Paint color search device

Abstract

The present paint color search device (100) is a paint color search device comprising a computer (2) having a paint color database, wherein the paint color database has: paint color basic information having paint color mixing information of the paint color; and paint color analysis information analyzed based on the spectral reflectance measured by a multi-angle spectrophotometer for the paint color. The paint color analysis information may include: chromaticity values ​​at each specified observation angle calculated based on the spectral reflectance; and a computer graphic image generated from the chromaticity values.

Description

Technical Field

[0001] The present invention relates to a paint color retrieval device. This application claims priority based on Japanese Patent Application No. 2019-050274 filed in Japan on March 18, 2019, and the contents thereof are cited herein. Background Art

[0002] It is difficult to match the paint color of paint applied to industrial products such as automobiles, especially the color of metallic paint whose color appearance changes depending on the viewing angle, with the designer's requirements. In most cases, the designer determines the paint color required by the designer by having a paint company prepare a paint panel (sample) painted with a candidate paint color and evaluating the paint panel.

[0003] Paint companies select paint colors with colors and textures that match the imagery required by designers from a huge color library that has been created in the past. The paint color is used as a reference color to adjust the color and texture to produce the paint color required by the designer. Designers often use abstract language to express the paint color they require, and there are bound to be many trial and errors in the communication of information and test board production between designers and paint companies. Therefore, in order to effectively retrieve paint colors with colors and textures that match the imagery required by designers and adjust to the paint color required by designers, various auxiliary methods and auxiliary devices have been designed.

[0004] The method of determining the optical properties of a metallic coating film described in Patent Document 1 can generate a computer graphic image (RGB image) at a wide range of viewing angles from highlights to shadows of a metallic coating color whose appearance changes depending on the viewing angle.

[0005] In the method for quickly searching for colors similar to metallic paint colors described in Patent Document 2, colors similar to metallic paint colors are quickly searched from a color library, and a computer graphic image of the searched similar colors is displayed on a display. Designers can visually confirm the displayed colors similar to the metallic paint colors, and can effectively find paint colors with colors and textures that match the imagery required by the designer.

[0006] The method for generating and displaying a changed color described in Patent Document 3 generates a changed color with adjusted brightness, hue, etc. from a reference metallic paint color based on a color library. Designers can visually determine the adjustment direction of the metallic paint color from computer graphics.

[0007] In the method of determining the paint color from a computer graphic image described in Patent Document 4, it is possible to retrieve a paint color similar to the computer graphic image from a color library based on a computer graphic image such as a photograph that matches the impression of the paint color required by the designer. The designer can use the computer graphic image such as the photograph to effectively convey the paint color required by the designer to the painting company.

[0008] According to the texture map of paint colors described in Patent Document 5, by presenting a "texture map" that classifies multiple paint colors based on multiple feature quantities to the designer, multiple candidate approximate colors can be relatively visualized, which can assist the designer in determining the paint color required.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 10-10045

[0012] Patent Document 2: Japanese Patent Application Publication No. 2002-259398

[0013] Patent Document 3: Japanese Patent Application Publication No. 2004-258854

[0014] Patent Document 4: Japanese Patent Application Publication No. 2005-157771

[0015] Patent Document 5: Japanese Patent Application Publication No. 2008-122335 Summary of the invention

[0016] Technical problem to be solved by the invention

[0017] The above methods and devices are useful for effectively searching for paint colors with colors and textures that match the image required by the designer and effectively adjusting the paint colors to the paint colors required by the designer. However, using these methods and devices according to the purpose requires professional knowledge, and therefore, in many cases, the help of an experienced person is required.

[0018] Based on the above circumstances, an object of the present invention is to provide a paint color search device that can easily search for a paint color requested by a designer from a database including a color library.

[0019] Technical solutions for solving technical problems

[0020] In order to solve the above technical problems, the invention proposes the following technical solutions.

[0021] The paint color retrieval device involved in the first aspect of the present invention is a paint color retrieval device including a computer having a paint color database, wherein the paint color database has: paint color basic information, paint color mixing information having paint colors; and paint color analysis information, which is obtained by analyzing the paint color based on the spectral reflectance measured using a multi-angle spectrophotometer.

[0022] Effects of the Invention

[0023] According to the paint color search device of the present invention, the paint color required by the designer can be easily searched from a database including a color library. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a configuration diagram of a paint color search device according to a first embodiment of the present invention.

[0025] Figure 2 This is a diagram showing the configuration of a computer of the paint color search device according to the first embodiment of the present invention.

[0026] Figure 3 This is a functional block diagram of a computer of the paint color search device according to the first embodiment of the present invention.

[0027] Figure 4 This is a diagram showing the configuration of a paint color database of the paint color search device according to the first embodiment of the present invention.

[0028] Figure 5 This is a diagram showing an example of measuring the spectral reflectance of paint colors.

[0029] Figure 6 This is a similar color display screen created by a similar color search unit of the paint color search device according to the first embodiment of the present invention.

[0030] Figure 7 This is a change color presentation screen created by a change color selection unit of the paint color search device according to the first embodiment of the present invention.

[0031] Figure 8 This is a sample color display screen created by a sample color search unit of the paint color search device according to the first embodiment of the present invention.

[0032] Fig. 9 This is a texture map display screen created by the texture map generation unit of the paint color search device according to the first embodiment of the present invention.

[0033] Fig.10 This is an image of the surface texture of a sedan in the case of a metallic paint job with the paint color Toyota 1D2 Gray M (Metallic Silver).

[0034] Fig.11 It is a two-dimensional image of a motor vehicle (sedan) from which the surface texture image is derived.

[0035] Fig.12 Is Fig.11 Generated painted surface image.

[0036] Fig.13 yes Fig.12 Histogram of .

[0037] Fig.14 This is a function selection menu screen displayed by the image output unit of the paint color search device according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0038] (First Embodiment)

[0039] refer to Figures 1 to 14 , a first embodiment of the present invention is described.

[0040] Figure 1 1 is a block diagram of a paint color search device 100. The paint color search device 100 includes an image input unit 1 such as a scanner, a computer 2 capable of executing a program, and an image output unit 3 such as an LCD display. The paint color search device 100 can be connected to a multi-angle spectrophotometer 200.

[0041] Figure 2 This is a diagram showing the structure of the computer 2.

[0042] The computer 2 is a processing device capable of executing programs, and includes a processor 20, a memory 21 capable of reading programs, a storage unit 22 capable of storing programs and data, and an input / output control unit 23. The functions of the computer 2 are realized by the processor 20 executing a program supplied to the computer 2.

[0043] The storage unit 22 is a nonvolatile recording medium that stores programs and necessary data. The storage unit 22 is composed of, for example, a hard disk, a ROM, and a flash memory. The storage unit 22 stores a paint color database D described later.

[0044] Figure 3 This is a functional block diagram of the computer 2 when the computer 2 executes the paint color search program of the paint color search device 100. The functional block includes: an approximate color search unit 51, a change color selection unit 52, a sample color search unit 53, a texture map generation unit 54, a surface texture display unit 55, and a paint color database D.

[0045] [Paint Color Database D]

[0046] Figure 4It is a diagram of the composition of the paint color database D.

[0047] The paint color database D is a database of data on a large number of paint colors including metallic paint colors. The paint color database D has paint color basic information D1, paint color analysis information D2, and paint color additional information D3. The paint color basic information D1 is information on paint colors selected from, for example, an automatic color card in a paint company's sample book. The paint color analysis information D2 is information obtained by analyzing a colored paper (sample) coated with paint using a multi-angle spectrophotometer 200. The paint color additional information D3 is information related to paint colors accumulated by the paint company.

[0048] The paint color basic information D1 includes a paint color identification ID, a paint color name, and paint color mixing information. The paint color identification ID is a different ID number assigned to the paint color data stored in the paint color database D. In addition, the paint color name is a model name, a product name, etc. set by a paint company.

[0049] The paint color mixing information stores information about the composition used in the mixing of the paint. Specifically, the paint color mixing information includes: the type of composition used in the mixing, the mixing materials constituting the composition and the property information of the mixing materials (properties, average particle size, etc.), the mixing amount of the composition, and the measurement data of the composition.

[0050] The measured data is based on the property values ​​of the formed film, molded product, etc. of the composition, the performance test value, or the property values ​​of the composition itself. For example, when the composition is a colorant composition selected from coatings, inks, and colorants, as its blending materials, attention is paid to coloring pigments and gloss materials. As the measured data based on the colorant composition using these as constituent components, color measurement data based on the color of the colorant composition can be cited.

[0051] The paint color analysis information D2 includes the spectral reflectance measured by the multi-angle spectrophotometer 200 for the colored paper (sample) coated with the paint. Figure 5 As shown, the spectral reflectance of the coating color of the color paper (sample) is measured under the conditions of incident light angle: 45 degrees, light receiving angle (five angles): highlight 15 degrees, 25 degrees, front 45 degrees, shadow 75 degrees, and 110 degrees. The coating color of the selected color paper (sample) is measured using, for example, a five-angle spectrophotometer MA68 from X-Rite and a spectrophotometer CM-512m3 from KONICA MINOLTA. The measured spectral reflectance is stored in the coating color database D stored in the storage unit 22 via the input and output control unit 23 of the computer 2.

[0052] When using the five-angle spectrophotometer MA68 from x-rite, the measurement angle is five angles. In this case, the regression equation and regression coefficient specified in Patent Document 1 (Kansai PAINT (Strain) Masuda Yutaka, Kawaguchi Yoichi; Method for determining the optical properties of metal coatings) are used to predict the spectral reflectance from highlights to shadows based on the reflectance at five angles. The Lab* value (or XYZ value) as the chromaticity value at each specified observation angle is calculated from the predicted value of the spectral reflectance, and a computer graphic image (RGB image) is obtained.

[0053] The paint color analysis information D2 includes the chromaticity values ​​(Lab* values, etc.) and RGB images at the above-mentioned predetermined observation angles. The chromaticity values ​​(Lab* values, etc.) and RGB images at the observation angles calculated in advance are stored in the paint color database D stored in the storage unit 22. Here, the RGB image can be displayed by outputting it to the image output unit 3.

[0054] The paint color analysis information D2 also includes feature quantities calculated from the spectral reflectance measured using the multi-angle spectrophotometer 200. Based on the method described in Patent Document 5 (Kansai PAINT Co., Ltd., Keisuke Sai, So Fujieda; Texture map of paint color, its production method, production program, production system and data structure), seven feature quantities IV, SV, FF, cFF, metal, depth, and senmei are calculated. The calculated feature quantities are stored in the paint color database D stored in the storage unit 22.

[0055] The paint color additional information D3 is the professional knowledge information related to paint colors accumulated by the paint company. For example, it is the rating (evaluation) of the performance of each paint color by an expert related to the paint color, the additional information related to the mixing of the paint, etc. The additional information also includes information on the combination of prohibiting the mixing of specific paints, etc.

[0056] The person in charge of the paint company communicates with the designer, and when determining the paint color required by the designer, the person in charge of the paint company makes use of the paint color basic information D1 and the paint color analysis information D2. If the person in charge of the paint company is an expert in paint color, the paint color required by the designer can be effectively determined based on the accumulated knowledge and experience using only the paint color basic information D1 and the paint color analysis information D2.

[0057] On the other hand, if the person in charge of the paint company is not an expert in paint colors, the paint color required by the designer cannot be effectively determined using only the paint color basic information D1 and the paint color analysis information D2. Therefore, the rating information obtained in advance from the expert and the information related to the mixing of the paint are stored as the paint color additional information D3 in the paint color search device 100. The person in charge who is not an expert can effectively determine the paint color required by the designer by making use of the paint color additional information D3.

[0058] [Paint color search program]

[0059] Next, the function blocks ( Figure 3 Reference) function is explained.

[0060] [Similar color search unit 51]

[0061] Figure 6 The similar color display screen 6 is created by the similar color search unit 51 and displayed as a GUI on the image output unit 3. The similar color search unit 51 selects a plurality of similar colors similar to the reference color selected by the user of the paint color search device 100 from the paint color database D and presents them.

[0062] The similar color search method can adopt, for example, Patent Document 2 (Kansai PAINT Co., Ltd., Yutaka Masuda; Method for quickly searching similar colors of metallic paint colors). The similar color search unit 51 selects a plurality of paint colors whose weighted angular average color difference values ​​are close to the weighted angular average color difference value of the reference color from the paint colors in the paint color database D.

[0063] like Figure 6 As shown, the approximate color display screen 6 displays a reference color and a plurality of selected approximate colors (approximate colors 1 to 4). The reference color is displayed in a reference color display area 60 on the right side of the screen. In addition, a plurality of approximate colors are displayed in an approximate color display area 61 arranged vertically on the left side of the screen.

[0064] The reference color display area 60 displays an RGB image 62 of the reference color. The RGB image 62 is a color simulation image (hereinafter referred to as a "CS image") that is a computer simulation image that can be used as a digital color palette, for example. The CS image is an image generated from computer graphic images (RGB images) of each specified observation angle stored in the paint color database D. The CS image is a computer simulation image that displays the paint color observed from a wide range of angles from highlights to shadows in a hierarchical manner. Designers can intuitively evaluate the paint color by observing the CS image.

[0065] The similar color display area 61 displays paint color basic information D1, paint color analysis information D2, and RGB images 62 (eg, CS images) related to similar colors. Designers can simultaneously observe RGB images 62 of multiple similar colors and can relatively evaluate similar colors.

[0066] The rating and additional information included in the paint color additional information D3 can also be displayed as auxiliary information for selecting paint colors in the approximate color display area 61. Even if the person in charge of the paint company has insufficient knowledge and experience in paint colors, this additional information can effectively assist the person in charge in selecting the paint color required by the designer.

[0067] [Change color selection section 52]

[0068] Figure 7 The change color selection unit 52 generates the change color presentation screen 7 and displays it in the GUI of the image output unit 3. The change color selection unit 52 selects a plurality of change colors from the paint color database D based on the chroma, hue, etc., of the reference color selected by the user of the paint color search device 100 from the paint color database D and presents them.

[0069] The method for presenting the changed color can adopt, for example, Patent Document 3 (Kansai PAINT Co., Ltd., Yutaka Masuda; Method and device for generating and displaying a changed color). A changed color that is a change of the base color based on the shade, chroma, hue (e.g., red tone, blue tone) and other indicators of the metallic paint color can be selected from the paint color database D.

[0070] like Figure 7 As shown, the change color presentation screen 7 displays the reference color and the selected change color. The reference color is displayed in a reference color display area 70 on the left side of the screen. In addition, the selected color is displayed in a change color display area 71 arranged on the right side of the reference color display area 70.

[0071] The reference color display area 70 and the changed color display area 71 display an RGB image 72 (e.g., a CS image). The designer can simultaneously observe the RGB image 72 of the changed color and relatively evaluate the changed color, thereby effectively determining the calibration policy based on the reference color. The reference color display area 70 and the changed color display area 71 may also display the paint color basic information D1 and the paint color analysis information D2.

[0072] For example, the changed color is a color that is a change of the base color based on the index shown below. For example, the changed color is a changed color that reduces the brightness of the shadow range of the base color. For example, the changed color is a changed color that reduces the brightness of the highlight range of the base color. For example, the changed color is a changed color that emphasizes the blue tone of the base color. For example, the changed color is a changed color that emphasizes the shadow sense of the base color. The designer observes the changed colors that are changed based on these indexes many times and can confirm the calibration method for adjusting the base color to the paint color required by the designer.

[0073] [Sample color search unit 53]

[0074] Figure 8 The sample color display screen 8 is created by the sample color search unit 53 and displayed as a GUI on the image output unit 3. The sample color search unit 53 selects and presents a similar paint color from the paint color database D to a sample color selected by a user of the paint color search device 100 from a computer graphic image such as a photograph.

[0075] When the designer prompts the image required by the designer, sometimes abstract words such as "metallic feeling" and "transparent feeling" are added to prompt an image board that combines magazine clippings, photos, etc. After that, the person in charge of the paint company searches the paint color from the paint color database D so that the image obtained from the paint color matches the prompted image. However, this search work depends on the skills of the person in charge of the paint company. Therefore, the color that matches the image is sampled from the prompted image such as the photo as a sample color.

[0076] The method of specifying the sample color and selecting the paint color close to the sample color can adopt, for example, Patent Document 4 (Kansai PAINT Co., Ltd., Yutaka Masuda and So Fujieda; Method of determining paint color from computer graphics).

[0077] like Figure 8 As shown in FIG. 1 , the sample color display screen 8 displays a computer graphic image 80 such as a photo input by the image input unit 1. The designer uses an input means such as a mouse connected to the computer 2 to specify the position of the computer graphic image 80 and determines the position of the computer graphic image 80 in accordance with the four light receiving angles (reference Figure 5 ) corresponding to the four angles (highlight 15 degrees, highlight 25 degrees, front 45 degrees, shadow 75 degrees). The sample color search unit 53 analyzes the color information (RGB data) corresponding to the four angles and displays the analyzed RGB values ​​as sample color data 81. In addition, the sample color search unit 53 generates and displays a CS image 82 based on the color information (RGB data) corresponding to the four angles.

[0078] The sample color search unit 53 searches for a similar paint color from the paint color database D for the sample color obtained by the above method. The selection of a paint color similar to the sample color specified by the RGB value is performed based on, for example, the "algorithm based on the Euclidean distance of the RGB value of the paint color" described in Patent Document 4. The sample color search unit 53 searches for an image with a small RGB color difference from the RGB value of the sample color from the RGB images of the paint color stored in the paint color database D. The sample color search unit 53 selects a plurality of RGB images with small RGB color difference values ​​as the similar paint color.

[0079] Select multiple similar colors to Figure 6 The similar color display screen 6 shown is displayed in the image output unit 3 in the same form. The designer can effectively convey the paint color required by the designer to the painting company using computer graphics such as photos. In addition, the designer can use the sample color input as the reference color and use the functions of the similar color search unit 51 and the change color selection unit 52 to select the paint color required by the designer.

[0080] [Texture map generation unit 54]

[0081] Fig. 9 The texture map display screen 9 is created by the texture map generation unit 54 and displayed as a GUI on the image output unit 3. The texture map generation unit 54 generates a "texture map" that classifies the paint colors stored in the paint color database D based on a plurality of feature quantities, and presents it to the designer.

[0082] The texture map generation method can adopt, for example, Patent Document 5 (Kansai PAINT Co., Ltd. Keisuke Sai and So Fujieda; Texture map of paint color, its creation method, creation program, creation system, and data structure). The texture map generation unit 54 uses the feature values ​​stored in the paint color database D to generate the texture map.

[0083] like Fig. 9 As shown, the texture map is a map that maps multiple paint colors to a mapping space based on a specific feature quantity. Fig. 9 In the texture map shown, the CS image of each paint color is displayed in the mapping space.

[0084] By presenting a "texture map" that classifies multiple paint colors based on multiple feature quantities to the designer, multiple candidate approximate colors can be relatively visualized. Even if the person in charge of the paint company lacks knowledge and experience related to paint colors, it is possible to assist the person in charge in determining the paint color required by the designer, which is mostly expressed in abstract terms.

[0085] It should be noted that the map generated by the texture map generating unit 54 is not limited to the texture map, and various classification maps can be generated using the feature values ​​stored in the paint color database D, for example, a "Hue-Tone map" can also be generated.

[0086] [Surface texture display unit 55]

[0087] Fig.10 The surface texture display unit 55 generates an image based on a surface texture image generated by another device (hereinafter referred to as a "surface texture display image generating device"), and the surface texture display screen 10 is displayed as a GUI on the image output unit 3. The surface texture display image generating device generates a "surface texture image" that is easy to predict the overall impression when the paint color, especially the metallic paint color, is applied to the painted surface of the industrial product based on the paint color database D. Fig.10 This is an image of the surface texture of a sedan in the case of a metallic paint job with the paint color Toyota 1D2 Gray M (Metallic Silver).

[0088] The CS image is an image that does not take into account the shadow changes of the painted surface. Therefore, it is difficult to predict the overall impression of the painted surface of an actual industrial product when the painted surface is painted with a metallic paint color based on the CS image. On the other hand, the surface texture image is an image that takes into account the shadow changes of the painted surface. Therefore, the surface texture image is easy to predict the overall impression of the painted surface of an industrial product when the painted surface is painted with a metallic paint color.

[0089] The surface texture display image generation device can generate a "surface texture image" that is easy to predict the overall impression when the painted surface is painted with a metallic paint color. The generation of the "surface texture image" is based on the change of the shadow of the painted surface image (two-dimensional image) that displays the painted surface suitable for industrial products, their models, etc. Fig.11 The change in the shadow of the illustrated car image generates a surface texture image when the painted surface of the car is painted with a metallic paint color.

[0090] First of all, Fig.11 The car image shown is subjected to a prior image processing, and a "painted surface image" is generated from the car image by cutting out only the image portion of the actual painted surface. Fig.12 The painted surface image is generated from the car image.

[0091] In this embodiment, the painted surface image is an image obtained by converting the car image as a color image into an 8-level grayscale image. It should be noted that the painted surface image is not limited to a grayscale image. The painted surface image can be an image composed of components (hereinafter referred to as "shade levels") corresponding to the brightness value of the image represented by an arbitrary level, such as the Y component of the YUV signal and the G component of the RGB signal.

[0092] The painted surface image is generated through the spectral reflectance calculation step S1 , the chromaticity value calculation step S2 , the histogram generation step S3 , the mapping step S4 , and the surface texture image generation step S5 .

[0093] The spectral reflectance calculation step S1 uses a method for determining the optical properties of a metal coating, such as that described in Patent Document 1 listed in the prior art literature, to calculate the spectral reflectance of the metal coating color at each specified angle within the observation angle range (0 degrees to 75 degrees) based on the spectral reflectance of the metal coating color measured at multiple light receiving angles.

[0094] Next, the surface texture display image generation device calculates the spectral reflectance of the metallic paint color at each specified angle in the observation angle range (0 degrees to 75 degrees) based on the measured spectral reflectance at the five angles. The surface texture display image generation device can also derive an equation for calculating the spectral reflectance of the metallic paint color at any angle. The specified angle in this embodiment is about 0.3 degrees (observation angle range / shade level = 75 degrees / 256 = about 0.3 degrees). The specified angle corresponding to the calculated spectral reflectance is recorded in the memory of the computer in the surface texture display image generation device.

[0095] The chromaticity value calculation step S2 uses, for example, the method for determining the optical properties of the metal coating described in Patent Document 1 cited in the prior art document, and calculates the chromaticity value (metallic color) at each specified angle in the observation angle range (0 degrees to 75 degrees) based on the calculated spectral reflectance. The surface texture display image generation device can also derive an equation for calculating the chromaticity value at any angle. The calculated chromaticity value is recorded in the memory of the computer in the surface texture display image generation device together with the corresponding specified angle.

[0096] The histogram generating step S3 measures the number of pixels at each gradation level of the painted surface image prepared in advance, and obtains the ratio of the number of pixels at each gradation level. Fig.13 This is a histogram of the painted surface image of a car. In this embodiment, the painted surface image is an 8-level grayscale image, so the shading level is 256 levels [0 to 255]. Fig.13In the figure, the area represented by "h" shows the highlight area (observation angle 15 degrees, 25 degrees), the area represented by "f" shows the front area (observation angle 45 degrees), and the area represented by "s" shows the shadow area (observation angle 75 degrees, 110 degrees).

[0097] The number of pixels at each shading level (the number of measured pixels) is determined based on the histogram of the painted surface image. The surface texture display image generation device generates a "corrected number of pixels" by subtracting the number of pixels near the maximum and minimum shading levels (for example, approximately black [0 to 5], approximately white [254 to 255]) from the measured number of pixels. The pixels near the maximum and minimum shading levels are likely not to represent the shadow of the painted surface generated based on the three-dimensional shape of the painted surface itself, so it is desirable to delete them during the generation of the surface texture image.

[0098] Next, the surface texture display image generating device obtains the ratio of the number of correction pixels for each gradation level [0 to 255] to the total number of correction pixels. Fig.11 The measured pixel count, corrected pixel count, and ratio calculated from the corrected pixel count of the painted surface image of the car shown in the figure are recorded in the memory of the computer in the surface texture display image generation device together with the corresponding shading level.

[0099] [Table 1]

[0100]

[0101] In the mapping step S4, the observation angles of each predetermined angle in the observation angle range (0 to 75 degrees) are associated with each shading level of the painted surface image. In the present embodiment, the shading level 255 (white) is associated with the highlight 0 degree, and the shading level 0 (black) is associated with the shadow 75 degrees. The highest shading level is associated with the smallest angle in the observation angle range, and the lowest shading level is associated with the largest angle in the observation angle range.

[0102] Table 2 shows the observation angles corresponding to the shading levels [0 to 255] calculated by linear interpolation.

[0103] [Table 2]

[0104] Observation angle Shade Level 75.0 0 74.7 1 74.4 2 74.1 3 73.8 4 73.5 5 73.2 6 72.9 7 72.6 8 72.4 9 72.1 10 71.8 11 71.5 12 71.2 13 70.9 14 70.6 15 22.1 180 21.8 181 21.5 182 21.2 183 20.9 184 20.6 185 20.3 186 20.0 187 19.7 188 19.4 189 2.9 245 2.6 246 2.4 247 2.1 248 1.8 249 1.5 250 1.2 251 0.9 252 0.6 253 0.3 254 0.0 255

[0105] The surface texture image generation step S5 generates a color-matched surface texture image by using the chromaticity values ​​(metallic colors) calculated at each specified angle within the observation angle range (0 to 75 degrees) in the order of the size of the observation angle and in accordance with the components corresponding to the ratio of the number of pixels at each shading level associated with the observation angle.

[0106] In this embodiment, the surface texture image is a two-dimensional image with a width of 128 pixels, a height of 200 pixels, and a total number of pixels of 25,600 pixels. The number of pixels for each shading level (hereinafter referred to as "CSX pixel number") is calculated by multiplying 25,600 pixels by the ratio shown in Table 1. Table 3 shows the calculated CSX pixel number. Table 3 also lists the measured pixel number, the corrected pixel number, the ratio obtained by the corrected pixel number, and the observation angle corresponding to each shading level [0 to 255] shown in Tables 1 and 2.

[0107] [Table 3]

[0108]

[0109] The surface texture display image generating device arranges the chromaticity values ​​calculated at each specified angle in the order of the size of the observation angle for the surface texture image. In the present embodiment, the chromaticity value of the observation angle of 0 degree is arranged for the pixel in the upper left of the two-dimensional image. The chromaticity value of the observation angle of 75 degree is arranged for the pixel in the lower right of the two-dimensional image. The corresponding observation angle increases from the upper left to the lower right of the two-dimensional image. The surface texture display image generating device can arrange the chromaticity values ​​in such a way that the corresponding observation angle increases from the lower right to the upper left of the two-dimensional image. That is, the two-dimensional surface texture image generated by the surface texture display image generating device is in the raster scanning order (scanning order) of the two-dimensional image, and the chromaticity values ​​are arranged in the order of the angle size of the observation angle range.

[0110] When the chromaticity values ​​calculated at each specified angle are used to color the surface texture image in the order of the size of the observation angle, the chromaticity values ​​are arranged in a component (number of pixels) corresponding to the ratio of the number of pixels of each shading level associated with the observation angle. The chromaticity values ​​of each specified angle in the observation angle range (0 degrees to 75 degrees) cannot be used to color the surface texture image evenly in the order of the size of the observation angle in the observation angle range.

[0111] In the surface texture image, the chromaticity values ​​(metallic colors) at each predetermined angle in the observation angle range (0 to 75 degrees) are not evenly arranged in the order of the observation angle in the observation angle range. The surface texture image takes into account the pixel ratio of the shading level associated with the observation angle.

[0112] That is, when the pixels of the corresponding shade level of the chromaticity value (metallic color) at a certain observation angle A are contained in a large number in the painted surface image, the surface texture image is configured with a large number of them. On the other hand, when the pixels of the corresponding shade level of the chromaticity value (metallic color) at a certain observation angle A are contained in a small number in the painted surface image, the surface texture image is configured with a small number of them.

[0113] Therefore, even without using shape data of three-dimensional CAD, the overall impression when the painted surface is painted with a metallic paint color can be predicted by using a surface texture image generated based on changes in the shadow of the painted surface in the painted surface image.

[0114] The surface texture display unit 55 selects the most appropriate surface texture image from the surface texture images generated by the surface texture display image generating device based on the input parameters, and generates the surface texture display screen 10. It should be noted that the surface texture image may be generated by the paint color search device 100 instead of the surface texture display image generating device.

[0115] [Operation of Paint Color Search Device 100]

[0116] Fig.14 This is a function selection menu screen 110 displayed by the image output unit 3 of the paint color search device 100. The person in charge of the paint company uses the paint color search device 100 when communicating with a designer, for example. Menu buttons corresponding to four functions of the paint color search device 100 (similar color search 101, change color selection 102, sample color search 103, texture map generation 104) are displayed on the function selection menu screen 110. The person in charge selects a menu corresponding to the function to be used using an input means such as a mouse connected to the computer 2.

[0117] When the menu button "similar color search 101" is selected, the paint color search device 100 functions as the similar color search unit 51. After the image output unit 3 displays a menu screen for inputting parameters required for activating the similar color search unit 51, the image output unit 3 displays Figure 6 The approximate color display screen 6 is shown.

[0118] When the menu button "Change Color Selection 102" is selected, the paint color search device 100 functions as the change color selection unit 52. After the image output unit 3 displays a menu screen for inputting parameters required for starting the change color selection unit 52, the image output unit 3 displays Figure 7 The color change prompt screen 7 is shown.

[0119] When the menu button "sample color search 103" is selected, the paint color search device 100 functions as the sample color search unit 53. After the image output unit 3 displays a menu screen for inputting parameters required for starting the sample color search unit 53, the image output unit 3 displays Figure 8 Sample color display screen 8 is shown.

[0120] When the menu button "texture map generation 104" is selected, the paint color search device 100 functions as the texture map generation unit 54. After the image output unit 3 displays a menu screen for inputting parameters required for starting the texture map generation unit 54, the image output unit 3 displays the texture map generation unit 54. Fig. 9 The texture map shown is displayed in screen 9.

[0121] When the menu button "Surface texture display 105" is selected, the paint color search device 100 functions as the surface texture display unit 55. After the image output unit 3 displays a menu screen for inputting parameters required for starting the surface texture display unit 55, the image output unit 3 displays Fig.10 The surface texture display screen 10 is shown.

[0122] The person in charge inquires the designer about the paint color requested by the designer, and selects a paint color with a color and texture that matches the image requested by the designer from the paint color database D. At this time, if the designer uses a computer graphic image such as a photo to convey the paint color requested by the designer to the person in charge, the person in charge selects "sample color search 103" on the function selection menu screen 110. The designer is asked to select a paint color with a color and texture that matches the image requested by the designer from the approximate colors output by the sample color search unit 53, and the paint color is used as the "reference color".

[0123] Alternatively, the person in charge may select "texture map generation 104" on the function selection menu screen 110 to cause the texture map generation unit 54 to generate a texture map. The person in charge generates a texture map classified based on the feature quantities expressed by the designer and related to the paint color, and presents it to the designer. The designer is asked to select a paint color with a color and texture that matches the image required by the designer from the paint colors mapped on the texture map output by the texture map generation unit 54, and the paint color is used as the "reference color".

[0124] In addition, the person in charge can also select "surface texture display 105" on the function selection menu screen 110 to display the surface texture image on the surface texture display unit 55. The person in charge presents the designer with the surface texture image generated based on the change in the shadow of the painted surface of the painted surface image. The designer can predict the overall impression when the painted surface is painted with the selected metallic paint color.

[0125] After selecting the reference color, the person in charge works to make the reference color closer to the paint color required by the designer. For example, the person in charge selects "similar color search 101" on the function selection menu screen 110, and causes the similar color search unit 51 to select a plurality of similar colors similar to the reference color from the paint color database D and present them. The designer can select a paint color closer to the paint color required by the designer from the plurality of presented similar colors.

[0126] When the designer instructs to change the reference color based on the shade, chroma, hue (e.g., red hue, blue hue) and other indicators of the metallic paint color, the person in charge selects "change color selection 102" on the function selection menu screen 110, and the change color selection unit 52 selects a plurality of change colors based on the chroma, hue and other indicators from the paint color database D for presentation. The designer observes the change colors that are changed based on these indicators multiple times, and can confirm the calibration method for adjusting the reference color to the paint color requested by the designer.

[0127] According to the paint color search device 100 involved in this embodiment, by properly using the five functions of the paint color search device 100, it is possible to effectively search for paint colors with colors and textures that match the image required by the designer from the paint color database D. Among the functions, according to the rating and additional information included in the paint color additional information D3, even if the person in charge of the paint company lacks knowledge and experience related to paint colors, it is possible to effectively assist the person in charge of selecting the paint color required by the designer.

[0128] Industrial Application Possibility

[0129] The present invention can be applied to the selection of paint colors for industrial products.

[0130] Description of reference numerals:

[0131] 100 Paint color search device

[0132] 1 Image input unit

[0133] 2 Computer

[0134] 3 Image output unit

[0135] 51 Similar color search department

[0136] 52 Change color selection section

[0137] 53 Sample color search department

[0138] 54 Texture map generation unit

[0139] 55 Surface texture display

[0140] 6 Approximate color display screen

[0141] 7 Change color prompt screen

[0142] 8 Sample color display screen

[0143] 9 Texture map display screen

[0144] 110 Function selection menu screen

[0145] 200 Multi-angle Spectrophotometer.

Claims

1. A paint color retrieval device, comprising a computer having a paint color database, The paint color database has: Basic information of paint colors, paint color mixing information with paint colors; and The paint color analysis information is obtained by analyzing the paint color based on the spectral reflectance measured by a multi-angle spectrophotometer. The paint color retrieval device implements: Retrieving similar colors, retrieving similar colors of the reference color from the paint color database; Selecting a changed color, selecting a changed color from the paint color database, which is a change of the reference color based on a specified index; Sample color retrieval, retrieving a paint color similar to the sample color from the paint color database; Texture map generation, generating a classification map according to the characteristic quantities of the paint color database; as well as Surface texture display, displaying a surface texture image, wherein the surface texture image predicts the overall impression when the paint color is applied to the painted surface based on the paint color database, The surface texture image is an image generated based on the number of pixels at each shading level of the painted surface image representing the painted surface.

2. The paint color search device according to claim 1, wherein: The paint color analysis information includes: The chromaticity value at each specified observation angle is calculated based on the spectral reflectance; and A computer graphics image is generated based on the chromaticity values.

3. The paint color search device according to claim 1, wherein: The paint color database also has paint color additional information, The paint color additional information includes rating information for the paint color.

4. The paint color search device according to claim 1, wherein: The paint color database also has paint color additional information, The paint color additional information includes information related to the mixing of the paint color.

Images