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

Abstract

The application discloses a color value calibration method, device, equipment and medium of a display panel, and generally relates to the technical field of display panels. The method comprises the following steps: determining two actual color values that satisfy a color similarity condition of a 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; 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 to represent a spatial position of the reference color value in the standard color space and satisfying a reference linear distribution, and the reference linear distribution is used to represent a spatial linear relationship of the 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] This disclosure generally relates to the field of display panel technology, and more particularly to a method, apparatus, device, and medium for color value calibration of a display panel. Background Technology

[0002] With the development of electronic technology, the display technology of electronic devices is also constantly evolving.

[0003] Among the many important attributes in display technology, color accuracy is a crucial factor affecting user experience. To ensure color accuracy, it is generally necessary to set color accuracy reference points for the display panel, assign standard chromaticity values ​​to these reference points, and then calculate the actual chromaticity values ​​of the display panel at the reference points. By comparing the actual chromaticity values ​​with the standard chromaticity values, the offset of the actual chromaticity values ​​can be obtained, allowing for correction of the display panel's chromaticity values.

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

[0005] In view of the above-mentioned defects or deficiencies in the related technologies, it is desirable to provide a method, apparatus, device and medium for color value calibration of display panels, which can solve the problem that determining the reference point often requires calculating a large number of actual chromaticity values ​​and comparing them, thus consuming a lot of resources, and can significantly reduce the time spent determining the reference point.

[0006] Firstly, a method for calibrating color values ​​of a display panel is provided, the method comprising:

[0007] Determine two actual color values ​​that satisfy the color similarity condition of the reference color value;

[0008] The first color space value of the reference color value in the standard color space is determined, as well as the two color space values ​​of the two actual color values ​​in the standard color space. Based on the first color space value and the two color space values, a correction parameter for the reference color value is determined. The correction parameter is used to characterize the spatial position of the reference color value in the standard color space that satisfies a 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.

[0009] The reference color value is corrected according to the correction parameters to obtain the actual color value of the reference color value.

[0010] In this application, when it is necessary to determine the reference color value of the display panel, firstly, two actual color values ​​that satisfy the color similarity condition of the reference color value are determined; then, 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 are determined, and a correction parameter for the reference color value is determined (this correction parameter is used to characterize the spatial position of the reference color value in the standard color space that satisfies the reference linear distribution, which 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, the reference color value is corrected according to the correction parameter to obtain the actual color value of the reference color value. Thus, in the process of determining the reference color value of the display panel, the color space values ​​of the two already determined actual color values ​​that satisfy the color similarity condition in the standard color space can be used to assist in correcting the actual color value of the reference color value. This eliminates the need to obtain the actual color values ​​of all reference color values ​​through measurement, significantly saving time in determining the actual color value of the display panel reference color value and improving the efficiency of determining the actual color value of the display panel reference color value.

[0011] Secondly, a color value calibration device for a display panel is provided, the device comprising:

[0012] A determining unit is used to determine two actual color values ​​that satisfy the color similarity condition of the reference color value;

[0013] The determining unit is further configured to 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 to determine the 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 that satisfies 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;

[0014] The acquisition unit is used to correct the reference color value according to the correction parameters to obtain the actual color value of the reference color value.

[0015] Thirdly, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the method described in the first aspect.

[0016] Fourthly, a computer-readable storage medium is provided having a computer program stored thereon, characterized in that the program, when executed by a processor, implements the method described in the first aspect above.

[0017] Fifthly, a computer program product is provided, which includes instructions that, when executed by a processor, implement the method described in the first aspect above.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0020] Figure 1 A schematic flowchart illustrating the color calibration method for a display panel provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the color calibration system structure for a display panel provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the structure of the color calibration device for the display panel provided in the embodiments of this application;

[0023] Figure 4 A schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0024] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The applicable scenarios of this application will be described below.

[0026] With the increasing sophistication of display functions and the continuous improvement of viewing quality in modern electronic devices, color accuracy has become a widely accepted indicator for quantifying whether a monitor's colors match the standard color gamut. Inaccurate color accuracy can be addressed through various methods, such as photoelectric curve calibration, color temperature adjustment calibration, 3D-LUT calibration, or other algorithm calibrations.

[0027] The principle behind 3D-LUT calibration algorithms is as follows: Display devices have non-standard native characteristics and varying performance. Each standard color space defines the color representation that each point in the RGB three channels should display. The tristimulus values ​​x, y, z in CIE 1931 are used as objective and unified indicators to define the colors of different display devices. To enable the display device under test to better display standard colors and to be calibrated to standard colors, 3D-LUT was invented based on the tristimulus values ​​of CIE 1931. It can map the reference pixels of the display panel in the RGB three channels to new corresponding points in sections. The mapped effect is close to the requirements of standard colors, thus allowing adjustment of the color accuracy of the RGB three channels.

[0028] Typically, the number of reference color values ​​used in the R×G×B three channels can be 33×33×33 or 17×17×17, etc., with various evenly distributed reference points. It can be understood that after determining the color values ​​of the reference colors, any target color value in the RGB three channels of the display device can be obtained using interpolation. Since this target color value lies between any two nearest reference color values, it has a color accuracy reference, thus ensuring that the color accuracy of any target color value can be accurately obtained.

[0029] As discussed above, selecting more reference pixels results in a more accurate color mapping closer to the standard. However, more pixels also require greater computational resources, placing a heavier burden on the chip. Conversely, too few pixels fail to achieve satisfactory correction. Therefore, selecting appropriate reference pixels is crucial for ensuring the accuracy of color value correction in display panels. Obtaining the most suitable reference color value, enabling the display panel to accurately determine the color accuracy of any reference color value while consuming minimal resources, is essential for high-quality color display.

[0030] Based on this, this application proposes a color value calibration method, apparatus, device and medium for a display panel, which can solve the problem that determining the reference point often requires calculating a large number of actual chromaticity values ​​and comparing them, which consumes a lot of resources, and can significantly reduce the time spent determining the reference point.

[0031] Figure 1 This is a flowchart illustrating a color value calibration method for a display panel provided in an embodiment of this application. The method includes the following steps:

[0032] Step 301: Determine two actual color values ​​that satisfy the color similarity condition of the above reference color value.

[0033] In this embodiment of the application, the aforementioned reference color value may be a reference color value in the display panel that needs to be confirmed and corrected.

[0034] In this embodiment of the application, the aforementioned 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.

[0035] In this embodiment, the reference color value is the signal value of the display color set by the display panel. For example, the reference color value is (0, 0, 64), meaning that the display panel needs to display the color indicated by (0, 0, 64) according to the signal value.

[0036] Understandably, for a display panel, assuming it is perfectly ideal, then according to a preset theoretical reference color value, the display panel should display the indicated color exactly according to that theoretical reference color value. For example, if the theoretical reference color value is (0, 0, 64), then the ideal display panel should display the color indicated by (0, 0, 64). That is, in the case of a perfectly ideal display panel, all reference color values ​​are linearly and uniformly distributed, such as (0, 0, 0), (0, 0, 32), (0, 0, 64), (0, 0, 96), (0, 0, 128), etc.

[0037] However, in reality, display panels always exhibit certain deviations during the manufacturing process. After assigning the aforementioned theoretical reference color values, they will not display according to those values. For example, assigning a value of (0, 0, 128) will result in the actual displayed color value of (0, 0, 120). To ensure that the reference color values ​​display according to their preset theoretical values, such as (0, 0, 128), correction is needed. For instance, measurements show that (0, 0, 132) displays the color value that the theoretical reference color value (0, 0, 128) should display. Since each reference color value exhibits this display deviation, this application requires calculation to obtain the actual color value corresponding to each reference color value. These reference color values ​​can then be used to locate other color values.

[0038] Furthermore, it can be understood that the more reference color values ​​mentioned above, the more accurate and refined the display panel will be. Different display panels can be set with different numbers of reference color values. The higher the color precision required by the display panel, the more reference color values ​​it needs; correspondingly, the lower the color precision required by the display panel, the fewer reference color values ​​it needs.

[0039] For example, the reference color values ​​required by the display panel can 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).

[0040] Furthermore, the aforementioned baseline color values ​​can be indicated by pixel values ​​(RGB).

[0041] In this embodiment of the application, the two actual color values ​​are predicted color values ​​in advance.

[0042] In the embodiments of this application, the above-mentioned color similarity condition is used to characterize the two actual color values ​​that are closest to the reference color value.

[0043] It is understood that the aforementioned reference color value refers to the reference color value to be determined and corrected in this application. The theoretical value of this reference color value has been determined; however, the actual color value corresponding to the theoretical value of the reference color value needs to be obtained through calculation. The two actual color values ​​mentioned above are used to confirm the actual color value of the reference color value. See the following description for details.

[0044] Furthermore, several, or multiple, actual color values ​​can be preset in advance, from which two actual color values ​​that meet the color pixel conditions can be selected.

[0045] Step 302: Determine the first color space value of the above reference color value in the standard color space, and the two color space values ​​of the above two actual color values ​​in the standard color space. Based on the first color space value and the two color space values, determine the correction parameters of the above reference color value.

[0046] In the embodiments of this application, the above-mentioned correction parameters are used to characterize the spatial position of the above-mentioned reference color value in the above-mentioned standard color space and satisfy the reference linear distribution.

[0047] In the embodiments of this application, the aforementioned reference linear distribution is used to characterize the spatial linear relationship between the two actual color values ​​and the two color space values ​​in the aforementioned standard color space.

[0048] It is understood that, in order to determine the actual color value of the reference color value, the reference color value and the two actual color values ​​need to be converted into a standard color space. In this space, 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 can be obtained through the spatial linear relationship between the two accurate actual color values, and then the correction parameters of the reference color value can be determined.

[0049] In one example, the standard color space mentioned above can be CIE1931, and the above reference color values ​​RGB can be converted to XYZ in CIE1931.

[0050] In this embodiment of the application, the color value is RGB and the color space value is the color space value in CIE1931. The color value and the color space value can correspond to each other.

[0051] Assuming the base color value is If the standard color space is CIE 1931, then the first color space value of this reference color value in the linear relationship of CIE 1931 is ( The two are converted through preset conversion parameters, as shown in Formula 1 below.

[0052] Formula 1

[0053] Accordingly, the two actual color values ​​mentioned above are respectively and Correspondingly, the color space values ​​of these two actual color values ​​in the standard color space are ( )and( ).

[0054] It should be noted that there are no restrictions on the positional relationship between the reference color value and the two actual color values ​​in the standard color space. For example, the two actual color values ​​can be the upper and lower neighbors of the reference color value, respectively; the two actual color values ​​can both be the upper neighbors of the reference color value; or the two actual color values ​​can both be the lower neighbors of the reference color value.

[0055] In this embodiment of the application, the aforementioned standard color space can spatialize the aforementioned color values, with each color value corresponding to a position in the standard color space. Then, by comparing the positional relationship between the reference color value in the first color space value in the standard color space and the two actual color values ​​in the two color space values ​​in the standard color space, the relative position of the reference color value relative to the actual color value can be obtained, thereby correcting the reference color value.

[0056] Step 303: Correct the reference color value according to the above correction parameters to obtain the actual color value of the reference color value.

[0057] It is understandable that since the standard color space is used to transform the color values ​​of a two-dimensional space into a three-dimensional space, the above correction parameters can be obtained by converting the color values ​​to the standard color space. Since the standard color space corresponds to the color values ​​of the two-dimensional space, the above reference color values ​​can be corrected using these correction parameters.

[0058] In the method provided in this application embodiment, when it is necessary to determine the reference color value of the display panel, firstly, two actual color values ​​that satisfy the color similarity condition of the reference color value are determined; then, 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 are determined, and a correction parameter for the reference color value is determined (this correction parameter is used to characterize the spatial position of the reference color value in the standard color space that satisfies the reference linear distribution, which 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, the reference color value is corrected according to the correction parameter to obtain the actual color value of the reference color value. Thus, in the process of determining the reference color value of the display panel, the color space values ​​of the two already determined actual color values ​​that satisfy the color similarity condition in the standard color space can be used to assist in correcting the actual color value of the reference color value. This eliminates the need to obtain the actual color values ​​of all reference color values ​​through measurement, significantly saving time in determining the actual color value of the display panel reference color value and improving the efficiency of determining the actual color value of the display panel reference color value.

[0059] In another embodiment of this application, a specific implementation method for obtaining correction parameters is also provided. For example, 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 a first difference between the two color space values, and a second difference between the first color space value and any one 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.

[0060] Understandably, in order to determine the correction parameter of the first color space value corresponding to the reference color value in the standard color space based on the two color space values ​​corresponding to the actual color value, it is necessary to determine 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 by following and referencing the reference linear distribution of the two color space values, which is the true, actual, and correct reference linear distribution.

[0061] For example, the aforementioned correction parameter can be characterized by a linear ratio between the first color space value and the two aforementioned color space values. That is, the correction parameter of the reference color value is characterized by the ratio of the second difference to the first difference.

[0062] Optionally, in this embodiment, since the reference color value is composed of values ​​from three channels, it is necessary to calculate correction parameters based on the three channels. For example, obtaining the first difference between the two color space values ​​and the second difference between the first color space value and any one of the two color space values ​​includes: obtaining the component values ​​of the first color space value in each channel and the component values ​​of the two color space values ​​in each channel; determining the first difference between the component values ​​of the two color space values ​​and the second difference between the component values ​​of the first color space value and any one of the two color space values, and determining the component ratio between the first difference and the second difference; determining the correction parameters of the reference color value based on the ratio of the second difference and the first difference includes: determining the correction parameters of the reference color value based on the component ratio.

[0063] It is understood that, in the embodiments of this application, since the above-mentioned color space values ​​also have component values ​​corresponding to each channel of the color value, the correction parameter should actually be corrected for each channel of the color space value.

[0064] In one example, when the standard color space is CIE1931, combining the two actual color values ​​mentioned above, the relationship between the reference color value and the actual color value is further extended to Formula 1 above as follows:

[0065]

[0066] Formula 1

[0067] in, That is and The difference between them; correspondingly, That is and The difference between them That is and The difference between them.

[0068] Understandably, the baseline pixel R channel value and The R channel value of the point, and the actual color value The R channel value of the point and The ratio of the R channel values ​​of the points is used This indicates that the corresponding reference pixel point... G channel value and The G channel value of the point, and the actual color value The G channel value of the point and The ratio of the G channel values ​​of the points is used Representation; reference pixel B channel value and The B channel value of the point, and the actual color value The B channel value of the point and The ratio of the B channel values ​​of the points is used express,( ) is used to characterize the ratio between the reference pixel value and two actual pixel values. Correspondingly, the color value is converted to the standard color space, then ( It can characterize the relative positional relationship between the reference pixel value and the two actual pixel values ​​in the standard color space.

[0069] Therefore, in the standard color space, since the standard color space is a linear space for calculation, the following relationship can be considered to exist:

[0070] ;

[0071] ；

[0072] ；

[0073] ；

[0074] ；

[0075] ；

[0076] ；

[0077] ；

[0078]

[0079] Given the aforementioned relationship, as shown in Formula 2 below, Formula 2 uses a standard color space with linear spatial properties to obtain correction parameters presented in vector form, which are respectively ( This yields the actual relative positional 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. Therefore, the three values ​​in this vector indicating the actual relative positional relationship can be used to correct the reference color value. ).

[0080] Formula 2

[0081] In obtaining the above formula two ( After determining the calibration parameters for the three channels, the following formula (3) can be used. )and and The relationship between the reference color values ​​is used to determine the actual color value of the reference color value, that is, to obtain the actual color value of the reference color value from the ( ) (The correction is performed.)

[0082] Formula 3

[0083] Optionally, in this embodiment of the application, as described above, the two actual color values ​​can be obtained through a filtering method, that is, multiple candidate color values ​​are pre-defined, and two actual color values ​​are selected from them as color values ​​for calculating correction parameters. For example, determining the two color space values ​​of the two actual color values ​​in the standard color space includes: determining multiple candidate color values ​​corresponding to each channel based on the component values ​​of each channel of the reference color value; the candidate color values ​​satisfying the single-channel color similarity condition of the reference color value; determining the candidate color space value of each candidate color value in the standard color space; determining the spatial distance between each candidate color space value and the first color space value in the standard color space; and determining the candidate color values ​​corresponding to the first two spatial distances after arranging the spatial distances in ascending order as the two actual color values.

[0084] It is understood that, in order to ensure the accuracy of the reference color value determination, the actual color values ​​of multiple display panels that are different from the reference color value can be preset and measured in advance as candidate color values.

[0085] Furthermore, the color space values ​​corresponding to the aforementioned candidate color values ​​can be evenly distributed in the standard color space. Thus, when it is necessary to confirm the correction parameter of any reference color value, among the multiple candidate color values ​​in the standard color space, two actual color values ​​for determining the correction parameter can be obtained near the first color space value corresponding to the reference color value.

[0086] For example, in the process of determining candidate color values, since it is in a two-dimensional planar space, multiple candidate color values ​​that meet the single-channel color similarity condition of the reference color value can be determined in advance based on 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 candidate color values ​​can be preset or user-defined.

[0087] Next, the candidate color space value corresponding to each candidate color value is identified, and the spatial distance between each candidate color space value and the first color space value in the standard color space is determined. Then, the candidate color values ​​corresponding to the first two spatial distances after ascending sorting are selected as the two actual color values.

[0088] For example, for the base color value In other words, they can be respectively , , One candidate color value was confirmed, and a total of three candidate color values ​​were confirmed, namely: , and Next, determine the candidate color space values ​​for these three candidate color values, that is ( ), ( )and( Then, calculate () respectively. )and( Spatial distance, ( )and( Spatial distance, ( )and( The spatial distances are calculated as follows: After sorting these three spatial distances in ascending order, the candidate color values ​​corresponding to the first two spatial distances are selected, i.e., (…). ), ( ) corresponding , As a reference color value The two actual color values.

[0089] Optionally, in this embodiment of the application, the actual color value can also be quickly determined according to actual needs. For example, determining the two actual color values ​​in the standard color space includes: obtaining the third difference between the component value of the target channel and the component value of the target channel of the candidate color value based on 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.

[0090] For example, the candidate color values ​​described above satisfy the single-channel color similarity condition of the reference color value.

[0091] Understandably, for some display panels, the actual requirements may be higher for one of the three channels, i.e., the target channel, or one of the three channels, i.e., the target channel, can represent the reference pixel value to determine the color space value. Therefore, the difference between a target channel component value and a number of preset candidate color values, i.e., the third difference, can be determined. Then, the third differences are sorted in ascending order, and the candidate color values ​​corresponding to the first two third differences are selected as the two actual color values.

[0092] Optionally, in this embodiment of the application, 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 the actual brightness value corresponding to the reference color value; obtaining a first ratio between the actual brightness value and the 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.

[0093] It is understandable that after obtaining the actual color value of the reference color value through interpolation calculation, due to the consistency of the characteristics of the light source and / or the test standard light source, the measured actual color value of the reference color value may still differ from the ideal display color value corresponding to the reference color value. Therefore, the actual color value of the reference color value can be further updated and corrected by using the brightness value of the brightness channel as a reference.

[0094] For example, the above-mentioned actual brightness value is the brightness value measured according to the actual color value corresponding to the aforementioned reference color value, that is, the brightness value of the display panel is measured and obtained under the signal value corresponding to the actual color value.

[0095] For example, the aforementioned preset brightness value refers to the theoretical brightness value of the display panel under the reference color value, that is, the ideal brightness value that the display panel theoretically wants to obtain under the reference color value.

[0096] It is understandable that by using the first ratio between the actual brightness value corresponding to the actual color value and the preset brightness value under ideal conditions, the relative relationship between the current actual brightness value and the ideal brightness value can be obtained, and the actual color value can be corrected and updated through this relative relationship.

[0097] As illustrated in the example below: assuming the actual color value obtained is as described above. The actual color value is the measured brightness value. The preset brightness is The first ratio between the aforementioned display panels is Then, each actual color value can be updated based on this first ratio. Specifically, the updated actual color value is ( , , The calculation process is shown in Formula 3 below.

[0098] , , Formula 4

[0099] Optionally, in this embodiment of the application, before determining the correction parameters of the reference color value based on the first color space value and the two color space values, the method further includes: obtaining at least two preset brightness values ​​of the display panel, and performing normalization processing on the actual color value corresponding to the reference color value, so that the reference color value corresponds to the digital signal under the at least two preset brightness values ​​of the display panel respectively.

[0100] Understandably, since display panels often have different display brightness, such as a 1000 nit brightness display panel or a 500 nit brightness display panel, the color space values ​​and actual color values ​​of the reference color values ​​corresponding to different display panels in the standard color space are different. In order to ensure that the color space values ​​and actual color values ​​of the reference color values ​​corresponding to display panels with different brightness are consistent, 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.

[0101] Optionally, in this embodiment of the application, the normalization process 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 brightness levels, includes: performing normalization processing on the actual chromaticity value corresponding to the reference chromaticity and the actual spatial color value corresponding to the reference chromaticity according to the at least two preset brightness levels of the display panel, so that the reference pixel corresponds to the same digital signal at different preset brightness levels.

[0102] Understandably, in order to unify the color space values ​​corresponding to the reference color values ​​of the display panels with different brightness levels, the normalized reference color value can be determined by obtaining the first brightness value corresponding to the actual color value of the display panel at the maximum color value, and then obtaining the ratio between the first brightness value and the color space value of the reference color value in the standard color space.

[0103] As shown in the example below:

[0104] 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 is (255, 255, 255). Subsequently, the normalized values ​​corresponding to the aforementioned reference color values ​​are calculated using the first color space values ​​corresponding to the reference color values. Thus, after obtaining the normalized ( After that, you can obtain ( The corresponding normalization . All are between 0 and 1.

[0105] Specifically, the normalized values ​​of the following reference pixels can be obtained. These are the normalized X, Y, and Z components of the tested display screen when R=1, G=0, and B=0, respectively. These are the normalized X, Y, and Z components of the tested display screen when R=0, G=1, B=0; These are the normalized X, Y, and Z components of the tested display screen when R=0, G=0, and B=1, respectively. , , The values ​​of R, G, and B are the specific values ​​displayed on the screen when P0 is shown. , , The values ​​of R, G, and B are given when the measured display shows P1.

[0106] The actual application process of the embodiments of this application will be described below.

[0107] First, the hardware entities that may be used in performing the above methods in the embodiments of this application are described as follows:

[0108] like Figure 2 As shown, the color value calibration method for the display panel described above in this application can be performed by the luminance and colorimeter 21 of the display device, the signal generator 22, and the process control device 23.

[0109] The aforementioned luminance and colorimeter 21 can be a CA-410 color analyzer, used to measure actual luminance and color, such as the color coordinates and corresponding tristimulus values ​​in the display panel 24; the aforementioned signal generator 22 can be a computer, an embedded system, or other devices with a display panel, which can support custom and programmable output of RGB three-channel values ​​to the display device, such as an FPGA; the aforementioned process control device 23 can be a computer or other embedded system, which can be used to run the entire calibration process and communicate with the signal generator 22 and the luminance and colorimeter 21, controlling the signal generator 22 to output specific signals at appropriate times, and then acquiring and calculating the values ​​of the luminance and colorimeter 21.

[0110] In one example, the process control device 23 and the signal generator 22 can be the same device (e.g., RK3399), or they can be directly designed into the embedded system corresponding to the display panel 24 to be measured. In this way, the calibration process can be completed without external devices.

[0111] In actual testing, the luminance and 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 can be placed aside and connected by cables. Figure 2 The luminance and colorimeter 21 and the process control device 23 are connected via an RS-232 serial port. It should be noted that the signal generator 22 and the process control device 23 are interconnected through their respective chips. In fact, there are many ways to connect them, and this embodiment does not limit this.

[0112] The specific display panel calibration method is as follows:

[0113] Step 1: In the measurement mode, the EOTF electro-optical conversion function to be used for each reference color value to be measured is confirmed. This 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.

[0114] Step 2: The process control device 23 sends a command to the signal generator 22, causing the signal generator 22 to determine all preset actual color values ​​(R, G, B) and the reference color value to be measured. In one example, assuming the color depth of the digital signal is n, then for channel R in the reference color value, its maximum value is... Similarly, for channels G and B in the reference color value, it should be noted that (R, G, B) are all normalized values. With the color depth of the digital signal as n, the number of pixel reference points is calculated to be m×m×m. The maximum value of channel R is 2n-1. Since it is a normalized value, when determining adjacent pixel reference points, the RGB channels use 1 / (m-1) as the interval between normalized adjacent reference color values, taking values ​​of 0 / (m-1), 1 / (m-1), 2 / (m-1), ..., (m-2) / (m-1), (m-1) / (m-1). Because each channel can take m values, the three channels can take m×m×m combinations of normalized pixel color values ​​corresponding to the RGB values.

[0115] 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 luminance and colorimeter 21 to measure and obtain the color space values ​​X, Y, Z corresponding to each RGB. This process is repeated to traverse all m×m×m RGB combination values. In one example, it is not necessary to calculate all m×m×m RGB combination values. Specifically, R can be taken as R = 2n×0 / (m-1), 2n×1 / (m-1), 2n×2 / (m-1)..., 2n×(m-2) / (m-1), 2n-1, while setting channels G and B to 0, thus obtaining these m points; similarly, the points for channels G and B are obtained, and so on, finally obtaining m+m+m points. Using the linear characteristics of XYZ, all measurement values ​​are obtained by combining them. For example, if RGB values ​​are {a, b, c}, then X(a, b, c) = X(a, 0, 0) + X(0, b, 0) + X(0, 0, c). Similarly, the X, Y, Z values ​​of m × m × m pixels can be obtained using the same method. This can significantly reduce calibration time.

[0116] Step 4: After converting all the theoretical pixel reference points requiring correction to the standard color space (i.e., linear space) in Step 3 (which is essentially the color representation observed by the human eye on the display device), for each theoretical pixel reference point's RGB value requiring correction, because the EOTF electro-optical conversion curve followed by each mode calibrated by the display panel 24 is different, a reverse conversion process needs to be performed to convert the light signal of the theoretical pixel reference point requiring correction into a digital electrical signal input to the 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 specified EOTF conversion curve and EOTF. -1 The calculation method.

[0117] Step 5: The XYZ values ​​in the standard color space can be converted using a standard-defined matrix. Taking the BT.709 matrix as an example...

[0118] ;

[0119] Using the above formula, the RGB value of any point specified by the BT.709 color standard can be converted to the XYZ value, thus obtaining the theoretical XYZ normalized value of each reference pixel in the m×m×m target.

[0120] Step 6: Use the calculation result XYZ from Step 5 as the first color space value corresponding to the reference pixel that needs correction. Calculate the correction parameters using Formula 1 and Formula 2 to help correct the theoretical XYZ of the reference pixel, and further correct it using Formula 3 through the luminance channel. Specifically, when calculating any pixel color value PT{a, b, c} to be corrected, taking m×m×m reference color values ​​with a color depth of n as an example, for each reference color value to be measured or corrected, the step value... For the pixel color values ​​PT{a, b, c} to be corrected, the two actual color values ​​are P0 and P1, where P0 takes the value of {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 summary, the color value PT of each pixel is calculated by interpolation of its upper and lower neighboring points. These neighboring points have been traversed and measured in step 2 above to obtain the preset actual color values. When the minimum value of 0 or the maximum value of 1 is encountered, the actual value is taken.

[0121] It should be noted that when calculating the results, P0 and P1 may be non-integer. In such cases, rounding or other rounding methods should be used. If a negative value or a value greater than 1 is encountered, it should be truncated to 0 or 1.

[0122] Step 7: Once all the reference pixels for confirmation and correction have been calculated, an RGB correspondence table with an input of m×m×m and an output of m×m×m can be obtained.

[0123] Step 8: Output all the corrected 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 values ​​after this calibration can be mapped and the calibration process of steps 1 to 7 above can be run again until the required threshold range is met.

[0124] Step 9: Save the RGB correspondence table that has been calibrated and meets the threshold range requirements, input it into the system of the display device as a parameter of its 3D-LUT function module, and perform real-time calculation on the display device to interpolate the remaining points.

[0125] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the training rule determination method described in this application. For example, it can execute... Figure 1 The steps of the method shown.

[0126] This application provides a computer program product containing instructions that are implemented by a processor at runtime. Figure 1 The steps of the method shown.

[0127] It should be noted that although the operation of the method of the present invention is described in a specific order in the accompanying drawings, this does not require or imply that the operations must be performed in that specific order, or that all the operations shown must be performed in order to achieve the desired result.

[0128] Figure 3 This is a block diagram of a credential request apparatus according to one embodiment of this application, which can be deployed on an authorization node (e.g., the first node described above). Reference Figure 3 The device includes a determining unit 601 and an acquiring unit 602.

[0129] A determining unit is used to determine two actual color values ​​that satisfy the color similarity condition of the reference color value;

[0130] The determining unit is further configured to 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 to determine the 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 that satisfies 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;

[0131] The acquisition unit is used to correct the reference color value according to the correction parameters to obtain the actual color value of the reference color value.

[0132] In one embodiment, the determining unit 601 is specifically used to obtain a first difference between the two color space values, and a second difference between the first color space value and any one of the two color space values;

[0133] The correction parameter for the reference color value is determined based on the ratio of the second difference to the first difference.

[0134] In one embodiment, the determining unit 601 is specifically used for:

[0135] Obtain the component values ​​of the first color space value in each channel and the component values ​​of the two color spaces in each channel;

[0136] Determine the first difference between each component value of the two color space values ​​and the second difference between each component value of the first color space value and each component value of any one of the two color space values, and determine the component ratio between each component value of the first difference and the second difference of each component value;

[0137] Based on the ratio of each component, the correction parameters for the reference color value are determined.

[0138] In one embodiment, the determining unit 601 is specifically used for:

[0139] Based on the component values ​​of each channel of the reference color value, multiple candidate color values ​​corresponding to each channel are determined; the candidate color values ​​satisfy the single-channel color similarity condition of the reference color value.

[0140] Determine the candidate color space value of each candidate color value in the standard color space, and determine the spatial distance between each candidate color value and the first color space value in the standard color space;

[0141] The candidate color values ​​corresponding to the first two spatial distances after sorting the spatial distances in ascending order are determined as the two actual color values.

[0142] In one embodiment, the determining unit 601 is specifically used for:

[0143] Based on the component values ​​of the target channel in the reference color value, obtain the third difference between the component values ​​of the target channel and the component values ​​of the target channel of the candidate color value;

[0144] The candidate color values ​​corresponding to the first two third differences after sorting the third differences in ascending order are determined as the two actual color values.

[0145] The candidate color values ​​satisfy the single-channel color similarity condition of the reference color value.

[0146] In one embodiment, the obtaining unit 602 is further configured to:

[0147] Obtain the actual brightness value corresponding to the reference color value;

[0148] Obtain a first ratio between the actual brightness value and the preset brightness value of the display panel corresponding to the reference color value;

[0149] The actual color value of the reference color value is updated based on the first ratio and the actual pixel value of the reference color value.

[0150] In one embodiment, the obtaining unit 602 is further configured to:

[0151] At least two preset brightness values ​​of the display panel are obtained, and the actual color value corresponding to the reference color value is normalized so that the digital signal corresponding to the reference color value under the at least two preset brightness values ​​of the display panel is obtained respectively.

[0152] In one embodiment, the acquisition unit 602 is specifically used for:

[0153] Based on at least two preset brightness levels 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 different preset brightness levels.

[0154] It should be understood that the units described in the color value calibration device for 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 also apply to the color value calibration device for the display panel and the units it contains, and will not be repeated here. The color value calibration device for the display panel can be pre-implemented in a browser or other security application of a computer device, or it can be loaded into a browser or other security application of a computer device by downloading. The corresponding units in the color value calibration device for the display panel can cooperate with the units in the computer device to implement the solution of the embodiments of this application.

[0155] The division of modules or units mentioned in the detailed description above is not mandatory. In fact, according to the embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0156] It should be noted that for details not disclosed in the color value calibration device of the display panel in the embodiments of this application, please refer to the details disclosed in the above embodiments of this application, which will not be repeated here.

[0157] The following is for reference. Figure 4 , Figure 4 A schematic diagram of a computer device suitable for implementing embodiments of this application is shown. For example... Figure 4As shown, the computer system 1700 includes a central processing unit (CPU) 1701, which can perform various appropriate actions and processes based on programs stored in read-only memory (ROM) 1702 or programs loaded from storage section 1708 into random access memory (RAM) 1703. RAM 1703 also stores various programs and data required for the system's operating instructions. CPU 1701, ROM 1702, and RAM 1703 are interconnected via bus 1704. Input / output (I / O) interface 1705 is also connected to bus 1704.

[0158] The following components are connected to I / O interface 1705: an input section 1706 including a keyboard, mouse, etc.; an output section 1707 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, 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, modem, etc. The communication section 1709 performs communication processing via a network such as the Internet. Drive 1710 is also connected to I / O interface 1705 as needed. Removable media 1711, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 1710 as needed so that computer programs read from them can be installed into storage section 1708 as needed.

[0159] Specifically, according to embodiments of this application, the flowchart above refers to... Figure 1 The described process can be implemented as a computer software program. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowchart. In such an embodiment, the computer program contains program code for performing the methods shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via communication section 1709, and / or installed from removable medium 1711. When the computer program is executed by central processing unit (CPU) 1701, it performs the functions defined in the system of this application.

[0160] It should be noted that the computer-readable medium shown in this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0161] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operational instructions of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two connected blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified functions or operational instructions, or using a combination of dedicated hardware and computer instructions.

[0162] The units or modules described in the embodiments of this application can be implemented in software or hardware. The described units or modules can also be housed in a processor; for example, a processor can be described as including a first receiving module, a second receiving module, and a transmitting module. The names of these units or modules do not, in certain circumstances, constitute a limitation on the unit or module itself.

[0163] In another aspect, this application also provides a computer-readable storage medium, which may be included in the electronic device described in the above embodiments, or may exist independently and not assembled into the electronic device. The aforementioned computer-readable storage medium stores one or more programs that, when used by one or more processors, execute the color value calibration method for the display panel described in this application.

[0164] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing disclosed concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for calibrating the color values ​​of a display panel, characterized in that, The method includes: Determine two actual color values ​​that satisfy the color similarity condition of the reference color value; the color similarity condition is used to characterize the two actual color values ​​that are closest to the reference color value. The first color space value of the reference color value in the standard color space is determined, as well as the two color space values ​​of the two actual color values ​​in the standard color space. Based on the first color space value and the two color space values, a correction parameter for the reference color value is determined. The correction parameter is used to characterize the spatial position of the reference color value in the standard color space that satisfies a 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. The reference color value is corrected according to the correction parameters to obtain the actual color value of the reference color value; The step of determining the correction parameters for the reference color value based on the first color space value and the two color space values ​​includes: Obtain a first difference between the two color space values, and a second difference between the first color space value and any one of the two color space values; The correction parameter for the reference color value is determined based on the ratio of the second difference to the first difference.

2. The method according to claim 1, characterized in that, The step of obtaining the first difference between the two color space values, and the second difference between the first color space value and any one of the two color space values, includes: Obtain the component values ​​of the first color space value in each channel and the component values ​​of the two color spaces in each channel; Determine the first difference between each component value of the two color space values ​​and the second difference between each component value of the first color space value and each component value of any one of the two color space values, and determine the component ratio between each component value of the first difference and the second difference of each component value; The step of determining the correction parameter for the reference color value based on the ratio of the second difference to the first difference includes: Based on the ratio of each component, the correction parameters for the reference color value are determined.

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

4. The method according to claim 1, characterized in that, Determining the two actual color values ​​in the standard color space includes: Based on the component values ​​of the target channel in the reference color value, obtain the third difference between the component values ​​of the target channel and the component values ​​of the target channel of the candidate color value; The candidate color values ​​corresponding to the first two third differences after sorting the third differences in ascending order are determined as the two actual color values. The candidate color values ​​satisfy the single-channel color similarity condition of the reference color value.

5. 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: Obtain the actual brightness value corresponding to the reference color value; Obtain a first ratio between the actual brightness value and the preset brightness value of the display panel corresponding to the reference color value; The actual color value of the reference color value is updated based on the first ratio and the actual pixel value of the reference color value.

6. The method according to claim 1, characterized in that, Before determining the correction parameters for 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 brightness values ​​of the display panel are obtained, and the actual color value corresponding to the reference color value is normalized so that the digital signal corresponding to the reference color value under the at least two preset brightness values ​​of the display panel is obtained respectively.

7. The method according to claim 6, characterized in that, The normalization process 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 brightness levels, includes: Based on at least two preset brightness levels 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 different preset brightness levels.

8. A color value calibration device for a display panel, characterized in that, include: A determining unit is used to determine two actual color values ​​that satisfy the color similarity condition of the reference color value; The color similarity condition is used to characterize the two actual color values ​​that are closest to the reference color value; The determining unit is further configured to 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 to determine the correction parameters 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 satisfying the reference linear distribution. The reference linear distribution is used to characterize the spatial linear relationship between the two actual color values ​​in the standard color space. The acquisition unit is used to correct the reference color value according to the correction parameters to obtain the actual color value of the reference color value; The step of determining the correction parameters for the reference color value based on the first color space value and the two color space values ​​includes: Obtain a first difference between the two color space values, and a second difference between the first color space value and any one of the two color space values; The correction parameter for the reference color value is determined based on the ratio of the second difference to the first difference.

9. 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, it implements the method as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1-7.

11. A computer program product, the computer program product comprising instructions, characterized in that, The instructions are executed by the processor to implement the method as described in any one of claims 1-7.

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