Color chart

Abstract

To provide a color chart that can measure and compare images taken with a wide variety of cameras.SOLUTION: A color chart has a plurality of patches, at least some of which are covered with a film that absorbs or reflects infrared and / or ultraviolet rays, and an amount of infrared and / or ultraviolet rays absorbed or reflected varies among the patches covered with the film that absorbs or reflects infrared and / or ultraviolet rays, and the plurality of patches are composed of achromatic patches and chromatic patches, and the patches covered with the film that absorbs or reflects infrared and / or ultraviolet rays are achromatic patches, and the achromatic patches are composed of at least gray patches, and the gray patches are formed only with black halftone dots.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a color chart. [Background technology]

[0002] Conventionally, it is known that a color chart on which patches of various colors are arranged is used to compare and measure colors in images captured by a digital camera (RGB camera) or the like (see, for example, Patent Document 1).

[0003] Recently, there are a wide variety of cameras available, including not only RGB cameras that use visible light, but also infrared cameras that use wavelengths other than visible light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-212640 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for color charts that can be used with a variety of cameras.

[0006] The present invention has been made to solve the above problems, and has as its object to provide a color chart that can be used to measure and compare images taken with a wide variety of cameras. [Means for solving the problem]

[0007] The present invention is a color chart having a plurality of patches, at least some of which are covered with a film that absorbs or reflects infrared and / or ultraviolet light.

[0008] Furthermore, the patches are formed so that the amount of infrared and / or ultraviolet light absorbed or reflected varies from patch to patch, each covered with a film that absorbs or reflects infrared and / or ultraviolet light.

[0009] The plurality of patches are composed of achromatic patches and chromatic patches, and the patches covered with the film that absorbs or reflects infrared and / or ultraviolet rays are the achromatic patches.

[0010] The achromatic patches are configured to include at least gray patches, and the gray patches are formed only with black halftone dots. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a color chart that can be used to measure and compare images taken with a wide variety of cameras. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a front view showing an entire color chart according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA showing the color chart according to the first embodiment. [Figure 3] 1A and 1B are diagrams showing how color charts according to the first and second embodiments are used; [Figure 4] FIG. 10 is a front view showing the entire color chart according to the second embodiment. [Figure 5] FIG. 10 is a cross-sectional view taken along the line BB showing a color chart according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] First Embodiment A color chart C according to a first embodiment of the present invention will be described below with reference to Figures 1 to 3. Note that directions (up-down direction, front-rear direction, and left-right direction) in the embodiments described below will be described based on the directions when looking at each drawing, unless otherwise specified.

[0014] (Color chart structure) As shown in Figure 1, the color chart C according to this embodiment is composed of a main body CB of the color chart C (hereinafter, sometimes simply referred to as the main body), a patch section CP, an automatic identification marker section CM, and an infrared absorbing section CL. First, the main body CB of the color chart will be described.

[0015] [Main body] The color chart main body CB is the base of the color chart C, and is made of a plate (sheet) with a predetermined thickness and a rectangular main surface, as shown in Figures 1 and 2. The material used for the main body CB when creating the color chart C may be any material that can print multiple patches P (described later) or that can be attached with a sheet on which they are printed; for example, the color chart main body CB may be made of paper, plastic, or the like.

[0016] The size of the color chart main body CB can be freely set. For example, it is preferable to set the size so that the color chart C can be easily held in one hand. Furthermore, in this embodiment, the color chart main body CB is configured to have a rectangular shape, but this is not limiting, and the shape can be freely set, for example, to have a circular shape.

[0017] [Patch section] The patch section CP is configured with a plurality of patches P, each consisting of a specific color and a fixed area, and the patches P that make up the patch section CP are configured with a plurality of achromatic patches PG and a plurality of chromatic patches PC (hereinafter, the achromatic patches PG and the chromatic patches PC may be simply referred to as patches P). Specifically, as shown in FIG. 1 , the plurality of achromatic patches PG and the plurality of chromatic patches PC are printed on the main body section CB of the color chart. Each of the achromatic patches PG and the chromatic patches PC is formed in a rectangular shape, and each patch P itself is formed to be the same size and shape. In this embodiment, a total of 20 patches P, including the achromatic patches PG and the chromatic patches PC, are arranged in 4 rows and 5 columns on the main body section CB of the color chart.

[0018] Incidentally, in the drawings, both the achromatic patches PG and the chromatic patches PC are displayed in grayscale, but the actual patches P are configured to have different colors such as blue, red, green, etc. Generally, colors related to printing are expressed using C (cyan), M (magenta), Y (yellow), and K (key tone (black)) values, but in this embodiment, for ease of understanding, the colors of the patches P will be explained using R (red), G (green), and B (blue) values.

[0019] The color of each patch P will be explained using RGB values ​​(decimal). The patch P in the top row (hereinafter referred to as the first row) in the rightmost column (hereinafter referred to as the first column) in the drawing is achromatic, and its RGB values ​​are a white patch PG1 composed of R (red) 255, G (green) 255, and B (blue) 255. The patch P in the row immediately below the first row (hereinafter referred to as the second row), also in the first column, is also achromatic, and its RGB values ​​are a gray patch PG2 composed of R192, G192, and B192. The patch P in the row immediately below the second row (hereinafter referred to as the third row), also in the first column, is also achromatic, and its RGB values ​​are a gray patch PG3 (a darker gray than the patch PG2 in the second row) composed of R85, G85, and B85. Similarly, the patch P provided in the row immediately below the third row (hereinafter referred to as the fourth row) in the first column is also achromatic, and its RGB values ​​are R0, G0, B0, which is a black patch PG4.

[0020] In the column adjacent to the left of the first column (hereinafter referred to as the second column), the patch P in the first row is a chromatic color and its RGB values ​​are R255, G0, B0, which is a red patch PC1. Similarly, in the second column, the patch P in the second row is a chromatic color and its RGB values ​​are R255, G255, B0, which is a yellow patch PC2. Also in the second column, the patch P in the third row is a chromatic color and its RGB values ​​are R128, G0, B0, which is a maroon patch PC3. Also in the second column, the patch P in the fourth row is a chromatic color and its RGB values ​​are R0, G128, B128, which is a teal patch PC4.

[0021] In the column adjacent to the left of the second column (hereinafter referred to as the third column), the patch P in the first row is a chromatic color, and its RGB values ​​are R255, G0, B255, which is a magenta patch PC5. Similarly, in the third column, the patch P in the second row is a chromatic color, and its RGB values ​​are R0, G255, B255, which is a cyan patch PC6. Similarly, in the third column, the patch P in the third row is a chromatic color, and its RGB values ​​are R0, G0, B255, which is a blue patch PC7. Similarly, in the third column, the patch P in the fourth row is a chromatic color, and its RGB values ​​are R128, G0, B128, which is a purple patch PC8.

[0022] In the column adjacent to the left of the third column (hereinafter referred to as the fourth column), the patch P in the first row is a chromatic color and its RGB values ​​are R0, G128, B0, which is a green patch PC9. Similarly, in the third column, the patch P in the second row is a chromatic color and its RGB values ​​are R0, G0, B255, which is a blue patch PC10. Similarly, in the fourth column, the patch P in the third row is a chromatic color and its RGB values ​​are R0, G255, B0, which is a lime patch PC11. Similarly, in the fourth column, the patch P in the fourth row is a chromatic color and its RGB values ​​are R128, G128, B0, which is an olive patch PC12.

[0023] Furthermore, in the column adjacent to the left of the fourth column (hereinafter referred to as the fifth column), the patch P in the first row is achromatic and has an RGB value of white patch PG5 composed of R (red) 255, G (green) 255, and B (blue) 255. Also in the fifth column, the patch P in the second row is also achromatic and has an RGB value of gray patch PG6 composed of R 192, G 192, and B 192. Also in the fifth column, the patch P in the third row is also achromatic and has an RGB value of gray patch PG7 composed of R 85, G 85, and B 85 (a darker gray than patch PG6 in the second row). Also in the fifth column, the patch P in the fourth row is also achromatic and has an RGB value of black patch PG8 composed of R 0, G 0, and B 0. In this manner, in this embodiment, the patches P in the fifth column are the same as the achromatic patches PG arranged in the first column.

[0024] As described above, in this embodiment, the first and fifth columns are all made up of achromatic patches PG, and the second, third, and fourth columns are all made up of chromatic patches PC.

[0025] In this embodiment, as described above, each patch P is formed in a rectangular shape, and 20 patches P are arranged in 4 rows and 5 columns on the main body CB of the color chart, but this is not limited to this. For example, each patch P is formed in a circular shape, and 18 patches P are arranged in 3 rows and 6 columns. The size, shape, number of patches P to be arranged, and arrangement positions of the patches P can be freely set. Furthermore, the color of each patch P can also be freely set.

[0026] Furthermore, in this embodiment, the color of each patch P has been described using RGB values ​​as described above. However, when the patches P are actually formed (printed) on the main body CB of the color chart by halftone dot printing, the gray patches PG2 and PG3 and the black patch PG4 among the achromatic patches PG are printed using only black dots (halftone dots). In particular, the gray patches PG2 and PG3 are printed with varying density of black halftone dots (changing the halftone dot density changes the shade of the gray patches PG2 and PG3). Note that here, halftone dots refer to image elements that represent the smallest unit of printing, and halftone dot printing refers to printing in which fine dots of ink are applied to the printing area. For example, the angles of the printed dots of each color are configured differently, so that the overlapping state of the dots is random.

[0027] Generally, in halftone dot printing, various colors are displayed (printed) by combining the colors cyan, magenta, yellow, and black (by overlapping halftone dots of each color). Even when printing gray patches PG2 and PG3, they are printed by combining multiple colors, but even when printing patches P of the same color, the number and size of halftone dots for each color (cyan, magenta, yellow, black) to be combined may differ depending on the model (manufacturer) of the printing machine used. In other words, depending on the model, the density of the halftone dots for each color may differ even when printing the same color.

[0028] Therefore, for example, even if the same gray patches PG2 and PG3 are printed, the light absorption (reflectance) rate of the printed patches P may differ depending on the model of printer. In this case, as will be described later, the infrared absorption (reflectance) rate of the gray patches PG2 and PG3 covered with the infrared absorbing film CL will differ. In other words, the infrared absorption rate of the gray patches PG2 and PG3 will differ depending on the model of printer used.

[0029] Therefore, in this embodiment, when the gray patches PG2 and PG3 are halftone printed, they are printed using only black halftone dots (only black), and the halftone dot density for each achromatic patch PG is predetermined.

[0030] [Automatic identification marker] The automatic identification marker part CM is configured so that information based on the automatic identification marker part CM can be acquired by reading the automatic identification marker part CM with a camera or the like. Examples of the automatic identification marker part CM include AR markers and two-dimensional codes. In this embodiment, the automatic identification marker part CM is configured with AR markers CM, and the AR markers CM are provided in two locations, the upper left corner and the lower right corner, of the color chart C. Furthermore, the shape and pattern of the AR marker CM vary depending on the information held by the AR marker CM. In this embodiment, for example, the distance from the camera of the color chart C, the orientation and position of the color chart C, and even the orientation and position of the patch P can be specified and identified based on the AR marker CM.

[0031] Furthermore, the AR marker CM according to this embodiment is a combination of a two-dimensional code having information such as the color of the patch P (specifically, the two-dimensional code is provided in the center of the AR marker CM). In this embodiment, by reading the AR marker CM and the two-dimensional code provided on the AR marker CM at the same time, it is possible to read information regarding the number and color of the patches P as well as the direction and distance of the color chart C.

[0032] [Infrared absorbing part] The infrared absorbing portion CL absorbs infrared rays that fall on the color chart C, and in this embodiment, the infrared absorbing portion CL is constituted by an infrared absorbing film CL formed on the color chart C. The infrared absorbing film CL is formed, for example, by applying a curable liquid containing a substance such as indium tin oxide (ITO) that has the property of absorbing infrared rays, which are invisible light, to the color chart C, and in this embodiment, the infrared absorbing film CL is provided on the surface of the color chart C so as to cover all of the achromatic patches PG (all of the patches P in the first row) (see FIG. 1).

[0033] As shown in Figure 2, the infrared absorbing film CL has a uniform thickness and is formed on the color chart C in a rectangular shape when viewed from the front. The infrared absorbing film CL is transparent so that the achromatic patches PG covered by the infrared absorbing film CL can be seen. In other words, it is transparent to visible light. The infrared absorbing film CL is configured so that the infrared absorptance is the same at every portion (location) of the infrared absorbing film CL.

[0034] As described above, each patch P constituting the first column is covered with an infrared-absorbing film CL that absorbs infrared rays, and therefore absorbs the infrared rays that strike each patch P. Meanwhile, the patches P arranged in the first column have different absorption (reflectance) rates for visible light. Specifically, the achromatic patch PG1 arranged in the first row of the first column is white and has an extremely low absorption rate for visible light (an extremely high reflectance for visible light), whereas the achromatic patch PG2 arranged in the second row directly below it is gray and has a higher absorption rate for visible light than the white patch PG1. Similarly, the achromatic patch PG3 arranged in the third row directly below the second row is grayish gray, and has a higher absorption rate for visible light than the patch PG2 arranged in the second row. The achromatic patch PG4 arranged in the fourth row directly below the third row is black, and has the highest absorption rate for visible light (the lowest reflectance for visible light) among the achromatic patches PG arranged in the first column.

[0035] Although the infrared absorption rate of the infrared absorbing film CL is uniform, the visible light absorption rate (reflectance) of each patch P arranged in the first column is different, so the infrared absorption rate of each patch in the first column is also relatively different. Specifically, the infrared absorption rate of the gray patch PG2 arranged in the second row of the first column is higher than that of the white patch PG1 arranged in the first row of the same column, and the infrared absorption rate of the dark gray patch PG3 arranged in the third row of the same column is higher than that of the gray patch PG2, and further the infrared absorption rate of the black patch PG4 arranged in the fourth row of the same column is higher than that of the dark gray patch PG3.

[0036] (using a color chart) Next, the manner of use of the color chart C configured as described above will be explained separately for when the color chart C is photographed with the RGB camera 1 and when the color chart C is photographed with the infrared camera 10. The color chart C is used, for example, when comparing or measuring the colors of images, such as when checking color reproducibility.

[0037] [RGB camera] For example, when a person P is photographed with an RGB camera (such as a digital video camera, digital camera, or smartphone camera that detects the wavelengths of the visible light colors R (red), G (green), and B (blue)) 1 and the image is displayed on a monitor, the monitor may display a different facial color from the actual facial color of the person P photographed, depending on the environment (shooting environment) at the time of shooting and the type of camera used for shooting.

[0038] Differences in the shooting environment include, for example, whether the photo was taken indoors or outdoors, and if the photo was taken indoors, the type of lighting, the brightness of the lighting, and the distance between the lighting and the subject.Differences in the type of camera also include the imaging element and image processing engine.

[0039] Therefore, color correction processing is performed on the image using a color chart C to address differences in color caused by differences in the shooting environment, etc. Specifically, as shown in Fig. 3, a color chart C is photographed with an RGB camera 1 along with a person P, a landscape, or other subject. A color chart C identical to the color chart C photographed together with the person P is also prepared next to a monitor (not shown). Then, using the color of a patch P of the color chart C prepared next to the monitor as a reference, the color of the image displayed on the monitor is adjusted while visually judging so that the color of the patch P of the color chart C displayed on the monitor matches the color of the patch P of the reference color chart C, thereby performing the correction processing.

[0040] Furthermore, the color correction process described above may be performed not only visually as described above, but also on a computer with a dedicated program for color correction installed. Specifically, an image of a subject such as a person and a color target C is captured with the RGB camera 1. The captured image is then displayed on a monitor or the like, and the image data is input into a computer.

[0041] Furthermore, the computer to which the image data is input stores information associated with the AR markers CM and two-dimensional codes on the color chart C, and is able to identify information such as the distance between the RGB camera 1 and the color chart C, the orientation of the patches P, and the number and color of the patches P based on the AR markers CM photographed together with the color chart C and the two-dimensional code combined with the AR markers CM. Then, based on this identified information, a dedicated program performs color correction processing on the image displayed on the monitor.

[0042] In this embodiment, information about the color chart C is identified and acquired from the AR marker CM, but this is not limiting. The user (photographer) may input data about the colors of the color chart C (data about the colors of each patch) into the computer.

[0043] Furthermore, when photographing a color chart C together with a subject, it is preferable to simultaneously photograph multiple color charts C. This is because arranging many color charts C and photographing multiple color charts C improves the accuracy when performing color correction processing on the image.

[0044] [Infrared camera] As with the RGB camera 1, the infrared camera 10 captures an image of a color target C along with a subject such as a person P or a landscape (see FIG. 3). The infrared camera 10 captures an image by emitting infrared light and detecting the infrared light reflected from an object, and is designed to detect and visualize infrared light, which has wavelengths other than visible light. As a result, the captured image is often displayed on a monochrome screen consisting of black and white, with areas that emit a lot of infrared light appearing bright (white) and areas that emit less infrared light appearing dark (black).

[0045] When the color chart C is photographed with the infrared camera 10, infrared rays emitted by the color chart C, such as those reflected by the color chart C, are detected, and an image of the color chart C is displayed on a monitor or the like along with the subject. Although not shown, the image of the color chart C displayed in this embodiment is also a black-and-white monochrome image, and the chromatic color patches PC are also displayed in black-and-white monochrome. Note that, as described above, each patch P arranged in the first column of the color chart C is covered with an infrared absorbing film CL. Therefore, a certain amount of infrared light hitting each patch P in the first column is absorbed by the infrared absorbing film CL, and therefore the amount of infrared light emitted (reflected) by each patch P in the first column is less than the amount of infrared light emitted by each patch P arranged in the second to fifth columns. As a result, in the image of the color chart C, each patch P in the first column appears darker than the patches P in the second to fifth columns.

[0046] Furthermore, as described above, the infrared absorbing film CL covers each patch P arranged in the first row with a uniform thickness, so the infrared absorptivity of the infrared absorbing film CL is uniform and does not change in any part. However, each patch P in the first row covered with the infrared absorbing film CL has a different absorption (reflection) rate for visible light, so the infrared absorptivity also differs for each patch P. Therefore, when an image of color chart C is displayed, the brightness of each patch P arranged in the first row differs from patch P to patch P.

[0047] Specifically, the white patch PG1, located in the first row of the first column, which has the lowest infrared absorption rate (highest amount of infrared reflection), is displayed the brightest (whitest), the gray patch PG2, located in the second row of the first column, which has the next lowest infrared absorption rate, is displayed second brightest after the white patch PG1, the dark gray patch PG3, located in the third row of the first column, which has the next lowest infrared absorption rate, is displayed second brightest after the gray patch PG2, and the black patch PG4, located in the fourth row of the first column, which has the highest infrared absorption rate among the patches P arranged in the first column, is displayed the darkest (blackest).

[0048] The amount of infrared light and its changes at the time of shooting can be determined from the degree of brightness and its changes of each patch P in the first row covered with the infrared absorbing film CL, and color correction processing of the image can be performed based on this.

[0049] As described above, some of the patches P (achromatic patches PG) provided on the color chart C are covered with an infrared absorbing film CL that absorbs infrared rays, and each patch P covered with the infrared absorbing film CL is configured to have a different infrared absorptivity. Therefore, for example, when the color chart C is photographed with the infrared camera 10, it is possible to determine the difference in brightness of the patches P and, from this change, the presence or absence of infrared rays at the photographing location and the amount of infrared rays hitting the subject, etc. Furthermore, when the color chart C is photographed as a video, it is also possible to determine the change in the amount of infrared rays at the photographing location (change over time). As a result, it is possible to perform correction processing on the image with high accuracy.

[0050] Furthermore, by photographing color chart C, it is possible to determine whether or not the camera that photographed color chart C has a function for detecting infrared rays (functions as an infrared camera).

[0051] Furthermore, in this embodiment, achromatic patches PG, such as gray patches PG2 and PG3 and black patch PG4, are configured with only black halftone dots, and the gray patches PG2 and PG3 are printed at a predetermined density of black halftone dots. Therefore, for example, even with different models of printers, it is possible to print a color chart C with achromatic patches PG having the same visible light absorption (reflectance) rate. In other words, even when printing patches P of the same color, it is possible to prevent the visible light absorption (reflectance) rate of the patches P from differing depending on the model of printer. As a result, it is possible to create a color chart C with patches P having the same infrared absorptance, even with different models of printers.

[0052] Furthermore, the color chart C of this embodiment is configured to include a plurality of chromatic patches PC and achromatic patches PG in addition to the patch P covered with the infrared absorbing film CL, and therefore is capable of performing color correction processing on an image captured by the RGB camera 1 while also being able to grasp the amount of infrared light when captured by the infrared camera 10. In this way, it is possible to measure and compare images captured by the RGB camera 1 and images captured by the infrared camera 10, and it is possible to handle images captured by a wide variety of cameras.

[0053] In this embodiment, an infrared absorbing film CL is provided to absorb the infrared rays that hit the patch P, but the present invention is not limited to this. For example, an infrared reflective film that reflects infrared rays may be provided to reflect the infrared rays that hit the patch P, and any film that changes the amount of infrared rays that hit the patch P may be used.

[0054] Furthermore, in the color chart C according to the present embodiment, an infrared-absorbing film CL is provided to cover the patches P, and the infrared absorbing film CL absorbs infrared light striking the patches P, thereby enabling comparison and measurement of images captured by the infrared camera 10. However, this is not a limitation. Instead of the infrared absorbing film CL, the patches P may be covered with, for example, an ultraviolet absorbing film containing a substance with ultraviolet-absorbing properties, such as ethylhexyl methoxycinnamate, or an ultraviolet reflective film containing a substance with ultraviolet-reflecting properties, such as titanium oxide. The color chart C may then be photographed with an ultraviolet camera that detects ultraviolet light, and the amount of ultraviolet light at the time of photographing may be determined from changes in the color density or brightness of the patches P, which change depending on the amount of ultraviolet light absorbed by the ultraviolet absorbing film or reflected by the ultraviolet reflective film, and the images may be compared or measured. Furthermore, an infrared absorbing film (or infrared reflective film) CL and an ultraviolet absorbing film (or ultraviolet reflective film) may be provided simultaneously on a single color chart C, or the patches P may be covered with a film that absorbs or reflects both infrared and ultraviolet light.

[0055] Furthermore, instead of or in addition to the infrared absorbing film CL or ultraviolet absorbing film, the patch P may be covered with an ultraviolet emitting film that emits visible light when exposed to ultraviolet light, and the patch P emitting light as it is exposed to ultraviolet light may be photographed with an RGB camera, and the image may be compared or measured based on changes in the color of the emitting patch P.

[0056] Furthermore, in this embodiment, the infrared absorbing portion CL is formed by uniformly applying a curable liquid onto the patch P, but this is not limited to this. For example, the infrared absorbing portion CL may be formed from a film or the like, and the film may be attached to the color chart C so as to cover the patch P, or a material that has the property of absorbing infrared rays, such as indium tin oxide (ITO), may be mixed into ink or the like, and the patch P may be printed on the main body portion CB of the color chart C. In other words, any material may be used for the patch P as long as it can absorb (reflect) infrared rays.

[0057] In the present embodiment, the patches P are composed of patches P covered with the infrared absorbing film CL and patches P not covered with the infrared absorbing film CL, but this is not limiting. For example, all of the patches P may be composed of achromatic patches PG, and all of the achromatic patches PG may be covered with the infrared absorbing film CL.

[0058] <Second embodiment> Next, a second embodiment, which is different from the first embodiment described above, will be described with reference to Figures 4 and 5. Note that the same components as those in the first embodiment will be assigned the same reference numerals and descriptions thereof will be omitted.

[0059] The color chart C according to the first embodiment described above has patches P arranged in 4 rows and 5 columns, with a plurality of achromatic patches PG arranged in the first column covered with an infrared absorbing film CL. Similarly, the color chart C1 according to the second embodiment has patches P arranged in 4 rows and 5 columns, with a plurality of achromatic patches P arranged in the first column covered with an infrared absorbing film CL1. The infrared absorbing film CL1 according to this embodiment is also formed by applying a curable liquid containing a substance such as indium tin oxide (ITO) that has the property of absorbing infrared rays to the color chart C, and is colorless and transparent, allowing the covered patches P to be visually recognized.

[0060] However, while the patches P covered by the infrared absorbing film CL of the color chart C according to the first embodiment have different lightness levels, the infrared absorbing film CL1 of the color chart C1 according to the second embodiment is configured to cover patches P of the same lightness level. Specifically, the achromatic patches PG covered by the infrared absorbing film CL1 are all white patches PG1, as shown in FIG.

[0061] Furthermore, while the infrared absorbing film CL according to the first embodiment has a uniform thickness, the infrared absorbing film CL1 according to the second embodiment has a thickness that varies depending on the region, as shown in Fig. 5. Specifically, in the infrared absorbing film CL1, a second region CL1b covering the patches P arranged in the second row is thicker than a first region CL1a covering the patches P arranged in the first row. Furthermore, a third region CL1c covering the patches P arranged in the third row is thicker than the second region CL1b, and further, a fourth region CL1d covering the patches P arranged in the fourth row is thicker than the third region CL1c. In this way, the thickness of the infrared absorbing film CL1 varies depending on the region covering the patches P, and the infrared absorptivity increases as the thickness increases.

[0062] Therefore, all of the achromatic patches PG covered by the infrared absorbing film CL1 are the same white patches PG1, and the amount of visible light absorption (reflection) in these patches P is the same, but the infrared absorbing film CL1 covering the patch P is configured so that the infrared absorption rate differs for each part covering the patch P, so in this embodiment as in the first embodiment, the white patches PG1 in the first row covered by the infrared absorbing film CL1 have different amounts of infrared absorption for each patch P.

[0063] As described above, the achromatic patches PG of the same color are covered with the infrared absorbing film CL1, which has different infrared absorptances in different thicknesses at different locations, so that changes in the infrared rays hitting the color chart C1 can be detected without being affected by the visible light absorbed (reflected) by the patches PG.

[0064] In this embodiment, the infrared absorbing film CL1 having different infrared absorptances at different thicknesses is configured to cover achromatic patches PG of the same color, but this is not limited to this, and the film may be configured to cover multiple achromatic patches PG of different brightnesses.

[0065] Furthermore, in this embodiment, as in the first embodiment described above, the infrared absorbing film CL1 may be configured as a film that reflects infrared rays, and may be configured as an ultraviolet absorbing film (ultraviolet reflective film) that absorbs (or reflects) ultraviolet rays instead of (or together with) the infrared absorbing film CL1.

[0066] Although the present invention has been described in the above embodiments, it is not limited to these. Modifications, changes, and changes in the combination of each component element can be made within the scope of the present invention. [Explanation of symbols]

[0067] C, C1 color chart P patch PG Neutral Patch PC chromatic patch PG2,PG3 Gray patch CL infrared absorbing film

Claims

1. A color chart having a plurality of patches, At least some of the patches are covered with a film that absorbs or reflects infrared and / or ultraviolet rays. A color chart characterized by:

2. The patches are formed so that the amount of infrared and / or ultraviolet light absorbed or reflected varies from patch to patch, each covered with a film that absorbs or reflects infrared and / or ultraviolet light.

2. The color chart according to claim 1.

3. the plurality of patches are composed of achromatic patches and chromatic patches, The patch covered with a film that absorbs or reflects infrared and / or ultraviolet rays is the achromatic patch.

3. The color chart according to claim 1 or 2.

4. the achromatic patches include at least gray patches; The gray patches are formed only with black halftone dots.

4. The color chart according to claim 3.

Images