Method for creating proof image data, proof image generation device, and program

Abstract

This improves the technique for adding texture to transparent backgrounds in proof images. [Solution] The method for creating proof image data includes the steps of: acquiring basic proof image data for reproducing the color distribution of a basic printed material, which is obtained by applying a basic backing to a printed fabric on which an image has been printed using a printing press, using a proof output device; acquiring four types of texture information based on four types of texture images; acquiring uniform dyeing characteristic information indicating the uniformity of ink dyeing onto the texture acquisition fabric using the four types of texture information; calculating transmission characteristic information indicating the degree of light transmission onto the texture acquisition fabric using the four types of texture information; and creating textured proof image data by applying a texture application process using the uniform dyeing characteristic information and the transmission characteristic information to the basic proof image data.

Description

[Technical Field]

[0001] This disclosure relates to a method for generating proof image data, a proof image generation apparatus, and a program. [Background technology]

[0002] Patent Document 1 describes a technique for creating print proofs. In this technique, a paper texture template is created based on the density distribution of the surface of a printed material, with the halftone area ratio data set to 100% for each type of printing paper. This paper texture template is used as a template to correct the texture according to the type of printing paper. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-270930 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The technology described in Patent Document 1 can express the "unevenness" and "roughness" of paper texture, but it does not consider how to impart texture to a medium where the background is transparent. Therefore, there is room for further improvement in the technology for imparting texture to a medium where the background is transparent in proof images. [Means for solving the problem]

[0005] This disclosure can be implemented in the following forms:

[0006] A method for creating proof image data is provided according to a first embodiment of this disclosure. This method for creating proof image data includes (a) acquiring basic proof image data for reproducing the color distribution of a basic printed material, which is a printed fabric on which an image has been printed using a printing press and to which a basic backing has been applied, using a proof output device; and (b) acquiring four types of texture information, wherein (i) an image of the non-printed area of ​​the texture acquisition fabric in which no image has been printed with ink, with a first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric in which a second backing of a different color from the first backing as the background; and (iii) the area of ​​the texture acquisition fabric in which an image has been printed with ink, with the first backing as the background. The process includes: (iv) acquiring four types of texture information based on four types of texture images, including (iv) an image of the printed area and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background; (c) acquiring uniform dyeing characteristic information indicating the uniformity of the ink on the texture acquisition fabric using the four types of texture information; (d) acquiring transmission characteristic information indicating the degree of light transmission of the texture acquisition fabric using the four types of texture information; and (e) creating textured proof image data by applying a texture application process using the uniform dyeing characteristic information and the transmission characteristic information to the basic proof image data.

[0007] A proof image generation device is provided according to a second embodiment of the present disclosure. This proof image generation device includes a basic proof image acquisition unit that acquires basic proof image data for reproducing the color distribution of a basic printed material, which is a printed fabric on which an image has been printed using a printing press and to which a basic backing has been applied, using a proof output device; (i) an image of the non-printed area of ​​the texture acquisition fabric in which no image has been printed with ink, with the first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric in which the second backing, which has a different color from the first backing as the background; (iii) an image of the printed area of ​​the texture acquisition fabric in which the image has been printed with the ink, with the first backing as the background; and (iv) the second backing The system includes: a texture information acquisition unit that acquires four types of texture information based on four types of texture images, including an image of the printed area of ​​the texture acquisition fabric with a background; a uniform dyeing characteristic acquisition unit that acquires uniform dyeing characteristic information indicating the uniformity of the ink on the texture acquisition fabric using the four types of texture information; a transmission characteristic acquisition unit that acquires transmission characteristic information indicating the degree of light transmission of the texture acquisition fabric using the four types of texture information; and a texture-applied proof image data creation unit that creates texture-applied proof image data by applying a texture application process using the uniform dyeing characteristic information and the transmission characteristic information to the basic proof image data.

[0008] A third embodiment of this disclosure provides a program for creating textured proof image data, which includes a function for acquiring basic proof image data for reproducing the color distribution of a basic printed material, which is obtained by applying a basic backing to a printed fabric on which an image has been printed using a printing press, using a proof output device; (i) an image of the non-printed area of ​​the texture acquisition fabric in which no image is printed with ink, with a first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric in which a second backing of a different color from the first backing as the background; and (iii) the printed area of ​​the texture acquisition fabric in which an image is printed with ink, with the first backing as the background. The computer is provided with the following functions: (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background, to acquire four types of texture information based on four types of texture images; (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background; (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background; (iv) an image of the uniform dyeing characteristics information and (iv) an image of the uniform dyeing characteristics information and (iv) an image of the print area of ​​the texture acquisition fabric, [Brief explanation of the drawing]

[0009] [Figure 1] This is an explanatory diagram showing a printing system for proofreading printed materials. [Figure 2] This is a block diagram showing the configuration of a proof image data creation device. [Figure 3] This is an explanatory diagram showing the flow of the proof image creation process. [Figure 4] This is an explanatory diagram illustrating an example of texture values ​​as texture information. [Figure 5] This is a flowchart showing the steps involved in creating proof image data. [Figure 6]It is an explanatory diagram showing an example of a window used for obtaining backing information. [Figure 7] It is a flowchart showing the detailed procedure of step S40 in FIG. 5. [Figure 8] It is an explanatory diagram showing an example of a printed fabric with different backing. [Figure 9] It is a top view and a cross-sectional view of an example of a fabric. [Figure 10] It is a graph showing an example of a background reference rate determination curve. [Figure 11] It is an explanatory diagram showing an example of a measurement result of the distribution of brightness in a map constituting a texture value. [Figure 12] It is a graph showing an example of an adjustment coefficient determination curve.

Mode for Carrying Out the Invention

[0010] A. First Embodiment: FIG. 1 is an explanatory diagram showing a printing system 500 for proofreading a printed matter. This printing system 500 includes a printing machine 100 that prints a printed matter PM according to input image data IM, a proof image data creation device 200 that creates proof image data using the input image data IM, and a proof printing device 300 that prints a proof according to the proof image data.

[0011] The printing machine 100 is, for example, a resist printing machine that performs resist printing on a cloth-based printing medium to create a printed fabric. In this embodiment, printed matters in which an image is printed on the following four types of fabrics are assumed. Note that since it is a fabric serving as a printing medium, fabrics with low evenness of ink are not assumed.

[0012] (T1) Non-transparent Dyeing Uniform Type: A fabric having a property that light does not pass through due to small gaps between the fabric weave and having high evenness of dye. In this specification, evenness of dye represents the degree of uniformity of dyeing by ink. High evenness of dye means that dyeing by ink is uniform. For example, it is a fabric made of polyester. (T2) Translucent Dye Uniform Type: This type of fabric has large gaps in its weave, allowing light to pass through and resulting in high uniform dyeability. Examples include chiffon, organza, and georgette. (T3) Non-transparent, unevenly dyed type: This type of fabric has a property of not being able to transmit light due to the small gaps between the weave fibers, resulting in poor uniformity in dyeing. Felt is an example. Felt includes woven felt, compressed felt, etc. In the case of compressed felt, light does not transmit because the gaps between the fibers that make up the fabric are small, but a texture can be applied to the roof image data in the same way as with woven felt. (T4) Translucent, unevenly dyed type: This type of fabric has large gaps in the weave, allowing light to pass through and resulting in poor uniform dyeing. For example, this type of fabric is made using knitting yarn primarily composed of natural wool.

[0013] Proofing includes hard proofing, which involves printing a proof printout HP using a proofing printer 300, and soft proofing, which displays a proof image SP on a display device 205 according to the proof image data. In hard proofing, the proofing printer 300 corresponds to the "proof output device," and in soft proofing, the display device 205 corresponds to the "proof output device." The image output from the proof output device is also called the "output image." In hard proofing, the proof printout HP corresponds to the "output image," and in soft proofing, the proof image SP corresponds to the "output image."

[0014] The proof image data creation device 200 is configured to perform at least one of hard proofing and soft proofing. In hard proofing, the proofing printer 300 prints a proof print HP according to the proof image data created by the proof image data creation device 200. If the proofing printer 300 is an inkjet printer, the proof image data creation device 200 applies color conversion processing and halftone processing to the proof image data to create dot data for printing, and supplies this dot data to the proofing printer 300 to print a proof print HP. In soft proofing, the proof image SP is displayed on the display device 205 according to the proof image data created by the proof image data creation device 200. This disclosure is applicable to both hard proofing and soft proofing. In this embodiment, the proof image data ultimately output by the proof image data creation device 200 represents an image that reproduces the texture of the printing medium.

[0015] Figure 2 is a block diagram showing the configuration of the proof image data creation device 200. The proof image data creation device 200 is a computer comprising a CPU (Central Processing Unit) 201 as a processor, a storage unit 202, an input / output interface 203, and a display device 205. The CPU 201, the storage unit 202, and the input / output interface 203 are connected via an internal bus so as to be able to communicate bidirectionally.

[0016] The CPU 201 functions as a basic proof image acquisition unit 210, a texture information acquisition unit 220, a backing color information acquisition unit 230, a uniform dyeing characteristic acquisition unit 240, a transmission characteristic acquisition unit 250, and a synthesis unit 260 by executing a proof image creation program PG pre-stored in the memory unit 202. At least a portion of the functions of each of these units 210 to 260 may be implemented by hardware circuits or on the cloud.

[0017] The input / output interface 203 is connected to the display device 205 and the proofing printer 300 by wire or wireless connection. The display device 205 is used to display input windows and proof images, which will be described later.

[0018] Figure 3 is an explanatory diagram showing the flow of the proof image creation process. The basic proof image acquisition unit 210 acquires basic proof image data BPF. The basic proof image data BPF is data that reflects the difference in color reproduction between the printing press 100 and the proof output device in the input image data IM. In other words, the basic proof image data BPF is data for the proof output device to reproduce the distribution of colors printed on the printing medium using the printing press 100. The texture of the fabric, which is the printing medium, is not reflected in the basic proof image data BPF. The basic proof image data BPF is used for the proof output device to reproduce the colors of the basic printed material with a basic backing applied to the printed fabric.

[0019] "Backing" refers to the backing material for printed fabrics. For example, basic backing is used when creating a media profile for a printing press 100 related to a fabric. Specifically, first, multiple solid color images are printed onto the fabric using the printing press 100 to create multiple color patches. Then, color measurements are taken with the basic backing applied to the color patches, and the media profile for the printing press 100 related to the fabric is created using the color measurement results. The basic backing may also be called "color measurement backing."

[0020] In this embodiment, the basic proof image acquisition unit 210 creates basic proof image data BPF from the input image data IM. This creation process uses, for example, the input profile of the input image data IM, the device profile and media profile of the proof output device, and various ICC profiles IPF such as the media profile of the printing press 100. However, if the basic proof image data BPF has already been created, the basic proof image acquisition unit 210 may acquire it by reading the basic proof image data BPF from the storage unit 202.

[0021] Any method can be used to create the basic proof image data (BPF). For example, the method described in Japanese Patent Publication No. 2024-81234, disclosed by the applicant of this disclosure, may be used. In this method, the following processes are executed sequentially. <Processing P1> The first image data is obtained by converting the color space of the input image data IM to the output color space of the printer 100 using the ICC profile IPF. <Processing P2> The first image data is transformed using a first transformation table to represent it in the profile connection space, and a white point transformation is performed on the background color area where no image is formed in the printed PM, using information on how it appears in a predetermined observation environment. This process yields the second image data, which is represented in the absolute XYZ color space. <Processing P3> Using the second conversion table, the second image data is converted into converted image data represented in the output color space of the proof output device. The output color space of the proof output device is, for example, the CMYK color space or the RGB color space.

[0022] Alternatively, proof images may be created using the methods described in the above-mentioned prior art (Japanese Patent Publication No. 09-270930) or Japanese Patent Publication No. 2006-30277. When using the method of Japanese Patent Publication No. 09-270930, a basic proof image data (BPF) that does not reflect the texture can be created by omitting the first and second corrections related to the texture of the paper.

[0023] In the first embodiment, the basic proof image data BPF is L * a * b * It shall be represented in a color space. However, it may also be represented in other device-independent color spaces such as the XYZ color space. If basic proof image data is created using the various methods described above and represented in the output color space of the proof output device, the output color space shall be changed to L using the output profile of the proof output device. *a * b * It can be converted into a color space. Also, when using the method described in Japanese Patent Application Laid-Open No. 2024-81234 mentioned above, the second image data expressed in the absolute XYZ color space is L * a * b * By converting it into a color space, basic proof image data BPF may be created. In the following description, L * a * b * will simply be denoted as "Lab".

[0024] The texture information acquisition unit 220 shown in FIG. 3 acquires texture information using a texture image TIM prepared in advance. The texture image TIM is an image obtained by imaging a texture acquisition fabric with a backing as the background. The texture information is used in the composite process of adding a texture to the basic proof image data BPF.

[0025] In the present embodiment, texture images TIM obtained by imaging each of the above four types of (T1) to (T4) as a texture acquisition fabric are prepared in advance and stored in the storage unit 202. The texture image TIM is an image obtained by imaging a texture acquisition fabric with the first backing Back1 or the second backing Back2 as the background. The first backing Back1 is white, and the second backing Back2 is black. The color of the texture acquisition fabric is white. For example, under a standard light source, the L * value and a * and b *Each measured value is pre-stored in the memory unit 202. Each of the texture acquisition fabrics (T1) to (T4) above includes a printed area PR and a non-printed area NR. The printed area PR is the area of ​​the texture acquisition fabric in which a solid black image in the device-dependent color space is printed by textile printing. The non-printed area NR is the area of ​​the texture acquisition fabric in which no image is printed. In the printing settings for forming the printed area PR on the texture acquisition fabric, it is desirable that the ink duty cycle value be set to a predetermined standard value or higher. The ink duty cycle value represents the amount of ink per unit area ejected onto the medium. By forming the printed area PR by printing with a high ink duty cycle value, a texture image TIM with a clear difference in brightness can be obtained when comparing the printed area PR and the non-printed area NR.

[0026] For each of the four types (T1) to (T4), the following four texture images TIM can be obtained by combining the printed area PR and non-printed area NR with the first backing and the second backing. (i) Texture image TIM1 obtained by capturing the non-printed area NR of the texture acquisition fabric superimposed on the first backing Back1. (ii) Texture image TIM2 obtained by capturing the non-printed area NR of the texture acquisition fabric superimposed on the second backing Back2. (iii) Texture image TIM3 obtained by capturing the print area PR of the texture acquisition fabric superimposed on the first backing Back1. (iv) Texture image TIM4 obtained by capturing the print area PR of the texture acquisition fabric superimposed on the second backing Back2.

[0027] Texture images TIM1 to TIM4 are represented in the Lab color space. The texture information acquisition unit 220 reads the texture images from the storage unit 202 and acquires texture information based on the texture images. The texture information is used to represent the unevenness of the fabric. The texture information acquisition unit 220 acquires texture information TI based on texture image TIM1. The texture information acquisition unit 220 similarly acquires texture values ​​Dtx based on each of the texture images TIM2 to TIM4. Texture image TIM1 is also called the "first texture image". Texture image TIM2 is also called the "second texture image". Texture image TIM3 is also called the "third texture image". Texture image TIM4 is also called the "fourth texture image". In this embodiment, the texture information TI includes at least the texture value for each pixel. If the printing medium is a (T2) transparent dyeing uniform type or a (T4) transparent dyeing non-uniform type, the texture information TI further includes transparency characteristic information described later.

[0028] Figure 4 is an explanatory diagram illustrating an example of texture value Dtx as texture information TI. Texture value Dtx is configured as a map representing the brightness of the print medium. In the example in Figure 4, the brightness takes values ​​in the range of 0 (black) to 100 (white).

[0029] The texture information acquisition unit 220 creates a brightness map as a texture value Dtx, which associates the brightness of each pixel of texture image TIM1 with the coordinates of the pixels. The texture information acquisition unit 220 similarly creates brightness maps as texture values ​​Dtx for texture images TIM2 to TIM4. Each texture value Dtx based on texture images TIM1 to TIM4 is used in the process of acquiring uniformity characteristic information by the uniformity characteristic acquisition unit 240 and the process of acquiring transparency characteristic information by the transparency characteristic acquisition unit 250, which will be described later. Hereinafter, the texture value Dtx based on texture image TIM1 may be called the first texture value Dtx1, the texture value Dtx based on texture image TIM2 may be called the second texture value Dtx2, the texture value Dtx based on texture image TIM3 may be called the third texture value Dtx3, and the texture value Dtx based on texture image TIM4 may be called the fourth texture value Dtx4. The first texture value Dtx1 is also called the "first brightness map". The second texture value Dtx2 is also called the "second brightness map." The third texture value Dtx3 is also called the "third brightness map." The fourth texture value Dtx4 is also called the "fourth brightness map."

[0030] The uniform dyeing characteristic acquisition unit 240 shown in Figure 3 acquires uniform dyeing characteristic information PE, which represents the uniformity of the ink dyeing onto the fabric.

[0031] In this embodiment, ink uniformity refers to the degree of color penetration due to the amount of fluffiness. In textile printing using a textile printing machine, ink droplets are ejected onto the fabric. In the case of fabrics with fluffiness, such as felt, the ink tends not to adhere well to the fluff. In this case, the presence of undyed fluff results in uneven dyeing, and consequently, uneven dyeing. Furthermore, in the case of fabrics with fluffiness and thickness, such as woven fabrics using knitting yarn, the ink tends not to adhere well to the fluff. In this case as well, the presence of undyed fluff results in uneven dyeing, and consequently, uneven dyeing. Moreover, in the case of fabrics with fluffiness and thickness, such as woven fabrics using knitting yarn, even if the ink has adhered to the fluff, the fluffiness and thickness of the fabric may make it appear as if the dyeing is uneven. Thus, even if ink droplets are dispensed uniformly, fabrics with a nap tend to have uneven dyeing, or appear to have uneven dyeing, compared to fabrics without nap.

[0032] The uniform dyeing characteristic acquisition unit 240 acquires uniform dyeing characteristic information PE using texture values ​​Dtx based on texture images TIM1 to TIM4, which are images of the same type of texture acquisition fabric as the printing medium fabric. The uniform dyeing characteristic information PE indicates whether the uniformity is high or low. Details of the processing of the uniform dyeing characteristic acquisition unit 240 will be described later.

[0033] The transmission characteristic acquisition unit 250 acquires transmission characteristic information TR, which represents the light transmission characteristics of the fabric. The transmission characteristic acquisition unit 250 acquires the transmission characteristic information TR using each texture value Dtx based on texture images TIM1 to TIM4, which are images of texture acquisition fabrics of the same type as the fabric of the printing medium. Details of the processing of the transmission characteristic information will be described later.

[0034] Figure 5 is a flowchart showing the procedure for creating proof image data. In step S10, the basic proof image acquisition unit 210 acquires the basic proof image data BPF. In step S20, the texture information acquisition unit 220 reads and acquires texture images TIM1 to TIM4, which are images of the same type of texture acquisition fabric as the fabric of the printing medium, from the storage unit 202.

[0035] In step S30, the backing color information acquisition unit 230 acquires backing color information BI. Here, the backing color information acquisition unit 230 acquires backing color information BI which includes the basic backing color BBC, the observed backing color OBC, the first backing color TBC1 of the first backing Back1 for texture acquisition, and the second backing color TBC2 of the second backing Back2 for texture acquisition.

[0036] Figure 6 is an explanatory diagram showing an example of window W1 used to acquire backing color information BI. This window W1 is provided with input fields IF21 for inputting the basic backing color BBC, IF22 for inputting the observed backing color OBC, IF23 for inputting the first backing color TBC1, and IF24 for inputting the second backing color TBC2. In this embodiment, the basic backing color BBC, the observed backing color OBC, the first backing color TBC1, and the second backing color TBC2 are each set using Lab values. In the example in Figure 6, the basic backing color BBC is white, the observed backing color OBC is black, the first backing color is white, and the second backing color is black. Note that each backing color can be changed as appropriate.

[0037] Furthermore, the basic backing color BBC, observation backing color OBC, first backing color TBC1, and second backing color TBC2 may be acquired as images. That is, the backing color information acquisition unit 230 may acquire a Lab image of the observation backing color OBC specified by the user.

[0038] As shown in Figure 5, in step S40, a synthesis process is performed in which a texture is added to the basic proof image data BPF using the texture information TI, and a textured proof image data is created. In this embodiment, the content of the synthesis process differs depending on the type of fabric of the printing medium.

[0039] Figure 7 is a flowchart showing the detailed procedure for step S40. In step S41, the uniform dyeing characteristic acquisition unit 240 determines whether or not the texture acquisition fabric has high uniform dyeing properties.

[0040] The uniform dyeing characteristic acquisition unit 240 determines whether the uniform dyeing is high or not as follows. First, the uniform dyeing characteristic acquisition unit 240 calculates the variance of brightness that constitutes the first texture value Dtx1 based on the texture image TIM1, which is an image of a texture acquisition fabric of the same type as the fabric of the printing medium. The calculated variance is denoted as Sp1. The formula (M1) for calculating the variance is shown below.

[0041]

number

[0042] The uniform dyeing characteristic acquisition unit 240 calculates the dispersion of brightness that constitutes the fourth texture value Dtx4 based on the texture image TIM4, which is an image of a texture acquisition fabric of the same type as the fabric of the printing medium, using formula (M1). The calculated dispersion is denoted as Sp4.

[0043] The uniform dyeing characteristic acquisition unit 240 determines that the ink uniformity of the ink on the printing medium is not high if the condition that dispersion Sp4 is greater than dispersion Sp1 and dispersion Sp4 is M times dispersion Sp1 (where M is a positive rational number) is met. If the above condition is not met, the uniform dyeing characteristic acquisition unit 240 determines that the ink uniformity of the printing medium is high. As shown in Figure 3, the uniform dyeing characteristic acquisition unit 240 outputs information on whether the ink uniformity is high or low as uniform dyeing characteristic information PE to the transmission characteristic acquisition unit 250.

[0044] As mentioned above, fabrics with a lot of fluff tend to have uneven dyeing, or appear to have uneven dyeing, compared to fabrics without fluff. Therefore, it is expected that the dispersion of brightness of the pixels constituting the captured image will be large. On the other hand, in the case of fabrics with less fluff, the dyeing will be uniform, so it is expected that the dispersion of brightness of the pixels constituting the captured image will be small. Therefore, the uniform dyeing characteristic acquisition unit 240 uses the dispersion of the first texture value Dtx1 based on the texture image TIM1 and the dispersion of the fourth texture value Dtx4 based on the texture image TIM4 to determine whether or not the uniform dyeing is high. Texture image TIM1 is an image of a non-printed area captured against a white first backing Back1 background. Texture image TIM4 is an image of a printed area where black in the device-dependent color space is printed against a black second backing Back2 background. By using the first texture value Dtx1 based on texture image TIM1 and the fourth texture value Dtx4 based on texture image TIM4, where the backing color and the fabric color are close, the fabric color and the backing color can be matched. Therefore, it is possible to suppress the effect of light transmitted through the fabric on the brightness of the texture image. Therefore, it is possible to suppress the influence of light passing through the fabric on the required brightness dispersion value.

[0045] As shown in Figure 7, if it is determined that the uniformity of staining is not high (step S41; NO), the process in step S42 is executed. If it is determined that the uniformity of staining is high (step S41; YES), the process in step S43 is executed.

[0046] In step S42, the light transmission characteristic acquisition unit 250 determines whether or not the fabric of the printing medium is a light-transmitting fabric. Examples of light-transmitting fabrics include fabrics with gaps of a certain size in the weave and fabrics woven with translucent threads. In this embodiment, in order to identify the texture of the fabric, it is determined whether or not the fabric of the printing medium is light-transmitting, and light transmission characteristic information, which will be described later, is acquired.

[0047] The transparency characteristics acquisition unit 250 determines whether the fabric of the printing medium is a light-transmitting fabric as follows: First, the transparency characteristics acquisition unit 250 calculates the average brightness of the third texture value Dtx3 based on the texture image TIM3, which is an image of a texture acquisition fabric of the same type as the fabric of the printing medium. The calculated average is set to Av3. The transparency characteristics acquisition unit 250 calculates the average brightness of the fourth texture value Dtx4 based on the texture image TIM4, which is an image of a texture acquisition fabric of the same type as the fabric of the printing medium. The calculated average is set to Av4.

[0048] The transmission characteristic acquisition unit 250 calculates the average transmittance using the following formula (M2). Average transmittance=1-((100-Av3) / (100-Av4))...(M2)

[0049] The light transmission characteristic acquisition unit 250 determines that the fabric of the printing medium is a light-transmitting fabric if the average transmittance calculated by formula (M2) is equal to or greater than a predetermined threshold Th2. On the other hand, if the calculated average transmittance is less than a predetermined threshold Th2, the light transmission characteristic acquisition unit 250 determines that the fabric of the printing medium is not a light-transmitting fabric, that is, a fabric that does not transmit light.

[0050] If it is determined that the fabric is not light-transmitting (step S42; NO), that is, if it is determined that the fabric does not transmit light, the process in step S45 is executed. If it is determined that the fabric is light-transmitting (step S42; YES), the process in step S47 is executed.

[0051] In step S43, the light transmission characteristic acquisition unit 250 determines whether or not the fabric of the printing medium is a light-transmitting fabric.

[0052] First, the transparency characteristic acquisition unit 250 calculates the average brightness of the first texture value Dtx1, which is based on the texture image TIM1, which is an image of a texture acquisition fabric of the same type as the fabric of the printing medium. The calculated average is set to Av1. The transparency characteristic acquisition unit 250 then calculates the average brightness of the second texture value Dtx2, which is based on the texture image TIM2, which is an image of a texture acquisition fabric of the same type as the fabric of the printing medium. The calculated average is set to Av2.

[0053] The transmission characteristic acquisition unit 250 calculates the average transmittance using the following formula (M3). Average transmittance=1-Av2 / Av1...(M3)

[0054] The light transmission characteristic acquisition unit 250 determines that the fabric of the printing medium is a light-transmitting fabric if the average transmittance calculated by formula (M3) is equal to or greater than a predetermined threshold Th3. On the other hand, if the calculated average transmittance is less than a predetermined threshold Th3, the light transmission characteristic acquisition unit 250 determines that the fabric of the printing medium is not a light-transmitting fabric, that is, a fabric that does not transmit light.

[0055] As mentioned above, if the uniformity of the dyeing is not high, in step S42, a third and fourth brightness map based on an image of the printed area is used. On the other hand, in step S43, if the uniformity of the dyeing is high, a first and second brightness map based on an image of the non-printed area is used. In this way, it is possible to easily determine whether or not the fabric is light-transmitting using four types of texture images.

[0056] If it is determined in step S43 that the fabric is not transparent to light (step S43; NO), that is, if it is determined that the fabric does not transmit light, the process in step S44 is executed. If it is determined that the fabric is transparent to light (step S43; YES), the process in step S46 is executed.

[0057] <(T1) If the fabric is a non-transparent, uniformly dyed type> In step S44, a synthetic process is performed to impart texture to a fabric that does not transmit light and has high uniform dyeability, i.e., a (T1) non-transparent, uniformly dyed fabric.

[0058] The synthesis unit 260 can perform a process similar to the one disclosed in Japanese Patent Application Publication No. 06-86045, for example, in order to apply a texture.

[0059] Specifically, the difference between the average value of the texture value Dtx and the individual texture value Dtx, multiplied by a gain, may be added to the pixel value of the basic proof image data BPF. Here, if the fabric of the printing medium is an opaque, uniformly dyed type, a first texture value Dtx1 based on a texture image TIM1 obtained by imaging an opaque, uniformly dyed fabric (T1) is used as the fabric for texture acquisition. Alternatively, texture may be applied according to other known methods. If the basic proof image data BPF is expressed in the Lab color system, the texture application process may be performed only on the brightness. If the basic proof image data BPF is expressed in the RGB color system, the texture application process may be performed on each color component of RGB. The synthesis unit 260 is also called the "texture application proof image data creation unit".

[0060] <(T3) If the fabric is a non-transparent, unevenly dyed type> In step S45, a synthetic process is performed to impart texture to a fabric that does not transmit light and does not have high uniform dyeing properties, i.e., a (T3) non-transparent, unevenly dyed fabric.

[0061] The synthesis unit 260 can perform a process similar to the one disclosed in Japanese Patent Publication No. 06-86045, for example, in order to apply a texture. Specifically, a value obtained by multiplying the difference between the average value of the texture value Dtx and the individual texture value Dtx by a gain may be added to the pixel value of the basic proof image data BPF. Here, if the fabric of the printing medium is an opaque, unevenly dyed type, a fourth texture value Dtx4 based on a texture image TIM4 captured of an opaque, unevenly dyed fabric (T3) is used as the fabric for texture acquisition.

[0062] <(T2) If the fabric is a permeable, uniformly dyed type> In step S46, if the fabric is transparent to light and has high uniform dyeability, i.e., a (T2) transparent dye uniform type fabric, a synthesis process is performed to impart texture.

[0063] Figure 8 is an explanatory diagram showing examples of light-transmitting fabrics with different backings. On the left side of Figure 8, the basic print material PM_basic is shown with the basic backing Back_basic applied to the unbacked printed fabric TPF. The color of the basic backing Back_basic is, for example, white. On the right side of Figure 8, the observation print material PM_obs is shown with the observation backing Back_obs applied to the unbacked printed fabric TPF. The color of the observation backing Back_obs is, for example, black. The basic proof image data BPF is data representing the color of the basic print material PM_basic.

[0064] The synthesis unit 260 can utilize the method described in Japanese Patent Application No. 2024-207035 (hereinafter referred to as Prior Application 1) filed by the applicant of this disclosure when performing a synthesis process to impart texture.

[0065] (Process for determining the basic color mixing ratio) The blending unit 260 determines the basic color mixing ratio according to the texture information TI. As mentioned above, if the printing medium is a (T2) transmissive dyeing uniform type or a (T4) transmissive dyeing non-uniform type, the texture information TI includes transmissive characteristic information TR in addition to the texture value Dtx.

[0066] The basic color mixing ratio is the mixing ratio of the basic backing color BBC when the color of the basic printed material PM_basic shown in Figure 8 is considered to be a mixture of the color of the printed fabric TPF and the basic backing color BBC. In other words, the basic color mixing ratio is the mixing ratio of the basic backing color BBC when the color represented by the basic proof image data BPF is considered to be a mixture of the color represented by the foreground color proof image data FPF and the basic backing color BBC. The foreground color proof image data FPF is data that represents the color of the printed fabric TPF as observed without backing.

[0067] If the basic color mixing ratio is Rmix_basic, the color mixing for the basic proof image data BPF is expressed by the following formula. Lab_basic = Lab_fore×(1 - Rmix_basic) + Lab_b.back×Rmix_basic …(q1) Here, Lab_basic is the Lab value of the basic proof image data BPF. Lab_fore is the Lab value of the foreground proof image data FPF. Lab_b.back is the Lab value of the basic backing color BBC. The basic color mixing ratio Rmix_basic is a value greater than 0 and less than 1.0.

[0068] The transmission characteristic information TR used to determine the basic color mixing ratio Rmix_basic includes the following five setting values. Prior application 1 discloses an example in which the user inputs the following five setting values, but in this embodiment, in step S46, the transmission characteristic acquisition unit 250 calculates the following four setting values. The method for calculating the four setting values ​​will be described later.

[0069] (1) Thread texture threshold Th_thread The thread texture threshold Th_thread is the minimum value of the texture value Dtx required to determine that each pixel is on a thread of the fabric.

[0070] Figure 9 shows a top view and a cross-sectional view of an example of fabric. "Above the threads" refers to the portion of the threads that make up the fabric when the weave or knit of the fabric is viewed in cross-section, and which is not located beneath other threads. In the AA cross-section of Figure 9, warp threads wr1, wr3, and wr5 are not located beneath other threads. In the AA cross-section, warp threads wr2, wr4, and wr6 are located beneath weft thread wf1. In the BB cross-section of Figure 9, warp threads wr1 to wr6 are not located beneath other threads. Thus, the portion of the thread that is not located beneath other threads includes the portion of the thread that is located above other threads and the portion of the thread that is not located above any thread. In other words, "above the threads" refers to the portion of the thread that is visible to the viewer of the fabric. Pixels whose texture value Dtx is greater than or equal to the thread texture threshold Th_thread are judged to be above the threads. The thread texture threshold Th_thread is set to a value greater than 0 and less than or equal to 100, for example. In the example shown in Figure 4, when Th_thread=100, pixels that are determined to be on the weave are shown as white areas without hatching.

[0071] If the printing medium is of the (T2) transparent, uniformly dyed type, the texture value to be judged is the second texture value Dtx2 based on the texture image TIM2, which is an image of the (T2) transparent, uniformly dyed fabric used as the fabric for texture acquisition. Furthermore, in step S47 described later, if the printing medium is of the (T4) transparent, non-uniformly dyed type, the texture value to be judged is the third texture value Dtx3 based on the texture image TIM3, which is an image of the (T4) transparent, non-uniformly dyed fabric used as the fabric for texture acquisition. The same applies to the settings in (2) to (5) below.

[0072] (2) Gap texture threshold Th_hole The gap texture threshold Th_hole is the maximum value of the texture value Dtx used to determine that each pixel corresponds to a gap in the fabric weave. That is, pixels whose texture value Dtx is less than or equal to the gap texture threshold Th_hole are determined to correspond to gaps in the weave. No threads exist in the gaps in the weave. If a backing is applied, the backing will be visible through the gaps in the weave. The gap texture threshold Th_hole is set to a value between 0 and 100, for example. Also, the gap texture threshold Th_hole is set to a smaller value (darker value) than the thread texture threshold Th_thread. In the example shown in Figure 4, when Th_hole=50, pixels determined to correspond to gaps in the weave are shown as dark gray areas. Pixels with intermediate brightness between threads and gaps are shown as light gray areas.

[0073] (3) Thread background reference rate Rb_thread The thread-based background reference ratio Rb_thread is the percentage of pixels on the thread that reference the backing color. Referencing the backing color means that the appearance of the fabric is influenced by the backing color. The backing color referenced can be either the base backing color or the observed backing color. The thread-based background reference ratio Rb_thread is set to a value between 0 and 1.0, for example.

[0074] (4) Gap background reference rate Rb_hole The gap background reference ratio Rb_hole is the percentage of pixels corresponding to gaps that reference the backing color. The gap background reference ratio Rb_hole is set to a value between 0 and 1.0, for example. Also, the gap background reference ratio Rb_hole is set to a value greater than the thread background reference ratio Rb_thread.

[0075] The fabric is made by weaving threads. Therefore, the color of the backing applied to the back of the fabric may be visible through the gaps in the weave, which affects the appearance of the fabric. Even for a fabric with a dense weave, the appearance of the fabric is affected by factors such as the thickness of the fabric and the color of the backing applied to the back of the fabric. The appearance of the thread part is also affected by factors such as the color and thickness of the thread and the color of the backing. The transmission characteristic information is information regarding the texture of the fabric that affects the appearance of the fabric. By considering the above (1) to (4) as the transmission characteristic information TR, the reproducibility of the texture of the fabric can be improved.

[0076] The synthesis unit 260 determines the pixel background reference rate Rb_px, which is the background reference rate of each pixel, according to the texture value Dtx, using the background reference rate determination curve determined by the transmission characteristic information. As described above, when the fabric of the printing medium is a uniformly transmissively dyed type of fabric, the second texture value Dtx2 based on the texture image TIM2 obtained by imaging a (T2) uniformly transmissively dyed type of fabric as the texture acquisition fabric is used.

[0077] FIG. 10 is a graph showing an example of the background reference rate determination curve Gr. The background reference rate determination curve Gr preferably shows the characteristic that the pixel background reference rate Rb_px becomes smaller as the brightness represented by the texture value Dtx increases. The pixel background reference rate Rb_px is determined as follows according to the texture value Dtx of each pixel. (a1) Pixels where the texture value Dtx is less than or equal to the gap texture threshold Th_hole: The pixel background reference rate Rb_px is set to a value equal to the gap background reference rate Rb_hole. (a2) Pixels where Th_hole < Dtx < Th_thread: The pixel background reference rate Rb_px is determined by linearly interpolating between the on-thread background reference rate Rb_thread and the gap background reference rate Rb_hole according to the texture value Dtx. (a3) Pixels where the texture value Dtx is greater than or equal to the on-thread texture threshold Th_thread: The pixel background reference rate Rb_px is set to a value equal to the on-thread background reference rate Rb_thread.

[0078] As described above, in this embodiment, using four brightness maps, the yarn texture threshold, gap texture threshold, yarn background reference rate, and gap background reference rate can be easily calculated as transparency characteristic information indicating the transparency characteristics of the fabric for texture acquisition.

[0079] The synthesis unit 260 calculates the average background reference rate Rb_ave by averaging the pixel background reference rates Rb_px within the image area of ​​the basic proof image data BPF.

[0080] The blending unit 260 determines the basic color mixing ratio Rmix_basic using the average background reference ratio Rb_ave or the pixel background reference ratio Rb_px. For example, the basic color mixing ratio Rmix_basic is determined by one of the following: Rmix_basic = Rb_ave …(q2-1) Rmix_basic = Rb_px …(q2-2)

[0081] Furthermore, for the basic color mixing ratio Rmix_basic, it is possible to use a positive value proportional to the average background reference rate Rb_ave or pixel background reference rate Rb_px, rather than the average background reference rate Rb_ave or pixel background reference rate Rb_px themselves.

[0082] When determining the basic color mixing ratio Rmix_basic using the average background reference rate Rb_ave, a constant basic color mixing ratio Rmix_basic is applied across the entire image area. On the other hand, when determining the basic color mixing ratio Rmix_basic using the pixel background reference rate Rb_px, a different basic color mixing ratio Rmix_basic is applied to each pixel. In the latter case, the process of calculating the average background reference rate Rb_ave may be omitted. However, it is preferable to determine the basic color mixing ratio Rmix_basic using the average background reference rate Rb_ave rather than the pixel background reference rate Rb_px. This is because if the basic color mixing ratio Rmix_basic is determined using the pixel background reference rate Rb_px, the amount of correction in the color correction process may become excessive in the gaps between fibers, potentially preventing the correct determination of the color of the foreground color proof image data FPF. Actual light-transmitting printed fabrics have a juxtaposition of colors between the gaps and the threads, and it is thought that when observed from a distance, they appear to have an average color. Therefore, in the color correction process, it is preferable to generate foreground color proof image data (FPF) that more accurately represents the color of the light-transmitting printed fabric as actually observed by removing the basic backing color using the average background reference ratio Rb_ave.

[0083] (Process for creating foreground color proof image data) The mixing unit 260 performs a color correction process to remove the basic backing color BBC from the color represented by the basic proof image data BPF according to the basic color mixing ratio Rmix_basic, thereby creating the foreground color proof image data FPF. As mentioned above, the foreground color proof image data FPF is data that represents the color of the printed fabric TPF as observed without the use of backing.

[0084] The color correction calculation is performed according to, for example, the following formula: Lab_fore = (Lab_basic - Lab_b.back×Rmix_basic) / (1 - Rmix_basic) …(q3) Here, Lab_fore is the Lab value of the foreground proof image data FPF. Lab_basic is the Lab value of the basic proof image data BPF. Lab_b.back is the Lab value of the basic backing color BBC. Rmix_basic is the basic color mixing ratio. The calculation using equation (q3) is performed on the L, a, and b values ​​of the basic proof image data BPF, respectively. Equation (q3) is equivalent to a modified version of equation (q1) described above.

[0085] (Process for determining the ratio of observed color mixing) The blending unit 260 determines the observed color mixing ratio according to the texture information TI. The observed color mixing ratio is the ratio of color when the color of the observation print PM_obs shown in Figure 8 is considered to be a mixture of the color of the print fabric TPF and the observation backing color OBC. In other words, the observed color mixing ratio is the ratio of color when the color represented by the observation proof image data OPF is considered to be a mixture of the color represented by the foreground color proof image data FPF and the observation backing color OBC.

[0086] In this embodiment, a positive value proportional to the average background reference rate Rb_ave or the pixel background reference rate Rb_px is used as the observed color mixing ratio Rmix_obs. For example, the value of the average background reference rate Rb_ave or the pixel background reference rate Rb_px itself may be used as the observed color mixing ratio Rmix_obs.

[0087] The observed color mixing ratio Rmix_obs may be the same as or different from the basic color mixing ratio Rmix_basic described above. However, it is preferable to use a value proportional to the average background reference rate Rb_ave as the basic color mixing ratio Rmix_basic and a value proportional to the pixel background reference rate Rb_px as the observed color mixing ratio Rmix_obs. By using a value proportional to the pixel background reference rate Rb_px as the observed color mixing ratio Rmix_obs, the difference between the background and foreground colors in the thread areas and gaps becomes clearer, so the texture of light-transmitting printed fabrics can be reproduced more appropriately.

[0088] (Process for creating observation probe image data) The synthesis unit 260 creates observation proof image data OPF by performing a synthesis process that combines the observation backing color OBC with the color represented by the foreground color proof image data FPF according to the observation color mixing ratio Rmix_obs. The observation proof image data OPF is data that represents the color of the observation print PM_obs shown in Figure 8.

[0089] The synthesis process is performed according to, for example, the following equation. Lab_obs = Lab_fore×(1 - Rmix_obs) + Lab_o.back×Rmix_obs …(q5) Here, Lab_obs is the Lab value of the observation proof image data OPF. Lab_fore is the Lab value of the foreground proof image data FPF. Lab_o.back is the Lab value of the observed backing color OBC. Rmix_obs represents the observed color mixing ratio.

[0090] By using the observation proof image data OPF generated in this way, it is possible to reproduce the observation print PM_obs of the printed fabric TPFF as a proof when any observation backing Back_obs is used.

[0091] <(T4) If the fabric is a translucent, unevenly dyed type> As shown in Figure 7, in step S47, if the fabric is transparent and does not have high uniformity, i.e., a (T4) transparent, non-uniformly dyed fabric, a synthesis process is performed to impart texture. The synthesis unit 260 can perform the same process as when the fabric is a (T2) transparent, uniformly dyed fabric in order to impart texture. However, if the fabric of the printing medium is a transparent, non-uniformly dyed fabric, a third texture value Dtx3 based on a texture image TIM3 of a (T4) transparent, non-uniformly dyed fabric is used as the fabric for texture acquisition.

[0092] Next, we will explain how to calculate (1) the thread texture threshold Th_thread, (2) the gap texture threshold Th_hole, (3) the thread background reference ratio Rb_thread, and (4) the gap background reference ratio Rb_hole used in steps S46 and S47 of Figure 7. These values ​​are calculated by the transmission characteristic acquisition unit 250 in steps S46 and S47.

[0093] <(1) Calculation of the thread texture threshold Th_thread> The thread texture threshold Th_thread is calculated as follows. The following process is the same whether the fabric of the printing medium is a (T2) uniformly dyed transparent fabric or a (T4) non-uniformly dyed transparent fabric.

[0094] First, the transparency characteristic acquisition unit 250 determines the maximum brightness LH1 and the minimum brightness LL1 from the brightness values ​​that constitute the first texture value Dtx1 based on the texture image TIM1, which is an image of the same type of fabric as the printing medium. Furthermore, the transparency characteristic acquisition unit 250 determines the maximum brightness LH2 and the minimum brightness LL2 from the brightness values ​​that constitute the second texture value Dtx2 based on the texture image TIM2, which is an image of the same type of fabric as the printing medium.

[0095] If the transparency characteristic acquisition unit 250 finds that the maximum brightness LH2 exceeds the maximum brightness LH1, it calculates the normalized value of the thread texture threshold Th_thread using the following formula (M4). Normalized value of thread texture threshold = (1 - (LH2 - LL1) / (LH2 - LL2)) × 100 ... (M4)

[0096] The transmission characteristic acquisition unit 250 calculates the normalized value of the thread texture threshold Th_thread using the following formula (M5) if the maximum brightness LH2 is less than or equal to the maximum brightness LH1. Normalized value of thread texture threshold = 100···(M5)

[0097] As shown in Figure 4, each brightness value in the map that constitutes the texture value Dtx is a normalized value and takes values ​​in the range of 0 (black) to 100 (white). Therefore, the normalized values ​​of the texture threshold on the thread calculated by equations (M4) and (M5) need to be transformed by the following equation (M6). Thread texture threshold = Normalized value of thread texture threshold × (Maximum brightness LH2 - Minimum brightness LL2) / 100 + Minimum brightness LL2 ... (M6)

[0098] Figure 11 is an explanatory diagram showing an example of the measurement results of the brightness distribution within the map that constitutes the texture value Dtx. The first row of Figure 11 shows the brightness distribution based on images of a fabric that does not transmit light. This fabric is either (T1) opaque uniform dyeing type or (T3) opaque non-uniform dyeing type. The brightness distribution based on images taken with a white backing against the non-printed area of ​​the fabric is shown by arrow w, and the brightness distribution based on images taken with a black backing against the non-printed area of ​​the fabric is shown by arrow b. The horizontal axis represents brightness, and the brightness increases as you move to the left. * This represents the brightness of the black backing. Note that the brightness of the black backing is just an example and does not necessarily match the value specified by the user in Figure 6. The same applies to the figures described below. For fabrics that do not transmit light, the range of brightness distribution is the same regardless of the backing color.

[0099] The second and third panels of Figure 11 show the brightness distribution in images of the fabric, including areas where light is transmitted and areas where light is not transmitted. This fabric is a (T4) non-transmitting, non-uniform dyeing type, such as a woven fabric using knitting yarn primarily made from natural wool. In the second and third panels, arrow w indicates the brightness distribution based on images taken with a white backing against the non-printed area of ​​the fabric, and arrow b indicates the brightness distribution based on images taken with a black backing against the non-printed area of ​​the fabric. * This represents the brightness of the white backing.

[0100] The example shown in the second paragraph and the example shown in the third paragraph have different brightness levels for the white backing. In the second paragraph, the brightness level of the white backing is wL * This shows the distribution of brightness when the brightness on the yarn exceeds the highest brightness. Note that the brightness of the white backing is just an example and does not necessarily match the value specified by the user in Figure 6. In the third row, the brightness of the white backing wL is shown when the highest brightness on the yarn is exceeded. * The above shows the distribution of brightness of the fabric.

[0101] As shown in the second and third paragraphs, the brightness based on the image captured with a white backing is equal to the brightness of the white backing wL. * The distribution is within a range close to this. Although not shown in the diagram, a similar distribution of brightness is observed in the (T2) uniform transmission staining type.

[0102] The fourth section shows the brightness distribution in images of fabrics that transmit light throughout their entire range. These fabrics are (T2) transmittance dye uniform type, such as chiffon, organza, and georgette. The brightness distribution based on images taken with a white backing against the non-printed areas of the fabric is shown by arrow w, and the brightness distribution based on images taken with a black backing against the non-printed areas of the fabric is shown by arrow b.

[0103] As shown in the fourth paragraph, when light is transmitted throughout the entire range, the range of brightness distribution based on the image acquired with a white backing does not overlap with the range of brightness distribution based on the image acquired with a black backing. Although not shown in the figure, a similar brightness distribution is observed in the (T4) transmission heterogeneous staining type. On the other hand, as shown in the first paragraph, when light is not transmitted, the range of brightness distribution is the same regardless of the backing color.

[0104] Based on the above, in this disclosure, the area where the lightness distribution when using a white backing overlaps with the lightness distribution when using a black backing is considered to be on the fabric's weave, that is, the area where the weave is visible. Equations (M4) to (M6) above are formulated based on these considerations.

[0105] <(2) Calculation of the gap texture threshold Th_hole> The gap texture threshold Th_hole is calculated as follows. The following process is the same whether the printing medium fabric is a (T2) permeable, uniformly dyed fabric or a (T4) permeable, non-uniformly dyed fabric. Gap texture threshold = Brightness of black backing + Correction value α...(M7) When using a black backing, the gaps in the fabric weave should reproduce the color of the black backing. However, considering that variations in brightness occur in the captured image due to light reflected by the black backing during shooting, in equation (M7), the gap texture threshold is set to the brightness of the black backing plus a correction value α. The correction value α is, for example, 5. The brightness of the black backing is also called "black brightness".

[0106] <(3) Calculation of the thread background reference rate Rb_thread> The thread background reference ratio Rb_thread is calculated as follows. The following process is the same whether the fabric of the printing medium is a (T2) uniformly dyed transparent fabric or a (T4) non-uniformly dyed transparent fabric.

[0107] The transmission characteristic acquisition unit 250 calculates the thread background reference ratio Rb_thread using the following formula (M8) with respect to the highest brightness LH1 and the highest brightness LH2. Thread background reference ratio = (LH1 - LH2) / (LH1 - brightness of black backing) ... (M8)

[0108] <(4) Calculation of the gap background reference ratio Rb_hole> The gap background reference ratio Rb_hole is calculated as follows. The following process is the same whether the print medium fabric is a (T2) permeable, uniformly dyed fabric or a (T4) permeable, non-uniformly dyed fabric.

[0109] The transmission characteristic acquisition unit 250 calculates the gap background reference ratio Rb_hole using the following formula (M9) with respect to the maximum brightness LH1 and minimum brightness LL2. Gap background reference ratio = (LH1 - LL2) / (LH1 - brightness of black backing) ... (M9)

[0110] As described above, in this embodiment, the reproduction of the texture of the medium can be improved in the textured proof image data in which texture is added to the proof image representing a medium with a transparent background. Furthermore, the thread texture threshold, gap texture threshold, thread background reference rate, and gap background reference rate, which are transparency characteristic information, can be easily determined using a brightness map based on four types of texture images that can be obtained by combining the presence or absence of printing and two backing colors.

[0111] B. Other embodiments: (B1) In the above embodiment, an example was described in which the synthesis unit 260 uses the method described in Prior Application 1 filed by the applicant of this disclosure when performing a synthesis process to impart texture. The synthesis unit 260 may also use the method described in Japanese Patent Application No. 2024-207036 (hereinafter referred to as Prior Application 2) filed by the applicant of this disclosure. Below, a configuration of the method described in Prior Application 2 that differs from that of Prior Application 1 will be described.

[0112] In Prior Application 2, the observed backing color OBC is set to change depending on the brightness of the basic proof image data BPF in order to change how the observed backing color OBC appears.

[0113] Prior Application 2 uses, in addition to the above-mentioned (1) thread texture threshold Th_thread, (2) gap texture threshold Th_hole, (3) thread background reference rate Rb_thread, and (4) gap background reference rate Rb_hole, (5) background reference rate correction coefficient K_set for black areas.

[0114] (5) Background reference ratio correction coefficient K_set for black areas The background reference rate correction coefficient K_set for the black area is a set value of an adjustment coefficient for adjusting the background reference rate in the pixels of the black area. The background reference rate correction coefficient K_set is set to a value greater than 0 and less than or equal to 1.0, for example. The background reference rate correction coefficient K_set for the black area is also referred to as the "black area background reference rate".

[0115] The synthesizing unit 260 determines an adjustment coefficient K_corr for the background reference rate according to the brightness of the basic proof image data BPF. The adjustment coefficient K_corr is determined to change depending on the brightness of the basic proof image data BPF using an adjustment coefficient determination curve determined by the transmission characteristic information.

[0116] FIG. 12 is a graph showing an example of the adjustment coefficient determination curve Gk. The adjustment coefficient K_corr is determined as follows according to the background reference rate correction coefficient K_set for the black area included in the transmission characteristic information TR and the white point Pwhite and the black point Pblack included in the media profile of the fabric. (b1) Pixels where the brightness L of the basic proof image data BPF is less than or equal to the black point Pblack: The adjustment coefficient K_corr is set to a value equal to the background reference rate correction coefficient K_set. (b2) Pixels where Pblack < L < Pwhite: The adjustment coefficient K_corr is determined by linearly interpolating between the background reference rate correction coefficient K_set and 1.0 according to the brightness L. (b3) Pixels where the brightness L of the basic proof image data BPF is greater than or equal to the white point Pwhite: The adjustment coefficient K_corr is set to 1.0.

[0117] The synthesizing unit 260 determines the basic mixing ratio Rmix_basic using a value obtained by multiplying the average background reference rate Rb_ave or the pixel background reference rate Rb_px by the adjustment coefficient K_corr. For example, the basic mixing ratio Rmix_basic is calculated by any of the following formulas. Rmix_basic = K_corr × Rb_ave …(q3-1) Rmix_basic = K_corr×Rb_px …(q3-2)

[0118] Furthermore, the average background reference rate Rb_ave or the pixel background reference rate Rb_px multiplied by the adjustment coefficient K_corr is used as the observed color mixing ratio Rmix_obs. That is, the observed color mixing ratio Rmix_obs is calculated using one of the following formulas. Rmix_obs = K_corr×Rb_ave …(q4-1) Rmix_obs = K_corr×Rb_px …(q4-2)

[0119] The observed color mixing ratio Rmix_obs, like the basic color mixing ratio Rmix_basic, is set to change according to the brightness L of the basic proof image data BPF.

[0120] The observed color mixing ratio Rmix_obs may be the same as or different from the basic color mixing ratio Rmix_basic described above. However, it is preferable to use the value obtained by multiplying the average background reference rate Rb_ave by the adjustment coefficient K_corr as the basic color mixing ratio Rmix_basic, and the value obtained by multiplying the pixel background reference rate Rb_px by the adjustment coefficient K_corr as the observed color mixing ratio Rmix_obs. By using the value obtained by multiplying the pixel background reference rate Rb_px by the adjustment coefficient K_corr as the observed color mixing ratio Rmix_obs, the difference between the background and foreground colors in the thread areas and gap areas becomes clearer, so the texture of the fabric can be reproduced more appropriately.

[0121] The background reference rate correction coefficient K_set for the black region represents the background reference rate of the black region. Therefore, first, the transparency characteristic acquisition unit 250 calculates the average brightness Lav3 that constitutes the third texture value Dtx3 based on the texture image TIM3, which is an image of the same type of fabric as the printing medium. Furthermore, the transparency characteristic acquisition unit 250 calculates the average brightness Lav4 that constitutes the fourth texture value Dtx4 based on the texture image TIM4, which is an image of the same type of fabric as the printing medium. The transparency characteristic acquisition unit 250 calculates the background reference rate correction coefficient K_set for the black region using the following formula (M10). Black area background reference ratio correction coefficient = 1 - (100 - Lav3) / (100 - Lav4) ... (M10)

[0122] For fabrics that do not transmit light, it is expected that the range of brightness distribution based on an image taken with a white backing against the printed area will be approximately the same as the range of brightness distribution based on an image taken with a black backing against the printed area. If the average Lav3 and average Lav4 are the same, the background reference rate correction coefficient for the black area will be 0.

[0123] In the case of a fabric that transmits light throughout its entire surface, the brightness differs significantly between the white and black backing colors. Therefore, it is expected that the range of brightness distribution based on the image captured with the printed area backed with a white backing will not overlap with the range of brightness distribution based on the image captured with the printed area backed with a black backing. Consequently, the larger the difference between average Lav3 and average Lav4, the larger the background reference ratio correction coefficient for the black area will be.

[0124] (B2) In the above embodiment, an example was described in which the fabric used for texture acquisition is white. However, the fabric used for texture acquisition may be a color other than white. For example, the L value, a value, and b value of the fabric used for texture acquisition, measured under a standard light source, may be stored in the storage unit 202 in advance.

[0125] C. Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit. For example, this disclosure can also be implemented in the following forms. The technical features in the embodiments described below that correspond to the technical features in each of the forms described below can be replaced or combined as appropriate in order to solve some or all of the problems of this disclosure, or to achieve some or all of the effects of this disclosure. Furthermore, if such technical features are not described as essential in this specification, they can be deleted as appropriate.

[0126] (1) According to a first embodiment of the present disclosure, a method for creating proof image data is provided. This method for creating proof image data includes (a) acquiring basic proof image data for reproducing the color distribution of a basic printed material, which is a printed fabric on which an image has been printed using a printing press and to which a basic backing has been applied, using a proof output device; and (b) acquiring four types of texture information, wherein (i) an image of the non-printed area of ​​the texture acquisition fabric in which no image has been printed with ink, with a first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric in which a second backing of a different color from the first backing as the background; and (iii) the area of ​​the texture acquisition fabric in which an image has been printed with ink, with the first backing as the background. The process includes: (iv) acquiring four types of texture information based on four types of texture images, including (iv) an image of the printed area and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background; (c) acquiring uniform dyeing characteristic information indicating the uniformity of the ink on the texture acquisition fabric using the four types of texture information; (d) acquiring transmission characteristic information indicating the degree of light transmission of the texture acquisition fabric using the four types of texture information; and (e) creating textured proof image data by applying a texture application process using the uniform dyeing characteristic information and the transmission characteristic information to the basic proof image data. According to the above configuration, in a proof image representing a medium with a transparent background, the accuracy of reproducing the texture of the medium can be improved in the textured proof image data in which texture has been added.

[0127] (2) In the method for creating proof image data according to the above embodiment, the first backing is white, the second backing is black, and the four types of texture information may include: a first brightness map generated based on a first texture image obtained by imaging the non-printing area with the white first backing as the background; a second brightness map generated based on a second texture image obtained by imaging the non-printing area with the black second backing as the background; a third brightness map generated based on a third texture image obtained by imaging the printing area with the white first backing as the background; and a fourth brightness map generated based on a fourth texture image obtained by imaging the printing area with the black second backing as the background.

[0128] (3) In the method for creating proof image data in the above form, the duty cycle of the ink in the printing area included in the texture acquisition fabric may be set to a predetermined standard value or higher. According to the above configuration, by increasing the duty cycle of the ink in the printed area, a texture image with a clear difference in brightness compared to the non-printed area can be obtained.

[0129] (4) In the method for creating proof image data in the above form, the printed area included in the texture acquisition fabric may be an area printed in black in the device-dependent color space.

[0130] (5) In the method for creating proof image data in the above form, the color of the fabric for texture acquisition is white, and in step (c), if the dispersion of lightness contained in the fourth lightness map is greater than the dispersion of lightness contained in the first lightness map, and the difference between the dispersion of lightness contained in the first lightness map and the dispersion of lightness contained in the fourth lightness map is greater than a predetermined value, it may be determined that the dyeing of the fabric for texture acquisition with the ink is uneven. According to the above configuration, by using a first texture map based on a first texture image and a fourth texture map based on a fourth texture image, in which the backing color and the fabric color are closely matched, it is possible to suppress the influence of light passing through the fabric on the required brightness dispersion value.

[0131] (6) A method for creating proof image data in the above-described form may further include: (f) If the uniform dyeing characteristic information obtained in step (c) indicates that the dyeing of the texture acquisition fabric with the ink is uneven, a step of determining whether the printed fabric is a light-transmitting fabric using the third lightness map and the fourth lightness map; and (g) If the uniform dyeing characteristic information obtained in step (c) indicates that the dyeing of the texture acquisition fabric with the ink is uniform, a step of determining whether the texture acquisition fabric is a light-transmitting fabric using the first lightness map and the second lightness map. According to the above configuration, when the uniformity of dyeing is high, a first and second brightness map based on an image of the non-printed area is used to determine whether or not it is a light-transmitting fabric. When the uniformity of dyeing is not high, a third and fourth brightness map based on an image of the printed area is used. Using four types of texture images, it is possible to easily determine whether or not it is a light-transmitting fabric.

[0132] (7) In the method for creating proof image data in the above form, the transparency characteristic information acquired in step (d) may include: a thread texture threshold for determining that each pixel representing the textured proof image data is on the threads of the printed fabric; a gap texture threshold for determining that each pixel is in the gaps of the weave of the printed fabric; a thread background reference rate which is the ratio of the pixels on the threads that reference the backing color; a gap background reference rate which is the ratio of the pixels in the gaps that reference the backing color; and a black region background reference rate used to adjust the background reference rate for pixels in black regions. According to the above configuration, the following transparency characteristic information can be obtained: thread texture threshold, gap texture threshold, thread background reference rate, gap background reference rate, and black area background reference rate.

[0133] (8) In the method for creating proof image data according to the above embodiment, in step (d), the thread texture threshold is calculated using the highest and lowest brightness included in the first brightness map and the highest and lowest brightness included in the second brightness map; the gap texture threshold is calculated using the black brightness, which is the brightness set for the second black backing; the thread background reference rate is calculated using the black brightness, the highest brightness included in the first brightness map and the highest brightness included in the second brightness map; the gap background reference rate is calculated using the black brightness, the highest brightness included in the first brightness map and the lowest brightness included in the second brightness map; and the black region background reference rate is calculated using the average of the brightness included in the third brightness map and the average of the brightness included in the fourth brightness map. According to the above configuration, the thread texture threshold, gap texture threshold, thread background reference rate, gap background reference rate, and black region background reference rate, which are transmission characteristic information, can be easily determined using four brightness maps.

[0134] (9) In the method for creating a proof image according to the above-described form, in step (e), one of the first brightness map, the second brightness map, the third brightness map, and the fourth brightness map may be selected as texture information to represent the unevenness of the printed fabric in the textured proof image data, according to the transparency characteristics of the printed fabric and the uniformity of the ink. According to the above configuration, the unevenness of the printed fabric can be represented in the textured proof image using one of the four brightness maps.

[0135] (10) According to a second embodiment of the present disclosure, a proof image generation device is provided. This proof image generation device includes a basic proof image acquisition unit that acquires basic proof image data for reproducing the color of printed fabric, which has an image printed on it using a printing press, with a proof output device; (i) an image of the non-printed area of ​​the texture acquisition fabric in which no image is printed with ink, with a first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric in which a second backing of a different color from the first backing as the background; (iii) an image of the printed area of ​​the texture acquisition fabric in which an image is printed with the ink, with the first backing as the background; and (iv) an image of the second backing as the background. The system includes: a texture information acquisition unit that acquires four types of texture information based on four types of texture images, including an image of the printed area of ​​the texture acquisition fabric in a certain state; a uniform dyeing characteristic acquisition unit that acquires uniform dyeing characteristic information indicating the uniformity of the ink on the texture acquisition fabric using the four types of texture information; a transparency characteristic acquisition unit that acquires transparency characteristic information indicating the transparency characteristics of the texture acquisition fabric using the four types of texture information; and a texture-applied proof image data creation unit that creates texture-applied proof image data by applying a texture application process using the uniform dyeing characteristic information and the transparency characteristic information to the basic proof image data. According to the above configuration, in a proof image representing a medium with a transparent background, the accuracy of reproducing the texture of the medium can be improved in the textured proof image data in which texture has been added.

[0136] (11) According to a third embodiment of the present disclosure, a program is provided. The program is for creating textured proof image data and includes a function for acquiring basic proof image data for reproducing the color distribution of a basic printed material, which is obtained by applying a basic backing to a printed fabric on which an image has been printed using a printing press, using a proof output device; (i) an image of the non-printed area of ​​the texture acquisition fabric in which no image has been printed with ink, with a first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric in which a second backing of a different color from the first backing as the background; and (iii) the printed area of ​​the texture acquisition fabric in which an image has been printed with ink, with the first backing as the background. The computer is provided with the following functions: (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background, to acquire four types of texture information based on four types of texture images; (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background; (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric, and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background; (iv) an image of the uniform dyeing characteristics information and (iv) an image of the uniform dyeing characteristics information and (iv) an image of the print area of ​​the texture acquisition fabric, According to the above configuration, in a proof image representing a medium with a transparent background, the accuracy of reproducing the texture of the medium can be improved in the textured proof image data in which texture has been added.

[0137] This disclosure can also be implemented in various forms other than those described above. For example, it can be implemented as a computer program that implements the functions of a proof image data creation device. It can also be implemented in the form of a non-transitory storage medium on which the computer program is recorded. [Explanation of Symbols]

[0138] Back_basic…Basic backing, Back_obs…Observation backing, BBC…Basic backing color, BI…Backing color information, BPF…Basic proof image data, Dtx…Texture value, Dtx1…First texture value, Dtx2…Second texture value, Dtx3…Third texture value, Dtx4…Fourth texture value, FPF…Foreground color proof image data, IM…Input image data, IPF…ICC profile, NR…Non-printable area, OBC…Observation backing color, OPF…Observation proof image data, PE…Uniform dyeing characteristic information, PG…Proof image creation program, PR…Printable area, SP…P Roof image, TBC1...First backing color, TBC2...Second backing color, TI...Texture information, TIM1~TIM4...Texture image, TIM...Texture image, TPF...Printed fabric, TR...Transparency characteristics information, 100...Printing machine, 200...Proof image data creation device, 201...CPU, 202...Storage unit, 203...Input / output interface, 205...Display device, 210...Basic proof image acquisition unit, 220...Texture information acquisition unit, 230...Backing color information acquisition unit, 240...Uniform dyeing characteristics acquisition unit, 250...Transparency characteristics acquisition unit, 260...Composite unit, 300...Proofing printing device, 500...Printing system

Claims

1. A method for creating proof image data, (a) A process to acquire basic proof image data in order to reproduce the color distribution of a basic printed material, which is a printed fabric on which an image has been printed using a printing press and to which a basic backing has been applied, using a proof output device, (b) A step of acquiring four types of texture information, A step of acquiring four types of texture information based on four types of texture images, including: (i) an image of the non-printed area of ​​the texture acquisition fabric where no image is printed with ink, with the first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric with the second backing having a different color from the first backing as the background; (iii) an image of the printed area of ​​the texture acquisition fabric where an image is printed with the ink, with the first backing as the background; and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background. (c) A step of obtaining uniform dyeing characteristic information that indicates the uniformity of the ink on the texture acquisition fabric using the four types of texture information, (d) A step of obtaining transmission characteristic information indicating the degree of light transmission of the fabric for texture acquisition using the four types of texture information, (e) A step of creating textured proof image data by applying a texture application process using the uniform dyeing characteristic information and the transparency characteristic information to the basic proof image data, A method for creating proof image data, including [specific data / features].

2. A method for creating proof image data according to claim 1, The first backing is white, and the second backing is black. The four types of texture information mentioned above are: A first brightness map generated based on a first texture image obtained by imaging the non-printed area with the first white backing as the background, A second brightness map generated based on a second texture image obtained by imaging the non-printed area against the black second backing background, A third brightness map generated based on a third texture image obtained by imaging the printing area with the first white backing as the background, A fourth brightness map generated based on a fourth texture image obtained by imaging the printing area with the black second backing as the background, including, How to create proof image data.

3. A method for creating proof image data according to claim 2, The duty cycle of the ink in the printing area included in the texture acquisition fabric is set to a predetermined standard value or higher. How to create proof image data.

4. A method for creating proof image data according to claim 3, The printed area included in the fabric for acquiring the texture is an area printed in black in the device-dependent color space. How to create proof image data.

5. A method for creating proof image data according to claim 4, The fabric used for obtaining the texture is white in color. In step (c) above, if the dispersion of lightness in the fourth lightness map is greater than the dispersion of lightness in the first lightness map, and the difference between the dispersion of lightness in the first lightness map and the dispersion of lightness in the fourth lightness map is greater than a predetermined value, it is determined that the dyeing of the texture acquisition fabric with the ink is uneven. How to create proof image data.

6. A method for creating proof image data according to claim 5, (f) If the uniform dyeing characteristic information obtained in step (c) indicates that the dyeing of the texture acquisition fabric with the ink is uneven, the step of determining whether the printed fabric is a light-transmitting fabric using the third lightness map and the fourth lightness map, (g) If the uniform dyeing characteristic information obtained in step (c) indicates that the dyeing of the texture acquisition fabric with the ink is uniform, the step of determining whether the texture acquisition fabric is the light-transmitting fabric using the first lightness map and the second lightness map, A method for creating proof image data, which further includes the following.

7. A method for creating proof image data according to claim 6, The transmission characteristic information obtained in step (d) above is: A yarn texture threshold for determining that each pixel representing the textured proof image data corresponds to a thread in the printed fabric, A gap texture threshold for determining that each of the aforementioned pixels corresponds to a gap in the weave of the printed fabric, The yarn-on-background reference rate is the percentage of pixels that reference the backing color on the aforementioned yarn, The gap background reference rate is the ratio to which the backing color is referenced in the pixels corresponding to the gap, The black region background reference rate used to adjust the background reference rate in pixels in the black region, A method for creating proof image data, including [specific data / features].

8. A method for creating proof image data according to claim 7, In step (d) above, The thread texture threshold is calculated using the highest and lowest brightness values ​​included in the first brightness map and the highest and lowest brightness values ​​included in the second brightness map. The gap texture threshold is calculated using the black brightness, which is the brightness set for the black second backing. The aforementioned background reference ratio on the thread is calculated using the black lightness, the highest lightness included in the first lightness map, and the highest lightness included in the second lightness map. The gap background reference ratio is calculated using the black lightness, the highest lightness included in the first lightness map, and the lowest lightness included in the second lightness map. The black region background reference ratio is calculated using the average of the lightness included in the third lightness map and the average of the lightness included in the fourth lightness map. How to create proof image data.

9. A method for creating a proof image according to claim 8, In step (e) above, In the textured proof image data, one of the following is selected as texture information to represent the unevenness of the printed fabric: the first brightness map, the second brightness map, the third brightness map, and the fourth brightness map, according to the transparency characteristics of the printed fabric and the uniformity of the ink. How to create proof image data.

10. A proof image generation device, A basic proof image acquisition unit acquires basic proof image data to reproduce the color distribution of a basic printed material, which is obtained by applying a basic backing to a printed fabric that has had an image printed on it using a printing press, using a proof output device. A texture information acquisition unit that acquires four types of texture information based on four types of texture images, including: (i) an image of the non-printed area of ​​the texture acquisition fabric where no image is printed with ink, with the first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric with the second backing, which has a different color from the first backing as the background; (iii) an image of the printed area of ​​the texture acquisition fabric where an image is printed with the ink, with the first backing as the background; and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background. A uniform dyeing characteristic acquisition unit that acquires uniform dyeing characteristic information indicating the uniformity of the ink on the texture acquisition fabric using the four types of texture information, A transmission characteristic acquisition unit that acquires transmission characteristic information indicating the degree of light transmission of the texture acquisition fabric using the four types of texture information, A textured proof image data creation unit creates textured proof image data by applying a texture application process using the uniform dyeing characteristic information and the transparency characteristic information to the basic proof image data. A proof image generation device equipped with the following features.

11. A program for creating textured proof image data, This function acquires basic proof image data for reproducing the color distribution of a basic printed material, which is created by applying a basic backing to a printed fabric with an image printed on it using a printing press, using a proof output device. A function to acquire four types of texture information based on four types of texture images, including: (i) an image of the non-printed area of ​​the texture acquisition fabric where no image is printed with ink, with the first backing as the background; (ii) an image of the non-printed area of ​​the texture acquisition fabric with the second backing, which has a different color from the first backing as the background; (iii) an image of the printed area of ​​the texture acquisition fabric where an image is printed with the ink, with the first backing as the background; and (iv) an image of the printed area of ​​the texture acquisition fabric with the second backing as the background. A function to acquire uniform dyeing characteristic information indicating the uniformity of the ink on the texture acquisition fabric using the four types of texture information, A function to acquire transmission characteristic information indicating the degree of light transmission of the texture acquisition fabric using the four types of texture information, A function to create textured proof image data by applying a texture application process using the uniform coloring characteristic information and the transparency characteristic information to the basic proof image data, A program to make a computer realize this.

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