Method for acquiring texture images, texture image acquisition device, and program

Abstract

Improve the technology for obtaining fabric texture information. [Solution] The method for acquiring a texture image includes the steps of: preparing a fabric including a backing with a first backing color region and a second backing color region, and a printed region with ink printed on it and a non-printed region with no ink printed on it; placing the fabric on the backing so that (i) a first partial region where the first backing color region and the non-printed region overlap, (ii) a second partial region where the second backing color region and the non-printed region overlap, (iii) a third partial region where the first backing color region and the printed region overlap, and (iv) a fourth partial region where the second backing color region and the printed region overlap, and then photographing the fabric to acquire an image; and obtaining texture image data by cutting out a selected partial region from the fabric image from the image.

Description

[Technical Field]

[0001] This disclosure relates to a method for acquiring texture images, a texture image acquisition apparatus, and an image method for a program. [Background technology]

[0002] In the technology described in Patent Document 1, the light transmittance of a transparent object is quantified based on an image obtained by photographing the transparent object with a board having a black and white pattern placed behind it. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2001-143085 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] A technique for creating proof images representing printed fabrics is known. In these proof images representing printed fabrics, it is necessary to reproduce the texture of the fabric used as the recording medium. While the technique described in Reference 1 considers light transmittance, it does not consider the degree of ink absorption. Therefore, there is room for further improvement in the technique for acquiring fabric texture information. [Means for solving the problem]

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

[0006] A first embodiment of the present disclosure provides a method for acquiring a texture image. This method for acquiring a texture image includes the steps of: (a) preparing a photographic jig having a light-transmitting window and a backing including at least a first backing color region and a second backing color region; (b) preparing a fabric including a printed region on which ink is printed and a non-printed region on which ink is not printed; and (c) placing the fabric on the backing, wherein (i) a first partial region where the first backing color region of the backing and the non-printed region of the fabric overlap; (ii) a second partial region where the second backing color region of the backing and the non-printed region of the fabric overlap; (iii) a third partial region where the first backing color region of the backing and the printed region of the fabric overlap; and (iv) the second backing color region of the backing (d) a step of placing the fabric on the backing such that a fourth partial region overlapping the printed area of ​​the fabric is provided; (e) a step of photographing the fabric together with the photographing jig after performing step (d) to acquire an image; (f) a step of selecting at least one partial region from the first partial region, the second partial region, the third partial region, and the fourth partial region as a target to be cut out from the fabric image included in the image; and (g) a step of cutting out the selected partial region from the fabric image to acquire texture image data.

[0007] A texture image acquisition device is provided according to a second embodiment of the present disclosure. The texture image acquisition device includes an imaging unit, in a state in which a fabric having an ink-printed area and an ink-unprinted area is superimposed on a backing having at least a first backing color area and a second backing color area, the imaging unit includes: (i) a first partial area where the first backing color area of ​​the backing and the unprinted area of ​​the fabric overlap; (ii) a second partial area where the second backing color area of ​​the backing and the unprinted area of ​​the fabric overlap; (iii) a third partial area where the first backing color area of ​​the backing and the printable area of ​​the fabric overlap; and (iv) a fourth partial area where the second backing color area of ​​the backing and the printable area of ​​the fabric overlap. The imaging unit captures an image of the fabric together with the imaging jig and acquires an image, with the fabric layered on the backing so that the first, second, third, and fourth partial regions are contained within the light-transmitting window portion of the imaging jig; the imaging unit selects at least one of the first, second, third, and fourth partial regions as a target to be cut out from the fabric image included in the image; and the cutting unit cuts out the selected partial region from the fabric image to acquire texture image data.

[0008] A third embodiment of the present disclosure provides a program for acquiring a texture image. The program has the function of imaging a fabric including an ink-printed area and an ink-unprinted area, and the program includes: (i) a first partial area where the first backing color area of ​​the backing, which includes at least a first backing color area and a second backing color area, overlaps with the unprinted area of ​​the fabric; (ii) a second partial area where the second backing color area of ​​the backing overlaps with the unprinted area of ​​the fabric; (iii) a third partial area where the first backing color area of ​​the backing overlaps with the printed area of ​​the fabric; and (iv) a fourth partial area where the second backing color area of ​​the backing overlaps with the printed area of ​​the fabric. The computer is provided with the following functions: a function to capture an image of the fabric together with the photographic jig and acquire an image, with the fabric placed on top of the jig and the first, second, third, and fourth partial regions placed on top of the fabric and the photographic jig having a light-transmitting window portion, so that the first partial region, the second partial region, the third partial region, and the fourth partial region are contained within the window portion of the photographic jig; a function to select at least one of the first, second, third, and fourth partial regions as the target to be cut out from the fabric image included in the image; and a function to cut out the selected partial region from the fabric image and acquire texture image data. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing the schematic configuration of the texture image acquisition device according to this embodiment. [Figure 2] This is an explanatory diagram of the shooting method in this embodiment. [Figure 3] This is an explanatory diagram showing an example of an captured image. [Figure 4] This is a flowchart illustrating the process of acquiring texture image data. [Figure 5] This is an explanatory diagram regarding the method for determining the cutting area. [Figure 6]It is an explanatory diagram of a guide marker. [Figure 7] It is an explanatory diagram of a configuration for fixing a photographing jig and a backing. [Figure 8] It is an explanatory diagram of an example in which a positioning mark is provided on a photographing jig. [Figure 9] It is an explanatory diagram of imaging using a backing having three backing color areas. [Figure 10] It is an explanatory diagram of imaging using a fabric having two printing areas. [Figure 11] It is an explanatory diagram of imaging using a backing having three backing color areas and a fabric having two printing areas. [Figure 12] It is an explanatory diagram of brightness correction.

Mode for Carrying Out the Invention

[0010] A. Embodiment: FIG. 1 is a block diagram showing a schematic configuration of a texture image acquisition device 10 according to the present embodiment. FIG. 2 is an explanatory diagram of a photographing method in the present embodiment. The texture image acquisition device 10 acquires a texture image using an image obtained by imaging a subject having a texture. In the present embodiment, the subject is a fabric FB. The acquired texture image is used, for example, in a process of imparting a texture to a proof image in order to reproduce the texture of the fabric FB in the proof image when generating a proof image for resist printing using the fabric FB as a printing medium.

[0011] The texture image acquisition device 10 includes an imaging unit 100, a photographing jig 200 (see FIG. 2), a backing 300 (see FIG. 2) which is a backing material, and an image processing device 400. In FIG. 1, the photographing jig 200 and the backing 300 are not shown.

[0012] The imaging unit 100 (see FIG. 1) is, for example, a camera and images the fabric FB. The imaging unit 100 is communicably connected to the image processing device 400 by wire or wirelessly. The imaging unit 100 transmits the captured image to the image processing device 400. The imaging unit 100 may be fixed, for example, using a stand connected to a mounting table for placing the subject, similar to the imaging unit described in Japanese Patent Application No. 2024-116006 (hereinafter, Prior Application 1) filed by the applicant of the present disclosure. As shown in FIG. 2, the fabric FB is imaged by the imaging unit 100 with the imaging jig 200 stacked thereon with the backing 300 against the back.

[0013] As the imaging jig 200, the imaging jig described in Prior Application 1 can be adopted. This imaging jig 200 is formed of a thin metal plate, a synthetic resin sheet, thick paper, or the like. A window portion, which is a rectangular opening, is provided at the center of the imaging jig 200. Three regions are provided around the window portion OP. A first region AR1, a buffer region AB, and a second region AR2 are provided around the window portion OP. The first region AR1, the buffer region AB, and the second region AR2 constitute a comparison pattern used for correcting the brightness of the captured image.

[0014] The first region AR1 is arranged so as to surround the window portion OP. The first region AR1 is a hollow rectangle, and its outer peripheral shape is configured as a rectangle concentric with the window portion OP. The color of the first region AR1 is white. For example, under a standard light source, the measured value of the brightness of the first region AR1 is stored in advance in the memory 410.

[0015] The buffer region AB is provided outside the first region AR1. The buffer region AB is arranged so as to surround the first region AR1. The buffer region AB is a hollow rectangle, and its outer peripheral shape is configured as a rectangle concentric with the window portion OP. The color of the buffer region AB is gray. Note that the buffer region AB may not be provided as the comparison pattern.

[0016] The second region AR2 is located outside the buffer region AB. The second region AR2 is positioned to surround the buffer region AB. The second region AR2 is a hollow rectangle, and its outer perimeter is configured as a rectangle concentric with the window region OP. The color of the second region AR2 is black. For example, a measurement of the brightness of the second region AR2 under a standard light source is pre-stored in the memory 410. Outside the second region AR2, there may be a region of the background color of the imaging jig 200.

[0017] In this embodiment, the fabric FB is imaged with the imaging jig 200 placed on top of it. The white color of the first region AR1 and the black color of the second region AR2 are used as a reference to correct for differences in the appearance of the fabric FB due to differences in the light source, the position of the light, etc.

[0018] The backing 300 is a backing material used during imaging. The backing 300 is made of a thin metal plate, a synthetic resin sheet, thick paper, etc. The backing 300 is rectangular in shape. The backing 300 has a first backing color area BR1 and a second backing color area BR2. The first backing color area BR1 occupies half of one side of the backing 300. The second backing color area BR2 occupies the other half of the other side of the backing 300. The color of the first backing color area BR1 is white. The color of the second backing color area BR2 is black. The first backing color area BR1 and the second backing color area BR2 are arranged on the backing 300 such that the boundary B1 between the first backing color area BR1 and the second backing color area BR2 is straight. The boundary B1 between the first backing color area BR1 and the second backing color area BR2 is also called the "first boundary".

[0019] The fabric FB is provided with a printed area PR, which is an area where an image is printed by textile printing, and a non-printed area NR, where no image is printed. The printed area PR is formed by printing a rectangular solid color image onto the fabric FB in black in the device-dependent color space. The rectangular solid color image may be printed with black ink, light black ink, or cyan, magenta, and yellow inks. Light black is a low-density black ink. The printed area PR is positioned on the fabric FB such that at least a portion of the printed area PR and at least a portion of the non-printed area NR are included in the area visible from the window OP when the imaging jig 200 is placed on the fabric FB. Since the printed image is rectangular, the boundary B2 between the printed area PR and the non-printed area NR is a straight line. The boundary B2 between the printed area PR and the non-printed area NR is also called the "second boundary".

[0020] The image processing device 400 shown in Figure 1 is, for example, a personal computer. The image processing device 400 generates a texture image using the image captured by the imaging unit 100. The image processing device 400 includes a memory 410, an interface circuit 420, an input device 430 and a display device 440 connected to the interface circuit 420, and a CPU 450 as a processor. The imaging unit 100 is further connected to the interface circuit 420. The image processing device 400 and the imaging unit 100 can communicate with each other. The input device 430 is, for example, a keyboard or a mouse. The display device 440 is, for example, a liquid crystal display or an organic EL (Electro-Luminescence) display.

[0021] The memory 410 stores the program PG. The CPU 450 executes the program PG, thereby realizing the functions of the correction processing unit 451, selection unit 452, and cropping unit 453, which will be described later. The CPU 450 also has the function of capturing images of a subject by instructing the imaging unit 100 to take an image and having the imaging unit 100 perform the imaging.

[0022] The correction processing unit 451 acquires target image data representing the fabric image inside the window portion OP in the captured image, and comparison image data representing the comparison pattern of the imaging jig 200 in the captured image, and corrects the target image data using the comparison image data.

[0023] Figure 3 is an explanatory diagram showing an example of an captured image. The selection unit 452 (see Figure 1) selects at least one sub-region from the four sub-regions described below. As shown in Figure 2, the fabric FB is imaged with the backing 300, which has a white first backing color region BR1 and a black second backing color region BR2, as the backing material. Therefore, as shown in Figure 3, the area visible from the window portion OP of the imaging jig 200 includes the following four sub-regions. (i) The first partial region PA1 in which the non-printed region NR of the fabric FB is superimposed on the first white backing color region BR1. (ii) Second subregion PA2 in which the non-printed region NR of the fabric FB is superimposed on the black second backing color region BR2. (iii) Third sub-region PA3 in which the printed area PR of the fabric FB is superimposed on the white first backing color area BR1 (iv) The fourth sub-region PA4 in which the printed area PR of the fabric FB is superimposed on the black second backing color region BR2.

[0024] The cutting unit 453 shown in Figure 1 cuts out the portion area selected by the selection unit 452 from the captured image and acquires texture image data.

[0025] Figure 4 is a flowchart illustrating the process of acquiring texture image data. In step S101, the user prepares the fabric FB. As mentioned above, the fabric FB has a printable area PR and a non-printable area NR. It is desirable that the prepared fabric FB is the same fabric as the printing medium, or a fabric with a texture similar to the printing medium.

[0026] In step S103, the user places the fabric FB on the backing 300. First, the backing 300 is positioned in a location where the imaging unit 100 can capture images. For example, the backing 300 is placed on a mounting platform for placing a subject as described in Prior Application 1. Then, the fabric FB is placed on the backing 300. Here, the fabric FB is placed on the backing 300 so that the first partial region PA1, the second partial region PA2, the third partial region PA3, and the fourth partial region PA4 described above are provided. More specifically, as shown in Figure 2, the fabric FB is placed on the backing 300 so that the boundary B2 between the printed region PR and the non-printed region NR of the fabric FB is rotated 90 degrees relative to the boundary B1 between the first backing color region BR1 and the second backing color region BR2 of the backing 300. Thus, four partial regions can be easily formed.

[0027] As shown in Figure 4, in step S105, the user places the imaging jig 200 on the fabric FB. Here, the imaging jig 200 is placed on the fabric FB such that the first partial region PA1, the second partial region PA2, the third partial region PA3, and the fourth partial region PA4 are contained within the window portion OP of the imaging jig 200.

[0028] In step S107, the fabric FB is imaged together with the imaging jig 200, and an image is acquired. The position and orientation of the imaging unit 100 are adjusted so that the entire imaging jig 200 is within the imaging range of the imaging unit 100. For example, in response to an operation instruction via the user input device 430, the CPU 450 of the image processing device 400 instructs the imaging unit 100 to take an image. The imaging unit 100 takes an image of the fabric FB, which is the subject, and transmits the image representing the captured image to the image processing device 400.

[0029] In step S109, the captured image is corrected. The targets of correction are noise contained in the captured image, such as distortion of the field of view, uneven lighting, low contrast due to underexposure, out-of-focus, luminance noise, and high-sensitivity noise. If the captured image acquired by the imaging unit 100 is represented in the RGB color space, first the captured image is L * a * b * The image is converted into a color space. Additionally, an affine transformation is applied to the captured image to correct for distortion of the field of view. The method of affine transformation is the same as that described in Prior Application 1. Subsequently, contrast correction is applied to the captured image. The method of contrast correction is the same as that described in Prior Application 1.

[0030] Figure 12 is an explanatory diagram of brightness correction. In the example shown in Figure 12, the captured image is arranged on the XY plane. The vertically downward direction is defined as the +Z axis, and the X and Y axes are perpendicular to the Z axis. Furthermore, brightness correction is applied to the captured image. The method of brightness correction using a comparison pattern is the same as the method described in Prior Application 1. Note that the image to be subjected to brightness correction is the image after the distortion of the field of view has been corrected by affine transformation and the contrast has been corrected.

[0031] Specifically, brightness correction can be performed using the following steps (1) to (6). <1> The rectangular position of the first region AR1 is determined from the captured image by edge detection. The pixel position within the first region AR1 is expressed as a 2D coordinate (x,y). <2> Using the brightness L(x,y) of the pixels that make up the image in the first region AR1, the average brightness of the four sides of the first region AR1 is calculated. As shown in Figure 12, for each pixel in the first region AR1, the average brightness Uav is calculated for each pixel position on the top edge, the average brightness Rav is calculated for each pixel position on the right edge, the average brightness Bav is calculated for each pixel position on the bottom edge, and the average brightness Lav is calculated for each pixel position on the left edge. The average brightness for each pixel position (x,y) is expressed as Uav(x,y). <3> Calculate the overall average Aav by further averaging the average brightness of the four sides.

[0032] <4> Using the average brightness values ​​Uav(x,y), Rav(x,y), Bav(x,y), and Lav(x,y) of the four sides, we assume a 2D mesh MS corresponding to all pixels in the region enclosed by the four sides, i.e., the window part OP, and obtain the distribution of brightness L Lip(x,y) of this mesh by interpolation. <5> The brightness correction value ΔL, which corrects the brightness Lg(x,y) of pixel g at position (x,y), is calculated using the following equation (1). ΔL(x,y)=Aav-Lip(x,y) ···(1) Here, Lip(x,y) is not the actual brightness of the image within the window section OP, but rather the distribution of brightness L obtained by interpolation from the average brightness of the four sides Uav(x,y), Rav(x,y), Bav(x,y), and Lav(x,y). <6> The calculated brightness correction value ΔL(x,y) is added to the actual brightness L(x,y) of each pixel g(x,y) in the image within the window section OP. This corrects the brightness L(x,y) of each pixel g(x,y).

[0033] The brightness correction described above can correct for cases where brightness differs depending on the location, such as in uneven lighting. Below, we show an example of calculating the brightness correction value ΔL for a 2D mesh, assuming the window section OP is 3x3 pixels in size. In the middle section of Figure 12, the average brightness values ​​Uav(x,y), Rav(x,y), Bav(x,y), and Lav(x,y) for the four sides are set to 1x3 or 3x1, and the distribution of brightness L interpolated from these values ​​is set to 3x3, as examples. In practice, this should be expanded according to the number of pixels in the image within the window section OP. If it is necessary to improve the accuracy of the brightness correction, for horizontally long sides such as the average brightness values ​​Uav(x,y) and Bav(x,y), the vertical direction is used as the width corresponding to multiple pixels, and for vertically long sides such as the average brightness values ​​Rav(x,y) and Lav(x,y), the horizontal direction is used as the width corresponding to multiple pixels, and the average brightness of the pixels arranged in the width direction is used as the representative brightness. Specifically, for example, if Uav(x,y) is configured with 10 pixels in the x direction and 100 pixels in the y direction, the average brightness L of 1x100 obtained by averaging the brightness L of the 10 pixels is used as the average brightness Uav(x,y).

[0034] Furthermore, sharpening or blurring processes may be applied to the captured image as needed. The methods described in Prior Application 1 can be used as specific methods for the above-mentioned affine transformation, contrast correction, brightness correction, sharpening, and blurring processes. The process in step S109 is performed by a CPU 450 functioning as a correction processing unit 451.

[0035] As shown in Figure 4, in step S111, the selection of a partial region to be cut out from the fabric image inside the window portion OP in the captured image is accepted. For example, a GUI (not shown) for accepting the selection of a partial region is displayed on the display device 440. The user selects at least one partial region using an input device. The processing in step S111 is performed by the CPU 450, which functions as a selection unit 452.

[0036] In step S113, the selected sub-region is cut out from the fabric image inside the window portion OP in the captured image. The texture image data TI, which is image data representing the cut-out sub-region, is stored in memory 410, for example. The processing in step S113 is performed by the CPU 450, which functions as a cutting unit 453. Here, when cutting out the sub-region, it is desirable that the edges, which are the boundaries with other adjacent sub-regions and the window portion, are not included in the cut-out range. This is because the brightness of the edges of the sub-region is expected to be affected by the shadows cast by the thickness of the imaging jig 200.

[0037] Figure 5 is an explanatory diagram of the method for determining the cropping area. The captured image is arranged on the XY plane. The vertically downward direction is defined as the +Z axis, and the X and Y axes are perpendicular to the Z axis.

[0038] Let's assume that the first subregion PA1 is selected as the target for extraction. Along the line segment Y1-Y1 passing through the center of the first subregion PA1 in the Y-axis direction, the brightness L of each pixel is... * When measured, as shown in the lower part of Figure 5, there is a slight increase in brightness L near the +Y boundary between the window portion OP and the first partial region PA1. *There may be a range SA where it decreases. At the bottom of FIG. 5, the brightness L of the pixels along the line segment Y1 - Y1 is shown. * A graph is shown. The horizontal axis represents the coordinates of the pixels, and the vertical axis represents the brightness.

[0039] Let the number of pixels corresponding to the width of the range SA in the Y-axis direction be P1. The pixels with the number of pixels P1 from the +Y side boundary of the first partial region PA1 toward the -Y direction are excluded from the extraction target.

[0040] Furthermore, it is assumed that it is affected by the diffuse reflected light and dot gain from the second partial region PA2 adjacent to the first partial region PA1. Therefore, also in the vicinity of the boundary with the second partial region PA2, the pixels corresponding to the range SB are excluded from the extraction range. For example, the number of pixels corresponding to the width of the range SB in the Y-axis direction is set to be the same as the number of pixels corresponding to the width of the range SA in the Y-axis direction.

[0041] Alternatively, regardless of the measured value of the brightness L of the pixels, pixels with a predetermined number of pixels from the four sides of the first partial region PA1 toward the center may be excluded from the extraction target. *

[0042] Here, when the weave or knitting of the fabric is viewed in cross-section, the weave or knitting shape of the yarns constituting the fabric has periodicity. It is desirable that the cut-out target includes at least two periods of this periodic shape.

[0043] Also, when measuring the brightness L of each pixel along the line segment X1 - X1 passing through the center of the first partial region PA1 in the X direction, there may be a range SC where the brightness L slightly decreases near the boundary between the window portion OP and the -X side of the first partial region PA1. It is desirable that this range is also excluded from the extraction range in the same manner as above. Furthermore, since it is assumed that it is affected by the diffuse reflected light and dot gain from the third partial region PA3 adjacent to the first partial region PA1, it is desirable that a part of the pixels is excluded from the extraction range also in the vicinity of the boundary with the third partial region PA3.​​​​

[0044] As described above, in this embodiment, four types of texture image data can be obtained in a single image capture by combining the presence or absence of a printed area on the fabric FB with two backing colors.

[0045] The four types of texture image data obtained can be used for the following purposes, for example:

[0046] Texture image data obtained by cutting out a second partial region PA2 in which the non-printed region NR of the fabric FB is superimposed on a second black backing color region BR2 can be used in the method for creating proof image data disclosed by the applicant of this disclosure in Japanese Patent Application Nos. 2024-207035 and 2024-207036. Here, it is assumed that a translucent fabric such as chiffon, tulle, organza, georgette, lace, mesh, lawn, and gauze is used as the fabric FB to obtain the texture image data. When creating proof image data representing a printed fabric with an image printed on a translucent fabric, the brightness contained in the texture image data can be used as texture information of the translucent fabric.

[0047] Texture image data extracted from the fourth sub-region PA4, where the printed area PR of the fabric FB is superimposed on the second black backing color region BR2, can be used to create proof image data representing fabrics with high ink absorption, such as felt, where the surface state changes after absorbing ink compared to before the ink was absorbed. Specifically, the brightness contained in the texture image data obtained by extracting the fourth sub-region PA4 from the captured image is used as texture information. Here, it is assumed that the target fabric is used as the fabric FB to obtain the texture image data.

[0048] Texture image data extracted from the third sub-region PA3, where the print area PR of the fabric FB is superimposed on the first white backing color region BR1, can be used to create proof image data representing fabrics made by knitting, such as mesh knit fabrics. Specifically, the brightness contained in the texture image data obtained by extracting the range of the third sub-region PA3 from the captured image is used as texture information. Texture information is not applied to the gaps between the weave of the fabric. Here, it is assumed that the target fabric is used as the fabric FB to obtain the texture image data.

[0049] Texture image data extracted from the first partial region PA1, where the non-printable region NR of the fabric FB is superimposed on the first white backing color region BR1, can be used to create proof image data representing fabrics other than the translucent fabrics, felt-like fabrics, mesh knit fabrics, and knitted lace fabrics mentioned above. Specifically, the brightness contained in the texture image data obtained by extracting the range of the first partial region PA1 from the captured image can be used as texture information.

[0050] B. Other embodiments: (B1) The adjacent boundaries of the first subregion PA1 to the fourth subregion PA4 may be detected by edge detection. Alternatively, the adjacent boundaries of the first subregion PA1 to the fourth subregion PA4 may be detected using guide markers.

[0051] Figure 6 is an explanatory diagram of the guide markers. In the example shown in Figure 6, guide marker GM1 is positioned within the window portion OP along the Y-axis direction. More specifically, guide marker GM1 is positioned at the boundary between the first and second sub-regions PA1 and PA2, and the third and fourth sub-regions PA3 and PA4. Furthermore, guide marker GM2 is positioned within the window portion OP along the X-axis direction. More specifically, guide marker GM2 is positioned at the boundary between the first and third sub-regions PA1 and PA3, and the second and fourth sub-regions PA2 and PA4. Guide markers GM1 and GM2 are, for example, resin rod-shaped members.

[0052] The user visually confirms the boundaries of a sub-region and places guide markers GM1 and GM2 at the boundaries. When placing guide markers GM1 and GM2, the backing 300 may be illuminated from the back to make it easier for the user to recognize the boundary B1 of the backing 300. It should be noted that when photographing the fabric FB, the backing 300 should not be illuminated from the back to make it easier to recognize. This is because it will reduce the reproducibility of the fabric texture in the texture image. As shown in the example in Figure 6, in the image of the fabric FB including guide markers GM1 and GM2, the accuracy of edge detection for detecting the boundaries of each sub-region is improved compared to the configuration without guide markers GM1 and GM2. A cross-shaped guide marker, in which two rod-shaped members are fixed perpendicularly to each other, may be used as the guide marker.

[0053] (B2) Figure 7 is an explanatory diagram of the configuration for fixing the imaging jig 200 and the backing 300. In the example shown in Figure 7, the +Y side end of the backing 300 and the +Y side end of the imaging jig 200 are fixed by a hinge HN. The imaging jig 200 is rotatable around a rotation axis along the X axis. When the imaging jig 200 is superimposed on the backing 300, the relative positions of the backing 300 and the imaging jig 200 in the XY plane are fixed such that the +Y side and -Y side of the window OP are parallel to the boundary B1 (see Figure 2) between the first backing color region BR1 and the second backing color region BR2 of the backing 300.

[0054] The user rotates the imaging jig 200 to lift it away from the backing 300, and then places the fabric FB on top of the backing 300. The user places the fabric FB on the backing 300 such that the boundary B2 between the printed area PR and the non-printed area NR of the fabric FB is rotated 90 degrees relative to the boundary B1 between the first backing color area BR1 and the second backing color area BR2 of the backing 300. After that, the user rotates the imaging jig 200 in the opposite direction to return it to its original position. In the example shown in Figure 7, the relative positions of the backing 300 and the imaging jig 200 in the XY plane are fixed, making it easy to position the imaging jig 200 when placing it on top of the fabric FB.

[0055] (B3) Figure 8 is an explanatory diagram of an example in which positioning marks are provided on the imaging jig 200. The imaging jig 200 is provided with a pair of positioning marks MK1 that indicate the position to align the boundary B1 between the first backing color region BR1 and the second backing color region BR2 of the backing 300. One positioning mark MK1 is located at the midpoint of the -X side edge of the imaging jig 200. The other positioning mark MK1 is located at the midpoint of the +X side edge of the imaging jig 200.

[0056] Furthermore, the imaging jig 200 is provided with a pair of positioning marks MK2 that indicate the position to align the boundary B2 between the printed area PR and the non-printed area NR of the fabric FB. One positioning mark MK2 is located at the midpoint of the +Y side of the window OP. The other positioning mark MK2 is located at the midpoint of the -Y side of the window OP.

[0057] The user can make the size of the printed area PR and the non-printed area NR visible within the window OP equal by simply placing the imaging jig 200 on the fabric FB so that the boundary B2 of the fabric FB aligns with the pair of positioning marks MK2.

[0058] The user can align the boundary B1 of the backing 300 with the boundary B1 of the backing 300 by simply placing the imaging jig 200 on the fabric FB, thereby making the +Y side and -Y side of the window OP parallel to the boundary B1 of the backing 300. As described in the above embodiment, it is desirable that the fabric FB be placed on the backing 300 such that the boundary B2 of the printed area PR and the non-printed area NR of the fabric FB is rotated 90 degrees with respect to the boundary B1 of the first backing color area BR1 and the second backing color area BR2 of the backing 300. In the example shown in Figure 8, it is easy to place the fabric FB on the backing 300 with the boundary B1 and boundary B2 orthogonal.

[0059] (B4) In the above embodiment, an example was described in which the shape of each sub-region is a square, but the shape of each sub-region may be a rectangle.

[0060] (B5) In the above embodiment, the first backing color region BR1 is white, and the second backing color region BR2 is black. By increasing the difference in brightness of the backing colors, for example, if a third sub-region PA3, which is a printed area with the white first backing color region BR1 as the background, and a fourth sub-region PA4, which is a printed area with the black second backing color region BR2 as the background, are selected, a texture image with a clear difference in brightness can be obtained when comparing the third sub-region PA3 and the fourth sub-region PA4. Also, for example, if a first sub-region PA1, which is a non-printed area with the white first backing color region BR1 as the background, and a second sub-region PA2, which is a non-printed area with the black second backing color region BR2 as the background, a texture image with a clear difference in brightness can be obtained when comparing the first sub-region PA1 and the second sub-region PA2.

[0061] (B6) In the above embodiment, an example was described in which the first backing color region BR1 is a white region and the second backing color region BR2 is a black region. However, the first backing color region BR1 and the second backing color region BR2 only need to have different shades, and are not limited to white and black. Different shades mean L * a * b * In the color space, L * This refers to the values ​​being different.

[0062] (B7) Figure 9 is an explanatory diagram for imaging using a backing 300 having three backing color regions. The left side of Figure 9 shows the fabric FB and imaging jig 200 being placed on top of the backing 300. The right side of Figure 9 shows a top view of the backing 300 with the fabric FB and imaging jig 200 placed on top. In addition to the first backing color region BR1 and the second backing color region BR2, the backing 300 may also be provided with a third backing color region BR3. It is desirable that the color of the third backing color region BR3 be the background color expected when actually observing the printed fabric.

[0063] As shown in the right side of Figure 9, the area visible from the window OP of the imaging jig 200 includes the following six subregions. Note that subregions (i) to (iv) are the same as in the embodiment described above. (i) The first partial region PA1 in which the non-printed region NR of the fabric FB is superimposed on the first white backing color region BR1. (ii) Second subregion PA2 in which the non-printed region NR of the fabric FB is superimposed on the black second backing color region BR2. (iii) Third sub-region PA3 in which the printed area PR of the fabric FB is superimposed on the white first backing color area BR1 (iv) The fourth sub-region PA4 in which the printed area PR of the fabric FB is superimposed on the black second backing color region BR2. (v) Fifth sub-region PA5 in which the printed area PR of the fabric FB is superimposed on the third backing color area BR3. (vi) The sixth subregion PA6 in which the non-printed region NR of the fabric FB is superimposed on the third backing color region BR3.

[0064] The texture image data obtained by extracting the fifth subregion PA5 from the captured image is a texture image data that captures the fabric with the background that would be expected when actually observing the printed fabric. The texture image data obtained by extracting the sixth subregion PA6 from the captured image is a texture image data that captures the fabric with the background that would be expected when actually observing the unprinted fabric.

[0065] (B8) Figure 10 is an explanatory diagram of imaging using a fabric FB having two printing areas. The left side of Figure 10 shows the fabric FB and imaging jig 200 being placed on top of the backing 300. The right side of Figure 10 shows a top view of the state in which the fabric FB and imaging jig 200 are placed on top of the backing 300. Similar to the embodiment described above, a backing 300 is used which has a first backing color area BR1 and a second backing color area BR2. In addition to the printing area PR, the fabric FB may also be provided with a second printing area PR2, which is another printing area. The second printing area PR2 is formed by printing a rectangular solid color image in a color different from black onto the fabric FB. It is desirable that the second printing area PR2 be formed using the color of the ink that is actually printed on the fabric to produce the printed fabric.

[0066] As shown in the right side of Figure 10, the area visible from the window OP of the imaging jig 200 includes the following six subregions. Note that subregions (i) to (iv) are the same as in the embodiment described above. (i) The first partial region PA1 in which the non-printed region NR of the fabric FB is superimposed on the first white backing color region BR1. (ii) Second subregion PA2 in which the non-printed region NR of the fabric FB is superimposed on the black second backing color region BR2. (iii) Third sub-region PA3 in which the printed area PR of the fabric FB is superimposed on the white first backing color area BR1 (iv) The fourth sub-region PA4 in which the printed area PR of the fabric FB is superimposed on the black second backing color region BR2. (vii) The seventh sub-region PA7 in which the second printing region PR2 of the fabric FB is superimposed on the first backing color region BR1. (viii) The eighth subregion PA8 in which the second printing region PR2 of the fabric FB is superimposed on the second backing color region BR2.

[0067] The texture image data obtained by extracting the seventh subregion PA7 from the captured image is a texture image of the fabric with the ink that will actually be printed on it, against a white backing background. The texture image data obtained by extracting the eighth subregion PA8 from the captured image is a texture image of the fabric with the ink that will actually be printed on it, against a black backing background.

[0068] (B9) Figure 11 is an explanatory diagram for imaging using a backing 300 having three backing color regions and a fabric FB having two print regions. The left side of Figure 11 shows the fabric FB and imaging jig 200 being placed on top of the backing 300. The right side of Figure 11 shows a top view of the state in which the fabric FB and imaging jig 200 are placed on top of the backing 300. In the illustrated example, a backing 300 having a first backing color region BR1, a second backing color region BR2, and a third backing color region BR3, and a fabric FB having a non-print region NR, a print region PR, and a second print region PR2 are used. As the color of the third backing color region BR3, for example, the background color expected when actually observing the printed fabric is adopted. The second print region PR2 is formed using, for example, the color of the ink actually printed on the fabric to create the printed fabric.

[0069] As shown in the right side of Figure 11, the area visible from the window OP of the imaging jig 200 includes the following five subregions. Note that subregions (i) to (iv) are the same as in the embodiment described above. (i) The first partial region PA1 in which the non-printed region NR of the fabric FB is superimposed on the first white backing color region BR1. (ii) Second subregion PA2 in which the non-printed region NR of the fabric FB is superimposed on the black second backing color region BR2. (iii) Third sub-region PA3 in which the printed area PR of the fabric FB is superimposed on the white first backing color area BR1 (iv) The fourth sub-region PA4 in which the printed area PR of the fabric FB is superimposed on the black second backing color region BR2. (ix) The ninth sub-region PA9 in which the second printing region PR2 of the fabric FB is superimposed on the third backing color region BR3. The texture image data obtained by extracting the ninth subregion PA9 from the captured image is a texture image of the fabric with the ink that will actually be printed on it, with the background that would be expected when actually observing the printed fabric facing away from it.

[0070] (B10) In the printing settings for forming a printable area PR on the fabric FB, it is desirable that the ink duty cycle is set to a predetermined standard value or higher. The ink duty cycle represents the amount of ink per unit area ejected onto the medium. By forming the printable area PR by printing with a high ink duty cycle, a textured image with a clear difference in brightness can be obtained when comparing the printable area PR with the non-printable area NR. Furthermore, the color of the image forming the printable area PR is not limited to black. Assuming that the ink duty cycle is set to a predetermined standard value or higher, it may be gray, for example.

[0071] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0072] C. Other forms: (1) According to a first embodiment of the present disclosure, a method for acquiring a texture image is provided. This method for acquiring a texture image includes the steps of: (a) preparing a photographic jig having a light-transmitting window and a backing including at least a first backing color region and a second backing color region; (b) preparing a fabric including a printed region on which ink is printed and a non-printed region on which ink is not printed; and (c) placing the fabric on the backing, wherein (i) a first partial region where the first backing color region of the backing and the non-printed region of the fabric overlap; (ii) a second partial region where the second backing color region of the backing and the non-printed region of the fabric overlap; (iii) a third partial region where the first backing color region of the backing and the printed region of the fabric overlap; and (iv) the second backing color region of the backing (d) a step of placing the fabric on the backing such that a fourth partial region overlapping the printed area of ​​the fabric is provided; (e) a step of photographing the fabric together with the photographing jig after performing step (d) to acquire an image; (f) a step of selecting at least one partial region from the first partial region, the second partial region, the third partial region, and the fourth partial region as a target to be cut out from the fabric image included in the image; and (g) a step of cutting out the selected partial region from the fabric image to acquire texture image data. According to the above configuration, four types of texture images can be obtained in a single image capture by combining the presence or absence of printing with two backing colors.

[0073] (2) In the method for obtaining the texture image of the above form, the first backing color region may be a white region and the second backing color region may be a black region. According to the above configuration, by increasing the difference in brightness of the backing color, a texture image with a clear difference in brightness can be obtained when comparing a printed area with a white backing with a printed area with a black backing. Similarly, a texture image with a clear difference in brightness can be obtained when comparing a non-printed area with a white backing with a non-printed area with a black backing.

[0074] (3) In the method for obtaining the texture image in the above form, the duty cycle of the ink in the printing area included in the 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.

[0075] (4) In the method for obtaining the texture image of the above form, the printed area included in the fabric may be an area printed in black in the device-dependent color space.

[0076] (5) In the method for obtaining the texture image of the above form, the first boundary, which is the boundary between the first backing color region and the second backing color region of the backing, is configured to be linear, and the second boundary, which is the boundary between the printed region and the non-printed region of the fabric, is configured to be linear, and in step (c), the fabric may be placed on the backing such that the second boundary is rotated 90 degrees with respect to the first boundary. According to the above configuration, four sub-regions can be easily formed.

[0077] (6) In the method for obtaining the texture image in the above form, the edge of the selected partial region in step (g) does not need to be included in the range cut out from the fabric image. In the above configuration, the thickness of the imaging jig can cast a shadow that affects the brightness of the edges of a partial region; therefore, the edges of the partial region are excluded from the cropping process.

[0078] (7) In the method for acquiring a texture image in the above form, in step (a), a photographing jig may be prepared which is provided with a comparison pattern that surrounds the window portion and includes a first region and a second region with different shades.

[0079] (8) A method for obtaining a texture image in the above form may further include (h) a step performed after step (e) of correcting the image data representing the fabric image using comparison image data representing the comparison pattern included in the captured image.

[0080] (9) In the method for acquiring a texture image in the above form, the object of correction in step (h) may include at least one of the following that may occur in step (e): distortion of the field of view, unevenness caused by lighting, low contrast due to underexposure, out of focus, luminance noise, and high sensitivity noise.

[0081] (10) A texture image acquisition device is provided according to a second embodiment of the present disclosure. The texture image acquisition device includes an imaging unit, in a state in which a fabric having printed areas with ink printed on it and unprinted areas without ink printed on it is superimposed on a backing having at least a first backing color area and a second backing color area, the imaging unit includes: (i) a first partial area where the first backing color area of ​​the backing and the unprinted area of ​​the fabric overlap; (ii) a second partial area where the second backing color area of ​​the backing and the unprinted area of ​​the fabric overlap; (iii) a third partial area where the first backing color area of ​​the backing and the printed area of ​​the fabric overlap; and (iv) a fourth partial area where the second backing color area of ​​the backing and the printed area of ​​the fabric overlap. The imaging unit captures an image of the fabric together with the imaging jig and acquires an image, with the fabric layered on the backing so that the first, second, third, and fourth partial regions are contained within the light-transmitting window portion of the imaging jig; the imaging unit selects at least one of the first, second, third, and fourth partial regions as a target to be cut out from the fabric image included in the image; and the cutting unit cuts out the selected partial region from the fabric image to acquire texture image data. According to the above configuration, four types of texture images can be obtained in a single image capture by combining the presence or absence of printing with two backing colors.

[0082] (11) According to a third embodiment of the present disclosure, a program for acquiring a texture image is provided. The program has the function of imaging a fabric including an ink-printed area and an ink-unprinted area, and the program has the function of (i) a first partial area where the first backing color area of ​​the backing, which includes at least a first backing color area and a second backing color area, overlaps with the unprinted area of ​​the fabric; (ii) a second partial area where the second backing color area of ​​the backing overlaps with the unprinted area of ​​the fabric; (iii) a third partial area where the first backing color area of ​​the backing overlaps with the printed area of ​​the fabric; and (iv) a fourth partial area where the second backing color area of ​​the backing overlaps with the printed area of ​​the fabric. The computer is provided with the following functions: a function to capture an image of the fabric together with the photographic jig and acquire an image, with the fabric placed on top of the jig and the first, second, third, and fourth partial regions placed on top of the fabric and the photographic jig having a light-transmitting window portion, so that the first partial region, the second partial region, the third partial region, and the fourth partial region are contained within the window portion of the photographic jig; a function to select at least one of the first, second, third, and fourth partial regions as the target to be cut out from the fabric image included in the image; and a function to cut out the selected partial region from the fabric image and acquire texture image data. According to the above configuration, four types of texture images can be obtained in a single image capture by combining the presence or absence of printing with two backing colors. [Explanation of Symbols]

[0083] 10...Texture image acquisition device, 100...Imaging unit, 200...Shooting jig, 300...Backing, 400...Image processing unit, 410...Memory, 420...Interface circuit, 430...Input device, 440...Display device, 450...CPU, 451...Correction processing unit, 452...Selection unit, 453...Cut-out unit, AB...Buffer area, AR1...First area, AR2...Second area, B1, B2...Boundary, BR1...First backing color area, BR2...Second backing color area, FB…Fabric, GM1,GM2…Guide markers, HN…Hinge, MK1,MK2…Positioning marks, NR…Non-printable area, OP…Window area, PA1…First sub-area, PA2…Second sub-area, PA3…Third sub-area, PA4…Fourth sub-area, PA5…Fifth sub-area, PA6…Sixth sub-area, PA7…Seventh sub-area, PA8…Eighth sub-area, PA9…Ninth sub-area, PG…Program, PR…Printable area, PR2…Second printable area, TI…Texture image data

Claims

1. This is a method for obtaining texture images. (a) A step of preparing a photographic jig having a light-transmitting window and a backing that includes at least a first backing color region and a second backing color region, (b) A step of preparing a fabric which includes a printed area on which ink is printed and a non-printed area on which ink is not printed, (c) A step of layering the fabric onto the backing, wherein (i) a first partial region where the first backing color region of the backing and the non-printed region of the fabric overlap, (ii) a second partial region where the second backing color region of the backing and the non-printed region of the fabric overlap, (iii) a third partial region where the first backing color region of the backing and the printed region of the fabric overlap, and (iv) a fourth partial region where the second backing color region of the backing and the printed region of the fabric overlap. (d) A step of placing the photographic jig on the fabric such that the first partial region, the second partial region, the third partial region, and the fourth partial region are contained within the window portion of the photographic jig, (e) After performing step (d) above, the step of taking an image of the fabric together with the photographic jig to obtain an image, (f) A step of selecting at least one of the first partial region, the second partial region, the third partial region, and the fourth partial region as the target to be cut out from the fabric image included in the captured image, (g) A step of cutting out the selected subregion from the fabric image to obtain texture image data, How to obtain texture images, including [specific elements].

2. A method for obtaining a texture image according to claim 1, The first backing color region is a white region, and the second backing color region is a black region. How to obtain texture images.

3. A method for obtaining a texture image according to claim 2, The duty cycle of the ink in the printing area contained in the fabric is set to a predetermined standard value or higher. How to obtain texture images.

4. A method for obtaining a texture image according to claim 3, The printed area included in the aforementioned fabric is an area printed in black in the device-dependent color space. How to obtain texture images.

5. A method for obtaining a texture image according to claim 4, The first boundary, which is the boundary between the first backing color region and the second backing color region of the backing, is configured in a straight line. The second boundary, which is the boundary between the printed area and the non-printed area of ​​the fabric, is configured in a straight line. In step (c) above, the fabric is placed on the backing such that the second boundary is rotated 90 degrees relative to the first boundary. How to obtain texture images.

6. A method for obtaining a texture image according to claim 5, In step (g) above, the edges of the selected subregion are not included in the range cut out from the fabric image. How to obtain texture images.

7. A method for obtaining a texture image according to claim 6, In step (a) above, a photographic jig is prepared, which is provided with a comparison pattern surrounding the window portion, the comparison pattern including a first region and a second region with different shades of gray. How to obtain texture images.

8. A method for obtaining a texture image according to claim 7, (h) A step performed after step (e) is performed, further comprising correcting the image data representing the fabric image using comparison image data representing the comparison pattern included in the captured image, How to obtain texture images.

9. A method for obtaining a texture image according to claim 8, The correction in step (h) includes at least one of the following that may occur in step (e): distortion of the field of view, unevenness caused by lighting, low contrast due to underexposure, out of focus, luminance noise, and high sensitivity noise. How to obtain texture images.

10. A texture image acquisition device, It is the imaging unit, In a state in which a fabric having an ink-printed area and an ink-unprinted area is superimposed on a backing that includes at least a first backing color area and a second backing color area, the following are provided: (i) a first partial area where the first backing color area of ​​the backing and the ink-unprinted area of ​​the fabric overlap; (ii) a second partial area where the second backing color area of ​​the backing and the ink-unprinted area of ​​the fabric overlap; (iii) a third partial area where the first backing color area of ​​the backing and the ink-printed area of ​​the fabric overlap; and (iv) a fourth partial area where the second backing color area of ​​the backing and the ink-printed area of ​​the fabric overlap. and, With the photographic jig superimposed on the fabric, the first, second, third, and fourth partial regions are housed in the light-transmitting window portion of the photographic jig, An imaging unit that images the fabric together with the imaging jig to acquire an image, A selection unit selects at least one of the first, second, third, and fourth partial regions as the target to be cut out from the fabric image included in the captured image, A cutting unit that cuts out the selected subregion from the fabric image to obtain texture image data, A texture image acquisition device equipped with the following features.

11. This is a program for obtaining texture images. A function for imaging a fabric that includes printed areas where ink is printed and unprinted areas where ink is not printed, With the fabric superimposed on the backing, the following are provided: (i) a first partial region where the first backing color region of the backing, which includes at least a first backing color region and a second backing color region, overlaps with the non-printed region of the fabric; (ii) a second partial region where the second backing color region of the backing overlaps with the non-printed region of the fabric; (iii) a third partial region where the first backing color region of the backing overlaps with the printed region of the fabric; and (iv) a fourth partial region where the second backing color region of the backing overlaps with the printed region of the fabric. and, With the photographic jig superimposed on the fabric, the first, second, third, and fourth partial regions are housed in the light-transmitting window portion of the photographic jig, The function includes capturing images of the fabric together with the photographic jig and acquiring the captured image, A function to select at least one of the first, second, third, and fourth partial regions as the target to be cut out from the fabric image included in the captured image, A function to extract the selected subregion from the fabric image and obtain texture image data, A program to make a computer realize this.

Images