Program and Information Processing Device

Abstract

To improve the reproducibility of the color of an image of a printed matter displayed on a screen compared to a case in which the color of image of printed matter is reproduced by considering only the reflected light from paper.SOLUTION: There is provided a program that causes a computer that reproduces the color of a printed matter and displays it on the screen before printing to function of generating an image that reproduces the color tone of the printed matter on the basis of a first component reflected by a metallic color material and a second component transmitted through the color material and reflected by the paper.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a program and an information processing apparatus.

Background Art

[0002] Before printing, it may be necessary to check the color tone of the image to be printed on the screen. A preview function is used for this check. By checking the color tone before printing, waste of paper and coloring materials can be reduced. In the field of color printing, four colors, C (cyan), M (magenta), Y (yellow), and K (black), are used as basic colors. Recently, in addition to the basic colors, metallic colors such as gold and silver may also be used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Today, various colored papers are used for printing. However, even when printing the same image, the color tone of the printed matter may appear different depending on the color of the paper. For example, the same image may appear to have a different color tone when printed on white paper (hereinafter referred to as "white paper") and when printed on blue paper. Therefore, when displaying the image of the printed matter by the preview function, a technique for correcting the appearance of the image of the printed matter when printed on white paper with a coefficient determined according to the color of the paper has been put into practical use.

[0005] However, the previous preview function did not account for cases where colorants corresponding to gold, silver, and other metallic colors were printed on colored paper (hereinafter referred to as "non-white paper"). In fact, when metallic colors were displayed using the previous preview function, there was a significant difference from the appearance of the actual printed product, unlike when printed on white paper. In particular, the difference in appearance from the actual printed product was large in areas where the density of colorants corresponding to metallic colors was high.

[0006] The present invention aims to improve the color reproduction accuracy of printed images displayed on a screen compared to the case where the color of a printed image is reproduced by considering only the reflected light from the paper. [Means for solving the problem]

[0007] The invention described in claim 1 is a program for a computer that reproduces the color of a printed material before printing and displays it on a screen, and which generates an image that reproduces the color of the printed material based on a first component reflected by a metallic colorant and a second component that passes through the colorant and is reflected by the paper. The invention described in claim 2 is a program according to claim 1, wherein the function for generating the image is to synthesize the first component and the second component in a proportion corresponding to the magnitude of the density value of the colorant, and generate the image. Claim 3 The invention described herein is a function for generating the image, wherein, when α is the value obtained by multiplying the reflectance coefficient of the colorant by the density value, the first component and the second component are added in a ratio of α:1-α. 2 This is the program described in [the document]. Claim 4 The invention described above is a program according to claim 1, wherein the function for generating the image sets the ratio of the second component according to the area ratio over which the colorant covers the surface of the paper. Claim 5 The invention described herein is the program according to claim 1, wherein the colorant is a toner that forms a layer on the surface of the paper. Claim 6 The invention described is the program according to claim 1, wherein the paper is a non-blank sheet of paper. Claim 7 The invention described herein is an information processing device having a processor, the processor generating an image that reproduces the color of a printed material based on a first component reflected by a metallic colorant and a second component transmitted through the colorant and reflected by the paper. [Effects of the Invention]

[0008] According to the invention described in claim 1, the accuracy of color reproduction of the printed image displayed on the screen can be improved compared to the case where the color of the printed image is reproduced by considering only the reflected light from the paper. According to the invention described in claim 2, the color can be adjusted according to the magnitude of the colorant's density value. Claim 3 According to the invention described, the ratio of the first and second components can be adjusted according to the density value of the colorant, making the image of the printed material closer to its actual appearance. Claim 4 According to the described invention, the color can be adjusted according to the area ratio of the colorant. Claim 5 According to the described invention, the image of a printed material printed with toner corresponding to a metallic color can be made to look closer to the actual appearance. Claim 6 According to the described invention, when printing metallic colors on non-white paper, the image of the printed material can be made to look closer to the actual appearance. Claim 7 According to the described invention, the accuracy of color reproduction of the printed image displayed on the screen can be improved compared to the case where the color of the printed image is reproduced by considering only the reflected light from the paper. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example configuration of the printing system used in the embodiment. [Figure 2] This figure shows an example of the hardware configuration of a control device. [Figure 3] This diagram illustrates an example of the data structure of a white DLUT. [Figure 4]This is a diagram showing an example of the functional configuration of a control device. [Figure 5] This is a diagram explaining the mechanism by which color is recognized and the arithmetic algorithm of a color paper DLUT. (A) is a diagram explaining how a white sheet of paper looks, (B) is a diagram explaining how the color of a part printed with yellow toner on the surface of a white sheet of paper looks, (C) is a diagram explaining how a blue sheet of paper looks, (D) is a diagram explaining how the color of a part printed with yellow toner on the surface of a blue sheet of paper looks, and (E) is the arithmetic algorithm of a color paper DLUT assuming the case of printing using primary colors on a blue sheet of paper. [Figure 6] This is a diagram explaining the influence of metallic color on color and the arithmetic algorithm of a color paper DLUT. (A) is a diagram explaining how the color of a part where silver toner and yellow toner are printed in sequence on the surface of a blue sheet of paper looks, and (B) is the arithmetic algorithm of a color paper DLUT assuming the case of printing using primary colors and metallic colors on a blue sheet of paper. [Figure 7] This is a flowchart showing an example of the processing operation regarding the display of a preview image by a control device. [Figure 8] This is a diagram explaining an example of the display of a preview image when no special features are used. (A) shows an example of a preview image when printing on white paper, and (B) shows an example of a preview image when printing on blue paper. [Figure 9] This is a diagram explaining an example of the display of a preview image when special features are used. (A) shows an example of a preview image when printing on white paper using silver toner as a base, (B) shows an example of a preview image when printing on blue paper using silver toner as a base, and (C) shows an example of a preview image when printing on blue paper using gold toner as a base.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. <System Configuration> FIG. 1 is a diagram showing a configuration example of a printing system 1 used in an embodiment. The printing system 1 shown in Figure 1 consists of a paper feeder 10, a printing device 20, a post-processing device 30, and a control device 40. In this context, printing system 1 is an example of an image forming system, printing device 20 is an example of an image forming device, and control device 40 is an example of an information processing device.

[0011] The printing system 1 shown in Figure 1 is also called a production printer. However, printing system 1 is not limited to a production printer; it can also be a printer used in an office or a printer used at home. Office printers have functions such as scanning and sending / receiving faxes in addition to printing. The main difference between office printers and home printers is their performance.

[0012] The printing system 1 shown in Figure 1 has two paper feeders 10 connected in series. The paper feeder 10 is a device that supplies paper to the printing device 20. In this embodiment, the paper feeder 10 contains cut sheets of paper. For example, the paper feeder 10 can hold 7,000 sheets of cut paper. However, the paper stored in the paper feeder 10 is not limited to cut sheets; roll paper may also be used. In this embodiment, the paper is not limited to so-called white paper (hereinafter also referred to as "white paper"), but the use of colored paper (hereinafter referred to as "non-white paper") is also considered.

[0013] In this embodiment, the non-white paper is not limited to cases where the entire sheet is a single color. For example, the paper may contain multiple colors. Furthermore, non-white paper includes not only dyed paper but also paper with only the surface colored. Therefore, paper with some kind of color applied to the surface beneath a metallic layer can also be broadly included in the category of non-white paper. The paper used here is an example of a recording medium.

[0014] The printing system 1 shown in Figure 1 has two printing devices 20 connected in series. In this embodiment, each printing device 20 has an engine (hereinafter also referred to as the "printing engine") that prints an image onto paper using an electrophotographic method. A printing engine prints an image onto paper through the processes of charging, exposure, development, transfer, and fixing. A printing engine is an example of a forming unit that uses multiple colorants to create an image on paper. Images include not only diagrams and photographs, but also text. Hereafter, the diagrams and photographs formed on the surface of the paper will also be referred to as objects.

[0015] The printing apparatus 20 used in this embodiment is capable of printing using four types of toner corresponding to basic colors and one or two types of toner corresponding to metallic colors. In this embodiment, gold, silver, and other metallic colors are assumed. Metallic colors are also called colors that have a higher reflectance coefficient to natural light compared to basic colors. Metallic colors are sometimes called "special colors" because they are colors other than basic colors. The toner used in the printing device 20 is an example of a colorant. In this embodiment, the printing device 20 has the function of printing on one side of the paper as well as the function of printing on both sides of the paper. The paper on which the image has been printed is called a printed document.

[0016] The printing system 1 shown in Figure 1 has two post-processing units 30 connected in series. The post-processing units 30 are equipped with processes such as stacking (i.e., stacking), stapling, and binding.

[0017] The control device 40 is a device that controls the movement of the printing device 20 and other devices. For example, the control device 40 controls the generation of DLUTs (Direct Look Up Tables), reading DLUTs, managing print jobs and document data used for printing, and RIP (Raster Image Processor) processing. DLUT is a table that maps the density values ​​of each toner color to the values ​​used to calculate each display color. DLUT is an example of a conversion table. Furthermore, the control device 40 also controls the generation of a preview image that reproduces the color of the printed material before printing, using the DLUT described above. In Figure 1, the control device 40 is located on the top of the housing of the printing device 20, but it may also be located inside the housing of the printing device 20.

[0018] A print job refers to a job that instructs the printing of a document. A single print job includes a data file (hereinafter also referred to as "document data") corresponding to the document to be printed. The data format of the document data is not restricted. Document data includes electronic documents generated by application programs (hereinafter referred to as "apps") and digitized documents generated from paper documents.

[0019] Electronic documents include, for example, electronic data generated by so-called office applications, electronic data generated by drafting applications, electronic data generated by accounting applications, and web pages displayed in applications for viewing websites (i.e., browsers). Digitized documents include, for example, electronic data output from scanners and electronic data output from cameras.

[0020] The document data in this embodiment includes objects such as shapes and text, and each object has a color assigned to it. The color of an object is given, for example, by the density values ​​of C (cyan), M (magenta), Y (yellow), K (black), and metallic colors. In this embodiment, the concentration value is expressed as, for example, 0 to 100%, or 0 to 255. 0% or 0 represents the minimum concentration value, and 100% or 255 represents the maximum concentration value.

[0021] <Control device configuration> Figure 2 shows an example of the hardware configuration of the control device 40. The control device 40 shown in Figure 2 includes a processor 41, a ROM (Read Only Memory) 42 in which the BIOS (Basic Input Output System) and other data are stored, a RAM (Random Access Memory) 43 used as the work area of ​​the processor 41, an auxiliary storage device 44, a user interface 45, a communication interface 46, and an I / O 47. The various parts of the control device 40 are connected via buses and other signal lines 48.

[0022] The processor 41 is a device that performs various functions through the execution of a program. In this embodiment, the processor 41 realizes various functions through program execution. The processor 41, ROM 42, and RAM 43 function as a computer. The auxiliary storage device 44 is, for example, a hard disk drive or semiconductor storage. The auxiliary storage device 44 is used to store programs, print jobs, etc. The term "program" is used as a general term for OS (Operating System) and application programs.

[0023] In addition, the auxiliary storage device 44 stores a DLUT (hereinafter referred to as "white DLUT") 44A that converts the density values ​​of each color provided by the document data into the display colors that would be observed if printed on white paper. Figure 3 illustrates an example of the data structure of the white DLUT44A. The left column of the data structure corresponds to the density values ​​specified in the document data, and the right column corresponds to the values ​​used to calculate the display color.

[0024] In Figure 3, the density values ​​are given by C (cyan), M (magenta), Y (yellow), K (black), and metallic colors. On the other hand, the values ​​used to calculate the display value are given by the R (red), G (green), and B (blue) gradation values ​​and the gloss level. The gradation values ​​are sometimes called "signal values." The gradation values ​​are expressed, for example, from 0 to 255. 0 is the minimum value and 255 is the maximum value. The gloss level is expressed, for example, from 0 to 100%. 0% is the minimum value and 100% is the maximum value. In Figure 3, specific numerical values ​​have been omitted.

[0025] Let's return to the explanation of Figure 2. The user interface 45 is an interface that accepts operations from a user using the printing device 20. The user interface 45 has an input section, such as operation buttons or a touch sensor that detects operations by the user's fingertips, and a display section, such as a liquid crystal display or an organic EL (=Electro-Luminescent) display.

[0026] The communication interface 46 is an interface for communicating with other terminals, etc. Wired or wireless communication methods can be used for the communication interface 46. Communication standards such as Ethernet® and Wi-Fi® can be used for the communication interface 46. I / O47 is a device used for communication between the processor 41 and the printing device 20 (see Figure 1), etc.

[0027] Figure 4 shows an example of the functional configuration of the control device 40. The functional units shown in Figure 4 are realized through the execution of a program by the processor 41 (see Figure 2). The functional units shown in Figure 4 can be broadly classified into an input receiving unit 410, an image processing unit 420, and an output unit 430.

[0028] The input receiving unit 410 is a functional unit that receives information necessary for predicting the color of printed materials. In Figure 4, the input receiving unit 410 receives input of document data 411, toner color 412, and paper color 413. The document data 411 is, for example, a color chart in which multiple colors with different hues are arranged in a matrix. The toner color 412 indicates the toner colors that the printing device 20 can use as colorants. The toner color 412 is given by, for example, C (cyan), M (magenta), Y (yellow), K (black), and metallic colors. The metallic color is, for example, silver. The paper color 413 is the color of the paper stored in the paper feeder 10 (see Figure 1), and is given by, for example, the density values ​​of C (cyan), M (magenta), Y (yellow), and K (black).

[0029] The image processing unit 420 is a functional unit that generates a preview image to predict the color of the printed material. In Figure 4, the image processing unit 420 consists of a preview image creation unit 421 and a white DLUT 44A. The preview image creation unit 421 is a functional unit that creates a color conversion table (hereinafter referred to as "color paper DLUT") that reproduces the colors observed when printing an object on the surface of non-white paper, and creates a preview image.

[0030] In this embodiment, the preview image creation unit 421 creates a colored DLUT using document data 411, toner color 412, paper color 413, and white DLUT 44A. The created colored paper DLUT is stored in the auxiliary storage device 44 (see Figure 2). The output unit 430 is a functional unit that displays a preview image on the display unit to predict the color of the printed material. In Figure 4, the output unit 430 consists of a preview unit 431. The preview unit 431, by referencing a blank DLUT and a colored DLUT, converts the colors of the objects specified in the document data 411 to colors that reproduce how they would appear when printed on non-white paper, and displays them on the display unit. In this embodiment, the preview image is displayed in three dimensions.

[0031] <Calculation algorithm for colored paper DLUT> The calculation algorithm for colored paper DLUT will be explained below using Figures 5 and 6. Figure 5 illustrates the mechanism by which colors are recognized and the calculation algorithm of the colored paper DLUT. (A) is a diagram illustrating how white paper looks, (B) is a diagram illustrating how the color of the area printed with yellow toner on the surface of white paper looks, (C) is a diagram illustrating how blue paper looks, (D) is a diagram illustrating how the color of the area printed with yellow toner on the surface of blue paper looks, and (E) is the calculation algorithm of the colored paper DLUT assuming printing on blue paper using basic colors.

[0032] In Figures 5(A) to (D), the incident and reflected R (red), G (green), and B (blue) light, as natural light, are represented by arrows. A downward-pointing arrow indicates incident light, and an upward-pointing arrow indicates reflected light. The length of the arrow represents the intensity of the light. In Figure 5(A), the intensity of the light component incident on the white paper is almost the same as the intensity of the light component reflected by the white paper. Therefore, R (red), G (green), and B (blue) are mixed together, making it appear white.

[0033] Incidentally, the B (blue) component is absorbed by the yellow toner. Therefore, in Figure 5(B), only the intensity of the reflected light component of B (blue) is reduced. As a result, the R (red) and G (green) components are mixed together, making it appear yellow. In Figure 5, the difference in the amount of absorbed components is represented by the size of the circles. On the other hand, in Figure 5(C), only the B (blue) component is reflected by the blue paper at the same level as the incident light component, while some of the R (red) and G (green) components are absorbed by the blue paper. As shown in Figure 5(C), the reflected light from the blue paper is predominantly B (blue). Consequently, the blue paper appears blue.

[0034] Furthermore, the red (R) component is absorbed more by blue paper than the green (G) component. Therefore, in Figure 5(C), the circle representing the absorption of the red (R) component is larger than the circle representing the absorption of the green (G) component, and the length of the arrow representing the intensity of reflected light is shorter for the red (R) component than for the green (G) component. Figure 5(D) illustrates the mechanism by which printing yellow toner on blue paper results in a greenish appearance. As shown in Figure 5(D), absorption occurs for the R (red) and G (green) components as explained in Figure 5(C), and absorption occurs for the B (blue) component as explained in Figure 5(B). As a result, the component of the reflected light that passes through the yellow toner and is output to the outside becomes predominantly green (G). This is why it appears greenish.

[0035] Figure 5(E) shows the calculation formula for the colored paper DLUT used to display the preview image when printing on non-white paper using basic colors. Colored paper DLUT[RGB] = Colored paper[RGB] × Blank paper DLUT[RGB] / Blank paper[RGB] Colored paper [RGB] is the signal value of the display color when printing metallic colors on non-white paper, and is given as an RGB value. White paper [RGB] is the signal value of the display color when printing metallic colors on white paper, and is given as an RGB value.

[0036] When using blank paper for printing, the same value appears in both the numerator and denominator, resulting in a formula consisting only of "Blank Paper DLUT[RGB]". The value in the denominator is used to normalize the effect of absorption on non-white paper as a relative value to white paper. In Figure 5(E), [RGB] corresponds to the display colors R (red), G (green), and B (blue) of the preview image.

[0037] Figure 6 illustrates the effect of metallic colors on color and the calculation algorithm of the colored paper DLUT. (A) is a diagram illustrating how the color appears in areas where silver toner and yellow toner are printed sequentially on the surface of blue paper, and (B) is the calculation algorithm of the colored paper DLUT assuming printing with basic colors and metallic colors on blue paper. Even at the maximum density of silver toner and other metallic colors, as shown in Figure 6(A), there are still components that pass through the silver toner and are reflected from the surface of the paper. One reason for this is that metallic toners such as silver toner do not completely cover the surface of the paper.

[0038] The percentage of the paper surface covered by toner per unit area is also called the "area ratio." The area ratio is proportional to the density value of each toner. In other words, the higher the density value, the larger the area ratio, and the lower the density value, the smaller the area ratio. Figure 6(A) shows a structure in which a layer of silver toner is formed on the surface of blue paper, and then a layer of yellow toner is formed on the surface of that layer.

[0039] As mentioned earlier, metallic colors are pigments with a higher reflectivity compared to basic colors. Therefore, Figure 6(A) shows arrows representing the components reflected by the paper surface and arrows representing the components reflected by the silver toner. The pairs of arrows to the left of each color represent the components that pass through the silver toner and are reflected off the blue surface of the paper. This component is an example of the second component. On the other hand, the pairs of arrows to the right of each color represent the components reflected by the silver toner. This component is an example of the first component.

[0040] Of these, the reflection of each component on the surface of the blue paper is the same as in Figure 5(C). That is, some of the R (red) and G (green) components are absorbed by the blue paper. Therefore, the intensity of the R (red) and G (green) components reflected from the surface of the paper is lower than the intensity of the incident components. On the other hand, in reflections on the surface of silver toner, the effect of absorption is negligible. Therefore, the intensity of the components reflected by the silver toner is basically the same as the intensity of each component at the time of incidence.

[0041] Furthermore, the higher the concentration of silver toner, the greater the component of light reflected by the silver toner, and relatively less the component of light that passes through the silver toner and is reflected by the surface of the underlying blue paper. In other words, the lower the concentration of silver toner, the less the component of light reflected by the silver toner, and relatively more the component of light that passes through the silver toner and is reflected by the surface of the blue paper.

[0042] By the way, the B (blue) component is also reflected from both the surface of the blue paper and the surface of the silver toner. The blue (B) component reflected from the surface of the blue paper passes through the silver toner, but some is absorbed by the yellow toner. This absorption is similar to that shown in Figure 5(D). Therefore, the length of the arrow representing the intensity of the blue (B) component reflected from the surface of the blue paper is shorter than that of the incident light. By the way, some of the B (blue) component is also reflected by the surface of the silver toner. Since this is reflection, we do not consider the reduction in intensity due to reflection. However, some of the B (blue) component reflected by the silver toner is also absorbed by the yellow toner.

[0043] As a result, the intensity of the B (blue) component that passes through the yellow toner and is output to the outside is less than that of R (red) and G (green). In other words, the light component reflected by the blue paper is similar to that in Figure 5(D), while the light component reflected by the silver toner is similar to that in Figure 5(B). Therefore, in areas where silver toner is formed on the surface of blue paper, and yellow toner is formed on the surface of that silver toner, the resulting area will appear as an intermediate color between Figure 5(B) and Figure 5(D), i.e., a yellowish-green. Figure 6(B) shows this calculation algorithm.

[0044] Figure 6(B) shows the calculation formula for the colored paper DLUT used to display the preview image when printing on non-white paper using basic colors and spot colors. Special color compatible colored paper DLUT [RGB] = Reflectance coefficient × Spot color Cin × Blank DLUT [RGB] + (1 - Reflectance coefficient × Special color Cin) × Colored paper [RGB] × Colored paper DLUT [RGB] / Blank paper [RGB]

[0045] Here, the first term corresponds to the light component reflected by the spot color toner, and the second term corresponds to the light component reflected by the paper. In the first term, the "reflection coefficient × spot color Cin" part represents the magnitude of the influence of the component reflected by the spot color toner. A distinctive feature here is the use of metallic colors such as silver and gold. The reflection coefficient is the reflection coefficient of the spot color used in printing. The reflection coefficient must be a value between 0 and 1.

[0046] Cin is the concentration value of the feature. The concentration value is a number between 0 and 1, with 0 being the minimum concentration and 1 being the maximum concentration. The concentration values ​​here are the normalized values ​​of the concentration values ​​in Figure 3. In other words, each concentration value is obtained by dividing it by the maximum concentration value of 100. Therefore, even with the same density value, the higher the reflection coefficient, the larger the value of "reflection coefficient × spot color Cin". Also, even with the same reflection coefficient, the higher the density value, the larger the value of "reflection coefficient × spot color Cin". In other words, the influence of the components reflected by the spot color toner becomes greater. Note that in item 1, the "Blank DLUT[RGB]" section represents how the colors appear when printed on blank paper.

[0047] The second term is a formula for calculating the influence of the colored paper DLUT, which reproduces the color tone when printing the basic colors explained in Figure 5(E) on non-white paper, on the overall color tone. In the second term, the part "1 - reflection coefficient × feature color Cin" is a coefficient that gives the apportionment ratio with the first term. In other words, the larger the value of "reflection coefficient × special color Cin", the smaller the value of "1 - reflection coefficient × special color Cin".

[0048] Here, if we let α be "reflection coefficient × special color Cin", Special color compatible colored paper DLUT [RGB] =α × blank DLUT[RGB] + (1-α) × colored DLUT[RGB] It is possible to express it as follows. α is a value between 0 and 1, inclusive.

[0049] In other words, the higher the density of the spot color toner, the greater the influence of the first component read out by the blank DLUT than the second component that is synthesized. Conversely, the lower the density of the spot color toner, the greater the influence of the second component read out by the colored DLUT than the first component that is synthesized. In other words, the proportion of the second component synthesized with the first component is inversely proportional to the density value of the spot color toner. The (R, G, B, gloss) output from a blank DLUT is an example of the first component, while the (R, G, B, gloss) output from a colored DLUT is an example of the second component.

[0050] <Example of processing operation> Figure 7 is a flowchart showing an example of the processing operation related to the display of a preview image by the control device 40. In the figure, the symbol S represents a step. The processing operations shown in Figure 7 are controlled through the execution of a program by the processor 41 (see Figure 2). The processing operation shown in Figure 7 is initiated when the processor 41 receives a request, for example, to display a preview image that reproduces the colors of the printed material before printing.

[0051] First, the processor 41 receives the document data, toner color, and paper color. The toner color is the color of the toner that the printing device 20 (see Figure 1) can actually use. As mentioned above, toner colors include basic colors and spot colors. In this embodiment, metallic colors are assumed as spot colors. The paper color is the color of the paper used to print the document data. Next, processor 41 acquires the white DLUT (step 2). The white DLUT is necessary for creating preview images of printouts that do not use spot toner, as well as for creating preview images of printouts that do use spot toner.

[0052] Once the white DLUT is obtained, the processor 41 creates a colored DLUT (step 3). The colored DLUT can be calculated using Figure 5(E). Next, the processor 41 converts the color of the document data using the blank DLUT and the colored DLUT (step 4). This conversion is performed by the calculation formula shown in Figure 6(B). Finally, the processor 41 displays a preview image created using the paper color received in step 1 and the color calculated in step 4 (step 5). In this embodiment, the preview image is displayed on the display unit of the control device 40.

[0053] <Example of preview image display> Figure 8 illustrates an example of a preview image when no spot colors are used. (A) shows an example of a preview image when printing on blank paper, and (B) shows an example of a preview image when printing on blue paper. Figures 8(A) and (B) show the same color chart printed on paper. In Figure 8(A), since the paper is white, the color of the color patch is reproduced almost exactly as the input value. Therefore, the color patch in the 3rd row and 4th column is displayed as yellow. However, when the paper is blue, as explained in Figure 5(D), the absorption of the R (red) and B (blue) components in the yellow toner is greater. As a result, in Figure 8(B), the color patch in the 3rd row and 4th column is labeled as green.

[0054] Figure 9 illustrates examples of preview images when using spot colors. (A) shows an example of a preview image when printing on white paper with silver toner as the base coat, (B) shows an example of a preview image when printing on blue paper with silver toner as the base coat, and (C) shows an example of a preview image when printing on blue paper with gold toner as the base coat. In the case of Figure 9, we assume that the same color chart as in Figure 8 is printed on paper.

[0055] In Figure 9(A), although the paper is white, a layer of silver toner is formed as the base for each color patch. Therefore, the color patch in the 3rd row and 4th column appears as a light yellow. Other color patches are also displayed in a generally lighter color compared to Figure 8(A). In Figure 9(B), the paper is blue. In this case, the color is affected by the density value of the silver toner, and a color between Figure 8(A) and Figure 8(B) is displayed as the preview image. In the example of Figure 9(B), the color patch in the 3rd row and 4th column is displayed as yellow-green. In Figure 9(C), the paper is blue, but gold toner is used as the metallic color. Therefore, the appearance of the preview image is different from when silver toner is used.

[0056] <Summary> As explained above, this embodiment focuses on the characteristic that light components incident on the surface of a printed material are reflected by a metallic-colored toner layer. Furthermore, noting that even with the same reflectance coefficient, the higher the density of metallic toner, the greater the metallic reflection component, the more significant the preview image becomes. As a result, when printing document data images on non-white paper using a metallic color as a base, it becomes possible to generate preview images that closely resemble the colors actually observed.

[0057] <Other Embodiments> (1) Although embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the embodiments described above. It is clear from the claims that embodiments with various modifications or improvements made to those described above are also included in the technical scope of the present invention.

[0058] (2) In the above-described embodiment, the ratio of the light component reflected by the metallic color layer, which is the first component, and the light component reflected by the surface of the paper, which is the second component, was determined by α, which is the product of the metallic color's reflection coefficient and its density value. However, the ratio of the first and second components may also be determined using the area ratio over which the metallic color covers the surface of the paper.

[0059] (3) In the above-described embodiment, the control device 40 (see Figure 1) is located on top of the housing of the printing device 20 (see Figure 1), but it may also be implemented as an independent information processing device, such as a server, connected via a network or signal lines.

[0060] (4) In the embodiments described above, toner is given as an example of a metallic colorant, but the colorant may also be ink.

[0061] (5) In the embodiments described above, silver and gold were given as examples of metallic colors, but metallic red, metallic blue, metallic green, metallic pink, etc. may also be used.

[0062] (6) The processor in the embodiments described above refers to a processor in a broad sense, and includes not only general-purpose processors (e.g., CPUs) but also specialized processors (e.g., GPUs (=Graphical Processing Units), ASICs (=Application Specific Integrated Circuits), FPGAs (=Field Programmable Gate Arrays), programmable logic devices, etc.). Furthermore, the processor operations in each of the embodiments described above may be performed by a single processor alone, or by multiple processors located in physically separate locations working together. Also, the order in which each operation is executed by the processor is not limited to the order described in each of the embodiments described above, but may be changed individually. [Explanation of symbols]

[0063] 1…Printing system, 10…Paper feeder, 20…Printing device, 30…Post-processing unit, 40…Control unit, 41…Processor, 44…Auxiliary storage device, 44A…White DLUT, 410…Input reception unit, 411…Document data, 412…Toner color, 413…Paper color, 420…Image processing unit, 421…Preview image creation unit, 430…Output unit, 431…Preview unit

Claims

1. Before printing, a computer reproduces the colors of the printed material and displays them on the screen. A function that generates an image that reproduces the color of the printed material based on a first component reflected by a metallic colorant and a second component that passes through the colorant and is reflected by the paper. A program to achieve this.

2. The function for generating the aforementioned image combines the first component and the second component in a proportion corresponding to the density value of the colorant, and generates the image. The program according to claim 1.

3. The function for generating the aforementioned image adds the first component and the second component in a ratio of α:1-α, where α is the value obtained by multiplying the reflectance coefficient of the colorant by the density value. The program according to claim 2.

4. The function for generating the image sets the ratio of the second component according to the area ratio over which the colorant covers the surface of the paper. The program according to claim 1.

5. The colorant is a toner that forms a layer on the surface of the paper. The program according to claim 1.

6. The aforementioned paper is not blank paper. The program according to claim 1.

7. It has a processor, The aforementioned processor, Based on a first component reflected by a metallic colorant and a second component transmitted through the colorant and reflected by the paper, an image is generated that reproduces the color of the printed material. Information processing device.

Images