Brightness and chrominance correction method and apparatus for lamp beads of LED display screen, and electronic device and storage medium

Abstract

The embodiments of the present disclosure relate to the technical field of display screens. Provided are a brightness and chrominance correction method and apparatus for lamp beads of an LED display screen, and an electronic device and a storage medium. The brightness and chrominance correction method for lamp beads of an LED display screen comprises: an FPGA pre-acquiring grayscale modes of partitions of a plurality of source image frames, so as to obtain temperature change values of the partitions, such that a temperature change that is about to occur in each partition can be acquired in advance, and then a second-layer correction coefficient of each partition is acquired in a timely manner. The second-layer correction coefficients within a preset time period are acquired, such that the second-layer correction coefficients can be updated in real time, so as to realize the dynamic real-time correction of the brightness and chrominance of lamp beads in the partitions, thereby improving the accuracy of the brightness and chrominance correction of the lamp beads. In the embodiments of the present disclosure, the brightness and chrominance of the lamp beads are corrected on the basis of both the second-layer correction coefficients and first-layer correction coefficients, thereby reducing the colour shift effect caused by temperature changes of the lamp beads, and also optimizing the brightness and chrominance correction of the lamp beads.

Description

Brightness correction method and device for lamp beads of LED display screen, electronic equipment and storage medium

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411230301.3, filed on September 3, 2024, and entitled "Brightness correction method and device for lamp beads of LED display screen, electronic equipment and storage medium", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to, but is not limited to, the technical field of display screen, for example, relates to a brightness correction method and device for lamp beads of LED display screen, electronic equipment and storage medium. BACKGROUND

[0004] A light-emitting diode (LED) display screen is composed of a module and a box body. Since the lamp beads of a display screen come from different batches of wafers, there will be differences, and the module and the box body cannot be completely guaranteed to be on the same plane, which leads to the display effect of the whole screen being a picture with uneven brightness. Therefore, it is necessary to correct the brightness of the display screen. The traditional LED display screen correction method in the industry is as follows: a red, green, blue and white image with 255 gray scales is played on the display screen, a high-definition camera is used to shoot a picture of the display effect of the display screen, and then the brightness and chromaticity values of each lamp point in the group of pictures are analyzed to generate a set of correction coefficients for compensating the brightness and chromaticity of each lamp point, so that the display effect of the display screen after loading the correction coefficients is more uniform.

[0005] SUMMARY

[0006] The following is a summary of the subject matter of the detailed description herein. This summary is not intended to limit the scope of the claims.

[0007] The embodiments of the present disclosure provide a brightness correction method and device for lamp beads of LED display screen, electronic equipment and storage medium, to solve the problem of inaccurate brightness correction of lamp beads of LED display screen, and to improve the accuracy of brightness correction of lamp beads of LED display screen.

[0008] The embodiment of the present disclosure provides a method for correcting the brightness and chroma of a lamp bead of an LED display screen, comprising: obtaining a first layer correction coefficient of the brightness and chroma of the lamp bead in the LED display screen; obtaining a gray mode of a partition of a plurality of frames of source images based on a field programmable gate array (FPGA) within a preset time period, obtaining a temperature change value of the partition based on the gray mode and a preset first mapping curve, the first mapping curve representing a mapping relationship between a gray level of the source image and a temperature of the corresponding lamp bead, and the gray mode being a gray level with the highest frequency within the preset time period; obtaining a color coordinate change value of the partition corresponding to the temperature change value of the partition based on a second mapping curve of the lamp bead temperature change and the lamp bead color coordinate change of the LED display screen, converting the color coordinate change value of the partition into a second layer correction coefficient of the partition; and correcting a current brightness and chroma of the lamp bead of the partition based on the first layer correction coefficient and the second layer correction coefficient.

[0009] According to the method for correcting the brightness and chroma of the lamp bead of the LED display screen provided by the embodiment of the present disclosure, the gray mode of the partition includes a partition gray mode maximum value and a partition gray mode minimum value, the first mapping curve includes first mapping curves of different color categories, and the temperature change value of the partition is obtained based on the gray mode and the preset first mapping curve, which comprises: obtaining a source image sequence number of the partition gray mode maximum value, a color category of the partition gray mode maximum value, a source image sequence number of the partition gray mode minimum value, and a color category of the partition gray mode minimum value; obtaining a maximum temperature value of the partition corresponding to the partition gray mode maximum value in the first mapping curve matching the color category of the partition gray mode maximum value; obtaining a minimum temperature value of the partition corresponding to the partition gray mode minimum value in the first mapping curve matching the color category of the partition gray mode minimum value; and determining the temperature change value of the partition based on the source image sequence number of the partition gray mode maximum value, the source image sequence number of the partition gray mode minimum value, the maximum temperature value of the partition, and the minimum temperature value of the partition.

[0010] According to the method for correcting the brightness and chroma of the lamp bead of the LED display screen provided by the embodiment of the present disclosure, the temperature change value of the partition is determined based on the source image sequence number of the partition gray mode maximum value, the source image sequence number of the partition gray mode minimum value, the maximum temperature value of the partition, and the minimum temperature value of the partition, which comprises: in the case that the source image sequence number of the partition gray mode maximum value is greater than the source image sequence number of the partition gray mode minimum value, the difference between the maximum temperature value of the partition and the minimum temperature value of the partition is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature rise difference; in the case that the source image sequence number of the partition gray mode maximum value is less than the source image sequence number of the partition gray mode minimum value, the absolute value of the difference between the minimum temperature value of the partition and the maximum temperature value of the partition is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature drop difference.

[0011] The method for correcting the brightness and chroma of the lamp beads of the LED display screen according to the embodiments of the present disclosure, the second mapping curve includes a temperature rising mapping curve and a temperature falling mapping curve, the temperature rising mapping curve represents the change of the chroma of the lamp beads when the temperature of the lamp beads rises, and the temperature falling mapping curve represents the change of the chroma of the lamp beads when the temperature of the lamp beads falls, the color coordinate change value of the partition corresponding to the temperature change value of the partition is obtained based on the second mapping curve of the LED display screen, including: obtaining the target color category of the temperature change value of the partition; and in the case that the temperature change value of the partition is a temperature rising difference, obtaining the color coordinate change value of the target color category of the partition corresponding to the temperature rising difference based on the temperature rising mapping curve of the target color category; in the case that the temperature change value of the partition is a temperature falling difference, obtaining the color coordinate change value of the target color category of the partition corresponding to the temperature falling difference based on the temperature falling mapping curve of the target color category.

[0012] The method for correcting the brightness and chroma of the lamp beads of the LED display screen according to the embodiments of the present disclosure, the temperature rising mapping curve is obtained based on the following steps: in the case that the LED display screen is cooled to a constant temperature after being powered off, obtaining the initial temperature of the LED display screen; after the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed on the LED display screen, the color coordinate change value corresponding to the unit temperature rising of the lamp beads is obtained as the temperature of the lamp beads rises, until the temperature of the lamp beads rises to a stable value; and a plurality of pairs of unit temperature rising and corresponding color coordinate change values are fitted by the least square method to obtain the temperature rising mapping curve.

[0013] The method for correcting the brightness and chroma of the lamp beads of the LED display screen according to the embodiments of the present disclosure, the temperature falling mapping curve is obtained based on the following steps: after the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed on the LED display screen until the temperature of the lamp beads rises to a stable value; the lamp beads are uniformly cooled, the color coordinate change value corresponding to the unit temperature falling of the lamp beads is obtained as the temperature of the lamp beads falls, until the temperature of the lamp beads falls to a stable value; and a plurality of pairs of unit temperature falling and corresponding color coordinate change values are fitted by the least square method to obtain the temperature falling mapping curve.

[0014] The method for correcting the brightness and chroma of the lamp beads of the LED display screen according to the embodiments of the present disclosure, the first mapping curve is obtained based on the following steps: a pure color calibration picture is displayed on the LED display screen, the pure color calibration picture includes a plurality of regions with different gray scales of the same color category; in the case that the temperature of the lamp beads is constant, the temperature of the lamp beads corresponding to each gray scale region is obtained; and a plurality of pairs of gray scales and corresponding lamp bead temperatures are fitted by the least square method to obtain the first mapping curve.

[0015] The embodiment of the present disclosure further provides a device for correcting the bright chroma of a lamp bead of an LED display screen, comprising: a first layer correction coefficient determination unit configured to obtain a first layer correction coefficient of the bright chroma of the lamp bead in the LED display screen; a temperature change value determination unit configured to obtain a gray scale mode of a partition of a plurality of frames of source images based on a field programmable gate array (FPGA) in a preset time period, and obtain a temperature change value of the partition based on the gray scale mode and a preset first mapping curve, the first mapping curve representing a mapping relationship between a gray scale level of the source image and a temperature of the corresponding lamp bead, and the gray scale mode being a gray scale with the highest frequency of occurrence in the preset time period; a second layer correction coefficient determination unit configured to obtain a color coordinate change value of the partition corresponding to the temperature change value of the partition based on a second mapping curve of the temperature change of the lamp bead of the LED display screen and the color coordinate change of the lamp bead, and convert the color coordinate change value of the partition into a second layer correction coefficient of the partition; and a correction unit configured to correct a current bright chroma of the lamp bead of the partition based on the first layer correction coefficient and the second layer correction coefficient.

[0016] The embodiment of the present disclosure further provides an electronic device, comprising a memory, a processor, and computer instructions stored in the memory and executable on the processor, and the processor implements the method for correcting the bright chroma of the lamp bead of the LED display screen when executing the computer instructions.

[0017] The embodiment of the present disclosure further provides a non-transitory computer readable storage medium having computer instructions stored thereon, and the computer instructions are executed by a processor to implement the method for correcting the bright chroma of the lamp bead of the LED display screen.

[0018] The embodiment of the present disclosure provides the method, device, electronic device and storage medium for correcting the bright chroma of the lamp bead of the LED display screen, the gray scale mode of the partition of the plurality of frames of source images is obtained in advance by the FPGA, and then the temperature change value of the partition is obtained, so that the temperature change to be occurred in each partition can be obtained in advance, and the second layer correction coefficient of each partition can be obtained in time. The second layer correction coefficient in the preset time period is obtained, so that the second layer correction coefficient can be updated in real time, and the dynamic real-time correction of the bright chroma of the lamp bead of the partition is realized, and the accuracy of the correction of the bright chroma of the lamp bead is improved. The bright chroma of the lamp bead is corrected according to the second layer correction coefficient and the first layer correction coefficient at the same time, the color deviation caused by the temperature change of the lamp bead is reduced, and the correction of the bright chroma of the lamp bead is optimized.

[0019] Other aspects can become apparent after reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions, the following will be a simple introduction to the drawings needed to be used in the embodiments, the drawings in the following description are some embodiments, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0021] Fig. 1 is a flowchart of the brightness correction method of the LED lamp bead of the LED display screen provided by the embodiment of the present disclosure.

[0022] Fig. 2 is a schematic diagram of a calibration picture provided by the embodiment of the present disclosure.

[0023] Fig. 3 is a flowchart of obtaining a first mapping curve and a second mapping curve provided by the embodiment of the present disclosure.

[0024] Fig. 4 is a flowchart of the brightness correction method of the LED lamp bead of the LED display screen provided by the embodiment of the present disclosure.

[0025] Fig. 5 is a schematic diagram of the brightness correction system of the LED lamp bead of the LED display screen provided by the embodiment of the present disclosure.

[0026] Fig. 6 is a structural schematic diagram of the brightness correction device of the LED lamp bead of the LED display screen provided by the embodiment of the present disclosure.

[0027] Fig. 7 is a structural schematic diagram of an electronic device provided by the embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] In order to make the technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be described clearly and completely in the following with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments, rather than all the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the embodiments of the present disclosure.

[0029] In the process of implementing the embodiments of the present disclosure, the applicant found that because the light-emitting characteristics of the LED lamp bead are greatly affected by temperature, after working for a period of time, the temperature rise of the lamp bead itself will cause the previously corrected effect to deteriorate and color deviation to occur. It can be seen that there is an inaccurate brightness correction of the LED lamp bead of the LED display screen.

[0030] The brightness correction method, device and electronic device of the LED lamp bead of the LED display screen of the embodiments of the present disclosure will be described below with reference to Figs. 1-7.

[0031] Fig. 1 is a flowchart of the brightness correction method of the LED lamp bead of the LED display screen provided by the embodiment of the present disclosure, as shown in Fig. 1, the method comprises steps S100 to S400, and each step is as follows.

[0032] S100: Obtain a first layer correction coefficient of a bright chroma of a lamp bead in an LED display screen.

[0033] Since the lamp beads of a display screen are from different batches of wafers, there will be differences, and the module and box splicing cannot be completely guaranteed on the same plane, which leads to the display effect of the whole screen as a picture with uneven bright chroma. The first layer correction coefficient is used to correct the uneven bright chroma display of the lamp beads in the LED display screen due to production and splicing.

[0034] As shown in FIG. 5, the bright chroma correction system of the lamp beads of the LED display screen includes a data acquisition part, a camera, a computer, a sending card and an LED display screen. After the LED display screen is aged for a long enough time, the acquisition data of the LED display screen is obtained through the camera, and the LED display screen is corrected according to the acquisition data to compensate for the uneven display bright chroma caused by the unevenness of production and splicing, so as to obtain the first layer correction coefficient of each lamp bead.

[0035] S200: Obtain the gray-scale mode of the partition of the plurality of frames of source images based on the field programmable gate array (FPGA) within a preset time period, and obtain the temperature change value of the partition based on the gray-scale mode and the preset first mapping curve.

[0036] The first mapping curve represents the mapping relationship between the gray scale of the source image and the temperature of the corresponding lamp bead, and the gray-scale mode is the gray scale with the highest frequency within the preset time period.

[0037] To improve the efficiency of loading the multi-layer correction coefficient, the calculation of the second layer correction coefficient is not accurate to a single pixel (or a single lamp bead), and the partition is set for calculation and superposition. Optionally, as shown in FIG. 5, the partition rule is in units of modules in the box of the LED display screen, and a partition includes a plurality of lamp beads, for example, a module is taken as a partition.

[0038] The source image is an image to be displayed on the LED display screen. The red green blue (RGB) gray scale distribution of each pixel point of each frame of source image on each partition is obtained by the field programmable gate array (FPGA). Since the temperature change caused by the gray scale change has hysteresis, the RGB gray scale distribution data of the plurality of frames of source images within a preset time period (for example, the preset time period is 30s) is accumulated.

[0039] According to the RGB gray scale distribution data of the plurality of frames of source images within the preset time period, the gray scale of the color category with the highest frequency within the preset time period of each partition of the source image is obtained, and the gray-scale mode of the partition (including the maximum value and the minimum value of the partition gray-scale mode) is obtained.

[0040] The first mapping curve of the LED display screen is calibrated in advance, for example, a red first mapping curve of red gray scale and corresponding lamp bead temperature, a green first mapping curve of green gray scale and corresponding lamp bead temperature, and a blue first mapping curve of blue gray scale and corresponding lamp bead temperature are obtained respectively.

[0041] According to the color category of the gray mode of the partition, the temperature of the partition corresponding to each gray mode is obtained from the first mapping curve of the matching color category. The temperature change value of the partition is obtained according to the temperature difference of the partition.

[0042] S300: Obtain the color coordinate change value of the partition corresponding to the temperature change value of the partition based on the second mapping curve of the LED display screen according to the change of the lamp bead temperature and the change of the lamp bead color coordinate. The color coordinate change value of the partition is converted into the second layer correction coefficient of the partition.

[0043] Obtain the temperature change value of the partition and the target color category corresponding to the temperature change value, and obtain the color coordinate change value of the target color category (red, green or blue) of the partition corresponding to the temperature change value of the partition from the second mapping curve of the matching target color category. The color coordinate change value represents the change of the chromaticity of the lamp bead.

[0044] According to the color coordinate change value of the current target color category of the lamp bead in the partition and the current bright chromaticity of the lamp bead, color space conversion is performed to obtain the second layer correction coefficient of the partition.

[0045] S400: Correct the current bright chromaticity of the lamp bead of the partition based on the first layer correction coefficient and the second layer correction coefficient.

[0046] The second layer correction coefficient of each partition is sent to the receiving card of the corresponding partition of the LED display screen. The second layer correction coefficient and the first layer correction coefficient of each partition are superimposed to obtain the superimposed correction coefficient. The gray scale of the lamp bead of the partition is corrected according to the superimposed correction coefficient. The second layer correction coefficient is updated according to the preset time period, for example, the second layer correction coefficient of each partition is updated every 30s. The superimposed correction coefficient of each partition is updated every 30s to realize dynamic correction of the bright chromaticity of the lamp bead of the LED display screen.

[0047] The method for correcting the brightness and chroma of the lamp beads of the LED display screen provided by the embodiments of the present disclosure can pre-acquire the partition gray mode of multiple frames of source images through an FPGA, and then obtain the temperature change value of the partition, so that the temperature change that will occur in each partition can be acquired in advance, and the second layer correction coefficient of each partition can be acquired in time. The second layer correction coefficient in a preset time period is acquired, so that the second layer correction coefficient can be updated in real time, and the dynamic and real-time correction of the brightness and chroma of the lamp beads of the partition is realized, and the accuracy of the correction of the brightness and chroma of the lamp beads is improved. The embodiments of the present disclosure correct the brightness and chroma of the lamp beads according to the second layer correction coefficient and the first layer correction coefficient at the same time, reduce the color deviation caused by the temperature change of the lamp beads, and optimize the correction of the brightness and chroma of the lamp beads.

[0048] Based on the above embodiments, the partition gray mode includes a partition gray mode maximum value and a partition gray mode minimum value, and the first mapping curve includes first mapping curves of different color categories. The temperature change value of the partition is acquired based on the partition gray mode and the preset first mapping curve, which includes steps S210 to S230, and each step is as follows.

[0049] S210: Acquire the source image sequence number of the partition gray mode maximum value, the color category of the partition gray mode maximum value, the source image sequence number of the partition gray mode minimum value, and the color category of the partition gray mode minimum value.

[0050] S220: Acquire the partition maximum temperature value corresponding to the partition gray mode maximum value in the first mapping curve matching the color category of the partition gray mode maximum value.

[0051] S230: Acquire the partition minimum temperature value corresponding to the partition gray mode minimum value in the first mapping curve matching the color category of the partition gray mode minimum value.

[0052] S240: Determine the temperature change value of the partition based on the source image sequence number of the partition gray mode maximum value, the source image sequence number of the partition gray mode minimum value, the partition maximum temperature value, and the partition minimum temperature value.

[0053] Determine the temperature change value of the partition based on the source image sequence number of the partition gray mode maximum value, the source image sequence number of the partition gray mode minimum value, the partition maximum temperature value, and the partition minimum temperature value, including: in the case where the source image sequence number of the partition gray mode maximum value is greater than the source image sequence number of the partition gray mode minimum value, the difference between the partition maximum temperature value and the partition minimum temperature value is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature rise difference; in the case where the source image sequence number of the partition gray mode maximum value is less than the source image sequence number of the partition gray mode minimum value, the difference between the partition minimum temperature value and the partition maximum temperature value is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature drop difference.

[0054] As shown in FIG. 4, the mode of the gray scale distribution of each frame of source image in each partition is calculated according to the FPGA. In the case that the preset time period is 30s, the mode of the gray scale distribution of the gray scale of the RGB three channels in the current partition of multiple source pictures within 30s is calculated to obtain multiple gray scales with the highest frequency (multiple modes of gray scale), the source image sequence number corresponding to each mode of gray scale, and the color category corresponding to each mode of gray scale.

[0055] The maximum value of the mode of gray scale of the partition, the source image sequence number of the maximum value of the mode of gray scale of the partition, the minimum value of the mode of gray scale of the partition, the source image sequence number of the minimum value of the mode of gray scale of the partition, the color category of the maximum value of the mode of gray scale of the partition, and the color category of the minimum value of the mode of gray scale of the partition are determined from the multiple modes of gray scale of the partition within 30s. The maximum value of the mode of gray scale of the partition and the minimum value of the mode of gray scale of the partition are substituted into the first mapping curve of the corresponding color category to obtain the maximum temperature value corresponding to the maximum value of the mode of gray scale of the partition and the minimum temperature value corresponding to the minimum value of the mode of gray scale of the partition.

[0056] The temperature change value of the partition is determined based on the source image sequence number of the maximum value of the mode of gray scale of the partition, the source image sequence number of the minimum value of the mode of gray scale of the partition, the maximum temperature value of the partition, and the minimum temperature value of the partition. Optionally, in the case that the source image sequence number of the maximum value of the mode of gray scale of the partition is greater than the source image sequence number of the minimum value of the mode of gray scale of the partition, the difference between the maximum temperature value of the partition and the minimum temperature value of the partition is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature rise difference. In the case that the source image sequence number of the maximum value of the mode of gray scale of the partition is less than the source image sequence number of the minimum value of the mode of gray scale of the partition, the absolute value of the difference between the minimum temperature value of the partition and the maximum temperature value of the partition is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature drop difference.

[0057] The size of the source image sequence number of the maximum value of the mode of gray scale of the partition and the source image sequence number of the minimum value of the mode of gray scale of the partition in each partition is compared. The sequence number of the source image represents the order of the display of the source image. The smaller the source image sequence number is, the earlier the source image is displayed. The larger the source image sequence number is, the later the source image is displayed.

[0058] In the case that the source image sequence number of the maximum value of the mode of gray scale of the partition is greater than the source image sequence number of the minimum value of the mode of gray scale of the partition in the same partition, it is indicated that the temperature of the partition within 30s is slowly increased from the minimum temperature value of the partition to the maximum temperature value of the partition. At this time, the difference between the maximum temperature value of the partition and the minimum temperature value of the partition is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature rise difference.

[0059] In a case where the source image sequence number of the partition gray scale mode minimum value is greater than the source image sequence number of the partition gray scale mode maximum value in the same partition, it is indicated that the temperature of the partition in 30s is slowly decreased from the partition maximum temperature value to the partition minimum temperature value. At this time, the absolute value of the difference between the partition minimum temperature value and the partition maximum temperature value is taken as the temperature change value of the partition, and the temperature change value of the partition is the cooling temperature difference.

[0060] The embodiment of the present disclosure compares the source image sequence number of the partition gray scale mode maximum value and the source image sequence number of the partition gray scale mode minimum value, realizes the judgment of the temperature change value as the heating temperature difference or the cooling temperature difference, and is beneficial to improve the accuracy of determining the second layer correction coefficient. The LED display screen is divided into multiple partitions, and the efficiency of obtaining the second layer correction coefficient of the LED display screen is improved.

[0061] Based on the above embodiment, the second mapping curve includes a heating mapping curve and a cooling mapping curve, the heating mapping curve represents the change of the colorimetric value of the lamp bead when the temperature of the lamp bead increases, and the cooling mapping curve represents the change of the colorimetric value of the lamp bead when the temperature of the lamp bead decreases. The second mapping curve based on the change of the temperature of the lamp bead of the LED display screen and the change of the color coordinate of the lamp bead is used to obtain the color coordinate change value of the partition corresponding to the temperature change value of the partition, which includes steps S310 to S330, and each step is as follows.

[0062] S310: Obtain the target color category of the temperature change value of the partition.

[0063] S320: In a case where the temperature change value of the partition is a heating temperature difference, obtain the color coordinate change value of the target color category of the partition corresponding to the heating temperature difference based on the heating mapping curve of the target color category.

[0064] S330: In a case where the temperature change value of the partition is a cooling temperature difference, obtain the color coordinate change value of the target color category of the partition corresponding to the cooling temperature difference based on the cooling mapping curve of the target color category.

[0065] In a case where the temperature change value of the current partition of the LED display screen is a heating temperature difference, the heating temperature difference is substituted into the heating mapping curve corresponding to the target color category to obtain the color coordinate change value corresponding to the heating temperature difference. Knowing the color coordinate change value of the LED display screen in the current partition, color space conversion is performed according to the bright colorimetric value and the color coordinate change value of the lamp bead in the current partition to obtain the second layer correction coefficient of the current partition.

[0066] In a case where the temperature change value of the current partition of the LED display screen is a cooling temperature difference, the cooling temperature difference is substituted into the cooling mapping curve of the corresponding target color category to obtain a color coordinate change value corresponding to the cooling temperature difference. Given the color coordinate change value of the LED display screen in the current partition, color space conversion is performed according to the light bead brightness and the color coordinate change value of the current partition to obtain the second layer correction coefficient of the current partition.

[0067] The embodiment of the present disclosure obtains the color coordinate change value according to the pre-calibrated temperature rise mapping curve or temperature drop mapping curve of the target color category, improves the efficiency and accuracy of determining the color coordinate change value of each partition, and is beneficial to improving the efficiency and accuracy of determining the second layer correction coefficient of each partition.

[0068] Based on the above embodiment, the temperature rise mapping curve is obtained based on steps S340 to S360, and each step is as follows.

[0069] S340: In a case where the LED display screen is powered off and cooled to a constant temperature, an initial temperature of the LED display screen is obtained.

[0070] S350: After the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed on the LED display screen. As the temperature of the light beads rises, the color coordinate change value corresponding to the unit temperature rise of the light beads is obtained until the temperature of the light beads rises to a stable value.

[0071] S360: A plurality of pairs of unit temperature rise and corresponding color coordinate change values are fitted by the least square method to obtain a temperature rise mapping curve.

[0072] As shown in FIG. 3, the temperature gun and the colorimeter are fixedly installed in the central region of the LED display screen. The LED display screen is powered off and cooled to a constant temperature (or room temperature), and the initial temperature of the current LED display screen is recorded. After the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed, for example, a white picture with a screen grayscale of 255. At the same time, the temperature change value and the color coordinate change value of the light beads are measured and recorded by using the temperature gun and the colorimeter. The temperature change of the temperature gun is observed, and the color change value of the light beads is measured and recorded every unit temperature rise (for example, every 0.1℃). The color change value is converted to a color coordinate change value in proportion, until the temperature of the light beads rises to a stable state (or no longer rises). A plurality of pairs of unit temperature rise and color coordinate change value mapping points are obtained. The plurality of pairs of unit temperature rise and color coordinate change value mapping points are fitted by the least square method to obtain a temperature rise mapping curve of white.

[0073] The above steps are repeated, the screen picture of the LED display screen is replaced by a red picture with a screen grayscale of 255, a green picture with a screen grayscale of 255, or a blue picture with a screen grayscale of 255, and a temperature rise mapping curve of red, a temperature rise mapping curve of green, and a temperature rise mapping curve of blue are obtained, respectively.

[0074] The embodiment of the present disclosure improves the accuracy of obtaining the temperature rising mapping curve by fitting the unit temperature rising temperature and the corresponding color coordinate change value under the pure color picture.

[0075] Based on the above embodiment, the temperature rising mapping curve is obtained based on steps S370 to S390, and each step is as follows.

[0076] S370: When the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed on the LED display screen until the temperature of the lamp beads rises to a stable value.

[0077] S380: The lamp beads are uniformly cooled to obtain the color coordinate change value corresponding to the unit temperature falling temperature of the lamp beads until the temperature of the lamp beads falls to a stable value.

[0078] S390: A least square fitting is performed on the multiple pairs of unit temperature falling temperature and corresponding color coordinate change value to obtain the temperature falling mapping curve.

[0079] As shown in FIG. 3, the temperature gun and the colorimeter in the data acquisition part are fixedly installed in the central region of the LED display screen. The display screen is powered off and cooled to a constant temperature (or room temperature) to obtain the initial temperature of the LED display screen. The LED display screen is powered on, and a pure color picture with a screen grayscale of 255 is displayed on the LED display screen, for example, a white picture with a screen grayscale of 255 is displayed, until the temperature of the LED display screen rises to a stable value. A physical method is used to uniformly cool the measurement region of the LED display screen. At the same time, the temperature change value and the color change value of the lamp beads are measured and recorded by using the temperature gun and the colorimeter, and the color change value is converted into the color coordinate change value in proportion. The temperature change of the temperature gun is observed, and the color coordinate change value of the lamp beads is measured and recorded every unit temperature falling temperature (for example, every 0.1°C), until the temperature of the lamp beads falls to a stable state (or the initial temperature). A plurality of pairs of mapping points of unit temperature falling temperature and color coordinate change value are obtained. The least square fitting is performed on the multiple pairs of mapping points of unit temperature falling temperature and color coordinate change value to obtain the temperature falling mapping curve of white.

[0080] The above steps are repeated, the screen picture of the LED display screen is replaced by a red picture with a screen grayscale of 255, a green picture with a screen grayscale of 255, or a blue picture with a screen grayscale of 255, and the temperature falling mapping curve of red, the temperature falling mapping curve of green, and the temperature falling mapping curve of blue are obtained respectively.

[0081] The embodiment of the present disclosure improves the accuracy of obtaining the temperature rising mapping curve by fitting the unit temperature rising temperature and the corresponding color coordinate change value under the pure color picture.

[0082] Based on the above embodiment, the first mapping curve is obtained based on steps S250 to S270.

[0083] S250: screen a pure color calibration picture to the LED display screen, the pure color calibration picture including a plurality of regions of different gray scales of the same color category.

[0084] S260: in the case that the temperature of the lamp bead is constant, the temperature of the lamp bead corresponding to each gray scale region is obtained.

[0085] S270: a least square fitting is performed on the plurality of pairs of gray scales and the corresponding temperatures of the lamp beads, to obtain a first mapping curve.

[0086] As shown in FIG. 2, three pure color calibration pictures of 1920*1080 resolution are made, which are pictures of the same color category arranged from 0 to 255 gray scales of red, green and blue respectively. The LED display screen is aged and corrected to obtain the first layer correction coefficient. The pure color calibration picture (for example, the red calibration picture) is screened to the LED display screen, and the screening time is long enough to make the temperature of the lamp bead constant. The temperature of the lamp bead corresponding to the region of different gray scales is measured by using the temperature gun, and the mapping points of the plurality of red gray scales and the temperature of the lamp bead are recorded. The least square method is used for data statistics, and the mapping points of the plurality of red gray scales and the temperature of the lamp bead are fitted to obtain the first mapping curve of red.

[0087] Optionally, the screened picture is replaced by the green calibration picture and the blue calibration picture, and the above steps are repeated to obtain the first mapping curve of green and the first mapping curve of blue.

[0088] The present application constructs the mapping relationship between the gray scale of the image and the temperature of the lamp bead by calibrating the gray scale and the temperature of the lamp bead, which is beneficial to realize the temperature change of the lamp bead by the gray scale change of the source image.

[0089] The following describes the bright chroma correction device of the lamp bead of the LED display screen provided by the embodiments of the present disclosure, which can be correspondingly referred to each other with the bright chroma correction method of the lamp bead of the LED display screen described above.

[0090] As shown in FIG. 6, a bright chroma correction device of a lamp bead of an LED display screen includes a first layer correction coefficient determination unit 601 configured to obtain a first layer correction coefficient of the bright chroma of the lamp bead in the LED display screen.

[0091] A temperature change value determination unit 602 is configured to obtain the gray scale mode of the partition of the plurality of frames of source images based on the field programmable gate array (FPGA) within a preset time period, and obtain the temperature change value of the partition based on the gray scale mode and the preset first mapping curve, the first mapping curve representing the mapping relationship between the gray scale of the source image and the temperature of the corresponding lamp bead, and the gray scale mode being the gray scale with the highest frequency within the preset time period.

[0092] The second layer correction coefficient determination unit 603 is configured to obtain the color coordinate change value of the partition corresponding to the temperature change value of the partition based on the second mapping curve of the LED display screen, and convert the color coordinate change value of the partition into the second layer correction coefficient of the partition.

[0093] The correction unit 604 is configured to correct the current brightness of the lamp bead of the partition based on the first layer correction coefficient and the second layer correction coefficient.

[0094] The LED display screen lamp bead brightness correction device provided by the embodiment of the present disclosure can obtain the gray mode of the partition of the plurality of source images in advance through the FPGA, and then obtain the temperature change value of the partition, so that the temperature change of each partition can be obtained in advance, and the second layer correction coefficient of each partition can be obtained in time. The second layer correction coefficient in the preset time period is obtained, so that the second layer correction coefficient can be updated in real time, and the dynamic real-time correction of the brightness of the lamp bead of the partition is realized, and the accuracy of the brightness correction of the lamp bead is improved. The brightness of the lamp bead is corrected according to the second layer correction coefficient and the first layer correction coefficient at the same time, so that the color deviation caused by the temperature change of the lamp bead is reduced, and the brightness correction of the lamp bead is optimized.

[0095] In one embodiment, the gray mode of the partition includes a partition gray mode maximum value and a partition gray mode minimum value, the first mapping curve includes a first mapping curve of different color categories, and the temperature change value determination unit 602 is configured to: obtain the source image sequence number of the partition gray mode maximum value, the color category of the partition gray mode maximum value, the source image sequence number of the partition gray mode minimum value, and the color category of the partition gray mode minimum value; obtain the maximum temperature value of the partition corresponding to the partition gray mode maximum value in the first mapping curve matching the color category of the partition gray mode maximum value; obtain the minimum temperature value of the partition corresponding to the partition gray mode minimum value in the first mapping curve matching the color category of the partition gray mode minimum value; and determine the temperature change value of the partition based on the source image sequence number of the partition gray mode maximum value, the source image sequence number of the partition gray mode minimum value, the maximum temperature value of the partition, and the minimum temperature value of the partition.

[0096] In one embodiment, the temperature change value determination unit 602 is configured to: in the case that the source image sequence number of the maximum gray value of the partition is greater than the source image sequence number of the minimum gray value of the partition, then the difference between the maximum temperature value of the partition and the minimum temperature value of the partition is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature rise difference; in the case that the source image sequence number of the maximum gray value of the partition is less than the source image sequence number of the minimum gray value of the partition, then the absolute value of the difference between the minimum temperature value of the partition and the maximum temperature value of the partition is taken as the temperature change value of the partition, and the temperature change value of the partition is a temperature drop difference.

[0097] In one embodiment, the second mapping curve includes a temperature rise mapping curve and a temperature drop mapping curve, the temperature rise mapping curve represents the change of the colorimetric value of the lamp bead when the temperature of the lamp bead rises, and the temperature drop mapping curve represents the change of the colorimetric value of the lamp bead when the temperature of the lamp bead drops, and the second layer correction coefficient determination unit 603 is configured to: obtain the target color type of the temperature change value of the partition; in the case that the temperature change value of the partition is a temperature rise difference, obtain the color coordinate change value of the target color type of the partition corresponding to the temperature rise difference based on the temperature rise mapping curve of the target color type; in the case that the temperature change value of the partition is a temperature drop difference, obtain the color coordinate change value of the target color type of the partition corresponding to the temperature drop difference based on the temperature drop mapping curve of the target color type.

[0098] In one embodiment, the second layer correction coefficient determination unit 603 is further configured to: in the case that the LED display screen is cooled to a constant temperature after power-off, obtain the initial temperature of the LED display screen; after the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed on the LED display screen, and the color coordinate change value corresponding to the unit temperature rise of the lamp bead is obtained as the temperature of the lamp bead rises until the temperature of the lamp bead rises to a stable value; a plurality of pairs of unit temperature rise and corresponding color coordinate change values are fitted by the least square method to obtain the temperature rise mapping curve.

[0099] In one embodiment, the second layer correction coefficient determination unit 603 is further configured to: when the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed on the LED display screen until the temperature of the lamp bead rises to a stable value; the lamp bead is uniformly cooled, the color coordinate change value corresponding to the unit temperature drop of the lamp bead is obtained as the temperature of the lamp bead drops until the temperature of the lamp bead drops to a stable value; a plurality of pairs of unit temperature drop and corresponding color coordinate change values are fitted by the least square method to obtain the temperature drop mapping curve.

[0100] In one embodiment, the temperature change value determination unit 602 is configured to: display a pure color calibration picture on the LED display screen, the pure color calibration picture including a plurality of regions of different gray scales of the same color category; obtain the temperature of the lamp bead corresponding to each gray scale region under the condition that the temperature of the lamp bead is constant; and perform least square fitting on the plurality of pairs of gray scales and the corresponding lamp bead temperatures to obtain a first mapping curve.

[0101] FIG. 7 shows a schematic diagram of the physical structure of an electronic device. As shown in FIG. 7, the electronic device can include a processor 710, a communications interface 720, a memory 730, and a communications bus 740, wherein the processor 710, the communications interface 720, and the memory 730 complete communications with each other through the communications bus 740. The processor 710 can invoke a logical instruction in the memory 730 to execute a bright color correction method for the lamp bead of the LED display screen, the method including: obtaining a first layer correction coefficient of the bright color of the lamp bead in the LED display screen; obtaining a gray scale mode of a partition of a plurality of frames of source images based on a field programmable gate array (FPGA) within a preset time period, obtaining a temperature change value of the partition based on the gray scale mode and a preset first mapping curve, the first mapping curve representing a mapping relationship between the gray scale of the source image and the temperature of the corresponding lamp bead, and the gray scale mode being a gray scale with the highest frequency of occurrence within the preset time period; obtaining a color coordinate change value of the partition corresponding to the temperature change value of the partition based on a second mapping curve of the lamp bead temperature change and the lamp bead color coordinate change of the LED display screen, converting the color coordinate change value of the partition into a second layer correction coefficient of the partition; and correcting the current bright color of the lamp bead of the partition based on the first layer correction coefficient and the second layer correction coefficient.

[0102] In addition, the logical instruction in the memory 730 described above can be implemented in the form of a software functional unit and sold or used as an independent product, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present disclosure essentially or in part or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present disclosure. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various other media that can store instructions.

[0103] In yet another aspect, the present disclosure also provides a non-transitory computer-readable storage medium having stored thereon computer instructions that, when executed by a processor, implement a method for correcting the bright chromaticity of a lamp bead of an LED display screen, the method comprising: obtaining a first layer correction coefficient of the bright chromaticity of the lamp bead in the LED display screen; obtaining, based on a field programmable gate array (FPGA), a gray-scale mode of a partition of a plurality of frames of source images within a preset time period, obtaining a temperature change value of the partition based on the gray-scale mode and a preset first mapping curve, the first mapping curve representing a mapping relationship between a gray scale of the source images and a temperature of the corresponding lamp bead, the gray-scale mode being a gray scale with the highest frequency of occurrence within the preset time period; obtaining a color coordinate change value of the partition corresponding to the temperature change value of the partition based on a second mapping curve of the temperature change of the lamp bead of the LED display screen and the color coordinate change of the lamp bead, converting the color coordinate change value of the partition into a second layer correction coefficient of the partition; and correcting a current bright chromaticity of the lamp bead of the partition based on the first layer correction coefficient and the second layer correction coefficient.

[0104] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected to implement the present embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0105] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be implemented by means of software plus a general hardware platform, and of course can also be implemented by hardware. Based on such understanding, the above technical solutions or the essential part or contribution made can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in the various embodiments or some parts of the embodiments.

[0106] The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the above-mentioned embodiments are described in detail, the technical solutions recorded in the above-mentioned embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the corresponding technical solutions deviate from the scope of the technical solutions of the present disclosure.

Claims

1. A method for correcting luminance of a lamp bead of an LED display screen, comprising: obtaining a first layer correction coefficient of luminance of a lamp bead in an LED display screen; obtaining a gray scale mode of a partition of a plurality of frames of source images based on a field programmable gate array (FPGA) within a preset time period, obtaining a temperature change value of the partition based on the gray scale mode and a preset first mapping curve, the first mapping curve representing a mapping relationship between a gray scale level of a source image and a temperature of a corresponding lamp bead, the gray scale mode being a gray scale with the highest frequency within the preset time period; obtaining a color coordinate change value of the partition corresponding to the temperature change value of the partition based on a second mapping curve of lamp bead temperature change and lamp bead color coordinate change of the LED display screen, converting the color coordinate change value of the partition into a second layer correction coefficient of the partition; and correcting a current luminance of the lamp bead of the partition based on the first layer correction coefficient and the second layer correction coefficient. The gray scale mode of the partition includes a maximum partition gray scale mode and a minimum partition gray scale mode, the first mapping curve includes first mapping curves of different color categories, and the obtaining of the temperature change value of the partition based on the gray scale mode and the preset first mapping curve comprises: obtaining a source image sequence number of the maximum partition gray scale mode, a color category of the maximum partition gray scale mode, a source image sequence number of the minimum partition gray scale mode, and a color category of the minimum partition gray scale mode; 2.The method of claim 1, wherein, obtaining a maximum temperature value of the partition corresponding to the maximum partition gray scale mode in the first mapping curve matching the color category of the maximum partition gray scale mode; obtaining a minimum temperature value of the partition corresponding to the minimum partition gray scale mode in the first mapping curve matching the color category of the minimum partition gray scale mode; and determining the temperature change value of the partition based on the source image sequence number of the maximum partition gray scale mode, the source image sequence number of the minimum partition gray scale mode, the maximum temperature value of the partition, and the minimum temperature value of the partition. The determining of the temperature change value of the partition based on the source image sequence number of the maximum partition gray scale mode, the source image sequence number of the minimum partition gray scale mode, the maximum temperature value of the partition, and the minimum temperature value of the partition comprises: in a case where the source image sequence number of the maximum partition gray scale mode is greater than the source image sequence number of the minimum partition gray scale mode, taking a difference between the maximum temperature value of the partition and the minimum temperature value of the partition as a temperature change value of the partition, the temperature change value of the partition being a temperature rise difference; 3. The method of claim 1 or 2, wherein, in a case where the source image sequence number of the maximum partition gray scale mode is less than the source image sequence number of the minimum partition gray scale mode, taking an absolute value of a difference between the minimum temperature value of the partition and the maximum temperature value of the partition as the temperature change value of the partition, the temperature change value of the partition being a temperature drop difference. ​ ​ 4. The method of claim 1-3, wherein, The second mapping curve includes a temperature rising mapping curve and a temperature falling mapping curve, the temperature rising mapping curve represents a change of the color coordinates of the lamp bead when the temperature of the lamp bead rises, and the temperature falling mapping curve represents a change of the color coordinates of the lamp bead when the temperature of the lamp bead falls, the second mapping curve based on the temperature change and the color coordinate change of the lamp bead of the LED display screen is used to obtain the color coordinate change value of the partition corresponding to the temperature change value of the partition, including: obtaining a target color category of the temperature change value of the partition; and in the case that the temperature change value of the partition is a temperature rising difference, obtaining the color coordinate change value of the target color category of the partition corresponding to the temperature rising difference based on the temperature rising mapping curve of the target color category; in the case that the temperature change value of the partition is a temperature falling difference, obtaining the color coordinate change value of the target color category of the partition corresponding to the temperature falling difference based on the temperature falling mapping curve of the target color category.

5. The method of claim 1-4, wherein, The temperature rising mapping curve is obtained based on the following steps: cooling the LED display screen to a constant temperature under power-off, obtaining an initial temperature of the LED display screen; after the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed on the LED display screen, and the color coordinate change value corresponding to the unit temperature rising of the lamp bead is obtained as the temperature of the lamp bead rises until the temperature of the lamp bead rises to a stable value; and performing least square fitting on multiple pairs of the unit temperature rising and the corresponding color coordinate change value to obtain the temperature rising mapping curve. The temperature falling mapping curve is obtained based on the following steps:

6. The method of claim 1-4, wherein, after the LED display screen is powered on, a pure color picture with a screen grayscale of 255 is displayed on the LED display screen until the temperature of the lamp bead rises to a stable value; uniformly cooling the lamp bead to obtain the color coordinate change value corresponding to the unit temperature falling of the lamp bead until the temperature of the lamp bead falls to a stable value; and performing least square fitting on multiple pairs of the unit temperature falling and the corresponding color coordinate change value to obtain the temperature falling mapping curve. The first mapping curve is obtained based on the following steps: displaying a pure color calibration picture on the LED display screen, the pure color calibration picture including multiple regions of different gray levels of the same color category; 7. The method of claim 1-6, wherein, obtaining the temperature of the lamp bead corresponding to each of the gray level regions when the temperature of the lamp bead is constant; and performing least square fitting on multiple pairs of the gray level and the corresponding temperature of the lamp bead to obtain the first mapping curve.

8. A bright color correction device for a lamp bead of an LED display screen, including: a first layer correction coefficient determination unit configured to obtain a first layer correction coefficient of the bright color of the lamp bead in the LED display screen; ​ ​ ​ The temperature change value determination unit is configured to obtain a gray-scale mode of a partition of a plurality of source images based on a field programmable gate array (FPGA) within a preset time period, and obtain a temperature change value of the partition based on the gray-scale mode and a preset first mapping curve, the first mapping curve representing a mapping relationship between a gray-scale level of the source image and a temperature of a corresponding lamp bead, the gray-scale mode being a gray-scale with the highest frequency within the preset time period; The second layer correction coefficient determination unit is configured to obtain a color coordinate change value of the partition corresponding to the temperature change value of the partition based on a second mapping curve of lamp bead temperature change and lamp bead color coordinate change of the LED display screen, and convert the color coordinate change value of the partition into a second layer correction coefficient of the partition; and The correction unit is configured to correct a current brightness of the lamp bead of the partition based on the first layer correction coefficient and the second layer correction coefficient. 9.An electronic device, comprising a memory, a processor, and computer instructions stored on the memory and executable on the processor, wherein the processor executes the computer instructions to implement the brightness correction method of the lamp bead of the LED display screen according to any one of claims 1 to 7. 10.A non-transitory computer readable storage medium having stored thereon computer instructions that, when executed by a processor, implement the brightness correction method of the lamp bead of the LED display screen according to any one of claims 1 to 7.

Images