Display screen color gamut evaluation method and system

Abstract

The invention provides a display screen color gamut evaluation method and system, and relates to the technical field of screen display, the display screen color gamut evaluation method comprises the following steps: obtaining M sampling tristimulus values in one-to-one correspondence with M display pictures, the M display pictures being in one-to-one correspondence with M RGB values, at least one RGB value in the M RGB values being not 255, and M being an integer greater than or equal to 3; based on the M sampling tristimulus values and the M standard tristimulus values, M first color appearance data and M second color appearance data are obtained; based on the M pieces of first color appearance data and the M pieces of second color appearance data, M color difference values are obtained, and the M color difference values are used for indicating color differences between the M pieces of first color appearance data and the M pieces of second color appearance data; based on the M color difference values, a histogram is constructed, and the histogram is used for representing color difference distribution between a display screen color gamut and a standard color gamut. The display screen color gamut evaluation accuracy can be improved.

Description

Technical Field

[0001] This application relates to the field of screen display technology, and more specifically, to a method and system for evaluating the color gamut of a display screen. Background Technology

[0002] With the development of display technology, displays are being used more and more widely, from everyday computer monitors and television screens to displays on various mobile devices. Therefore, the requirements for display color gamut are becoming increasingly stringent; the more natural colors a display can accommodate, the richer the image it displays.

[0003] Evaluating a display's color gamut allows for the analysis of the colors displayed on the screen, thus assessing the monitor's display quality. Currently, methods using manual color charts to evaluate color gamut rely heavily on operator perception, resulting in high subjectivity, low efficiency, and inaccurate evaluation results. While two-dimensional color gamut evaluation can effectively assess chromaticity, as display color gamut coverage expands, two-dimensional evaluation methods can no longer distinguish true color differences on the screen, nor can they evaluate the monitor's color performance at different brightness levels.

[0004] Therefore, improving the accuracy of color gamut evaluation for displays is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a method and system for evaluating the color gamut of a display screen. By obtaining the sampled tristimulus values ​​corresponding to any RGB, performing color difference analysis between them and the tristimulus values ​​in the standard color gamut, and combining the results with a histogram to visually represent the color difference between the display screen color gamut and the standard color gamut, the color gamut at any gray level can be evaluated, thereby improving the accuracy of the display screen color gamut evaluation.

[0006] Firstly, a method for evaluating the color gamut of a display screen is provided. This method may include: acquiring M sampled tristimulus values ​​corresponding one-to-one with M display images, where each of the M display images corresponds to one of the M RGB values, and at least one of the M RGB values ​​is not 255, where M is an integer greater than or equal to 3; obtaining M first color appearance data and M second color appearance data based on the M sampled tristimulus values ​​and M standard tristimulus values, where the M standard tristimulus values ​​are tristimulus values ​​in the standard color gamut, and the M first color appearance data and M sampled tristimulus values ​​correspond one-to-one, and the M second color appearance data and M standard tristimulus values ​​correspond one-to-one; obtaining M color difference values ​​based on the M first color appearance data and M second color appearance data, where the M color difference values ​​indicate the color difference between the M first color appearance data and the M second color appearance data; and constructing a histogram based on the M color difference values, where the histogram represents the color difference distribution between the display screen color gamut and the standard color gamut.

[0007] In this embodiment, by obtaining the sampled tristimulus values ​​corresponding to any RGB and performing color difference analysis between them and the tristimulus values ​​in the standard color gamut, and combining the histogram to intuitively represent the color difference between the display color gamut and the standard color gamut, the color gamut under any gray level can be evaluated, thereby improving the accuracy of the display color gamut evaluation.

[0008] In conjunction with the first aspect, in some implementations of the first aspect, based on M sampled tristimulus values ​​and M standard tristimulus values, M first color appearance data and M second color appearance data are obtained, including: selecting a color appearance model; and analyzing the color appearance attributes of the M sampled tristimulus values ​​and M standard tristimulus values ​​based on the color appearance model to obtain M first color appearance data and M second color appearance data.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, obtaining the M tristimulus values ​​corresponding one-to-one with the M display images includes: selecting K grayscale values, where K is an integer greater than or equal to 2; and determining M RGB values ​​based on the K grayscale values, wherein the M RGB values ​​correspond one-to-one with the M tristimulus values, and M=K. 3 Based on M RGB values, construct M display images and collect data from the M display images to obtain M sampled tristimulus values.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: constructing a first dot map of the M first color appearance data in color gamut coordinates based on M first color appearance data; constructing a second dot map of the M second color appearance data in color gamut coordinates based on M second color appearance data; and determining a first value based on the first dot map and the second dot map, the first value being used to indicate the proportion of the color gamut of the display screen in the standard color gamut.

[0011] In this embodiment, the color appearance data of the M sampled tristimulus values ​​and the color appearance data of the M standard tristimulus values ​​are displayed in the color gamut coordinates, and the color appearance data of the M standard tristimulus values ​​are also displayed in the color gamut coordinates. This allows for a direct view of the color gamut of the display screen.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, determining the first value based on the first point map and the second point map includes: determining the first volume of the intersection of the first point map and the second point map based on the first point map and the second point map; determining the first value based on the first volume and the second volume, wherein the second volume is the volume of the second point map.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: constructing a first color gamut ring diagram of the M first color appearance data in the color gamut coordinates based on M first color appearance data; constructing a second color gamut ring diagram of the M second color appearance data in the color gamut coordinates based on M second color appearance data; and determining the coverage range of the display screen's color gamut in the standard color gamut based on the first color gamut ring diagram and the second color gamut ring diagram.

[0014] In conjunction with the first aspect, in some implementations of the first aspect, constructing a first gamut ring map of the M first chromaticity data in gamut coordinates based on M first chromaticity data includes: constructing a first gamut map of the M first chromaticity data in gamut coordinates based on M first chromaticity data; converting the first gamut map into a first gamut ring map; constructing a second gamut ring map of the M second chromaticity data in gamut coordinates based on M second chromaticity data includes: constructing a second gamut map of the M second chromaticity data in gamut coordinates based on M second chromaticity data; converting the second gamut map into a second gamut ring map.

[0015] In this embodiment, the color gamut of the M sampled tristimulus values ​​and the color gamut of the M standard tristimulus values ​​are displayed in the color gamut coordinates, so that the color gamut of the display screen can be seen intuitively.

[0016] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: constructing a grid of M sampled tristimulus values ​​in the color gamut coordinates based on M RGB values.

[0017] In this embodiment of the application, a grid diagram corresponding to the M sampled tristimulus values ​​can be drawn in the color gamut coordinates using M RGB values, so that the color gamut grid diagram of the M sampled tristimulus values ​​can be seen intuitively.

[0018] In conjunction with the first aspect, in some implementations of the first aspect, constructing a mesh diagram of M sampled tristimulus values ​​in the color gamut coordinates based on M RGB values ​​includes: constructing a first matrix and a second matrix based on the M RGB values, wherein the elements of the first matrix and the second matrix include M RGB values, and the dimensions of the first matrix and the second matrix are M. 2 ×1; Based on the first matrix, the second matrix, the all-zero matrix, and the all-one matrix, construct the third matrix; Based on the third matrix and the fourth matrix, obtain the reference triangles included in each face of the mesh graph. The row elements of the fourth matrix are used to indicate the vertices of the reference triangles. The dimension of the fourth matrix is ​​T×3, and the value of T is 6×M×M; Based on the reference triangles included in each face of the mesh graph, construct the mesh graph.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: constructing a color gamut triangle diagram corresponding to K gray levels in the color gamut coordinates based on M sampled tristimulus values; and constructing a standard color gamut triangle diagram in the color gamut coordinates based on M standard tristimulus values.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, a histogram is constructed based on M color difference values, including: performing statistics on the M color difference values ​​to obtain statistical results, the statistical results including at least one of the following: the maximum color difference value among the M color difference values, the minimum color difference value among the M color difference values, the number of color difference values ​​among the M color difference values ​​in the range [n, j], or the number of color difference values ​​among the M color difference values ​​that are greater than or equal to a preset threshold, where 0 < n < j; and constructing a histogram based on the statistical results.

[0021] Secondly, a display screen color gamut evaluation system is provided. This system includes: an acquisition module, used to acquire M sampled tristimulus values ​​corresponding one-to-one with M display images, wherein the M display images correspond one-to-one with M RGB values, and at least one of the M RGB values ​​is not 255, where M is an integer greater than or equal to 3; a processing module, used to obtain M first chromaticity data and M second chromaticity data based on the M sampled tristimulus values ​​and M standard tristimulus values, wherein the M standard tristimulus values ​​are tristimulus values ​​in the standard color gamut, and the M first chromaticity data correspond one-to-one with the M sampled tristimulus values ​​and the M second chromaticity data correspond one-to-one with the M standard tristimulus values; the processing module is further used to obtain M color difference values ​​based on the M first chromaticity data and M second chromaticity data, the M color difference values ​​indicating the color difference between the M first chromaticity data and the M second chromaticity data; and to construct a histogram based on the M color difference values, the histogram representing the color difference distribution between the display screen color gamut and the standard color gamut.

[0022] Thirdly, a display screen color gamut evaluation apparatus is provided, comprising: a processor; and a memory storing computer-executable instructions, which, when executed, cause the processor to perform the method of the first aspect or any implementation thereof.

[0023] Fourthly, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method of the first aspect or any implementation thereof. Attached Figure Description

[0024] Figure 1 This is a schematic flowchart of a display screen color gamut evaluation method provided in an embodiment of this application.

[0025] Figure 2 This is a schematic diagram of a user interface provided in an embodiment of this application.

[0026] Figure 3 This is a schematic diagram of another user interface provided in the embodiments of this application.

[0027] Figure 4 This is a schematic diagram of another user interface provided in the embodiments of this application.

[0028] Figure 5 This is a schematic diagram of another user interface provided in the embodiments of this application.

[0029] Figure 6 This is a schematic diagram of a planar color gamut display of an LCD screen provided in an embodiment of this application.

[0030] Figure 7 This is a schematic diagram of the stereoscopic color gamut display of an LCD screen provided in an embodiment of this application.

[0031] Figure 8 This is a schematic diagram of a stereoscopic color gamut comparison analysis of an LCD display screen provided in an embodiment of this application.

[0032] Figure 9 This is a schematic diagram of data analysis of an LCD display screen provided in an embodiment of this application.

[0033] Figure 10 This is a schematic diagram of another planar color gamut display of the LCD screen provided in the embodiments of this application.

[0034] Figure 11 This is a schematic diagram of another type of stereoscopic color gamut display of the LCD screen provided in the embodiments of this application.

[0035] Figure 12 This is a schematic diagram illustrating another type of stereoscopic color gamut comparison analysis of the LCD display screen provided in the embodiments of this application.

[0036] Figure 13 This is a schematic diagram of another type of data analysis for the LCD display screen provided in the embodiments of this application.

[0037] Figure 14 This is a schematic block diagram of a display screen color gamut evaluation system provided in an embodiment of this application.

[0038] Figure 15 This is a schematic block diagram of a display screen color gamut evaluation device provided in an embodiment of this application. Detailed Implementation

[0039] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0040] This application will present various aspects, embodiments, or features relating to a system comprising multiple devices, components, modules, etc. It should be understood and appreciated that individual systems may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. Furthermore, combinations of these approaches are also possible.

[0041] Furthermore, in the embodiments of this application, the words "exemplary," "for example," etc., are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" in the embodiments of this application should not be construed as being better or more advantageous than other embodiments or design schemes. Specifically, the use of the term "exemplary" is intended to present the concept in a concrete manner.

[0042] The business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0043] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0044] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0045] The following describes the technical content related to the embodiments of this application.

[0046] With the development of display technology, displays are being used more and more widely, from everyday computer monitors and television screens to displays on various mobile devices. At the same time, users have increasingly higher demands for displays to accurately and naturally reproduce natural colors, meaning they require a wider color gamut. The more natural colors a display can accommodate, the richer the image. To address this, display panel manufacturers are expanding the color gamut of their displays using technologies such as quantum dot, organic light-emitting diode (OLED), and mini-LED backlighting.

[0047] A display's color gamut indicates its ability to display colors; the larger the color gamut area covered, the richer the colors the display can display. Evaluating a display's color gamut is a key technique for assessing its display quality. By evaluating the display's color gamut, the colors displayed on the screen can be analyzed to assess its display quality. To quantify the richness of colors, a series of standard color gamuts have been established in the field, such as sRGB, AdobeRGB, or DCI-P3.

[0048] Currently, the field has proposed an evaluation method using artificial color cards, which uses the construction of color cards to quickly visually assess the color accuracy of displays. Although this effectively overcomes the limitations of traditional methods that use professional color measurement equipment and systems to assess the color accuracy of displays, it requires manual operation and human eye color discrimination to obtain evaluation results. It relies too much on the operator's perception, making the evaluation results highly subjective, inefficient, and inaccurate.

[0049] Another method proposed in this field is to evaluate the color gamut of a display screen using a two-dimensional color gamut. This method projects all the colors that the display screen can display onto the CIE color space, calculates the area of ​​the triangle formed by the coordinate points of the three primary colors (red, R), green, G, and blue, and uses the percentage of the area compared to a certain standard color gamut (such as sRGB) as the core indicator. This method can evaluate chromaticity well. However, as the color gamut coverage of the display screen becomes wider and wider, the three-dimensional characteristics of color make the two-dimensional color gamut evaluation method unable to distinguish the true color differences of the display screen, let alone evaluate the color performance of the display screen at different brightness levels.

[0050] Therefore, improving the accuracy of color gamut evaluation for displays is an urgent problem to be solved.

[0051] In view of this, this application proposes a method and system for evaluating the color gamut of a display screen. By obtaining the sampled tristimulus values ​​corresponding to any RGB, performing color difference analysis between them and the tristimulus values ​​in the standard color gamut, and combining the histogram to intuitively represent the color difference between the display screen color gamut and the standard color gamut, the color gamut at any gray level can be evaluated, thereby improving the accuracy of the display screen color gamut evaluation.

[0052] Figure 1 This is a schematic flowchart of a display screen color gamut evaluation method provided in this application. Figure 1 As shown, the display screen color gamut evaluation method 100 includes the following steps.

[0053] S110, obtain M sampled tristimulus values ​​that correspond one-to-one with M display screens, M display screens correspond one-to-one with M RGB values, and at least one of the M RGB values ​​is not 255, where M is an integer greater than or equal to 3.

[0054] S120, based on M sampled tristimulus values ​​and M standard tristimulus values, obtains M first chromaticity data and M second chromaticity data. The M standard tristimulus values ​​are tristimulus values ​​in the standard color gamut. The M first chromaticity data correspond one-to-one with the M sampled tristimulus values, and the M second chromaticity data correspond one-to-one with the M standard tristimulus values.

[0055] S130, based on M first color appearance data and M second color appearance data, obtain M color difference values, which are used to indicate the color difference between the M first color appearance data and the M second color appearance data.

[0056] S140, based on M color difference values, constructs a histogram, which is used to represent the color difference distribution between the display color gamut and the standard color gamut.

[0057] In step S110, the M sampled tristimulus values ​​corresponding to the M display screens correspond one-to-one with the M RGB values, that is, each sampled tristimulus value has a corresponding RGB value.

[0058] For example, the sampled tristimulus values ​​can be understood as: the tristimulus values ​​obtained by actual measurement; or the M sampled tristimulus values ​​obtained by measuring M images through optical equipment. The M sampled tristimulus values ​​can be called M measured tristimulus values ​​or M measurement data, or measurement data.

[0059] In some possible implementations, obtaining M tristimulus values ​​that correspond one-to-one with M display images includes: selecting K grayscale values, where K is an integer greater than or equal to 1; and determining M RGB values ​​based on the K grayscale values, where the M RGB values ​​correspond one-to-one with the M tristimulus values, and M=K. 3K is an integer greater than or equal to 2; based on M RGB values, M display images are constructed, and M sampled tristimulus values ​​are obtained from the M display images.

[0060] For example, some grayscale values ​​or all grayscale values ​​can be selected from 256 grayscale values. For instance, K grayscale values ​​can be selected from 256 grayscale values, denoted as (gray1, gray2, ..., grayK). These K grayscale values ​​are then combined to obtain M RGB values, i.e., M red, green, and blue images. These M RGB values ​​are then displayed on a screen to obtain the aforementioned M display images. Optical data, such as luminance and chromaticity coordinates, are then measured on these M display images using optical equipment, and the measured data is recorded. This yields the aforementioned M sampled tristimulus values. Table 1 shows some RGB values ​​and their corresponding sampled tristimulus values.

[0061] Table 1

[0062] In Table 1, the sample ID is the sequence number of each sampled tristimulus value, RGB_R, RGB_G, and RGB_B are the RGB values ​​of each display screen, and XYZ_X, XYZ_Y, and XYZ_Z are the sampled tristimulus values ​​of each display screen.

[0063] It should be understood that if the output mode of the optical device is set to tristimulus values ​​XYZ, then the output data of the optical device can be directly used as the aforementioned M sampled tristimulus values. If the output mode of the optical device is set to brightness (… l ), chromaticity coordinates ( x,y That is, when measuring M display images through optical equipment, the output is lxy Then, the following formula can be used to... lxy Convert to tristimulus values ​​XYZ:

[0064] After obtaining the aforementioned M sampled tristimulus values, a dot plot of these M tristimulus values ​​can be drawn in the color gamut coordinates of the standard color gamut. In this embodiment, the dot plot of the M tristimulus values ​​can also be referred to as an XYZ plot.

[0065] In some possible implementations, the method 100 further includes: constructing a color gamut triangle diagram corresponding to K grayscale values ​​in the color gamut coordinates based on M sampled tristimulus values; and constructing a standard color gamut triangle diagram in the color gamut coordinates based on M standard tristimulus values.

[0066] Specifically, the M sampled tristimulus values ​​are plotted in the gamut coordinates of the standard color gamut (e.g., CIE 1931 color gamut coordinates). If the selected grayscale value is (gray1, gray2, ..., grayK), then all grayscale values ​​are traversed, and the color gamut triangles corresponding to all grayscale values ​​are plotted in the gamut coordinates of the standard color gamut. For example, when the k-th grayscale value grayk is selected, the three sampled tristimulus values ​​corresponding to RGB values ​​of (grayk,0,0), (0,grayk,0), and (0,0,grayk) are found among the above M sampled tristimulus values ​​and used as the three vertices of the color gamut triangle corresponding to the grayscale value grayk. This color gamut triangle is the color gamut range corresponding to the grayscale value grayk. Similarly, following the above process, the color gamut triangles corresponding to the above K grayscale values ​​are plotted in the gamut coordinates of the standard color gamut. Furthermore, based on M standard tristimulus values, a standard color gamut triangle is drawn in the color gamut coordinates of the standard color gamut, so that the contrast between the color gamut triangle of the display screen and the standard color gamut triangle can be seen in the same color gamut coordinates.

[0067] Seeing the color gamut triangle of the display screen and the standard color gamut triangle in the same color gamut coordinate system can be called the process of displaying a three-dimensional (3D) color gamut in color gamut coordinate system.

[0068] For example, a standard color gamut can be any of the following: sRGB, DCI-P3, D65-P3, D60-P3, AdobeRGB1988, or BT.2020. The color gamut coordinates of a standard color gamut can also be called a standard color gamut space. A standard color gamut space refers to a color space that plots all colors perceived by the human eye on a coordinate system, forming a "horseshoe" shape. Different color gamut standards are developed for different industries, representing smaller color spaces within the horseshoe shape.

[0069] In some possible implementations, the three sampled tristimulus values ​​corresponding to RGB(255,0,0), (0,255,0), and (0,0,255) from the M RGB values ​​are used as the three vertices of the color gamut triangle, and these three vertices are drawn in the color gamut coordinates of the standard color gamut. This allows the display's color gamut coverage within the standard color gamut to be seen in the color gamut coordinates. For example, the XY coordinates of the three tristimulus values ​​corresponding to (255,0,0), (0,255,0), and (0,0,255) are ( x 1, y 1), ( x 2, y 2), ( x 3, y 3), will ( x 1, y 1), ( x 2, y 2), (x 3, y 3) Plotting it in the color gamut coordinates of the standard color gamut yields the color gamut of the display screen.

[0070] Will( x 1, y 1), ( x 2, y 2), ( x 3, y 3) Drawing in the color gamut coordinates of the standard color gamut can be called the process of displaying a two-dimensional (2D) color gamut in color gamut coordinates.

[0071] In some possible implementations, if one of the aforementioned standard color gamuts is selected, after drawing the standard color gamut triangle and the display screen's color gamut triangle in the standard color gamut coordinates, the color gamut coverage of the display screen can be visually observed within the standard color gamut triangle. For example, the coordinates of the three vertices of the display screen's color gamut triangle are: ( x 1, y 1), ( x 2, y 2), ( x 3, y 3) The coordinates of the three vertices of the standard color gamut triangle are: ( x std1 , y std1 ), ( x std2 , y std2 ), ( x std3 , y std3 Therefore, the area of ​​the color gamut triangle of the display screen is: S1 = 0.5 × | x 1×( y 2- y 3)+ x 2×( y 3- y 1)+ x 3×( y 1- y 2) The area of ​​the standard color gamut triangle is: S² = 0.5 × | x std1 ×( y std2 - y std3 )+ x std2 ×( y std3 - y std1 )+ xstd3 ×( y std1 - y std2 The ratio of S1 to S2 is taken as the coverage ratio of the display screen's color gamut in the standard color gamut, i.e., coverage ratio = S1 / S2.

[0072] The process of constructing the color gamut triangle diagram, the dot diagram of M tristimulus values, and the color gamut diagram of the display screen can be collectively referred to as the planar color gamut display process.

[0073] In step S120, based on M sampled tristimulus values ​​and M standard tristimulus values, the color gamut of the display screen can be displayed in the color appearance model.

[0074] In one possible implementation, based on M sampled tristimulus values ​​and M standard tristimulus values, M first color appearance data and M second color appearance data are obtained, including: selecting a color appearance model; and analyzing the color appearance attributes of the M sampled tristimulus values ​​and M standard tristimulus values ​​based on the color appearance model to obtain the M first color appearance data and M second color appearance data.

[0075] For example, a color appearance model is a mathematical model constructed after quantitatively calculating the color appearance attributes such as lightness, apparent lightness, apparent chroma, saturation, and hue.

[0076] For example, for the M RGB values ​​mentioned above, M corresponding sampled tristimulus values ​​are found. Then, these M sampled tristimulus values ​​are subjected to color adaptive transformation to obtain the transformed M sampled tristimulus values. Then, the color appearance attributes of the M sampled tristimulus values ​​after color adaptive transformation are calculated using a color appearance model to obtain M first color appearance data. Similarly, the color appearance attributes of the M standard tristimulus values ​​mentioned above are calculated to obtain M second color appearance data.

[0077] The following is an exemplary description of the implementation of "calculating the color appearance attributes of M sampled tristimulus values ​​after color adaptive transformation using a color appearance model to obtain M first color appearance data".

[0078] First, the M sampled tristimulus values ​​are subjected to color adaptive transformation using the Bradford color adaptation transform with a standard light source (D50, D60, or D65). It is assumed that the relative values ​​of the tristimulus values ​​under the standard light source are (...). x d , y d , z d ), the m-th sampled tristimulus value among M sampled tristimulus values ​​is (X m Y m Zm Then, after transforming the m-th sampled tristimulus value among the M sampled tristimulus values, we obtain the m-th absolute tristimulus value: Dm = ( x d ×X m , y d ×Y m , z d ×Z m )=(X m ' Y m ' Z m ' Assuming the adaptive transformation matrix is ​​P, then (X) m Y m Z m After adaptive transformation, we get: (X) m Y m Z m )×P×Dm×P -1 Then, through the appearance model, (X) is obtained. m Y m Z m The first appearance data corresponding to ).

[0079] Taking the CIELab color appearance model as an example, (X m Y m Z m The corresponding first appearance data is:

[0080] in, .

[0081] The above explanation uses the m-th sampled tristimulus value as an example. The calculation process for the first color appearance data corresponding to other sampled tristimulus values ​​is the same as that for the first color appearance data corresponding to the m-th sampled tristimulus value, thus obtaining M first color appearance data.

[0082] It should be understood that the above color appearance model is for illustrative purposes only, and other color appearance models can also be used to obtain the first color appearance data, such as the CAM16 model. The CAM16 model can be used to analyze (X...) m Y m Z m After calculating the color appearance attributes, the first color appearance data obtained corresponds to the visual value (J), red-green hue (a), and yellow-blue hue (b). For detailed implementation, please refer to the description of the international standard model.

[0083] Furthermore, the obtained M first color appearance data can be plotted in the color gamut coordinates, so that the distribution of the display screen's color gamut in the color appearance model space can be intuitively seen in the color gamut coordinates.

[0084] The implementation of "calculating the color appearance attributes of M standard tristimulus values ​​using a color appearance model to obtain M second color appearance data" can refer to the calculation process of M first color appearance data. However, it should be noted that in the standard color gamut, the Y stimulus value in the standard tristimulus values ​​is in G255 units, and the XZ tristimulus values ​​in the standard tristimulus values ​​are the ratio of Y.

[0085] Furthermore, the M first chromaticity data and the M second chromaticity data can be plotted in the color gamut coordinates to form a dot plot of the M first chromaticity data and a dot plot of the M second chromaticity data.

[0086] In some possible implementations, method 100 further includes: constructing a first dot map of the M first color appearance data in color gamut coordinates based on M first color appearance data; constructing a second dot map of the M second color appearance data in color gamut coordinates based on M second color appearance data; and determining a first value based on the first dot map and the second dot map, the first value being used to indicate the proportion of the color gamut of the display screen in the standard color gamut.

[0087] In other words, by drawing the first and second dot plots in the color gamut coordinate system, the contrast between the display's color gamut and the standard color gamut can be visually observed.

[0088] For example, the first dot plot is a color gamut dot plot of the display screen, or a three-dimensional color gamut dot plot of the display screen, and the second dot plot is a dot plot of the standard color gamut, or a three-dimensional color gamut dot plot of the standard color gamut. The first value can also be described as the proportion of the display screen's color gamut dot plot in the standard color gamut dot plot.

[0089] For example, determining a first value based on a first dot plot and a second dot plot includes: determining a first volume of the intersection of the first dot plot and the second dot plot based on the first dot plot and the second dot plot; and determining the first value based on the first volume and the second volume, wherein the second volume is the volume of the second dot plot.

[0090] Specifically, the intersection of the first dot plot and the second dot plot in the color gamut coordinates is obtained to obtain the color gamut intersection. Then, the volume V1 of the color gamut intersection and the volume V2 of the standard color gamut are calculated, and the first value is obtained based on V1 and V2.

[0091] For example, the intersection of color gamuts can be obtained based on cylindrical coordinate mapping, and then V1 and V2 can be calculated using the color gamut volume scoring formula in cylindrical coordinates. For detailed implementation process, please refer to the existing technology, which will not be elaborated here.

[0092] In one possible implementation, method 100 further includes: constructing a first color gamut ring map of the M first color appearance data in the color gamut coordinates based on M first color appearance data; constructing a second color gamut ring map of the M second color appearance data in the color gamut coordinates based on M second color appearance data; and determining the coverage range of the display screen's color gamut in the standard color gamut based on the first color gamut ring map and the second color gamut ring map.

[0093] In the embodiments of this application, the color gamut ring refers to the two-dimensional representation of the color gamut formed by forming an area within any brightness and hue angle range in order to visualize the three-dimensional color gamut model and more effectively display the color gamut.

[0094] For example, constructing a first gamut ring map of M first chromaticity data in gamut coordinates based on M first chromaticity data includes: constructing a first gamut map of M first chromaticity data in gamut coordinates based on M first chromaticity data; converting the first gamut map into a first gamut ring map; constructing a second gamut ring map of M second chromaticity data in gamut coordinates based on M second chromaticity data includes: constructing a second gamut map of M second chromaticity data in gamut coordinates based on M second chromaticity data; converting the second gamut map into a second gamut ring map.

[0095] For example, the first color gamut map is a stereoscopic color gamut map of the display screen, and the second dot map is a stereoscopic color gamut map of the standard color gamut.

[0096] In this embodiment, after obtaining M first color appearance data and M second color appearance data, the boundary can be calculated using a 3D planar point cloud precise boundary algorithm. Then, the corresponding RGB values ​​are normalized, and color rendering is performed on the boundary and the corresponding vertex positions. This allows drawing a first color gamut map and a second color gamut map in the color gamut, and the color of each boundary position can be intuitively seen through the first color gamut map. RGB value normalization can be understood as dividing the RGB values ​​by 255.

[0097] For example, after obtaining the first and second color gamut maps, the method proposed by Masaoka for converting three-dimensional color gamut maps into two-dimensional color gamut maps can be used to convert the first and second color gamut maps into a first color gamut ring map and a second color gamut ring map, respectively. Furthermore, the color gamut shape in all color directions can be analyzed, and the luminance L or lightness J can be uniformly divided into 10 parts, such that each color gamut ring corresponds to a lightness L or luminance J, where the area of ​​each color gamut ring can represent the color gamut volume from luminance L or lightness J to the target luminance L or target lightness J.

[0098] It should be noted that the above-mentioned methods of "finding the boundary through the precise boundary algorithm of 3D planar point cloud" and "converting the 3D color gamut map into a 2D color gamut map" are only examples. This application may use other methods to calculate the boundary and color gamut map, and does not limit the scope of the application.

[0099] In one possible implementation, method 100 further includes: constructing a grid of M sampled tristimulus values ​​in the color gamut coordinates based on the M RGB values.

[0100] For example, a grid diagram can also be called a stereo gamut grid diagram.

[0101] For example, constructing a mesh of M sampled tristimulus values ​​in color gamut coordinates based on M RGB values ​​includes: constructing a first matrix and a second matrix based on the M RGB values, wherein the elements of the first matrix and the second matrix include the M RGB values, and the dimensions of the first matrix and the second matrix are M. 2 ×1; Based on the first matrix, the second matrix, the all-zero matrix, and the all-one matrix, construct the third matrix; Based on the third matrix and the fourth matrix, obtain the reference triangles included in each face of the mesh graph. The row elements of the fourth matrix are used to indicate the vertices of the reference triangles. The dimension of the fourth matrix is ​​T×3, and the value of T is 6×M×M; Based on the reference triangles included in each face of the mesh graph, construct the mesh graph.

[0102] Specifically, taking M=3 as an example; construct a first matrix and a second matrix based on these 8 RGB values. For example, the first matrix is ​​denoted as... The second matrix is ​​denoted as Assuming the 8 RGB values ​​are (RGB_R1, RGB_G1, RGB_B1), (RGB_R2, RGB_G2, RGB_B2), ..., (RGB_R8, RGB_G8, RGB_B8), first, construct the matrix. J sum matrix G ,matrix J sum matrix G They represent:

[0103] Among them, matrix J The first column of matrix J consists of 8 values: RGB_R1, RGB_R2, ..., RGB_R8. The second column of matrix J consists of 8 values: RGB_G1, RGB_G2, ..., RGB_G8. The third column of matrix J consists of 8 values: RGB_B1, RGB_B2, ..., RGB_B8.

[0104] Among them, matrix G The first column consists of 24 elements: 8 RGB_R1, 8 RGB_R2, ..., 8 RGB_R8. G The second column consists of 24 values: 8 RGB_G1, 8 RGB_G2, ..., 8 RGB_G8. GThe third column consists of 24 values: 8 RGB_B1, 8 RGB_B2, ..., 8 RGB_B8. In other words, the elements in the array are created by repeating the first RGB value M times, then the second RGB value M times, and so on, until the last RGB value.

[0105] Furthermore, the matrix J sum matrix G The elements are constructed in the order of the first column, then the second column, and finally the third column. J _flat and G _flat . J _flat and G _flat They are represented as follows: J _flat =[ ] T

[0106] Furthermore, based on matrix J _flat ,matrix G _flat The third matrix is ​​constructed using a matrix consisting entirely of zeros and a matrix consisting entirely of ones. Specifically, in the matrix... J _flat sum matrix G _flat Select the first M 2 1 element, to obtain the matrix sum matrix And then based on the matrix t ,matrix The third matrix constructed from the matrix of all zeros and the matrix of all ones is represented as follows:

[0107] in, Lower Represents a matrix of all zeros. Upper Represents a matrix consisting entirely of 1s. Lower sum matrix Upper Dimensions and matrices or matrix With the same dimensions, the third matrix can also be called the RGB grid vertex list matrix. ref .

[0108] Furthermore, a fourth matrix corresponding to the third matrix is ​​constructed, with dimensions 384×3. Specifically, the number of elements in each row of the third matrix, i.e., the number of elements in the RGB matrix...ref For each row, count the number of elements and calculate a vertex index. Then, calculate the indices of the vertices of the two triangles corresponding to that row, and so on, until the matrix RGB... ref The last row gives the elements of each row in the fourth matrix.

[0109] For example, the process of constructing the fourth matrix described above can be represented by the following code: for s=1:6 / / Loop through the RGB matrix ref 6 lines of for q=1:M-1 / / Process rows in a loop on a single surface for p=1:M-1 / / Process columns in a loop on a single surface j = M²*(s-1) + M*(q-1) + p; / / Calculate vertex index TRI_ref(idx,:)=[j, j+i, j+1]; / / Index values ​​of the three vertices of the first triangle TRI_ref(idx+1,:)=[j+i, j+i+1, j+1]; / / Index values ​​of the three vertices of the second triangle idx = idx + 2; end end end Where s represents the RGB matrix ref number of rows.

[0110] It should be noted that the matrix RGB ref The number of rows corresponds to the number of faces in the mesh, i.e., the RGB matrix. ref The number of rows determines the number of rows in the grid diagram. M can be equal to 8, or any other value; there are no restrictions.

[0111] After obtaining the fourth matrix, the corresponding RGB values ​​for each row can be found based on the fourth matrix, thus drawing a grid of M RGB values ​​in the color gamut coordinates.

[0112] The process of constructing the first dot plot, the first color gamut plot, the first color gamut ring plot, and the grid plot can be collectively referred to as three-dimensional color gamut display. If the first dot plot and the second dot plot are constructed in the same color gamut coordinate system, and the first color gamut ring plot and the second color gamut plot are constructed in the same color gamut coordinate system, this can be collectively referred to as three-dimensional color gamut comparison analysis.

[0113] In step S130, based on M first color appearance data and M second color appearance data, the color difference between the M first color appearance data and the M second color appearance data can be calculated.

[0114] Specifically, the M standard RGB values ​​in the standard color gamut are sorted according to the order of the M RGB values ​​mentioned above, so that the M standard RGB values ​​correspond one-to-one with the M RGB values ​​mentioned above. Then, the M second color appearance data corresponding to the M standard RGB values ​​are also sorted accordingly, and then the color difference between the M first color appearance data and the M second color appearance data is calculated.

[0115] For example, the color difference between M first color appearance data and M second color appearance data is calculated using the international standard DE2000. Taking the m-th first color appearance data and the m-th second color appearance data from the M first color appearance data as an example, and using CIELab as the color appearance model, the color difference between the m-th first color appearance data and the m-th second color appearance data satisfies:

[0116] in, , and Lab represents the m-th second color feature data.

[0117] If the color appearance model is CAM16, the color difference between the m-th first color appearance data and the m-th second color appearance data satisfies:

[0118] in, J m , and b m Jab, representing the m-th first color feature data, J std , and b std Jab represents the m-th second-color feature data.

[0119] It can be understood that, through the above formula, the color difference between the above M first color appearance data and M second color appearance data can be calculated, that is, the above M color difference values ​​can be obtained.

[0120] In step S140, after obtaining M color difference values, the M color difference values ​​can be statistically analyzed to obtain statistical results, and then a histogram can be drawn based on the statistical results.

[0121] Specifically, based on the M color difference values, a histogram is constructed, including: performing statistics on the M color difference values ​​to obtain statistical results, the statistical results including at least one of the following: the maximum color difference value among the M color difference values, the minimum color difference value among the M color difference values, the number of color difference values ​​among the M color difference values ​​in the range [n, j], or the number of color difference values ​​among the M color difference values ​​that are greater than or equal to a preset threshold, where 0 < n < j; and constructing a histogram based on the statistical results.

[0122] For example, the number of color difference values ​​in the range [n, j] among M color difference values ​​can include: the number of color difference values ​​in the range of 1 to 2 among M color difference values, the number of color difference values ​​in the range of 2 to 3 among M color difference values, the number of color difference values ​​in the range of 3 to 4 among M color difference values, and so on.

[0123] The process of constructing a histogram as described above can be referred to as a data analysis process.

[0124] In this embodiment of the application, the user can view the display of the acquired M sampled tristimulus values ​​in the color gamut coordinates through an application (APP).

[0125] Figure 2 This is a schematic diagram of the user interface provided in this application. For example... Figure 2 As shown, by clicking the "Select Data" button, the user can obtain M sampled tristimulus values. For example, by switching different display screens through a pattern generator (PG), and then measuring the optical data of the display screen through an optical device, M sampled tristimulus values ​​can be obtained.

[0126] like Figure 2 As shown, the first row of the user interface includes buttons for selecting data, G255 target brightness, standard color gamut, stereo color gamut space, generating graphics, and saving data; the second row includes buttons for planar color gamut display, stereo color gamut display, stereo color gamut comparison analysis, and data analysis. For example, Figure 2 The XYZ diagram, CIE1931 color gamut, 2D color gamut, and 3D color gamut displayed are the interfaces that appear after clicking the "Plane Color Gamut Display" button.

[0127] exist Figure 2The user interface allows users to import data by clicking the "Select Data" button. The M sampled tristimulus values ​​will be referred to as measurement data. Next, the target brightness value for G255 is set, and the standard color gamut and stereo color gamut space are selected. It should be understood that users can choose not to select either the standard or stereo color gamut space; in this case, the default standard and stereo color gamut spaces will be used. Clicking the "Generate Graph" button will then display all the graphs and calculated data on the user interface. Users can switch between other standard or stereo color gamut spaces by clicking the corresponding buttons.

[0128] It should be noted that if the selected standard color gamut or solid color gamut space changes, the graphics and calculations corresponding to the previously selected standard color gamut and solid color gamut space on the user interface will be cleared. After obtaining the graphics and calculations, users can click the "Save Data" button to save the obtained data and graphics to a Word document for viewing and subsequent analysis.

[0129] The standard color gamut can include sRGB, DCI-P3, D65-P3, D60-P3, AdobeRGB1988, and BT.2020. The stereo color gamut space is the color appearance model mentioned above, which can include CIELab and CAM16 models.

[0130] In this embodiment of the application, if the user clicks the "Generate Data" button without selecting any data, the following will appear on the user interface: Figure 3 The error dialog box shown reads "ERROR: please choose input data!!!".

[0131] If the user closes the app, the following will appear on the user interface: Figure 4 The program exit process is shown to prompt the user "Are you sure you want to exit the program?" If the user is sure they want to exit, they can click the "OK" button; if the user does not want to exit, they can click the "Cancel" button. This can prevent the user from accidentally clicking the close button.

[0132] If a user clicks the "Save Data" button before any graph has been generated, and no data or graph has been created yet, the user interface will display an error message like this: Figure 5 The error dialog box shown prompts the user with "Error: No data saved or click the <Generate Graph> button to regenerate the data." The user can click the "OK" button to continue generating the graph.

[0133] The first example uses a liquid crystal display (LCD) screen as an example to illustrate the graphic display results of evaluating the color gamut of an LCD screen using the above-mentioned screen evaluation method. In this example, the target brightness of G255 is 700, the selected standard color gamut is sRGB, the stereo color gamut space is CIELab, and the histogram step size is 5.

[0134] Figure 6 This is a schematic diagram of a planar color gamut display of an LCD screen provided in an embodiment of this application. For example... Figure 6 As shown, the XYZ diagram displays the input measurement data in 3D space; the CIE1931 color gamut diagram is a comparison of the display's color gamut and the standard color gamut in the horseshoe diagram. The black line represents the display's color gamut (or measurement data), the white line represents the standard color gamut sRGB, the yellow line represents the standard color gamut AdobeRGB1988, the blue line represents the standard color gamut DCI-P3, D65-P3, or D60-P3, and the purple line represents the standard color gamut BT.2020. The 2D gamut is a diagram showing the coverage between the standard color gamut sRGB and the display's color gamut. Blue represents the measurement data, red represents the standard color gamut sRGB, and the display's color gamut covers 115.7707% of the standard color gamut. The 3D gamut is a comparison of the measurement data's color gamut at each grayscale value with the standard color gamut. Pink represents the measurement data, and black represents the standard color gamut sRGB.

[0135] Figure 7 This is a schematic diagram of a stereoscopic color gamut display of an LCD screen provided in an embodiment of this application. For example... Figure 7 As shown, the dot plot is the display of the first color appearance data Lab obtained after analyzing the color appearance attributes of the measurement data based on the CIELab stereo color gamut space. The volume of this dot plot is 486430. The grid plot is the space occupied by the LCD display screen in the stereo color gamut space. The color map can be understood as the first color gamut map mentioned above, which is the display image after the measurement data has been color-rendered. The color gamut ring is the first color gamut ring map mentioned above, which is a two-dimensional display of the first color gamut map. Each color gamut ring represents a different brightness, and the arrows represent different hues.

[0136] Figure 8 This is a schematic diagram illustrating a stereoscopic color gamut comparison analysis of an LCD display screen provided in an embodiment of this application. For example... Figure 8As shown, the diagram corresponding to the standard color gamut is the second dot plot mentioned above, and the diagram corresponding to the measured data color gamut is the first dot plot mentioned above. The comparison diagram between the standard color gamut and the measured color gamut is the comparison diagram between the first dot plot and the second dot plot. The diagram corresponding to the standard color gamut ring is the second color gamut ring diagram mentioned above, and the diagram corresponding to the measured data color gamut ring is the first color gamut ring diagram mentioned above. The comparison diagram between the standard color gamut ring and the measured color gamut ring is the comparison diagram between the first color gamut ring diagram and the second color gamut ring diagram, from which the comparison between the display screen's color gamut and the standard color gamut can be seen. Then, the volume of the standard color gamut (i.e., the second volume mentioned above) can be calculated as 830732.36, and the volume of the intersection between the display screen's color gamut and the standard color gamut (i.e., the first volume mentioned above) is 486429.7304. Therefore, the volume ratio between the display screen's color gamut and the standard color gamut is 52.1575%, that is, the first value is 52.1575%.

[0137] Figure 9 This is a schematic diagram illustrating data analysis of an LCD display screen provided in an embodiment of this application. For example... Figure 9 As shown, among the M color difference values, the maximum value of DE2000 is 69.831, the minimum value of DE2000 is 0, the average value of DE2000 is 25.5205, the number of DE2000 values ​​in the range [0,1] is 3, the number of DE2000 values ​​in the range [1,2] is 7, the number of DE2000 values ​​in the range [2,3] is 3, the number of DE2000 values ​​in the range [3,4] is 8, and the number of DE2000 values ​​greater than 5 is 581.

[0138] The second example, still using an LCD display as an example, explains the graphic display results of evaluating the color gamut of an LCD display using the above display evaluation method. In this example, the target brightness of G255 is 700, the selected standard color gamut is DCI-P3, the stereo color gamut space is CAM16, and the histogram step size is 3.

[0139] Figure 10 This is a schematic diagram of another planar color gamut display of the LCD screen provided in the embodiments of this application. For example... Figure 10As shown, the XYZ diagram displays the input measurement data in 3D space; the CIE1931 color gamut diagram is a comparison of the display's color gamut and the standard color gamut in the horseshoe diagram. The black line represents the display's color gamut (or measurement data), the white line represents the standard color gamut sRGB, the yellow line represents the standard color gamut AdobeRGB1988, the blue line represents the standard color gamut DCI-P3, D65-P3, or D60-P3, and the purple line represents the standard color gamut BT.2020. The 2D gamut is a diagram showing the coverage between the standard color gamut sRGB and the display's color gamut. Blue represents the measurement data, red represents the standard color gamut sRGB, and the display's color gamut covers 85.26% of the standard color gamut. The 3D gamut is a comparison of the measurement data's color gamut at each grayscale value with the standard color gamut. Pink represents the measurement data, and black represents the standard color gamut sRGB.

[0140] Figure 11 This is a schematic diagram illustrating another type of stereoscopic color gamut display of the LCD screen provided in this application embodiment. For example... Figure 11 As shown, the dot plot is the display of the first color appearance data Lab obtained after analyzing the color appearance attributes of the measurement data based on the CIELab stereo color gamut space. The volume of this dot plot is 338775. The grid plot is the space occupied by the LCD display screen in the stereo color gamut space. The color map can be understood as the first color gamut map mentioned above, which is the display image after the measurement data has been color-rendered. The color gamut ring is the first color gamut ring map mentioned above, which is a two-dimensional display of the first color gamut map. Each color gamut ring represents a different brightness, and the arrows represent different hues.

[0141] Figure 12 This is a schematic diagram illustrating another type of stereoscopic color gamut comparison analysis of the LCD display screen provided in this application embodiment. For example... Figure 12 As shown, the diagram corresponding to the standard color gamut is the second dot plot mentioned above, and the diagram corresponding to the measured data color gamut is the first dot plot mentioned above. The comparison diagram between the standard color gamut and the measured color gamut is the comparison diagram between the first dot plot and the second dot plot. The diagram corresponding to the standard color gamut ring is the second color gamut ring diagram mentioned above, and the diagram corresponding to the measured data color gamut ring is the first color gamut ring diagram mentioned above. The comparison diagram between the standard color gamut ring and the measured color gamut ring is the comparison diagram between the first color gamut ring diagram and the second color gamut ring diagram, from which the comparison between the display screen's color gamut and the standard color gamut can be seen. Then, the volume of the standard color gamut (i.e., the second volume mentioned above) can be calculated as 420329.7537, and the volume of the intersection between the display screen's color gamut and the standard color gamut (i.e., the first volume mentioned above) is 338775.2711. Therefore, the volume ratio between the display screen's color gamut and the standard color gamut is 79.665%, that is, the first value is 79.665%.

[0142] Figure 13This is a schematic diagram illustrating another type of data analysis for the LCD display screen provided in an embodiment of this application. For example... Figure 13 As shown, among the M color difference values, the maximum value of DE2000 is 47.6105, the minimum value of DE2000 is 0.053136, the average value of DE2000 is 21.1764, the number of DE2000 values ​​in the range [0,1] is 1, the number of DE2000 values ​​in the range [1,2] is 1, the number of DE2000 values ​​in the range [2,3] is 2, the number of DE2000 values ​​in the range [3,4] is 5, and the number of DE2000 values ​​greater than 5 is 593.

[0143] This application also provides a display screen color gamut evaluation system.

[0144] Figure 14 This is a schematic block diagram of a display screen color gamut evaluation system 1400 provided in an embodiment of this application. The system 1400 may include: an acquisition module 1410 and a processing module 1420.

[0145] The acquisition module 1410 is used to acquire M sampled tristimulus values ​​that correspond one-to-one with M display screens. The M display screens correspond one-to-one with M RGB values. Among the M RGB values, at least one RGB value is not 255. M is an integer greater than or equal to 3.

[0146] The processing module 1420 is used to obtain M first chromaticity data and M second chromaticity data based on M sampled tristimulus values ​​and M standard tristimulus values. The M standard tristimulus values ​​are tristimulus values ​​in the standard color gamut. The M first chromaticity data correspond one-to-one with the M sampled tristimulus values, and the M second chromaticity data correspond one-to-one with the M standard tristimulus values.

[0147] The processing module 1410 is further configured to obtain M color difference values ​​based on M first color appearance data and M second color appearance data, wherein the M color difference values ​​are used to indicate the color difference between the M first color appearance data and the M second color appearance data; and to construct a histogram based on the M color difference values, wherein the histogram is used to represent the color difference distribution between the display color gamut and the standard color gamut.

[0148] In addition, system 1400 may also include any other modules configured for display color gamut evaluation according to embodiments of the present disclosure as described above.

[0149] The system 1400 can implement the steps or processes corresponding to the method embodiments according to the embodiments of this application. The system 1400 may include modules for performing the method embodiments. Furthermore, each module in the system 1400 and the other operations and / or functions described above are respectively for implementing the corresponding processes of the method embodiments.

[0150] It should be understood that the specific process of each module performing the above-mentioned steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0151] Figure 15 This is a schematic block diagram of a display screen color gamut evaluation device 1500 provided in an embodiment of this application. The device 1500 may include a processor 1510. Optionally, the device 1500 may further include a memory 1520 storing computer-executable instructions.

[0152] The processor 1510 is used to acquire M sampled tristimulus values ​​corresponding one-to-one with M display images, where each of the M display images corresponds to one of the M RGB values, and at least one of the M RGB values ​​is not 255, where M is an integer greater than or equal to 3; based on the M sampled tristimulus values ​​and M standard tristimulus values, it obtains M first color appearance data and M second color appearance data, where the M standard tristimulus values ​​are tristimulus values ​​in the standard color gamut, and the M first color appearance data corresponds one-to-one with the M sampled tristimulus values, and the M second color appearance data corresponds one-to-one with the M standard tristimulus values; based on the M first color appearance data and M second color appearance data, it obtains M color difference values, which are used to indicate the color difference between the M first color appearance data and the M second color appearance data; and based on the M color difference values, it constructs a histogram, which is used to represent the color difference distribution between the display color gamut and the standard color gamut.

[0153] The memory 1520 can be used to store program code and data for executing the method embodiments of the present application.

[0154] It should be understood that the processor 1510 may also perform any other steps / processes of the display color gamut evaluation method according to the embodiments of the present disclosure as described above.

[0155] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the methods in any of the above embodiments.

[0156] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0157] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0158] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0159] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0160] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0161] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0162] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for evaluating the color gamut of a display screen, characterized in that, The method includes: Obtain M sampled tristimulus values ​​that correspond one-to-one with M display images, wherein the M display images correspond one-to-one with M RGB values, and at least one of the M RGB values ​​is not 255, and M is an integer greater than or equal to 3; Based on the M sampled tristimulus values ​​and M standard tristimulus values, M first color appearance data and M second color appearance data are obtained. The M standard tristimulus values ​​are tristimulus values ​​in the standard color gamut. The M first color appearance data correspond one-to-one with the M sampled tristimulus values, and the M second color appearance data correspond one-to-one with the M standard tristimulus values. Based on the M first color appearance data and the M second color appearance data, M color difference values ​​are obtained, and the M color difference values ​​are used to indicate the color difference between the M first color appearance data and the M second color appearance data; Based on the M color difference values, a histogram is constructed, which is used to represent the color difference distribution between the display screen color gamut and the standard color gamut.

2. The method according to claim 1, characterized in that, The process of obtaining M first color appearance data and M second color appearance data based on the M sampled tristimulus values ​​and M standard tristimulus values ​​includes: Choose a color appearance model; Based on the color appearance model, color appearance attribute analysis is performed on the M sampled tristimulus values ​​and the M standard tristimulus values ​​to obtain the M first color appearance data and the M second color appearance data.

3. The method according to claim 1 or 2, characterized in that, The acquisition of the M tristimulus values ​​corresponding one-to-one with the M display screens includes: Select K grayscale values, where K is an integer greater than or equal to 2; Based on the K grayscale values, the M RGB values ​​are determined, and the M RGB values ​​correspond one-to-one with the M tristimulus values, where M=K. 3 ; Based on the M RGB values, the M display images are constructed, and the M display images are collected to obtain the M sampled tristimulus values.

4. The method according to any one of claims 1 to 3, characterized in that, The method further includes: Based on the M first color appearance data, a first point map of the M first color appearance data is constructed in the color gamut coordinates; Based on the M second color appearance data, a second point map of the M second color appearance data is constructed in the color gamut coordinates; Based on the first dot plot and the second dot plot, a first value is determined, which indicates the proportion of the color gamut of the display screen in the standard color gamut.

5. The method according to claim 4, characterized in that, Determining the first value based on the first point map and the second point map includes: Based on the first point map and the second point map, determine the first volume of the intersection of the first point map and the second point map; Based on the first volume and the second volume, the first value is determined, where the second volume is the volume of the second dot plot.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: Based on the M first color appearance data, a first color gamut ring diagram of the M first color appearance data is constructed in the color gamut coordinates; Based on the M second color appearance data, a second color gamut ring diagram of the M second color appearance data is constructed in the color gamut coordinates; Based on the first color gamut ring diagram and the second color gamut ring diagram, the coverage range of the color gamut of the display screen in the standard color gamut is determined.

7. The method according to claim 6, characterized in that, The step of constructing a first color gamut ring map of the M first color appearance data in color gamut coordinates includes: Based on the M first color appearance data, a first color gamut map of the M first color appearance data is constructed in the color gamut coordinates; Convert the first color gamut map into the first color gamut ring map; The step of constructing a second color gamut ring diagram of the M second color appearance data in color gamut coordinates includes: Based on the M second color appearance data, a second color gamut map of the M second color appearance data is constructed in the color gamut coordinates; Convert the second color gamut map into the second color gamut ring map.

8. The method according to any one of claims 1 to 7, characterized in that, The method further includes: Based on the M RGB values, a grid diagram of the M sampled tristimulus values ​​is constructed in the color gamut coordinates.

9. The method according to claim 8, characterized in that, The step of constructing a grid of the M sampled tristimulus values ​​in the color gamut coordinates based on the M RGB values ​​includes: Based on the M RGB values, a first matrix and a second matrix are constructed. The elements of the first matrix and the second matrix include the M RGB values. The dimensions of the first matrix and the second matrix are both M. 2 ×1; Construct a third matrix based on the first matrix, the second matrix, the all-zero matrix, and the all-one matrix; Based on the third and fourth matrices, the reference triangles included in each face of the mesh are obtained. The row elements of the fourth matrix are used to indicate the vertices of the reference triangles. The dimension of the fourth matrix is ​​T×3, and the value of T is 6×M×M. The mesh diagram is constructed based on the reference triangles included in each face of the mesh diagram.

10. The method according to any one of claims 3 to 9, characterized in that, The method further includes: Based on the M sampled tristimulus values, a color gamut triangle diagram corresponding to the K grayscale values ​​is constructed in the color gamut coordinates; Based on the M standard tristimulus values, a standard color gamut triangle is constructed in the color gamut coordinates.

11. The method according to any one of claims 1 to 10, characterized in that, The process of constructing a histogram based on the M color difference values ​​includes: The M color difference values ​​are statistically analyzed to obtain statistical results, which include at least one of the following: The maximum color difference value among the M color difference values, the minimum color difference value among the M color difference values, the number of color difference values ​​in the range [n, j] among the M color difference values, or the number of color difference values ​​among the M color difference values ​​that are greater than or equal to a preset threshold, wherein 0 < n < j; Based on the statistical results, the histogram is constructed.

12. A display screen color gamut evaluation system, characterized in that, The system includes: The acquisition module is used to acquire M sampled tristimulus values ​​that correspond one-to-one with M display screens. The M display screens correspond one-to-one with M RGB values. Among the M RGB values, at least one RGB value is not 255, and M is an integer greater than or equal to 3. The processing module is used to obtain M first color appearance data and M second color appearance data based on the M sampled tristimulus values ​​and M standard tristimulus values. The M standard tristimulus values ​​are tristimulus values ​​in the standard color gamut. The M first color appearance data correspond one-to-one with the M sampled tristimulus values, and the M second color appearance data correspond one-to-one with the M standard tristimulus values. The processing module is configured to obtain M color difference values ​​based on the M first color appearance data and the M second color appearance data, wherein the M color difference values ​​are used to indicate the color difference between the M first color appearance data and the M second color appearance data; and Based on the M color difference values, a histogram is constructed, which is used to represent the color difference distribution between the display screen color gamut and the standard color gamut.

13. A display screen color gamut evaluation device, characterized in that, include: processor; as well as A memory storing computer-executable instructions, which, when executed, cause the processor to perform the method as described in any one of claims 1 to 11.

14. A computer-readable storage medium, characterized in that, It stores a computer program thereon, which, when executed by a processor, implements the method as described in any one of claims 1 to 11.

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