Color value calibration method and device of display panel, equipment and medium

Abstract

The invention discloses a color value calibration method and device of a display panel, equipment and a medium, and generally relates to the technical field of display panels. The method comprises the following steps: determining two actual color values meeting the color similarity condition of the reference color value; determining a first color space value of the reference color value in a standard color space and two color space values of the two actual color values in the standard color space, and determining a correction parameter of the reference color value based on the first color space value and the two color space values; the correction parameter is used for representing a reference color value in the standard color space and satisfying a spatial position of reference linear distribution, and the reference linear distribution is used for representing a spatial linear relation of two color space values of the two actual color values in the standard color space; and correcting the reference color value according to the correction parameter to obtain an actual color value of the reference color value.

Description

Technical Field

[0001] The present disclosure generally relates to the field of display panel technology, and more particularly to a method, device, equipment and medium for calibrating color values ​​of a display panel. Background Art

[0002] With the development of electronic technology, the display technology of electronic equipment is also developing continuously.

[0003] There are many important attributes in display technology, among which the color accuracy of the display is an important attribute related to the user experience. In order to ensure color accuracy, it is generally necessary to set the color accuracy reference points of the display panel and set standard chromaticity values ​​for these reference points. Then, by calculating the actual chromaticity value of the display panel at the reference point and comparing the actual chromaticity value with the standard chromaticity value, the offset of the actual chromaticity value can be obtained, and the chromaticity value of the display panel can be corrected.

[0004] However, in the above process, in order to ensure the accuracy of the chromaticity value correction of the display panel, it is often necessary to calculate a large number of actual chromaticity values ​​and perform comparisons, which consumes a lot of resources. Summary of the invention

[0005] In view of the above-mentioned defects or deficiencies in the related art, it is desired to provide a method, device, equipment and medium for color value calibration of a display panel, which can solve the problem that the current determination of the reference point often requires calculating a large number of actual chromaticity values ​​and comparing them, which consumes a lot of resources and can greatly reduce the time spent on determining the reference point.

[0006] In a first aspect, a method for calibrating a color value of a display panel is provided, the method comprising: Determine two actual color values ​​that satisfy a color similarity condition of the reference color value; Determine a first color space value of the reference color value in a standard color space, and two color space values ​​of the two actual color values ​​in the standard color space, and determine a correction parameter of the reference color value based on the first color space value and the two color space values; the correction parameter is used to characterize a spatial position of the reference color value in the standard color space and satisfies a reference linear distribution, and the reference linear distribution is used to characterize a spatial linear relationship between the two color space values ​​of the two actual color values ​​in the standard color space; The reference color value is corrected according to the correction parameter to obtain an actual color value of the reference color value.

[0007] In the present application, when it is necessary to determine the reference color value of the display panel, first determine two actual color values ​​that meet the color similarity condition of the reference color value; then determine the first color space value of the reference color value in the standard color space and the two color space values ​​of the two actual color values ​​in the standard color space, and determine the correction parameter of the reference color value (the correction parameter is used to characterize the spatial position of the reference color value in the standard color space and meets the reference linear distribution, and the reference linear distribution is used to characterize the spatial linear relationship between the two color space values ​​of the two actual color values ​​in the standard color space); finally, correct the reference color value according to the correction parameter to obtain the actual color value of the reference color value. In this way, in the process of determining the reference color value of the display panel, the color space values ​​of the two color values ​​that meet the color similarity condition of the actual color value that have been determined can be used to assist in correcting the actual color value of the reference color value. In addition, there is no need to obtain the actual color values ​​of all the reference color values ​​by measurement, which greatly saves the time for determining the actual color value of the reference color value of the display panel and improves the efficiency of determining the actual color value of the reference color value of the display panel.

[0008] In a second aspect, a color value calibration device for a display panel is provided, the device comprising: A determination unit, configured to determine two actual color values ​​that satisfy a color similarity condition of the reference color value; The determination unit is further used to determine a first color space value of the reference color value in a standard color space, and two color space values ​​of the two actual color values ​​in the standard color space, and determine a correction parameter of the reference color value based on the first color space value and the two color space values; the correction parameter is used to characterize a spatial position of the reference color value in the standard color space and satisfies a reference linear distribution, and the reference linear distribution is used to characterize a spatial linear relationship between the two color space values ​​of the two actual color values ​​in the standard color space; An acquiring unit is used to calibrate the reference color value according to the calibration parameter to obtain an actual color value of the reference color value.

[0009] In a third aspect, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method described in the first aspect is implemented.

[0010] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, characterized in that when the program is executed by a processor, the method described in the first aspect is implemented.

[0011] In a fifth aspect, a computer program product is provided. The computer program product includes instructions, and the instructions are executed by a processor to implement the method described in the first aspect.

[0012] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 A schematic diagram of a flow chart of a color calibration method for a display panel provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of a color calibration system for a display panel provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of a color calibration device for a display panel provided in an embodiment of the present application; Figure 4 A schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0014] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0015] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The applicable scenarios of the present application will be described below.

[0016] Nowadays, electronic devices have more and more display functions and the viewing quality is constantly improving. In order to quantify the display color, color accuracy has been widely accepted as an indicator to measure whether the display color matches the standard color gamut. There are many ways to solve the problem of color accuracy failure, such as photoelectric curve calibration, color temperature adjustment calibration, 3D-LUT calibration or other algorithm calibration.

[0017] The principle of 3D-LUT calibration algorithm is as follows: the native characteristics of display devices are not standard and their performance varies. Each standard color space defines the color performance that each point in the three RGB channels should present. The three stimulus values ​​x, y, and z in CIE1931 are used to objectively and uniformly define the colors of different display devices. In order to enable the display device to be tested to better display standard colors and be calibrated to standard colors, people invented 3D-LUT based on the three stimulus values ​​of CIE1931. It can map the reference pixel points of the three RGB channels of the display panel to new corresponding points between partitions. The effect after mapping is close to the requirements of standard colors, and the color accuracy of the three RGB channels can be adjusted.

[0018] Usually, the number of reference color values ​​of the three channels R×G×B can be 33×33×33 or 17×17×17, etc., with various evenly distributed reference points. It can be understood that after the color value of the reference color value is determined, the reference color value can be used to obtain any target color value in the three channels RGB of the display device by interpolation. Since the target color value is between any two reference color values ​​closest to the target color value, the target color value has a color accuracy reference, and the color accuracy of any target color value can be accurately obtained.

[0019] From the above content, we can know that the more points are selected, the closer the mapped color is to the standard. However, the more points are selected, the more computing resources are consumed, which puts greater demands or burdens on the chip. At the same time, too few points will not produce a good correction effect. Therefore, selecting appropriate reference pixel points is an important basis for ensuring the accuracy of the display panel's chromaticity value correction. How to obtain the most appropriate reference color value so that the display panel can accurately determine the color accuracy of any reference color value while consuming the least resources is very important for the high-quality color display of the display panel.

[0020] Based on this, the present application proposes a method, device, equipment and medium for calibrating the color value of a display panel, which can solve the problem that the current determination of the reference point often requires calculating a large number of actual chromaticity values ​​and comparing them, which consumes a lot of resources and can greatly reduce the time spent on determining the reference point.

[0021] Figure 1 1 is a flow chart of a method for calibrating the color value of a display panel provided by an embodiment of the present application, the method comprising the following steps: Step 301: Determine two actual color values ​​that satisfy the color similarity condition of the reference color value.

[0022] In the embodiment of the present application, the above-mentioned reference color value may be a reference color value to be confirmed and corrected in the display panel.

[0023] In the embodiment of the present application, the above-mentioned reference color values ​​can be preset, and each display panel can be set with a different number of reference color values ​​according to user needs.

[0024] In the embodiment of the present application, the reference color value is a signal value of the display color set by the display panel. For example, the reference color value is (0, 0, 64), that is, the display panel needs to display the color indicated by (0, 0, 64) according to the signal value.

[0025] It can be understood that, for the display panel, assuming that the display panel is a completely ideal display panel, then, according to the preset theoretical reference color value, the display panel should display the color indicated by the theoretical reference color value completely. For example, if the theoretical reference color value is (0, 0, 64), the ideal display panel should display the color indicated by (0, 0, 64). That is, when the display panel is completely ideal, all reference color values ​​are linearly and evenly distributed, for example, (0, 0, 0), (0, 0, 32), (0, 0, 64), (0, 0, 96), (0, 0, 128), and so on.

[0026] However, in reality, there will always be certain deviations in the manufacturing process of the display panel. After assigning the above theoretical reference color value to it, it will not be displayed according to the theoretical reference color value. For example, it is assigned a value of (0, 0, 128), and its actual displayed color value is (0, 0, 120). In order to make the reference color value display according to its preset theoretical value, for example, according to the above (0, 0, 128), it is necessary to correct the reference color value. For example, through measurement, it can be known that the color value displayed by (0, 0, 132) is the color value that the theoretical reference color value (0, 0, 128) should display. Since each reference color value has such a display deviation, the present application needs to obtain the actual color value actually corresponding to the above reference color value by calculation. Therefore, these reference color values ​​can be used to locate other color values.

[0027] Furthermore, it is understood that the more the above-mentioned reference color values ​​are, the more accurate and detailed the display panel will be. Different display panels can set different numbers of reference color values. The higher the chromaticity fineness required by the display panel, the more the number of reference color values; correspondingly, the lower the chromaticity fineness required by the display panel, the fewer the number of reference color values.

[0028] For example, the reference color values ​​required by the display panel may include 5×5×5 signal values ​​(125 signal values), 9×9×9 signal values ​​(792 signal values), or 17×17×17 signal values ​​(4913 signal values).

[0029] Furthermore, the reference color value may be indicated by a pixel value (RGB).

[0030] In the embodiment of the present application, the above two actual color values ​​are color values ​​predicted in advance.

[0031] In the embodiment of the present application, the above color similarity condition is used to represent: two actual color values ​​closest to the reference color value.

[0032] It is understood that the above-mentioned reference color value refers to: the reference color value to be determined and corrected in this application. The theoretical value of the reference color value has been determined, but the actual color value corresponding to the theoretical value of the reference color value needs to be obtained by calculation. The above-mentioned two actual color values ​​are used to confirm the actual color value of the reference color value. Please refer to the subsequent description for details.

[0033] Furthermore, several, that is, multiple actual color values ​​may be preset in advance, from which two actual color values ​​that meet the color pixel condition are selected.

[0034] Step 302: Determine a first color space value of the reference color value in a standard color space, and two color space values ​​of the two actual color values ​​in the standard color space, and determine correction parameters of the reference color value based on the first color space value and the two color space values.

[0035] In the embodiment of the present application, the correction parameter is used to characterize the spatial position of the reference color value in the standard color space and satisfying the reference linear distribution.

[0036] In the embodiment of the present application, the reference linear distribution is used to characterize the spatial linear relationship between the two color space values ​​of the two actual color values ​​in the standard color space.

[0037] It can be understood that in the embodiment of the present application, in order to determine the actual color value of the above-mentioned reference color value, it is necessary to convert the reference color value and the two actual color values ​​into a standard color space, in which the spatial distribution relationship between the reference color value and the two actual color values ​​can be obtained, that is, the spatial position of the reference color value is obtained through the spatial linear relationship between the two accurate actual color values, and then the correction parameters of the reference color value are determined.

[0038] In an example, the standard color space may be CIE1931, and the reference color value RGB may be converted into XYZ in CIE1931.

[0039] In the embodiment of the present application, the above color value is RGB, and the color space value is the color space value in CIE1931. The color value and the color space value may correspond to each other.

[0040] Assume that the base color value is , the standard color space is CIE1931, then the first color space value of the reference color value in the linear relationship of CIE1931 is ( ), and the two are transformed through preset transformation parameters, as shown in the following formula 1.

[0041] Formula 1 Correspondingly, the above two actual color values ​​are and , accordingly, the color space values ​​of these two actual color values ​​in the standard color space are ( )and( ).

[0042] It should be noted that the positional relationship between the reference color value and the above two actual color values ​​in the standard color space is not limited. For example, the two actual color values ​​can be the upper adjacent point and the lower adjacent point of the reference color value respectively; the two actual color values ​​can both be the upper adjacent point of the reference color value; the two actual color values ​​can both be the lower adjacent point of the reference color value.

[0043] In an embodiment of the present application, the above-mentioned standard color space can spatialize the above-mentioned color values, and each color value corresponds to a position in the standard color space. Then, by comparing the first color space value of the reference color value in the standard color space and the positional relationship between the two color space values ​​of the two actual color values ​​in the standard color space, the relative position of the reference color value compared to the actual color value can be obtained, thereby correcting the reference color value.

[0044] Step 303: Correct the reference color value according to the correction parameter to obtain the actual color value of the reference color value.

[0045] It can be understood that since the standard color space is used to make the color value space of the two-dimensional space three-dimensional, the above-mentioned correction parameters can be obtained by converting the color values ​​into the standard color space. Since the standard color space corresponds to the color values ​​of the two-dimensional space, the above-mentioned reference color values ​​can be corrected by the correction parameters.

[0046] In the method provided by the embodiment of the present application, when it is necessary to determine the reference color value of the display panel, first determine two actual color values ​​that meet the color similarity condition of the reference color value; then determine the first color space value of the reference color value in the standard color space and the two color space values ​​of the two actual color values ​​in the standard color space, and determine the correction parameter of the reference color value (the correction parameter is used to characterize the spatial position of the reference color value in the standard color space and meets the reference linear distribution, and the reference linear distribution is used to characterize the spatial linear relationship between the two color space values ​​of the two actual color values ​​in the standard color space); finally, correct the reference color value according to the correction parameter to obtain the actual color value of the reference color value. In this way, in the process of determining the reference color value of the display panel, the color space values ​​of the two color values ​​that meet the color similarity condition of the actual color value that have been determined can be used to assist in correcting the actual color value of the reference color value. In addition, there is no need to obtain the actual color values ​​of all the reference color values ​​by measurement, which greatly saves the time for determining the actual color value of the reference color value of the display panel and improves the efficiency of determining the actual color value of the reference color value of the display panel.

[0047] In another embodiment of the present application, a specific implementation method for obtaining the correction parameters is also provided. Exemplarily, the specific implementation of "determining the correction parameters of the reference color value based on the first color space value and the two color space values" mentioned above includes: obtaining the first difference between the two color space values, and the second difference between the first color space value and any color space value of the two color space values; determining the correction parameters of the reference color value according to the ratio of the second difference to the first difference.

[0048] It can be understood that in order to determine the correction parameters of the first color space value corresponding to the reference color value based on the two color space values ​​corresponding to the actual color value in the standard color space, it is necessary to obtain the positional relationship between the first color space value and the two color space values ​​in the standard color space, that is, to determine the true, actual, and correct spatial position of the first color space value in accordance with and with reference to the reference linear distribution of the two color space values, that is, the true, actual, and correct reference linear distribution.

[0049] Exemplarily, the correction parameter may be represented by a linear ratio parameter between the first color space value and the two color space values, that is, the correction parameter of the reference color value may be represented by the ratio of the second difference value to the first difference value.

[0050] Optionally, in an embodiment of the present application, since the reference color value is composed of values ​​of three channels, it is necessary to calculate the correction parameters based on the three channels. Exemplarily, the above-mentioned obtaining of the first difference between the above-mentioned two color space values, and the second difference between the above-mentioned first color space value and any color space value of the above-mentioned two color space values, includes: obtaining each component value of the above-mentioned first color space value in each channel and each component value of the above-mentioned two color space values ​​in each channel; determining the first difference between each component value of the above-mentioned two color space values ​​and the second difference between each component value of the above-mentioned first color space value and each component value of any color space value of the above-mentioned two color space values, and determining each component ratio between the first difference between each component value and the second difference between each component value; the above-mentioned determining of the correction parameters of the above-mentioned reference color value according to the ratio of the above-mentioned second difference and the above-mentioned first difference includes: determining the correction parameters of the above-mentioned reference color value according to the above-mentioned each component ratio.

[0051] It can be understood that, in the embodiment of the present application, since the above-mentioned color space value also has component values ​​corresponding to each channel of the color value, therefore, in fact, the correction parameter should also be corrected for each channel of the color space value.

[0052] In an example, when the standard color space is CIE1931, in combination with the above two actual color values, the relationship between the reference color value and the actual color value is further expanded to the above formula 1 as follows:

[0053] Formula 1 in, That is and The difference between That is and The difference between That is and The difference between .

[0054] It is understandable that the reference pixel The R channel value is The R channel value of the point and the actual color value The R channel value of the point is The ratio of the R channel values ​​of the points is Represents; then the corresponding reference pixel point The G channel value is The G channel value of the point and the actual color value The G channel value of the point The ratio of the G channel values ​​of the points is Represents; reference pixel The B channel value is The B channel value of the point, and the actual color value The B channel value of the point The ratio of the B channel values ​​of the points is expressed as express,( ) is used to characterize the ratio between the reference pixel value and the two actual pixel values. Correspondingly, the color value is converted to the standard color space, then ( ) can characterize the relative position relationship between the reference pixel value and the two actual pixel values ​​in the standard color space.

[0055] Therefore, in the standard color space, since the standard color space is a linear space calculation, it can be considered that the following relationship exists: ; ； ； ； ； ； ； ；

[0056] In the case of the above relationship, as shown in the following formula 2, the correction parameters presented in the form of vectors are obtained through a standard color space with linear space properties, which are ( ), thereby obtaining the actual relative position relationship between the first color space value corresponding to the reference pixel value and the color space values ​​corresponding to the two actual pixel values ​​in the standard color space, so that the three values ​​in this vector indicating the actual relative position relationship can be used to correct the reference color value ( ).

[0057] Formula 2 In obtaining the above formula 2 ( ) After the calibration parameters of the three channels are obtained, the following formula ( )and and The relationship between the reference color value is used to obtain the actual color value of the reference color value, that is, the reference color value ( ) for correction.

[0058] Formula 3 Optionally, in an embodiment of the present application, as described above, two actual color values ​​can be obtained by screening, that is, a plurality of candidate color values ​​are pre-prepared, and two actual color values ​​are screened out as color values ​​for calculating correction parameters. Exemplarily, the above-mentioned determination of the two color space values ​​of the two actual color values ​​in the above-mentioned standard color space includes: determining a plurality of candidate color values ​​corresponding to each channel according to the component values ​​of each channel of the above-mentioned reference color value; the above-mentioned candidate color values ​​satisfy the single-channel color similarity condition of the above-mentioned reference color value; determining the candidate color space value of each of the above-mentioned candidate color values ​​in the above-mentioned standard color space, and determining the spatial distance between each of the above-mentioned candidate color space values ​​and the above-mentioned first color space value in the above-mentioned standard color space; after arranging the above-mentioned spatial distances in ascending order, the candidate color values ​​corresponding to the first two spatial distances are determined as the above-mentioned two actual color values.

[0059] It can be understood that in the embodiment of the present application, in order to ensure that the reference color value is accurately determined, the actual color values ​​of the color values ​​different from the reference color value in multiple display panels can be preset and measured in advance as candidate color values.

[0060] Furthermore, the color space values ​​corresponding to the above-mentioned candidate color values ​​can be evenly distributed in the standard color space. In this way, when it is necessary to confirm the correction parameters of any benchmark color value, among the multiple candidate color values ​​in the standard color space, two actual color values ​​for determining the correction parameters can be obtained near the first color space value corresponding to the benchmark color value.

[0061] For example, in the process of determining the candidate color values, since it is in a two-dimensional plane space, multiple candidate color values ​​that meet the single-channel color similarity condition of the reference color value can be determined first according to the component values ​​of each channel of the reference color value. For each channel, one or more candidate color values ​​can be determined, and the number of the candidate color values ​​can be preset or user-defined.

[0062] Afterwards, the candidate color space value corresponding to each candidate color value is confirmed, and the spatial distance between each candidate color space value and the first color space value in the standard color space is determined, and then the candidate color values ​​corresponding to the first two spatial distances after ascending order are selected as two actual color values.

[0063] For example, for the base color value For , , Confirm a candidate color value, and confirm three candidate color values ​​in total, which are , and . Then, determine the candidate color space values ​​of the three candidate color values, that is, ( )、( )and( Then, calculate ( )and( ) spatial distance, ( )and( ) spatial distance, ( )and( ) spatial distance. After arranging the three spatial distances in ascending order, the candidate color values ​​corresponding to the first two spatial distances are selected, that is, ( )、( ) corresponding to , As the base color value The two actual color values.

[0064] Optionally, in an embodiment of the present application, the actual color value can also be quickly determined according to actual needs. Exemplarily, the determination of two color space values ​​of two actual color values ​​in the standard color space includes: obtaining a third difference between the component value of the target channel and the component value of the target channel of the candidate color value according to the component value of the target channel in the reference color value; and determining the candidate color values ​​corresponding to the first two third differences after arranging the third differences in ascending order as the two actual color values.

[0065] Exemplarily, the candidate color value satisfies a single-channel color similarity condition of the reference color value.

[0066] It is understandable that for some display panels, the actual requirements may be higher for one of the three channels, that is, the target channel, or one of the three channels, that is, the target channel, can represent the reference pixel value to determine the color space value. Therefore, the difference between a component value of a target channel and a plurality of preset candidate color values, that is, the third difference value, can be determined, and then the third difference values ​​can be arranged in ascending order, and the candidate color values ​​corresponding to the first two third difference values ​​can be selected as the two actual color values.

[0067] Optionally, in an embodiment of the present application, after the reference color value is corrected according to the color ratio parameter to obtain the actual color value of the reference color value, the method further includes: obtaining an actual brightness value corresponding to the reference color value; obtaining a first ratio between the actual brightness value and a preset brightness value of the display panel corresponding to the reference color value; and updating the actual color value of the reference color value according to the first ratio and the actual pixel value of the reference color value.

[0068] It is understandable that after the actual color value of the reference color value is obtained by the interpolation calculation as mentioned above, the actual color value of the reference color value measured is likely to still be different from the ideal display chromaticity corresponding to the reference color value due to the consistency of the characteristics of the light source and / or the test standard light source. Therefore, the actual color value of the reference color value can be further updated and corrected again by using the brightness value of the brightness channel as a reference.

[0069] Exemplarily, the actual brightness value is a brightness value measured corresponding to the actual color value of the reference color value, that is, the display panel measures and obtains the brightness value of the display panel under the signal value corresponding to the actual color value.

[0070] Exemplarily, the above-mentioned preset brightness value refers to: a theoretical brightness value corresponding to the display panel under the reference color value, that is, an ideal brightness value that the display panel theoretically wants to obtain under the reference color value.

[0071] It can be understood that the relative relationship between the current actual brightness value and the ideal brightness value can be obtained through the first ratio between the actual brightness value corresponding to the above actual color value and the preset brightness value under ideal conditions, and the above actual color value can be corrected and updated through the relative relationship.

[0072] As described in the following example: Assume that the actual color value obtained is The actual color value is measured as , the preset brightness is Then the first ratio between the above display panels is , each actual color value can be updated according to the first ratio. Specifically, the updated actual color value is ( , , ), the calculation process is shown in the following formula 3.

[0073] , , Formula 4 Optionally, in an embodiment of the present application, before determining the correction parameters of the above-mentioned reference color value based on the above-mentioned first color space value and the above-mentioned two color space values, the above-mentioned method also includes: obtaining at least two preset brightnesses of the above-mentioned display panel, and performing normalization processing on the actual color value corresponding to the above-mentioned reference color value, so that the above-mentioned reference color value corresponds to a digital signal at at least two preset brightnesses of the above-mentioned display panel.

[0074] It is understandable that since display panels often have different display brightness, for example, a display panel with a brightness of 1000 nit or a display panel with a brightness of 500 nit, the color space values ​​corresponding to different display panels in the standard color space and the actual color values ​​of the reference color values ​​are different. In order to ensure that the color space values ​​corresponding to display panels with different brightness and the actual color values ​​of the reference color values ​​are unified, normalization processing can be used to make the same reference color value correspond to the same digital signal in display panels with different preset brightness.

[0075] Optionally, in an embodiment of the present application, the normalization processing is performed on the actual chromaticity value corresponding to the reference chromaticity so that the reference chromaticity corresponds to the same digital signal within the at least two preset brightnesses, including: according to the at least two preset brightnesses of the display panel, the actual chromaticity value corresponding to the reference chromaticity and the actual spatial color value corresponding to the reference chromaticity are respectively normalized so that the reference pixel points correspond to the same digital signal at the different preset brightnesses.

[0076] It can be understood that in order to help unify the color space values ​​corresponding to the display panels of different brightness and the actual color values ​​of the reference color values, the first brightness value corresponding to the actual color value of the display panel at the maximum color value can be obtained, and then the ratio of the first brightness value to the color space value of the reference color value in the standard color space can be obtained to determine the normalized reference color value.

[0077] As shown in the following example: The first brightness value corresponding to the actual color value of the display panel at the maximum color value is: the actual brightness value when the actual color value corresponding to (255, 255, 255) is , then, the normalized value corresponding to the above-mentioned reference color value is calculated by the first color space value corresponding to the reference color value, . Thus, after obtaining the normalized ( ) and you can get ( ) corresponds to the normalized . All are between 0 and 1.

[0078] Specifically, the normalized values ​​of the following reference pixel points may be obtained. They are the normalized X, Y, and Z components of the tested display when R=1, G=0, and B=0; They are the normalized X, Y, and Z components of the tested display when R=0, G=1, and B=0; They are the normalized X, Y, and Z components of the tested display when R=0, G=0, and B=1; , , The specific R, G, B values ​​when the measured display screen displays P0; , , The specific R, G, and B values ​​when the measured display shows P1.

[0079] The actual application process of the embodiment of the present application is described below.

[0080] First, the hardware entities that may be used in executing the above method in the embodiment of the present application are described as follows: like Figure 2 As shown, the color value calibration method of the display panel in the present application can be performed by a brightness colorimeter 21 for measuring the display device, a signal generator 22 and a process control device 23.

[0081] Among them, the above-mentioned brightness colorimeter 21 can be a CA-410 color analyzer, which is used to measure the actual brightness and chromaticity, for example, the color coordinates in the display panel 24 and the tristimulus values ​​corresponding to the color coordinates; the above-mentioned signal generator 22 can be a computer, or an embedded system or other device with a display panel, which can support customized and programmatic output of RGB three-channel values ​​to the display device, such as FPGA; the above-mentioned process control device 23 can be a computer or other embedded system, and the process control device 23 can be used to run the entire calibration process, and communicate with the signal generator 22 and the brightness colorimeter 21, control the signal generator 22 to output a specific signal at an appropriate time, and then obtain the value of the brightness colorimeter 21 and calculate.

[0082] In one example, the process control device 23 and the signal generator 22 may be the same device (eg, RK3399), or may be directly designed on an embedded system corresponding to the display panel 24 to be measured, so that the calibration process can be completed without external devices.

[0083] In the actual test process, the brightness colorimeter 21 can be fixed in the middle of the display panel 24 of the reference color point to be measured, and the process control device 23 and the signal generator are placed aside and connected with cables. Figure 2The brightness colorimeter 21 and the process control device 23 are connected via the serial port RS-232. It should be noted that the signal generator 22 and the process control device 23 are connected to each other via their respective chips. In fact, there can be multiple connection methods, which are not limited in the embodiment of the present application.

[0084] The specific display panel calibration method is as follows: Step 1: The display device 24 is in the measurement mode, and the EOTF electro-optical conversion function to be used for each reference color value to be measured is confirmed. The function is used to obtain the digital signal of each reference color value to be measured. Specifically, the input signal can be processed by the 1D-LUT method.

[0085] Step 2: The process control device 23 sends a command to the signal generator 22, so that the signal generator 22 determines all preset actual color values ​​(R, G, B) and the reference color value to be measured. In one example, assuming that the color depth of the digital signal is n, for the channel R in the reference color value, its maximum value is , the same is true for channel G and channel B in the reference color value. It should be noted that the above (R, G, B) are all normalized values. Taking the color depth of the digital signal as n, the number of pixel reference points calculated is m×m×m, and the maximum value of channel R is 2n-1. Since it is a normalized value, when determining adjacent pixel reference points, the three channels of RGB take 1 / (m-1) as the interval between the normalized and adjacent reference color values, and take 0 / (m-1), 1 / (m-1), 2 / (m-1),…,(m-2) / (m-1), (m-1) / (m-1). Since each channel can take m values, the three channels can take m×m×m combinations of RGB corresponding to the normalized pixel color values.

[0086] Step 3: The process control device 23 controls the signal generator 22 to output each of the above RGB combination values ​​and then controls the brightness colorimeter 21 to measure, and obtains the color space values ​​X, Y, and Z corresponding to each RGB, and repeats this process to traverse all m×m×m RGB combination values. In one example, all m×m×m RGB combination values ​​may not be calculated. Specifically, R=2n×0 / (m-1), 2n×1 / (m-1), 2n×2 / (m-1)…, 2n×(m-2) / (m-1), 2n -1 can be taken respectively, and at the same time, channel G and channel B are set to 0 to obtain these m points; similarly, the points of channel G and channel B are obtained, and in this way, m+m+m points are finally obtained, and all measured values ​​are obtained by combining using the linear characteristics of XYZ. For example, if RGB is {a, b, c}, then X(a, b, c) = X(a, 0, 0) + X(0, b, 0) + X(0, 0, c). The above method can also be used to obtain the X, Y, and Z values ​​of m×m×m pixel color values. This can greatly save calibration time. Step 4: After all the theoretical pixel reference points RGB that need to be corrected are converted to the standard color space, that is, the linear space (actually, the color representation observed by the human eye on the display device) through step 3, for each theoretical pixel reference point RGB value that needs to be corrected, because the EOTF electro-optical conversion curves followed by the various modes calibrated by the display panel 24 are different, an inverse conversion process needs to be performed to convert the optical signal of the theoretical pixel reference point that needs to be corrected into a digital electrical signal for the input signal generator 22. Taking the electro-optical conversion curve Gamma2.2 as an example, R 数字电信号 =R 光信号 1 / 2.2 Specifically, each standard has its own EOTF conversion curve and EOTF -1 The calculation method of .

[0087] Step 5: The XYZ of the standard color space can be converted through the matrix specified by the standard. Take the matrix BT.709 as an example. ; The above formula can be used to convert the RGB value of any point specified by the BT.709 color standard into an XYZ value, thus obtaining the theoretical XYZ normalized value of each reference pixel point in the target m×m×m.

[0088] Step 6: Take the calculation result XYZ of the above step 5 as the first color space value corresponding to the reference pixel point to be corrected, calculate the correction parameters through the above formulas 1 and 2 to help the theoretical XYZ of the reference pixel point to be corrected, and further correct it through the brightness channel through formula 3. Specifically, when calculating any pixel color value PT{a, b, c} to be corrected, take the reference color value with a color depth of n, m×m×m as an example, for each reference color value to be measured or corrected, the step value For the pixel color value PT{a, b, c} to be corrected, the two actual color values ​​are P0 and P1, where P0 is {a- , b- , c- }, P1 takes {a+ , b+ , c+ }. Thus, the RGB channel values ​​of PT are obtained according to Formula 1, Formula 2 and Formula 3. In short, each pixel color value PT is calculated by interpolating the upper and lower adjacent points of each channel. These adjacent points have been traversed and measured in the above step 2 to obtain the preset actual color values. When encountering the minimum value 0 or the maximum value 1, the body can be taken.

[0089] It should be noted that the calculated result may be a non-integer when P0 and P1 are taken according to the result. In this case, rounding or other rounding methods are used. If a negative value or a value greater than 1 is encountered, it should be truncated to 0 or 1.

[0090] Step 7: After all the reference pixels for confirmation and correction are calculated, an RGB correspondence table with an input of m×m×m and an output of m×m×m can be obtained.

[0091] Step 8: Output all the calibrated reference color values ​​through the signal generator 22, and backtest according to the standard color difference calculation method. If it is not accurate enough, the calibrated value can be mapped and the calibration process of the above steps 1 to 7 can be run again until it meets the required threshold range.

[0092] Step 9: Save the RGB correspondence table that has been corrected and meets the threshold range requirements, input it into the display device system, use it as the parameter of its 3D-LUT function module, and perform real-time calculations on the display device to interpolate the remaining points.

[0093] The present application also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the training rule determination method described in the present application is implemented. For example, the following can be executed: Figure 1 The individual steps of the method are shown.

[0094] The present invention provides a computer program product, which includes instructions that are executed by a processor when the processor executes the instructions. Figure 1 The individual steps of the method are shown.

[0095] It should be noted that although the operations of the method of the present invention are described in a particular order in the drawings, this does not require or imply that the operations must be performed in this particular order or that all illustrated operations must be performed to achieve desired results.

[0096] Figure 3 FIG. 1 is a block diagram of a credential requesting device according to an embodiment of the present application. The device may be deployed in an authorization node (eg, the first node described above). Figure 3 The device includes a determining unit 601 and an acquiring unit 602.

[0097] A determination unit, configured to determine two actual color values ​​that satisfy a color similarity condition of the reference color value; The determination unit is further used to determine a first color space value of the reference color value in a standard color space, and two color space values ​​of the two actual color values ​​in the standard color space, and determine a correction parameter of the reference color value based on the first color space value and the two color space values; the correction parameter is used to characterize a spatial position of the reference color value in the standard color space and satisfies a reference linear distribution, and the reference linear distribution is used to characterize a spatial linear relationship between the two color space values ​​of the two actual color values ​​in the standard color space; An acquiring unit is used to calibrate the reference color value according to the calibration parameter to obtain an actual color value of the reference color value.

[0098] In one embodiment, the determining unit 601 is specifically configured to obtain a first difference between the two color space values, and a second difference between the first color space value and any color space value of the two color space values; A correction parameter of the reference color value is determined according to a ratio of the second difference to the first difference.

[0099] In one embodiment, the determining unit 601 is specifically configured to: Obtaining each component value of the first color space value in each channel and each component value of the two color space values ​​in each channel; Determine a first difference between the component values ​​of the two color space values ​​and a second difference between the component values ​​of the first color space value and the component values ​​of any one of the two color space values, and determine a ratio of each component between the first difference between the component values ​​and the second difference between the component values; According to the ratios of the components, correction parameters of the reference color value are determined.

[0100] In one embodiment, the determining unit 601 is specifically configured to: Determine, according to the component values ​​of each channel of the reference color value, a plurality of candidate color values ​​corresponding to each channel; wherein the candidate color values ​​satisfy a single-channel color similarity condition of the reference color value; Determine a candidate color space value of each candidate color value in the standard color space, and determine a spatial distance between each candidate color space value and the first color space value in the standard color space; The candidate color values ​​corresponding to the first two spatial distances after the spatial distances are arranged in ascending order are determined as the two actual color values.

[0101] In one embodiment, the determining unit 601 is specifically configured to: According to the component value of the target channel in the reference color value, obtaining a third difference between the component value of the target channel and the component value of the target channel of the candidate color value; After arranging the third differences in ascending order, the candidate color values ​​corresponding to the first two third differences are determined as the two actual color values; The candidate color value satisfies a single-channel color similarity condition of the reference color value.

[0102] In one embodiment, the acquisition unit 602 is further configured to: Obtaining an actual brightness value corresponding to the reference color value; Acquire a first ratio between the actual brightness value and a preset brightness value of the display panel corresponding to a reference color value; The actual color value of the reference color value is updated according to the first ratio and the actual pixel value of the reference color value.

[0103] In one embodiment, the acquisition unit 602 is further configured to: At least two preset brightnesses of the display panel are obtained, and normalization processing is performed on the actual color value corresponding to the reference color value, so that the reference color value is a digital signal corresponding to each of the at least two preset brightnesses of the display panel.

[0104] In one embodiment, the acquisition unit 602 is specifically used to: According to at least two preset brightnesses of the display panel, actual chromaticity values ​​corresponding to the reference chromaticity and actual spatial color values ​​corresponding to the reference chromaticity are respectively normalized so that the reference pixels correspond to the same digital signal at the different preset brightnesses.

[0105] It should be understood that the units recorded in the color value calibration device of the display panel correspond to the various steps in the method described in the accompanying drawings. Therefore, the operations and features described above for the method are also applicable to the color value calibration device of the display panel and the units contained therein, and will not be repeated here. The color value calibration device of the display panel can be pre-implemented in a browser or other security application of a computer device, or can be loaded into a browser or its security application of a computer device by downloading or the like. The corresponding units in the color value calibration device of the display panel can cooperate with the units in the computer device to implement the solution of the embodiment of the present application.

[0106] For the several modules or units mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into multiple modules or units to be embodied.

[0107] It should be noted that for details not disclosed in the color value calibration device of the display panel in the embodiment of the present application, please refer to the details disclosed in the above embodiments of the present application, which will not be repeated here.

[0108] Reference below Figure 4 , Figure 4 FIG. 1 is a schematic diagram showing a structure of a computer device suitable for implementing an embodiment of the present application. Figure 4 As shown, the computer system 1700 includes a central processing unit (CPU) 1701, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 1702 or the program loaded from the storage part 1708 to the random access memory (RAM) 1703. In the RAM 1703, various programs and data required for the operation instructions of the system are also stored. The CPU 1701, the ROM 1702, and the RAM 1703 are connected to each other through a bus 1704. An input / output (I / O) interface 1705 is also connected to the bus 1704.

[0109] The following components are connected to the I / O interface 1705: an input section 1706 including a keyboard, a mouse, etc.; an output section 1707 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 1708 including a hard disk, etc.; and a communication section 1709 including a network interface card such as a LAN card, a modem, etc. The communication section 1709 performs communication processing via a network such as the Internet. A drive 1710 is also connected to the I / O interface 1705 as needed. A removable medium 1711, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 1710 as needed, so that a computer program read therefrom is installed into the storage section 1708 as needed.

[0110] In particular, according to an embodiment of the present application, the above reference flow chart Figure 1 The described process can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through the communication part 1709, and / or installed from a removable medium 1711. When the computer program is executed by the central processing unit (CPU) 1701, the above-mentioned functions defined in the system of the present application are executed.

[0111] It should be noted that the computer-readable medium shown in the present application may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium such as a computer-readable storage medium that can send, propagate or transmit a program for use by or in conjunction with an instruction execution system, device or device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0112] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, functions and operating instructions of the system, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the aforementioned module, program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, the boxes represented by two connections can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operating instruction, or can be implemented with a combination of dedicated hardware and computer instructions.

[0113] The units or modules involved in the embodiments described in the present application may be implemented by software or hardware. The units or modules described may also be set in a processor. For example, it may be described as: a processor includes a first receiving module, a second receiving module, and a sending module. The names of these units or modules do not, in some cases, constitute limitations on the units or modules themselves.

[0114] As another aspect, the present application further provides a computer-readable storage medium, which may be included in the electronic device described in the above embodiment, or may exist independently without being assembled into the electronic device. The above computer-readable storage medium stores one or more programs, and when the above programs are used by one or more processors to execute the color value calibration method of the display panel described in the present application.

[0115] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the aforementioned disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

Claims

1. A method for calibrating the color value of a display panel, characterized in that: The method comprises: Determine two actual color values ​​that satisfy a color similarity condition of a reference color value; Determine a first color space value of the reference color value in a standard color space, and two color space values ​​of the two actual color values ​​in the standard color space, and determine a correction parameter of the reference color value based on the first color space value and the two color space values; the correction parameter is used to characterize a spatial position of the reference color value in the standard color space and satisfies a reference linear distribution, and the reference linear distribution is used to characterize a spatial linear relationship between the two color space values ​​of the two actual color values ​​in the standard color space; The reference color value is corrected according to the correction parameter to obtain an actual color value of the reference color value.

2. The method according to claim 1, characterized in that The step of determining the correction parameter of the reference color value based on the first color space value and the two color space values ​​includes: Obtaining a first difference between the two color space values, and a second difference between the first color space value and any color space value of the two color space values; A correction parameter of the reference color value is determined according to a ratio of the second difference to the first difference.

3. The method according to claim 2, characterized in that The obtaining of a first difference between the two color space values, and a second difference between the first color space value and any color space value of the two color space values, comprises: Obtaining each component value of the first color space value in each channel and each component value of the two color space values ​​in each channel; Determine a first difference between the component values ​​of the two color space values ​​and a second difference between the component values ​​of the first color space value and the component values ​​of any one of the two color space values, and determine a ratio of each component between the first difference between the component values ​​and the second difference between the component values; The step of determining the correction parameter of the reference color value according to the ratio of the second difference to the first difference includes: According to the ratios of the components, correction parameters of the reference color value are determined.

4. The method according to claim 1, characterized in that: Determining two color space values ​​of two actual color values ​​in the standard color space includes: Determine, according to the component values ​​of each channel of the reference color value, a plurality of candidate color values ​​corresponding to each channel; wherein the candidate color values ​​satisfy a single-channel color similarity condition of the reference color value; Determine a candidate color space value of each candidate color value in the standard color space, and determine a spatial distance between each candidate color space value and the first color space value in the standard color space; The candidate color values ​​corresponding to the first two spatial distances after the spatial distances are arranged in ascending order are determined as the two actual color values.

5. The method according to claim 1, characterized in that Determining two color space values ​​of two actual color values ​​in the standard color space includes: According to the component value of the target channel in the reference color value, obtaining a third difference between the component value of the target channel and the component value of the target channel of the candidate color value; After arranging the third differences in ascending order, the candidate color values ​​corresponding to the first two third differences are determined as the two actual color values; The candidate color value satisfies a single-channel color similarity condition of the reference color value.

6. The method according to claim 1, characterized in that After correcting the reference color value according to the color ratio parameter to obtain the actual color value of the reference color value, the method further includes: Obtaining an actual brightness value corresponding to the reference color value; Acquire a first ratio between the actual brightness value and a preset brightness value of the display panel corresponding to a reference color value; The actual color value of the reference color value is updated according to the first ratio and the actual pixel value of the reference color value.

7. The method according to claim 1, characterized in that Before determining the correction parameter of the reference color value based on the first color space value and the two color space values, the method further includes: At least two preset brightnesses of the display panel are obtained, and normalization processing is performed on the actual color value corresponding to the reference color value, so that the reference color value is a digital signal corresponding to each of the at least two preset brightnesses of the display panel.

8. The method according to claim 7, characterized in that The performing normalization processing on the actual chromaticity value corresponding to the reference chromaticity so that the reference chromaticity corresponds to the same digital signal within the at least two preset brightnesses includes: According to at least two preset brightnesses of the display panel, actual chromaticity values ​​corresponding to the reference chromaticity and actual spatial color values ​​corresponding to the reference chromaticity are respectively normalized, so that the reference pixels correspond to the same digital signal at different preset brightnesses.

9. A color value calibration device for a display panel, characterized in that: include: A determination unit, used to determine two actual color values ​​that satisfy a color similarity condition of a reference color value; The determining unit is further configured to determine a first color space value of the reference color value in a standard color space, and two color space values ​​of the two actual color values ​​in the standard color space, and determine a correction parameter of the reference color value based on the first color space value and the two color space values; The correction parameter is used to characterize the spatial position of the reference color value in the standard color space and satisfies the reference linear distribution, and the reference linear distribution is used to characterize the spatial linear relationship between two color space values ​​of the two actual color values ​​in the standard color space; An acquiring unit is used to calibrate the reference color value according to the calibration parameter to obtain an actual color value of the reference color value.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 8 is implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

12. A computer program product, comprising instructions, characterized in that: When the instructions are executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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