Image processing system, output profile, image output apparatus, image processing method, and program

Abstract

To provide an image processing system, an output profile, an image output device, an image processing method, and a program that can use an output profile dedicated to a metallic color in an actual user workflow in which metallic color printing is performed in combination with an input profile.SOLUTION: According to an aspect of the present invention, there is provided an image processing system for generating and printing plates of five or more colors including a metallic color material from an input image whose tone continuously changes, the image processing system including an acquisition unit configured to acquire print data which is formed from CMYK or RGB and does not include designation of a spot color, an input profile designation unit configured to designate an input profile for converting the print data into color values in a device-independent space, an output profile designation unit configured to designate an output profile for the metallic color material, and a generation unit configured to generate a printed material by separating the print data into five or more plates including the metallic color material using the designated input profile and output profile.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an image processing system, an output profile, an image output device, an image processing method, and a program. [Background technology]

[0002] In recent electrophotography, in addition to the conventional CMYK color materials, special color materials are sometimes used to expand color expression. For example, by using metallic color (metallic gloss color) materials such as gold toner and silver toner, or glitter color materials such as pearl color materials and mica color materials, it is possible to form glossy color images.

[0003] Traditionally, metallic colors have mainly been produced by offset printing using glitter colorants. In offset printing, commercially available color sample patches are used to print ideal metallic colors. When a user specifies a spot color on a color sample patch, colorants are mixed and created to reproduce the color sample patch, and the printing company then prints using these mixed colorants. Here, the colors registered on commercially available color sample patches are called spot colors (spot colors).

[0004] For example, Patent Document 1 discloses an example in which metallic toner is used in accordance with the amount of CMYK toner in order to enhance the metallic feel of highlights. Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, electrophotography, like offset printing, allows for the designation of spot colors (special colors) for objects in image data, which are then broken down into five plates on the image forming device. However, this system requires special image editing tools such as Photoshop and the necessary skills, placing a burden on the printing order party. Furthermore, the designation of spot colors is generally "solid," making them unsuitable for expressing gradations. Even if spot colors are not designated, simply creating a plate with a uniformly assigned silver color, for example, requires some effort.

[0006] Another advantage of electrophotography is that images are formed by overlapping toner layers of various colors, eliminating the need for color material blending as in offset printing, and enabling on-demand printing. However, metallic toners, which generally use metals as toner materials, have higher shielding properties than process color toners, which use pigments. Therefore, when mixing with process colors, metallic toners are placed in the bottom layer closest to the paper. Even in such cases, the silver toner color in the lower layer may be covered and shielded by the process color toner color in the upper layer, making it impossible to reproduce the desired metallic effect. In other words, for shadow colors or high-saturation colors that require a large amount of process toner in the upper layer, even using expensive metallic toners may be less effective and not justify the cost.

[0007] Furthermore, to easily print metallic colors, it is better to use a five-color output profile for metallic colors and convert it on the printer, rather than specifying spot colors in the image data. However, while the above technology creates a five-color output profile, it does not match the workflow that the user actually follows when printing. For example, the technology described in Patent Document 1 does not solve the problem of creating an output profile that takes into account the actual user workflow, which is to perform metallic printing in combination with an input profile.

[0008] The present invention has been made in consideration of the above, and aims to provide an image processing system, an output profile, an image output device, an image processing method, and a program that enable the use of an output profile dedicated to metallic colors in an actual user workflow of printing metallic colors in combination with an input profile. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, the present invention provides an image processing system that generates and prints five or more color plates containing metallic color materials from an input image with continuously changing gradations, and includes an acquisition means that acquires printing data that is composed of CMYK or RGB and does not include the specification of spot colors, an input profile designation means that designates an input profile for converting the printing data into color values ​​in a device-independent space, an output profile designation means that designates an output profile for the metallic color materials, and a generation means that uses the designated input profile and output profile to generate a printed product in which the printing data is separated into five or more plates containing the metallic color materials. [Effects of the Invention]

[0010] According to the present invention, it is possible to use an output profile dedicated to metallic colors in an actual user workflow in which metallic color printing is performed in combination with an input profile. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of a functional configuration of an image processing system according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the overall operation of the image processing system according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of the overall operation of the image processing system according to the first embodiment. [Figure 4]FIG. 4 is a diagram illustrating an example of a hardware configuration of the image forming apparatus in the image processing system according to the first embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of a measurement unit included in the image processing system according to the first embodiment. [Figure 6] FIG. 6 is a diagram illustrating the functional configuration of a processing unit involved in creating a five-color output profile in the image processing system according to the first embodiment. [Figure 7] FIG. 7 is a diagram for explaining an example of a color prediction model created in the image processing system according to the first embodiment. [Figure 8] FIG. 8 is a diagram illustrating an example of a profile generation process in the image processing system according to the first embodiment. [Figure 9] FIG. 9 is a diagram showing lattice points expressed in Lab coordinates in the PCS space of the B2A table generated in the image processing system according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating setting of a target metallic value on the LC plane in the image processing system according to the first embodiment. [Figure 11] FIG. 11 is a flowchart illustrating an example of the flow of operations of the search unit in the image processing system according to the first embodiment. [Figure 12] FIG. 12 is a diagram illustrating a part of the functional configuration of the controller of the image processing system according to the first embodiment. [Figure 13] FIG. 13 is a diagram illustrating an example of a UI in the image processing system according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an image processing system, an output profile, an image output device, an image processing method, and a program will be described in detail with reference to the accompanying drawings.

[0013] First, the objectives of this embodiment will be described. The objectives of this embodiment are the following two: (1) To easily perform printing using metallic color materials (metallic printing) without using spot color specification. In particular, to perform metallic printing using the same workflow as printing with process colors. (2) To achieve both quality and cost when printing with a mixture of process toner and metallic toner in electrophotography.

[0014] First, we will explain how to address the objective (challenge) in (1). Typical input data at printing companies is CMYK or RGB image data with no spot color designation. To easily perform metallic printing based on such image data, it is preferable to perform color separation using a profile on the image forming device, similar to the process color printing workflow.

[0015] Prior art describes a method for creating a five-color output profile (five-color output profile) and a color conversion method, but it assumes the use of a device link profile. Therefore, it cannot be used when the input image data is RGB data. In color conversion using a device link profile (hereinafter simply referred to as a profile) in printing, it is desirable to use an input profile and an output profile and combine them in a PCS (Profile Connection Space), and this embodiment can support such a workflow.

[0016] Here, we will explain profiles. An ICC (International Color Consortium) profile, which is generally used in color management, is data that represents the correspondence between device-dependent colors and device-independent colors of a printing press. Device-dependent colors are expressed as coordinate values ​​in a device-dependent color space, such as CMYK values ​​that represent the usage amounts of C, M, Y, and K. Device-independent colors are expressed, for example, as color values ​​in the CIE (International Commission on Illumination) Lab color space or the CIE XYZ color space, which are device-independent color spaces.

[0017] ICC profiles include input profiles and output profiles. Input profiles have an A2B table. For example, the A2B table can convert CMYK values ​​defined in Japan Color into color values ​​(e.g., Lab values) in the device-independent PCS (Profile Connection Space) according to the input profile; this is called A2B conversion. In other words, the input profile is an example of an input profile for converting a print job (an example of print data) into color values ​​in a device-independent space.

[0018] On the other hand, the output profile has a B2A table. For example, the B2A table can convert device-independent color values ​​into device-dependent CMYK values ​​(device values) for electrophotographic and other printing machines, which is called B2A conversion. In other words, the output profile is an example of an output profile for metallic color materials.

[0019] For process colors, the B2A table describes the relationship between the CMYK values ​​at the grid points and the Lab values ​​(colorimetric values) obtained by printing and measuring the colors using those CMYK values. The Lab values ​​are values ​​obtained using diffuse reflected light (0 / 45). However, when the object being measured is a metallic print, the colorimetric values ​​that match the visual perception are physical quantities consisting of diffuse reflected light and specular reflected light (details will be explained later). Therefore, the device values ​​for obtaining the color of any metallic patch are obtained using diffuse reflected light and specular reflected light.

[0020] On the other hand, to print metallic colors from the above-mentioned general input data, it is better to have the values ​​in the PCS space of the output profile correspond to the Lab values ​​of the process colors. In other words, in the case of a five-color output profile for metallic colors, the Lab values ​​in the B2A table do not have to be the colorimetric values ​​when printing with device values ​​(CMYK + Si values). Here, Si stands for silver, and will be referred to as Si hereafter.

[0021] Next, we will explain how to address the objective (problem) of (2). Metallic toner should not be used for colors where the silver toner color in the lower layer is covered and shielded by the process color toner color in the upper layer, making it impossible to reproduce the desired metallic feel, or for colors where a large amount of process toner is placed in the upper layer, i.e., shadow colors or high saturation colors.

[0022] (First embodiment) In this embodiment, an example will be described in which a five-plate ICC profile (five-color output profile) is created using CMYK process colors and silver. Here, the characteristics of the reproduction target values ​​include color and metallic feel, with the physical quantity of color being represented as a color value and the physical quantity of metallic feel being represented as a metallic value. The reproduction printing machine in this embodiment is the image forming apparatus 400 in FIG. 1, which will be described later.

[0023] Also, the device values ​​of the reproduction printing machine to be acquired are assumed to be C, M, Y, K, and Si (metallic silver) values. Note that in the following explanation, high metallicity or metallic value means high brilliance, and high chromaticity or color value means high saturation or deep color.

[0024] FIG. 1 is a diagram illustrating an example of the functional configuration of an image processing system according to a first embodiment. The image processing system according to this embodiment is an example of an image processing system that generates and prints five or more color plates containing metallic color materials from an input image in which the gradation changes continuously. As shown in FIG. 1, the image processing system according to this embodiment includes a processing unit 100, a controller 200, an operation unit 300, an image forming device 400 (an example of an image output device), and a measurement unit 500, and these components are connected to each other via a control bus or a network.

[0025] The operation unit 300 receives user instructions and displays the status via a keyboard, mouse, display, etc. Specifically, the user issues print instructions via the operation unit 300 by specifying an input image, and for actual printing, specifying an input profile and an output profile.

[0026] During actual printing, the controller 200 receives a print job from the processing unit 100, performs color conversion using the input profile and output profile, and transmits the result to the image forming apparatus 400 to issue instructions such as printing. Here, the print job is an example of print data that is composed of CMYK or RGB and does not include the specification of spot colors. In other words, the controller 200 functions as an example of an acquisition unit that acquires a print job. In this embodiment, the controller 200 transmits a chart for creating a five-color output profile to the image forming apparatus 400 to issue instructions such as printing.

[0027] The image forming device 400 receives instructions such as printing from the controller 200 and prints an image.

[0028] The measurement unit 500 measures a plurality of colorimetric values ​​for patches (metallic patches) on a printed chart (metallic chart) for creating a five-color output profile, and transmits the data to the processing unit 100.

[0029] The processing unit 100 receives the color measurement values ​​from the measurement unit 500 , creates a five-color output profile consisting of device values ​​for five colors including silver, and transmits the five-color output profile to the controller 200 .

[0030] 2 and 3 are diagrams for explaining an example of the overall operation of the image processing system according to the first embodiment. Fig. 2 is a flowchart for explaining an example of the flow of actual printing using a five-color output profile in the image processing system according to the first embodiment.

[0031] The user specifies a print job for a CMYK or RGB image with no spot color specification (step S401) via the operation unit 300. Next, the user specifies an input profile such as Japan Color or sRGB via the operation unit 300, and also specifies a five-color output profile for five plates including a silver plate, and issues a print instruction (step S402).

[0032] The controller 200 acquires the print job specified by the user (step S403). Next, the controller 200 performs color conversion processing using the specified input profile and five-color output profile, and sends the image data after color conversion processing to the image forming device 400 (step S404). The image forming device 400 receives the image data from the controller 200 and performs printing in five plates (step S405).

[0033] 3 is a flowchart showing an example of the flow of a process for creating a five-color output profile in the image processing system according to the first embodiment. When a user issues an instruction to print a metallic chart for creating a five-color output profile via operation unit 300, the metallic chart (patches of metallic colors) is printed (step S501). Next, the user uses measurement unit 500 via operation unit 300 to measure colorimetric values ​​in multiple directions for all metallic patches of the printed metallic chart (step S502).

[0034] The processing unit 100 receives the colorimetric values ​​measured by the measurement unit 500 and creates a prediction model (color prediction model) that calculates color values ​​and metallic values ​​based on the received colorimetric values ​​(step S503). Next, the processing unit 100 sets target color values ​​and target metallic values ​​for all lattice points in the PCS space of the B2A table of the five-color output profile (step S504).

[0035] Next, the processing unit 100 uses the prediction model obtained in step S503 to obtain device values ​​that realize the target color values ​​and target metallic values ​​set for all lattice points in the PCS space (step S505). Next, the processing unit 100 sets the device values ​​obtained in step S505 for all lattice points in the B2A table and generates a five-color output profile (step S506). Finally, the processing unit 100 stores the generated five-color output profile in a storage device (step S507).

[0036] 4 is a diagram illustrating an example of the hardware configuration of an image forming apparatus in the image processing system according to the first embodiment. For example, the image forming apparatus 400 includes an intermediate transfer belt, multiple photosensitive drums, a paper feed tray, conveying rollers, transfer rollers, and a fixing roller.

[0037] Specifically, image forming apparatus 400 has a configuration in which photosensitive drums 403S, 403Y, 403M, 403C, and 403K (hereinafter referred to as photosensitive drums 403) of the respective colors are arranged along intermediate transfer belt 402, which is an endless moving means. In other words, the example shown in the figure is a so-called tandem type.

[0038] Photoconductor 403Y forms a yellow plate (Y color), photoconductor 403M forms a magenta plate (M color), photoconductor 403C forms a cyan plate (C color), photoconductor 403K forms a black plate (K color), and photoconductor 403S forms a special color (a metallic color, a fluorescent color such as fluorescent yellow or fluorescent pink, or a special color such as white) that is different from the process colors CMYK colors. Note that although CMYK colors are defined as process colors, CMY colors may also be used as process colors, or red (R color), green (G color), and blue (B color) may be used as process colors instead of CMY colors.

[0039] First, a recording medium such as paper is fed from a paper feed tray 408 and conveyed by conveyance rollers 401. For transfer, photosensitive drums 403 are arranged in the order of, for example, photosensitive drum 403S, photosensitive drum 403Y, photosensitive drum 403M, photosensitive drum 403C, and photosensitive drum 403K, from the upstream side in the conveyance direction along intermediate transfer belt 402 on which an intermediate transfer image is formed.

[0040] The arrangement order of the photosensitive drums 403 is not limited to this, and may be reversed, such as from upstream to downstream, photosensitive drum 403K, photosensitive drum 403C, photosensitive drum 403M, photosensitive drum 403Y, and photosensitive drum 403S. However, the special color is not limited to being arranged at the most downstream or most upstream position, and may be arranged at another position.

[0041] An image of each color is formed on the surface of each photosensitive drum 403 by developing it with toner. The images of each color are then transferred onto the intermediate transfer belt 402 in a superimposed state. In this way, a full-color image is formed on the intermediate transfer belt 402. The full-color image formed on the intermediate transfer belt 402 is then transferred onto paper (recording medium) by the function of transfer roller 404 in the paper (recording medium) transport path (shown by the dashed line in FIG. 4). Next, the paper on which the image has been formed is further transported, and the image is fixed by fixing roller 405 (i.e., the image is formed). In this embodiment, as shown in FIG. 2, underprinting is assumed, in which the metallic layer is the bottom layer.

[0042] 5 is a diagram illustrating an example of a measurement unit included in the image processing system according to the first embodiment. The measurement unit 500 outputs a plurality of colorimetric values ​​obtained by measuring a metallic patch, which is a measurement object, from a plurality of directions.

[0043] Specifically, the measurement unit 500 is a multi-angle spectrophotometer. The colorimetric values ​​measured by the measurement unit 500 consist of spectral reflectance in each direction. As shown in FIG. 5, the measurement unit 500 outputs colorimetric values ​​in multiple directions necessary to obtain metallic values ​​and color values, which will be described later.

[0044] For example, when the measurement object is irradiated with light from an oblique direction, the measurement unit 500 outputs colorimetric values ​​of the measurement object measured in the front direction (45 degrees), which is the normal direction of the measurement object, and colorimetric values ​​of the measurement object measured in the diffuse light direction (110 degrees), which is closer to the incident direction of the irradiated light than the front direction (45 degrees). Furthermore, the measurement unit 500 may output colorimetric values ​​of the measurement object measured in the specular reflection direction (0 to 15 degrees) of the irradiated light, as necessary.

[0045] Fig. 6 is a diagram illustrating the functional configuration of a processing unit involved in creating a five-color output profile in the image processing system according to the first embodiment. Fig. 7 is a diagram illustrating an example of a color prediction model created in the image processing system according to the first embodiment. As shown in Fig. 6, processing unit 100 includes measurement value receiving unit 101, reproducibility characteristic acquiring unit 102, color prediction model acquiring unit 103, profile creating unit 104, and storage unit 105.

[0046] The measurement value receiving unit 101 receives the colorimetric values ​​in multiple directions output by the measurement unit 500. Specifically, the measurement value receiving unit 101 receives the colorimetric values ​​of the metallic patch used to create the five-color output profile to be printed in step S501.

[0047] The reproducibility characteristic acquisition unit 102 calculates two physical quantities, a metallic value and a color value, from the multiple colorimetric values ​​received by the measurement value receiving unit 101, and transmits the metallic value and the color value to the color prediction model acquisition unit 103.

[0048] The color prediction model acquisition unit 103 constructs a color prediction model (metallic value prediction model, color value prediction model) for the target output paper based on the device values, and transmits it to the profile creation unit 104.

[0049] The profile creation unit 104 sets target color values ​​and target metallic values ​​at grid points in each Lab color space of the B2A table, calculates optimal device values ​​using the metallic value prediction model and color value prediction model, and generates a five-color output profile. The profile creation unit 104 also sends the generated five-color output profile to the storage unit 105. This allows the device values ​​of five plates, including metallic color materials, to correspond to the Lab coordinates of the PCS, enabling users to perform metallic printing directly from CMYK or RGB image data by profile conversion.

[0050] The storage unit 105 stores the five-color output profile sent from the profile creation unit 104 .

[0051] Next, among the components constituting the processing unit 100, the reproduction characteristic acquisition unit 102, the color prediction model acquisition unit 103, and the profile creation unit 104 will be described in detail.

[0052] The reproducibility characteristic acquisition unit 102 receives multiple colorimetric values ​​from the measurement value receiving unit 101 and calculates a metallic value and a color value. Here, the metallic value is a physical quantity that digitizes the brilliance of the object measured by the measurement unit 500, and is generally expressed using colorimetric values ​​measured in multiple directions.

[0053] In this embodiment, the Flop Index, which is generally used as a method for measuring color involving optical anisotropy, is used. As shown in Fig. 5, the Flop Index is calculated by receiving light at three angles of 15 degrees, 45 degrees, and 110 degrees with respect to an illumination angle of 45 degrees from the normal, and using the L values ​​at these angles, and basically normalizing the difference between the L values ​​at 15 degrees and 110 degrees by 45 degrees. The calculation formula is shown in Equation 1 below.

number

[0054] The flop index is a physical quantity in which the higher the value, the more brilliant the color. In other words, the more metallic the color. In contrast, the color value is a traditional index that expresses saturation and color depth using the L, a, and b values ​​at a light receiving angle of 45 degrees.

[0055] The color prediction model acquisition unit 103 acquires a color prediction model. Here, the color prediction model is a model that inputs the adhesion amount characteristics of the single colors C, M, Y, K, and Si, which are device values ​​of the reproduction printing machine, and outputs a metallic value and a color value. In this embodiment, the color prediction model outputs the flop index shown in formula (1) as the metallic value, and the predicted values ​​of the L, a, and b values ​​at a light receiving angle of 45 degrees as the color value.

[0056] Here, a method for creating a color prediction model will be described with reference to Fig. 7. First, the reproducibility characteristic acquisition unit 102 acquires colorimetric values ​​measured in multiple directions for patches of various combinations of C, M, Y, K, and Si values ​​(device values) on a metallic chart printed by the image forming apparatus 400 in step S501 of Fig. 3 using the colorimetric method shown in Fig. 5 and the measurement unit 500. As a result, a metallic value and a color value are obtained for each patch.

[0057] Then, based on these values, the color prediction model acquisition unit 103 inputs the C, M, Y, K, and Si values ​​(device values) to create a metallic value prediction model that can obtain metallic values ​​and a color value prediction model that can obtain color values. Note that the functions used in these color value prediction models can be general functions for color prediction models, such as multiple regression equations, neural networks, and interpolation using direct lookup tables.

[0058] Returning to Fig. 6, the profile creation unit 104 has a target value setting unit 104a and a search unit 104b. First, the target value setting unit 104a will be described with reference to Figs. 8 and 9. Fig. 8 is a diagram for explaining an example of a profile generation process in the image processing system according to the first embodiment. Fig. 9 is a diagram showing lattice points expressed in Lab coordinates in the PCS space of the B2A table generated in the image processing system according to the first embodiment.

[0059] As shown in Figure 8, printing using a profile involves color conversion of input image data consisting of CMYK or RGB components into PCS space (Lab values) using the input profile. Here, the input profile specifies Japan Color if the input image data (input image data) is CMYK, sRGB if it is RGB, etc., and the Lab values ​​resulting from color conversion to PCS space are designated Lab1. Device-dependent output profile 1 describes the relationship between the device values ​​(colorant amounts (C1, M1, Y1, K1)) required to obtain Lab values ​​(= Lab2) in PCS space. In process color printing, Lab1 and Lab2 are relative to paper white. If the input image data is (C, M, Y, K) = (0, 0, 0, 0), the device values ​​obtained after input / output profile conversion (color conversion) will also be (C1, M1, Y1, K1) = (0, 0, 0, 0).

[0060] Suppose the printer uses metallic (hereafter referred to as silver) in addition to process colors, and you want to print with a metallic feel in the highlights using output profile 2. In other words, the input image data is (C,M,Y,K)=(0,0,0,0), and the device values ​​you want to obtain after input / output profile conversion (color conversion) are (C2,M2,Y2,K2,Si2)=(0,0,0,0,100). In this case, some ingenuity is required for output profile 2 with 5 plates. This is because, while the white point in the PCS space is paper white in the input profile, the result of output profile conversion must be silver.

[0061] The white point in the PCS space of an output profile normally records the Lab information of the printing paper. This is set to Lab2 = (90,0,0). Lab2 is the colorimetric value when printing with (C,M,Y,K,Si) = (0,0,0,0,0). On the other hand, even if the colorimetric value (Lab value) when printing with (C,M,Y,K,Si) = (0,0,0,0,100) is Lab3 = (70,0,0), Lab2 is used in the PCS space of output profile 2 to maintain paper white relativeness. However, the device value (C,M,Y,K,Si) = (0,0,0,0,100) must be recorded at the grid point corresponding to paper white. In other words, the color obtained by printing the device values ​​registered in output profile 2 will not match the Lab value in the PCS space of output profile 2.

[0062] Therefore, the target value setting unit 104a sets a target color value and a target metallic value for each grid point. In other words, the target value setting unit 104a functions as an example of a target value setting means that sets a target value for each Lab coordinate (an example of coordinates) of grid point K in a device-independent color space (e.g., PCS space) of the five-color output profile. For example, the target value may be a target value (target color value and target metallic value) that is a physical quantity consisting of a diffuse reflection light component and a specular reflection light component. The Lab coordinates of grid point K in FIG. 9 are (ak, bk, Lk). If the target color value of grid point K is (at, bt, Lt), Lt can be expressed as the following equation (2) using a conversion formula from CIE XYZ.

number

[0063] That is, the profile creation unit 104 generates an output profile in which more metallic color material is assigned to grid points K on the highlight color side compared to shadow colors and high saturation colors. This makes it possible to achieve both quality and cost by deliberately not using metallic color material for colors for which the metallic color material has little effect.

[0064] FIG. 10 is a diagram illustrating the setting of a target metallic value in the LC plane of the image processing system according to the first embodiment. The target value setting unit 104a sets the metallic value so that it is lower for shadows and high-saturation color gamuts. In the example of FIG. 10, the white point (point O) is divided into four parts, from the minimum lightness point (point A) to the maximum saturation point (point B), and target metallic values ​​m1, m2, and m3 are set (m1>m2>m3). In FIG. 10, the metallic value is set to m1 or more in region 1, m2 or more and m1 or less in region 2, m3 or more and m2 or less in region 3, and m3 or less in region 4.

[0065] Next, the search unit 104b will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of the flow of operations of the search unit in the image processing system according to the first embodiment. The search unit 104b acquires the metallic value prediction model and the color value prediction model transmitted by the color prediction model acquisition unit 103 (step S301). The search unit 104b also acquires the target color value and the target metallic value at each lattice point K expressed in Lab coordinates in the PCS space in the B2A table set by the target value setting unit 104a (step S302).

[0066] The search unit 104b also inputs the metallic value and color value of the target color and searches for and acquires the optimal five-color device values ​​that satisfy them (step S303). Here, the search conditions may be a device value where the metallic value is within the target range and the color difference in the color value is minimized. Next, the search unit 104b searches for the five-color device values ​​for all lattice points in the B2A table (step S304), and ends the search for the five-color device values. In other words, the search unit 104b functions as an example of a device value acquisition means that acquires device values ​​for five or more colors that reproduce the target values ​​(target color value, target metallic value).

[0067] Finally, the search unit 104b sets the searched device values ​​at each grid point K in the B2A table, which is expressed in Lab coordinates in the PCS space, and creates a five-color output profile. The created five-color output profile is sent to the storage unit 105.

[0068] 12 is a diagram illustrating a part of the functional configuration of the controller of the image processing system according to the first embodiment. As shown in FIG. 12, the controller 200 includes a profile acquisition unit 201, a print job receiving unit 202, and a color conversion unit 203.

[0069] The profile acquisition unit 201 acquires the input profile and the five-color output profile stored in the storage unit 105 included in the processing unit 100, and transmits them to the color conversion unit 203. In other words, the profile acquisition unit 201 functions as an example of an input profile designation means that designates an input profile, and an output profile designation means that designates an output profile.

[0070] A print job receiving unit 202 receives a print job including image data and transmits it to a color conversion unit 203 .

[0071] The color conversion unit 203 performs a process of separating the image data included in the print job into plates for each color material using an input profile and a five-color output profile, and transmits the result to the image forming apparatus 400. In other words, the color conversion unit 203 functions as an example of a generation unit that uses the input profile and the five-color output profile to generate a printed material in which the print job is separated into five or more plates including a metallic color material. For example, the color conversion unit 303 may generate an output profile using the device values ​​acquired by the search unit 104b and Lab coordinates in the PCS space. This makes it possible to easily generate metallic printed material without specifying a spot color.

[0072] As described above, in the process of creating a five-color output profile in the image processing system according to the first embodiment, metallic values ​​and color values ​​are obtained from a plurality of colorimetric values ​​acquired by the measurement unit 500, a color prediction model is obtained, target color values ​​and target metallic values ​​are set for each grid point expressed in Lab coordinates in the PCS space in the B2A table, device values ​​that satisfy these are obtained, and a five-color output profile can be created using the Lab coordinates and device values.

[0073] Furthermore, by combining the five-color output profile and input profile created in the first embodiment, color separation into five plates becomes possible on the image forming device 400, making it possible to easily perform metallic printing.

[0074] (Second embodiment) In this embodiment, the user selects print data on the user interface (UI), indicates that metallic printing will be performed, and sets an input profile and a five-color output profile. In the following explanation, explanations of the same configuration as in the first embodiment will be omitted.

[0075] In this embodiment, the operation unit 300 functions as an example of a user interface for inputting designations of a print job, an input profile, and a five-color output profile. In this embodiment, the profile acquisition unit 201 designates an input profile and an output profile in accordance with the input profile and the five-color output profile input from the operation unit 300.

[0076] Fig. 13 is a diagram for explaining an example of a UI in the image processing system according to the second embodiment. Here, Fig. 13 corresponds to the screen in step S402 in the flowchart shown in Fig. 2, and on this screen, the user selects an input profile, an output profile, and sets the fifth color toner attached to the toner station (photoconductor 403S) shown in Fig. 6.

[0077] In this way, the image processing system according to the second embodiment can achieve the same effects as those of the first embodiment.

[0078] In this embodiment, the measurement value receiving unit 101, the reproducibility characteristic acquiring unit 102, the color prediction model acquiring unit 103, the profile creating unit 104, the profile acquiring unit 201, the print job receiving unit 202, the color conversion unit 203, etc. are provided outside the image forming device 400 (the processing unit 100, the controller 200), but may also be provided inside the image forming device 400.

[0079] The program executed by the image processing system of this embodiment is provided in advance in a ROM (Read Only Memory) etc. The program executed by the image processing system of this embodiment may be provided by being recorded in an installable or executable file format on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk).

[0080] Furthermore, the program executed by the image processing system of this embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Also, the program executed by the image processing system of this embodiment may be provided or distributed via a network such as the Internet.

[0081] The program executed by the image processing system of this embodiment has a modular configuration including the above-mentioned units (measurement value receiving unit 101, reproducibility characteristic acquisition unit 102, color prediction model acquisition unit 103, profile creation unit 104, profile acquisition unit 201, print job receiving unit 202, and color conversion unit 203), and in actual hardware, a processor such as a CPU (Central Processing Unit) reads and executes the program from the above-mentioned ROM, thereby loading the above-mentioned units onto the main memory, and the measurement value receiving unit 101, reproducibility characteristic acquisition unit 102, color prediction model acquisition unit 103, profile creation unit 104, profile acquisition unit 201, print job receiving unit 202, and color conversion unit 203 are generated on the main memory.

[0082] In the above embodiment, the image forming apparatus of the present invention is described as being applied to a multifunction peripheral having at least two of the functions of a copy function, a printer function, a scanner function, and a facsimile function, but the present invention can be applied to any image forming apparatus such as a copier, printer, scanner device, or facsimile device.

[0083] For example, aspects of the present invention are as follows. <1> An image processing system that generates and prints five or more color plates containing metallic color materials from an input image in which gradations change continuously, An acquisition means for acquiring printing data that is composed of CMYK or RGB and does not include a designation of a spot color; an input profile designation means for designating an input profile for converting the printing data into color values ​​in a device-independent space; an output profile designation means for designating an output profile for the metallic color material; a generating means for generating a printed matter in which the printing data is separated into five or more plates including the metallic color material using the designated input profile and output profile; An image processing system comprising: <2> a target value setting means for setting a target value for each coordinate of a lattice point in a device-independent color space of the output profile; a device value acquisition means for acquiring device values ​​of five or more colors that reproduce the target value; the generating means includes a generating means for generating the output profile using the acquired device values ​​and the coordinates, The target value is a physical quantity consisting of a diffuse reflection light component and a specular reflection light component. <1> 2. The image processing system according to claim 1 . <3> the output profile allocates more of the metallic colorant to the grid points on the highlight color side compared to shadow colors or high saturation colors; <2> 2. The image processing system according to claim 1 . <4> a user interface for inputting the print data, the input profile, and the output profile; Equipped with <1> from <3> 10. The image processing system according to claim 9, wherein: <5> <2> An output profile produced by the described image processing system. <6> <1> from <4> 10. An image output device comprising the means described in any one of the above. <7> An image processing method executed by an image processing system that generates and prints five or more color plates having metallic color materials from an input image whose gradation changes continuously, comprising: A step of acquiring printing data that is composed of CMYK or RGB and does not include a designation of a spot color; specifying an input profile for converting the print data into color values ​​in a device-independent space; specifying an output profile for the metallic colorant; generating a printed matter by separating the printing data into five or more plates containing the metallic color material using the specified input profile and output profile; An image processing method comprising: <8> A computer that controls an image processing system that generates and prints five or more color plates having metallic color materials from an input image whose gradation changes continuously, An acquisition means for acquiring printing data that is composed of CMYK or RGB and does not include a designation of a spot color; an input profile designation means for designating an input profile for converting the printing data into color values ​​in a device-independent space; an output profile designation means for designating an output profile for the metallic color material; a generating means for generating a printed matter in which the printing data is separated into five or more plates including the metallic color material using the designated input profile and output profile; A program to make it function as such. [Explanation of symbols]

[0084] 100 Processing section 101 Measurement value receiving unit 102 Reproduction characteristic acquisition unit 103 Color prediction model acquisition unit 104 Profile Creation Department 105 Storage area 200 Controller 201 Profile Acquisition Unit 202 Print job receiving unit 203 Color conversion unit 300 Operation section 400 Image forming device 500 Measuring part [Prior art documents] [Patent documents]

[0085] [Patent Document 1] Japanese Patent Publication No. 2022-178256

Claims

1. An image processing system that generates and prints five or more color plates having metallic color materials from an input image in which gradations change continuously, An acquisition means for acquiring printing data that is configured with CMYK or RGB and does not include a designation of a spot color; an input profile designation means for designating an input profile for converting the printing data into color values ​​in a device-independent space; an output profile designation means for designating an output profile for the metallic color material; a generating means for generating a printed matter in which the printing data is separated into five or more plates including the metallic color material using the designated input profile and output profile; An image processing system comprising:

2. a target value setting means for setting a target value for each coordinate of a lattice point in a device-independent color space of the output profile; a device value acquisition means for acquiring device values ​​of five or more colors that reproduce the target value, the generating means includes a generating means for generating the output profile using the acquired device values ​​and the coordinates, 2. The image processing system according to claim 1, wherein the target value is a physical quantity consisting of a diffuse reflection light component and a specular reflection light component.

3. 3. The image processing system according to claim 2, wherein the output profile allocates more of the metallic colorant to the grid points on the highlight color side compared to shadow colors or highly saturated colors.

4. a user interface for inputting the print data, the input profile, and the output profile; 4. The image processing system according to claim 1, comprising:

5. An output profile generated by the image processing system of claim 2.

6. An image output device that generates and prints five or more color plates containing metallic color materials from an input image whose gradation changes continuously, An acquisition means for acquiring printing data that is configured with CMYK or RGB and does not include a designation of a spot color; an input profile designation means for designating an input profile for converting the printing data into color values ​​in a device-independent space; an output profile designation means for designating an output profile for the metallic color material; a generating means for generating a printed matter in which the printing data is separated into five or more plates including the metallic color material using the designated input profile and output profile; An image output device comprising:

7. An image processing method executed by an image processing system that generates and prints five or more color plates having metallic color materials from an input image in which gradations change continuously, the method comprising: A step of acquiring printing data that is configured in CMYK or RGB and does not include a designation of a spot color; specifying an input profile for converting the print data into color values ​​in a device-independent space; specifying an output profile for the metallic colorant; generating a printed matter by separating the printing data into five or more plates containing the metallic color material using the specified input profile and output profile; An image processing method comprising:

8. A computer that controls an image processing system that generates and prints five or more color plates having metallic color materials from an input image whose gradation changes continuously, An acquisition means for acquiring printing data that is configured with CMYK or RGB and does not include a designation of a spot color; an input profile designation means for designating an input profile for converting the printing data into color values ​​in a device-independent space; an output profile designation means for designating an output profile for the metallic color material; a generating means for generating a printed matter in which the printing data is separated into five or more plates including the metallic color material using the designated input profile and output profile; A program to make it function as such.

Images