conversion section 31 converts the signal value of the RGB color space representing the image data input from the input device 10 into the signal value of the YMCKP color space that can be reproduced by the printing device 20 using the color conversion profile in which the special color conversion ratio and the K color conversion ratio are determined according to the nature of the image. Then, the color conversion device 30 outputs the image data represented by the signal value of the YMCKP color space after the conversion to the printing device 20. In the printing device 20, the image is printed on paper using the image data represented by the signal value of the YMCKP color space acquired from the color conversion device 30.

[0126] Thus, compared with the case where the color conversion of image data is performed using a color conversion profile with special color conversion ratios and K color conversion ratios not determined according to the properties of the image, the image printed by the printing device 20 is more likely to have the properties desired by the user.

[0127] In the above embodiment, the case where the color conversion device 30 converts the signal value of the RGB color space representing the image data into the signal value of the YMCKP color space including the signal value of the P color corresponding to the usage amount of the P color material is described as an example.

[0128] The special color is not limited to the fluorescent pink (P) mentioned above, and any color may be used as long as it is different from the YMCK colors that are normal colors.

[0129] In addition, a plurality of different special colors may be used as special colors. Incidentally, the color conversion device 30 may convert the signal value of the RGB color space representing the image data into the signal value of the color space including the signal values ​​of the plurality of special colors corresponding to the usage amounts of the colorants of the plurality of special colors. Here, a case is considered where the color conversion device 30 converts the signal value of the RGB color space representing the image data into the signal value of the color space including the signal values ​​of two special colors, the first special color and the second special color, which are the plurality of special colors.

[0130] In the printing device 20 that prints an image using a plurality of special color materials, the properties of the printed image may differ depending on the usage amount of the special color materials. Incidentally, the properties of the image may differ between the case where the usage amount of the first special color material (e.g., fluorescent pink) is increased and the case where the usage amount of the second special color material (e.g., metallic color) is increased.

[0131] When converting signal values ​​of an RGB color space representing image data into signal values ​​of a color space including a plurality of special colors, it is preferred that the color conversion device 30 individually sets a ratio of signal values ​​converted into a first special color, i.e., a first special color conversion ratio, and a ratio of signal values ​​converted into a second special color, i.e., a second special color conversion ratio.

[0132] For example, the color conversion device 30 may be configured to operate the display unit 35 (see Figure 2 ) displayed on the selection screen 90 (refer to Figure 3 ), the usage amount of the first special color color material and the usage amount of the second special color color material are individually selected. Then, the color conversion device 30 sets the first special color conversion ratio and the second special color conversion ratio individually based on the usage amount of the first special color color material and the usage amount of the second special color color material selected by the operation on the selection screen 90, and generates a color conversion profile.

[0133] Thus, compared with the case where the first special color conversion ratio and the second special color conversion ratio are uniformly set to be the same without distinguishing and generating the color conversion profile, the image printed by the printing device 20 is more likely to have properties corresponding to the usage amount of the colorant of each special color.

[0134] In the above-mentioned embodiment, the profile generation unit 40 of the color conversion device 30 generates a color conversion profile that converts the signal value of the RGB color space into the signal value of the YMCKP color space that can be reproduced by the printing device 20, but the present invention is not limited thereto. For example, the profile generation unit 40 of the color conversion device 30 may generate a color conversion profile that converts the signal value of the RGB color space into the signal value of the YMCKP color space that can be reproduced by the printing device 20. * a * b * In this case, the color conversion device 30 converts the signal value of the RGB color space representing the image data input from the input device 10 into the signal value of the YMCKP color space using other color conversion profiles or the like. * a * b * After the signal value of the color space is obtained, L is converted using the color conversion profile generated by the profile generation unit 40. * a * b * The signal value of the color space is converted into the signal value of the YMCKP color space.

[0135] In addition, as the signal value representing the image data input from the input device 10 to the color conversion device 30, the signal value of the RGB color space is exemplified, but the present invention is not limited thereto. The signal value representing the image data input from the input device 10 to the color conversion device 30 may be a signal value represented by a color space such as YMCK or YMCKRGB in addition to the RGB color space.

[0136] In the color conversion device 30, the first conversion unit 41 of the profile generation unit 40 converts the signal value of the RGB color space into the L color space which is independent of the device. * a * b * The signal value of the color space is not limited to L, but does not depend on the color space of the device. * a * b * Color space. For example, it can also be XYZ color space, Yxy color space, L * u * v * Color space, HLS color space, etc.

[0137] As described above, the embodiments of the present invention have been described, but the technical scope of the present invention is not limited to the scope described in the above embodiments. According to the description of the claims, various changes or improvements to the above embodiments are also included in the technical scope of the present invention.

[0138] The processor in the above-mentioned embodiment refers to a processor in a broad sense, which includes, in addition to general-purpose processors (such as CPU (=Central Processing Unit)), special-purpose processors (such as GPU (=Graphical Processing Unit), ASIC (=Application Specific Integrated Circuit), FPGA (=Field Programmable Gate Array), programmable logic devices, etc.).

[0139] In addition, the operation of the processor in this embodiment can be performed individually by one processor, or can be performed collaboratively by multiple processors located in physically separated positions. In addition, the execution order of each operation in the processor is not limited to the order described in the above-mentioned embodiment, and can also be changed individually.

[0140] <Note> (((1)))

[0142] A color conversion device comprises a processor,

[0143] The processor

[0144] When converting the signal value of the first color space representing an image into the signal value of the second color space including the YMCK signal corresponding to the usage amount of the YMCK color colorant and the special color signal corresponding to the usage amount of the colorant of the color other than the YMCK color, i.e., the special color conversion ratio, the ratio of converting the signal value of the first color space into the special color signal is set according to the nature of the image printed using the signal value of the second color space. (((2)))

[0146] The color conversion device according to (((1))), wherein:

[0147] The processor sets a ratio for converting the signal value of the first color space into a K color signal, ie, a K color conversion ratio, and the special color conversion ratio according to properties of an image printed using the signal value of the second color space. (((3)))

[0149] The color conversion device according to (((2))), wherein:

[0150] The processor sets the special color conversion ratio in conjunction with the K color conversion ratio according to a property of an image to be printed using the signal value of the second color space. (((4)))

[0152] The color conversion device according to (((3))), wherein:

[0153] The processor changes the K color conversion ratio so as to increase the usage amount of the K color material when the special color conversion ratio is changed so as to reduce the usage amount of the special color color material from a preset reference value. (((5)))

[0155] The color conversion device according to (((3))) or (((4))), wherein:

[0156] The processor does not change the K color conversion ratio when changing the special color conversion ratio so that the usage amount of the color material of the special color increases from a preset reference value. (((6)))

[0158] The color conversion device according to any one of (((1))) to (((5))), wherein:

[0159] When the processor converts the signal value of the first color space into the signal value of the second color space including the YMCK signal and a plurality of special color signals corresponding to the usage amounts of colorants of a plurality of special colors, the processor individually sets the ratios for converting the signal value of the first color space into each of the special color signals, i.e., a plurality of special color conversion ratios, according to the properties of an image printed using the signal value of the second color space. (((7)))

[0161] The color conversion device according to any one of (((1))) to (((6))), wherein:

[0162] The processor causes a display unit that displays information to display a display image that indicates correspondence between the usage amount of the special color material and the property of an image printed using the signal value of the second color space. (((8)))

[0164] The color conversion device according to (((7))), wherein:

[0165] The processor acquires information related to the usage amount of the special color material according to the operation on the display image,

[0166] The special color conversion ratio is set based on the usage amount of the colorant of the special color. (((9)))

[0168] The color conversion device according to (((8))), wherein:

[0169] The processor sets the usage amount of the K color material in conjunction with the usage amount of the special color color material acquired according to the operation on the display image, and then individually sets the usage amount of the special color color material or the usage amount of the K color color material according to the operation on the display image.

[0170] The special color conversion ratio is set based on the usage of the special color pigment,

[0171] Based on the usage amount of the K color material, a K color conversion ratio is set as a ratio for converting the signal value of the first color space into a K color signal. (((10)))

[0173] The color conversion device according to any one of (((1))) to (((9))), wherein:

[0174] The processor sets the special color conversion ratio for converting the signal value of the first color space representing the specific area satisfying a preset condition in an image printed using the signal value of the second color space into the special color signal according to the property of the specific area of ​​the image. (((11)))

[0176] A color conversion table creation device, characterized by comprising a processor,

[0177] The processor creates a color conversion table, which converts the signal value of the first color space representing the image into the signal value of the second color space including the YMCK signal corresponding to the usage amount of the YMCK color colorant and the special color signal corresponding to the usage amount of the colorant of the color other than the YMCK color, i.e., the special color, and sets the ratio of converting the signal value of the first color space into the special color signal, i.e., the special color conversion ratio, according to the nature of the image printed using the signal value of the second color space. (((12)))

[0179] A program, characterized in that it causes a computer to implement:

[0180] When converting a signal value of a first color space representing an image into a signal value of a second color space including a YMCK signal corresponding to the usage amount of a YMCK color colorant and a special color signal corresponding to the usage amount of a colorant of a color other than YMCK colors, i.e., a special color, a function is set to convert the signal value of the first color space into the special color signal in a ratio, i.e., a special color conversion ratio, according to the nature of an image printed using the signal value of the second color space.

[0181] According to (((1))), an image having properties desired by the user can be easily obtained compared to a case where the conversion ratio of the special color signal in converting the signal value of the first color space into the signal value of the second color space is set to be uniform.

[0182] According to (((2))), an image having properties desired by the user can be easily obtained compared to a case where the conversion ratio of the K color signal in converting the signal value of the first color space into the signal value of the second color space is uniformly set to the same.

[0183] According to (((3))), compared with the case where the special color conversion ratio and the K color conversion ratio are set non-linkedly, an image having the properties desired by the user can be obtained by a simpler operation.

[0184] According to (((4))), compared with the case where the K color conversion ratio is changed in a manner such that the amount of K color material used is reduced when the special color conversion ratio is changed in a manner such that the amount of special color color material used is reduced compared to a reference value, it is easy to make the light fastness of the image which is the property of the image and the cost required for printing the image better.

[0185] According to (((5))), it is easier to make the granularity of the image, which is a property of the image, good compared to the case where the K color conversion ratio is changed by increasing the amount of K color material used when the special color conversion ratio is changed by increasing the amount of special color color material used compared to the reference value.

[0186] According to (((6))), compared with the case where a plurality of special color conversion ratios are uniformly set to be the same, an image having the properties desired by the user can be easily obtained.

[0187] According to (((7))), the user can easily understand the difference in image properties caused by changing the amount of special color material used, compared to a case where the display unit does not display the correspondence between the amount of special color material used and the image properties.

[0188] According to (((8))), the user can set the usage amount of the special color material by operating the displayed image while confirming the correspondence between the usage amount of the special color material and the property of the image on the display unit.

[0189] According to (((9))), an image having properties desired by the user can be easily obtained compared to a case where information on the usage amount of the special color material or the usage amount of the K color material is not acquired individually.

[0190] According to (((10))), an image having the properties desired by the user can be easily obtained compared to a case where a special color conversion ratio for converting a signal value of a first color space representing a specific area into a special color signal is not set according to the properties of the specific area.

[0191] According to (((11))), an image having properties desired by the user can be easily obtained compared to a case where the conversion ratio of the special color signal in converting the signal value of the first color space into the signal value of the second color space is set to be uniform.

[0192] According to (((12))), an image having the properties desired by the user can be easily obtained compared to a case where the conversion ratio of the special color signal in converting the signal value of the first color space into the signal value of the second color space is set to be uniformly the same.

Claims

1. A color conversion device, characterized in that: With processor, When the processor converts the signal value of the first color space representing the image into the signal value of the second color space including the YMCK signal corresponding to the usage amount of the YMCK color colorant and the special color signal corresponding to the usage amount of the colorant of the color other than the YMCK color, i.e., the special color, the processor sets the ratio of converting the signal value of the first color space into the special color signal, i.e., the special color conversion ratio, according to the nature of the image printed using the signal value of the second color space.

2. The color conversion device according to claim 1, wherein: The processor sets a ratio for converting the signal value of the first color space into a K color signal, ie, a K color conversion ratio, and the special color conversion ratio according to properties of an image printed using the signal value of the second color space.

3. The color conversion device according to claim 2, wherein: The processor sets the special color conversion ratio in conjunction with the K color conversion ratio according to a property of an image to be printed using the signal value of the second color space.

4. The color conversion device according to claim 3, wherein: The processor changes the K color conversion ratio so as to increase the usage amount of the K color material when the special color conversion ratio is changed so as to reduce the usage amount of the special color color material from a preset reference value.

5. The color conversion device according to claim 3 or 4, wherein: The processor does not change the K color conversion ratio when changing the special color conversion ratio so that the usage amount of the color material of the special color increases from a preset reference value.

6. The color conversion device according to any one of claims 1 to 5, wherein: When the processor converts the signal value of the first color space into the signal value of the second color space including the YMCK signal and a plurality of special color signals corresponding to the usage amounts of colorants of a plurality of special colors, the processor individually sets the ratios for converting the signal value of the first color space into each of the special color signals, i.e., a plurality of special color conversion ratios, according to the properties of an image printed using the signal value of the second color space.

7. The color conversion device according to any one of claims 1 to 6, wherein: The processor causes a display unit that displays information to display a display image that indicates correspondence between the usage amount of the special color material and the property of an image printed using the signal value of the second color space.

8. The color conversion device according to claim 7, wherein: The processor acquires information related to the usage amount of the special color material according to the operation on the display image, The special color conversion ratio is set based on the usage amount of the colorant of the special color.

9. The color conversion device according to claim 8, wherein: The processor sets the usage amount of the K color material in conjunction with the usage amount of the special color color material acquired according to the operation on the display image, and then individually sets the usage amount of the special color color material or the usage amount of the K color color material according to the operation on the display image. The special color conversion ratio is set based on the usage of the special color pigment, Based on the usage amount of the K color material, a K color conversion ratio is set as a ratio for converting the signal value of the first color space into a K color signal.

10. The color conversion device according to any one of claims 1 to 9, wherein: The processor sets the special color conversion ratio for converting the signal value of the first color space representing the specific area satisfying a preset condition in an image printed using the signal value of the second color space into the special color signal according to the property of the specific area of ​​the image.

11. A color conversion table creation device, characterized in that: With processor, The processor creates a color conversion table, which converts the signal value of the first color space representing the image into the signal value of the second color space including the YMCK signal corresponding to the usage amount of the YMCK color colorant and the special color signal corresponding to the usage amount of the colorant of the color other than the YMCK color, i.e., the special color, and sets the ratio of converting the signal value of the first color space into the special color signal, i.e., the special color conversion ratio, according to the nature of the image printed using the signal value of the second color space.

12. A storage medium, which is a computer-readable medium, storing a program for causing a computer to execute a process, characterized in that: The processing is as follows: When converting the signal value of the first color space representing an image into the signal value of the second color space including the YMCK signal corresponding to the usage amount of the YMCK color colorant and the special color signal corresponding to the usage amount of the colorant of the color other than the YMCK color, i.e., the special color conversion ratio, the ratio of converting the signal value of the first color space into the special color signal is set according to the nature of the image printed using the signal value of the second color space.

13. A color conversion method, characterized in that: When converting the signal value of the first color space representing an image into the signal value of the second color space including the YMCK signal corresponding to the usage amount of the YMCK color colorant and the special color signal corresponding to the usage amount of the colorant of the color other than the YMCK color, i.e., the special color conversion ratio, the ratio of converting the signal value of the first color space into the special color signal is set according to the nature of the image printed using the signal value of the second color space.

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