Brightness uniformity correction methods, electronic devices and storage media

Abstract

This application discloses a brightness uniformity correction method, electronic device, and storage medium, relating to the field of display technology. The brightness uniformity correction method includes: determining the target optical center coordinates of pixel units in the display module at a preset grayscale based on a first image of the display module; determining the brightness observation value of the pixel unit at the preset grayscale based on the target optical center coordinates and the grayscale value of the pixel in the first image; determining the grayscale response parameters of the pixel unit based on the brightness observation values ​​of the pixel unit at different grayscales; constructing a grayscale compensation mapping relationship for the display module based on the grayscale response parameters; determining the actual driving grayscale corresponding to each pixel unit at the current input grayscale based on the grayscale compensation mapping relationship, and driving the display module to display based on the actual driving grayscale. This application effectively solves the problem of uneven brightness in display modules.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to brightness uniformity correction methods, electronic devices, and storage media. Background Technology

[0002] Micro LED (micro-light-emitting diode) display technology is considered a strong contender for next-generation display technology due to its superior characteristics such as high brightness, low power consumption, and high response speed. However, limited by the precision of mass transfer processes and the consistency constraints of LED epitaxial wafer growth, Micro LED screens are prone to brightness unevenness (mura), which reduces display quality and affects the user's visual experience. Summary of the Invention

[0003] The main objective of this application is to provide a brightness uniformity correction method, an electronic device, and a storage medium. The embodiments of this application effectively solve the problem of uneven brightness in display modules.

[0004] To achieve the above objectives, this application proposes a brightness uniformity correction method, the method comprising: Based on the first image of the display module, the target optical center coordinates of the pixel units of the display module under a preset grayscale are determined, wherein the display module displays a fully bright image under the preset grayscale in the first image; Based on the target optical center coordinates and the grayscale values ​​of the pixels in the first image, the brightness observation value of the pixel unit at the preset grayscale is determined; The grayscale response parameters of the pixel unit are determined based on the observed brightness values ​​of the pixel unit at different grayscale levels. Based on the grayscale response parameters, a grayscale compensation mapping relationship for the display module is constructed, wherein the grayscale compensation mapping relationship is used to indicate the driving grayscale corresponding to each pixel unit of the display module under different input grayscale levels; Based on the grayscale compensation mapping relationship, the actual driving grayscale corresponding to each pixel unit under the current input grayscale is determined, and the display module is driven to display based on the actual driving grayscale.

[0005] In one embodiment, the step of determining the target optical center coordinates of the pixel units of the display module at a preset grayscale based on the first image of the display module includes: When the preset grayscale is the reference grayscale, the initial optical center coordinates of the pixel units of the display module under the preset grayscale are determined according to the first image; Based on the local gray-level centroid method, the initial optical center coordinates are corrected to obtain the target optical center coordinates under the preset gray level.

[0006] In one embodiment, the step of determining the initial optical center coordinates of the pixel units of the display module at the preset grayscale based on the first image includes: Based on the physical resolution of the display module, a standard grid associated with the display module is constructed, wherein the corner points of the standard grid correspond to the pixel units of the display module; Obtain the corner information of the first pixel unit of the display module; Based on the corner information of the first pixel unit and the standard grid, a homography matrix is ​​determined, wherein the homography matrix is ​​used to indicate the mapping relationship between the grid system coordinates of the standard grid and the image coordinate system of the first image; Based on the homography matrix, the grid intersections in the standard grid are mapped to the image coordinate system to obtain the initial optical center coordinates.

[0007] In one embodiment, the step of obtaining the corner information of the first pixel unit of the display module includes: A second image of the display module is obtained, wherein the display module displays a preset sparse dot matrix pattern in the second image, the sparse dot matrix pattern includes illuminated pixel units arranged at preset intervals, and each corner area of ​​the display module includes at least one illuminated pixel unit. Based on the effective bright spots in the second image, the corner information of the first pixel unit of the display area of ​​the display module is determined, wherein the effective bright spots correspond to the lit pixel units in the display module.

[0008] In one embodiment, the step of determining the target optical center coordinates of the pixel units of the display module at a preset grayscale based on the first image of the display module includes: When the preset grayscale is a non-reference grayscale, obtain the corner information of the second pixel unit of the display module at the preset grayscale; Calculate the corner offset between the corner information of the second pixel unit and the corner information of the pixel unit under the reference gray level; If the corner offset is less than a preset offset threshold, the target optical center coordinates under the reference gray level are determined as the target optical center coordinates under the preset gray level. If the corner offset is greater than or equal to a preset offset threshold, the target optical center coordinates under the reference grayscale are offset compensated according to the corner offset to obtain the target optical center coordinates under the preset grayscale.

[0009] In one embodiment, the step of obtaining the corner information of the second pixel unit of the display module under the preset grayscale includes: Edge recognition is performed in the corner interest region of the first image to obtain physical corner information, wherein the corner interest region is determined based on the pixel unit corner information under the reference gray level; Based on the imaging radius of the pixel unit and the physical corner information, the corner information of the second pixel unit under the preset grayscale is determined.

[0010] In one embodiment, the step of determining the brightness observation value of the pixel unit at the preset grayscale based on the target optical center coordinates and the grayscale value of the pixel in the first image includes: A sampling window is constructed with the target optical center coordinates as the center, wherein the size of the sampling window matches the size of the pixel unit; Based on the overlap area between each pixel in the first image and the sampling window, the brightness weight associated with each pixel in the first image is determined, wherein the brightness weight is positively correlated with the overlap area; The brightness observation value is determined based on the grayscale value of each pixel in the first image and its associated brightness weight.

[0011] In one embodiment, the step of determining the grayscale response parameter of the pixel unit based on the brightness observation values ​​of the pixel unit at different grayscale levels includes: Based on the brightness observation values ​​of the pixel unit at different gray levels, a gray level response model of the pixel unit is constructed, wherein the gray level response model is used to indicate the mapping relationship between gray levels and brightness observation values; The grayscale response parameters are determined based on the grayscale response model.

[0012] In one embodiment, the step of constructing the grayscale compensation mapping relationship of the display module based on the grayscale response parameters includes: Based on the standard grayscale response curve associated with the display module, determine the target brightness corresponding to each input grayscale. Based on the grayscale response parameters, the driving grayscale required for the pixel unit to achieve each of the target brightnesses is determined, and the grayscale compensation mapping relationship is constructed.

[0013] Furthermore, to achieve the above objectives, this application also proposes an electronic device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the brightness uniformity correction method described above.

[0014] Furthermore, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the brightness uniformity correction method described above.

[0015] In addition, to achieve the above objectives, this application also proposes a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the brightness uniformity correction method described above.

[0016] One or more technical solutions proposed in this application have at least the following technical effects: A brightness uniformity correction method is provided. By acquiring a first image of a fully bright screen displayed at a preset grayscale by a display module, the target optical center coordinates of pixel units in the display module at the preset grayscale are determined, thereby achieving precise positioning of each pixel unit in the image. Furthermore, the brightness observation value of the pixel unit at the preset grayscale is determined by combining the grayscale value of the pixel in the first image, so that the brightness extraction can accurately reflect the true luminous intensity of each pixel unit. Further, by using the brightness observation values ​​of the pixel unit at different grayscales obtained in the above manner, the grayscale response parameters of each pixel unit are determined, thereby obtaining the unique grayscale response characteristics of each pixel unit. A grayscale compensation mapping relationship for the display module is constructed based on these grayscale response parameters. This mapping relationship records the driving grayscale required by each pixel unit of the display module at different input grayscales. Then, when the display module is displaying, the actual driving grayscale corresponding to each pixel unit can be obtained by querying this mapping relationship based on the current input grayscale, and the display module is driven by this actual driving grayscale. Since the actual driving grayscale of each pixel unit is calculated in reverse based on its own grayscale response parameters, the pixel units that originally had inconsistent brightness responses can output a similar brightness value when receiving the same current input grayscale. This effectively eliminates the problem of uneven brightness caused by the difference in grayscale response characteristics between pixel units, and improves the display uniformity and image quality consistency of the display module. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the first embodiment of the present application; Figure 2 A flowchart illustrating the second embodiment of this application; Figure 3 A flowchart illustrating the third embodiment of this application; Figure 4 This is a flowchart illustrating the fourth embodiment of the present application; Figure 5 This is a schematic diagram of the hardware operating environment of the electronic device involved in the embodiments of this application.

[0020] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0022] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0023] The first embodiment of this application provides a brightness uniformity correction method. It should be noted that the subject executing the brightness uniformity correction method can be an electronic device. The electronic device can be a local device, such as a television, computer, laptop, mobile phone, smartwatch, etc., or it can be a virtual device. This embodiment of the application does not limit this. For ease of description, the execution subject is omitted from the following description of each embodiment.

[0024] Reference Figure 1 Brightness uniformity correction methods include: Step S10: Determine the target optical center coordinates of the pixel units of the display module at a preset grayscale based on the first image of the display module.

[0025] In the first image, the display module shows a fully bright image at a preset grayscale.

[0026] In one feasible embodiment, the display module is controlled to display a fully bright image at a preset grayscale, and an image acquisition device is used to acquire an image of the display module to obtain a first image of the display module. Based on the first image, the target optical center coordinates of each pixel unit of the display module at the preset grayscale are determined.

[0027] Optionally, a display module refers to a functional unit that includes a display panel and its driving circuitry. For example, a display module can be a Micro LED display module, which is a display device composed of a micro light-emitting diode (Micro LED) array, including multiple pixel units, a driving chip for driving each pixel unit to emit light, and related interface circuitry and a flexible circuit board. A display module can be a standalone display panel or a complete display assembly with integrated driving circuitry.

[0028] Optionally, a pixel unit refers to the smallest display unit in a display module that can be independently controlled to emit light. For example, in Micro LED display technology, one pixel unit corresponds to one or more Micro LED chips. Pixel units are the basic elements that constitute the display image, and each pixel unit emits light of a corresponding brightness under the control of a driving signal.

[0029] Optionally, a preset grayscale level refers to a pre-defined gray level used to quantize the brightness levels of the display module from the darkest to the brightest. For example, in digital display systems, grayscale levels are typically represented by integers from 0 to 255, where 0 corresponds to the lowest brightness (complete black) and 255 corresponds to the highest brightness (complete bright). In the embodiments of this application, the preset grayscale level can be any grayscale value, such as 255 grayscale (highest brightness), 240 grayscale, 224 grayscale, etc., or it can be a set of multiple grayscale levels. The preset grayscale level is used to control the input signal of the pixel unit so as to obtain the actual brightness response of the pixel unit at that grayscale level.

[0030] Optionally, a fully bright screen refers to a screen where all pixel units in the display module are lit up (i.e., in an luminous state). In a fully bright screen, each pixel unit receives the same grayscale signal, thus emitting light simultaneously. This allows for the simultaneous capture of the light spots of all pixel units in a single frame, thereby achieving efficient positioning and brightness extraction of all pixel units.

[0031] Optionally, the optical center coordinates refer to the coordinates of the center position of a pixel unit in an image captured by an image acquisition device (e.g., an industrial camera). Since each pixel unit forms a light spot with a certain brightness distribution in the image, the center of the light spot (i.e., the brightness-weighted centroid) is the optical center of that pixel unit.

[0032] Optionally, the target optical center coordinates can be the optical center coordinates obtained after correction processing.

[0033] Step S20: Determine the brightness observation value of the pixel unit at a preset gray level based on the target optical center coordinates and the gray value of the pixel in the first image.

[0034] In one feasible embodiment, the brightness observation value of the pixel unit at a preset gray level is determined based on the target optical center coordinates of the pixel unit and the gray value of the pixel at the corresponding position of the target optical center coordinates in the first image.

[0035] Optionally, the first image is a digital image obtained by the image acquisition device after capturing the display module. The image consists of a large number of pixels arranged in a matrix, and each pixel corresponds to a value that represents the light intensity at that position. This value is the grayscale value.

[0036] Optionally, the brightness observation value refers to the numerical value extracted from the first image that characterizes the luminous intensity of a certain pixel unit at a specific grayscale. This value is proportional to the actual physical brightness of the pixel unit and serves as the basis for subsequent fitting of grayscale response parameters.

[0037] Step S30: Determine the grayscale response parameters of the pixel unit based on the brightness observation values ​​of the pixel unit at different grayscale levels.

[0038] In one feasible embodiment, in order to achieve brightness compensation across the entire grayscale range, it is necessary to determine the grayscale response parameters of the pixel unit based on the brightness observation values ​​of the pixel unit at different grayscale levels.

[0039] Optionally, the brightness observation values ​​at different gray levels can be determined according to the above steps S10~S20. By setting the preset gray level to different gray level values, the brightness observation values ​​of the pixel unit at different gray levels can be obtained.

[0040] Optionally, the grayscale response parameter is a mathematical parameter that describes the mapping relationship between the input grayscale of a pixel unit and the output brightness.

[0041] Alternatively, the mapping relationship between input grayscale and output brightness can be represented by a power function model: L=a×G γ +b; Where L is the output brightness (i.e., the brightness observation value), a is the gain coefficient, G is the input gray level, γ is the gray level response index (i.e., the Gamma value), which reflects the nonlinearity of brightness change with gray level, and b is the bias term.

[0042] Step S40: Based on the grayscale response parameters, construct the grayscale compensation mapping relationship of the display module.

[0043] Among them, the grayscale compensation mapping relationship is used to indicate the driving grayscale corresponding to each pixel unit of the display module under different input grayscale.

[0044] In one feasible embodiment, a grayscale compensation model of the display module is constructed based on the grayscale response parameters of each pixel unit in the display module, and the grayscale compensation mapping relationship is used to indicate the actual driving grayscale corresponding to each pixel unit of the display module under different input grayscale.

[0045] Optionally, the grayscale compensation mapping relationship can be a functional relationship or a lookup table, used to determine the driving grayscale required for each pixel unit under different input grayscale levels.

[0046] Step S50: Based on the grayscale compensation mapping relationship, determine the actual driving grayscale corresponding to each pixel unit under the current input grayscale, and drive the display module to display based on the actual driving grayscale.

[0047] In one feasible embodiment, ideally, all pixel units of a display module should have identical grayscale response characteristics; that is, when the input grayscale is the same, the output brightness of all pixel units should be the same. However, due to differences in manufacturing processes, the grayscale response parameters of different pixel units may differ, leading to inconsistent output brightness under the same input grayscale, thus causing brightness uniformity (Mura). This embodiment addresses this by constructing a grayscale compensation mapping relationship for the display module. Based on this relationship, it determines the driving grayscale (i.e., the actual driving grayscale) required for each pixel unit of the display module to output the desired target brightness under the current input grayscale. Then, based on the actual driving grayscale, it drives the display module to display, achieving brightness uniformity correction (De-Mura) for the actual module.

[0048] Optionally, the grayscale compensation mapping relationship obtained in the embodiments of this application can be decoupled from the specific hardware driver bit width, which has good system compatibility and portability, and can be easily integrated into driver chips or FPGA (Field Programmable Gate Array) platforms of different specifications to support rapid product deployment.

[0049] In this embodiment, by acquiring a first image of the display module displaying a fully bright image at a preset grayscale, the target optical center coordinates of the pixel units in the display module at the preset grayscale are determined, thereby achieving precise positioning of each pixel unit in the image. Then, the brightness observation value of the pixel unit at the preset grayscale is determined by combining the grayscale values ​​of the pixels in the first image, ensuring that the brightness extraction accurately reflects the true luminous intensity of each pixel unit. Furthermore, by using the brightness observation values ​​of the pixel units at different grayscales obtained in the above manner, the grayscale response parameters of each pixel unit are determined, thereby obtaining the unique grayscale response characteristics of each pixel unit. Based on these grayscale response parameters, a grayscale compensation mapping relationship for the display module is constructed. This mapping relationship records the driving grayscale required by each pixel unit of the display module at different input grayscales. Then, when the display module is displaying, this mapping relationship can be queried according to the current input grayscale to obtain the actual driving grayscale corresponding to each pixel unit, and the display module is driven by this actual driving grayscale. Since the actual driving grayscale of each pixel unit is calculated in reverse based on its own grayscale response parameters, the pixel units that originally had inconsistent brightness responses can output a similar brightness value when receiving the same current input grayscale. This effectively eliminates the problem of uneven brightness caused by the difference in grayscale response characteristics between pixel units, and improves the display uniformity and image quality consistency of the display module.

[0050] Based on the first embodiment described above, a second embodiment of the brightness uniformity correction method of this application is proposed. In this embodiment, step S10, which determines the target optical center coordinates of the pixel units of the display module under a preset grayscale based on the first image of the display module, includes: Step S11: With the preset grayscale as the reference grayscale, determine the initial optical center coordinates of the pixel units of the display module at the preset grayscale based on the first image.

[0051] In one feasible embodiment, with a preset grayscale as the reference grayscale, the initial optical center coordinates of each pixel unit of the display module under the reference grayscale are determined according to the first image, thereby locking the optical center position of each pixel unit within a few pixels, which greatly reduces the search area for subsequent fine positioning.

[0052] Optionally, the reference grayscale refers to a specific grayscale value used to obtain high-precision optical center coordinates as a reference for subsequent multiplexing.

[0053] Optionally, the highest grayscale level that the display module can display (such as 255 grayscale levels) can be selected as the reference grayscale level. At the highest grayscale level, the pixel unit has the highest brightness, the brightest spot, and the highest signal-to-noise ratio, which is beneficial for image acquisition and sub-pixel positioning, and can obtain the most accurate optical center coordinates.

[0054] Optionally, the initial optical center coordinates are the optical center coordinates estimated from the coarse center position of each pixel unit in the image. The accuracy of the initial optical center coordinates is usually at the pixel level. Although it is close to the true optical center position, it is not enough to be directly used for high-precision brightness extraction.

[0055] Step S12: Based on the local gray-scale centroid method, the initial optical center coordinates are corrected to obtain the target optical center coordinates under the preset gray level.

[0056] In one feasible embodiment, the local gray-scale centroid method (also known as the gray-scale centroid method) is a sub-pixel precision spot center localization algorithm. By treating the gray value of each pixel as the quality of the pixel in the local image area where the spot is located, the weighted average position of all pixels in the area is calculated as the center coordinates of the spot, and the target optical center coordinates of the pixel unit under the preset gray level (i.e., the reference gray level) are obtained.

[0057] Optionally, the local gray-scale centroid method uses the gray-scale distribution information of the light spot to calculate the weighted centroid, eliminating the sub-pixel phase error caused by the light center falling into the pixel gap, and improving the light center positioning accuracy to within 1.5 pixels.

[0058] Optionally, all pixel units of the display module can be processed synchronously and in parallel using a parallel architecture, enabling a task that originally required millions of serial calculations to be completed within 60 ms, obtaining the precise optical center coordinates (i.e., target optical center coordinates) of all pixel units of the display module at the reference grayscale. The target optical center coordinates can not only be directly used for brightness extraction at the reference grayscale, but also serve as reference data for coordinate reuse at other grayscales, thereby further saving computational resources in multi-grayscale correction scenarios.

[0059] In this embodiment, by first performing global coarse positioning under the reference grayscale to obtain the initial optical center coordinates, and then using the local grayscale centroid method for sub-pixel level fine correction, the brightness extraction error caused by optical center offset is effectively avoided. High-precision acquisition of pixel unit optical center coordinates is achieved with low computational cost, thereby improving the accuracy and reliability of brightness uniformity correction of the display module.

[0060] In one feasible embodiment, step S11, determining the initial optical center coordinates of the pixel units of the display module at a preset grayscale based on the first image, includes: Step S111: Construct a standard grid associated with the display module based on the physical resolution of the display module.

[0061] In this system, the corner points of the standard grid correspond to the pixel units of the display module.

[0062] In one feasible embodiment, a standard grid associated with the display module is constructed based on the physical resolution of the display module. The standard grid is an idealized grid model in which each intersection corresponds one-to-one with a pixel unit of the display module.

[0063] Optionally, the number of rows and columns of the standard grid are equal to the number of pixel units in the vertical and horizontal directions of the physical resolution of the display module, respectively.

[0064] Optionally, a regular rectangular grid can be formed with the position of the first pixel unit in the upper left corner as the origin and the distance between adjacent pixel units as the unit length, to serve as a standard grid representing the arrangement of pixel units under ideal distortion-free conditions.

[0065] Optionally, the physical resolution of the display module is the number of pixel units contained in the display module in the horizontal and vertical directions. For example, a display module with a resolution of 1920×1080 contains 1920 pixel units in the horizontal direction and 1080 pixel units in the vertical direction.

[0066] Step S112: Obtain the corner information of the first pixel unit of the display module.

[0067] In one feasible embodiment, the corner information of the first pixel unit of the display module is obtained.

[0068] Optionally, the corner information of the first pixel unit refers to the actual position coordinates of the pixel units at the four corners of the display module in the image coordinate system.

[0069] Step S113: Determine the homography matrix based on the corner information of the first pixel unit and the standard grid.

[0070] The homography matrix is ​​used to indicate the mapping relationship between the grid coordinate system of the standard grid and the image coordinate system of the first image.

[0071] In one feasible embodiment, the homography matrix is ​​determined based on the corner information of the first pixel unit and the standard grid, thereby realizing the transformation between the grid coordinate system of the standard grid and the image coordinate system of the first image.

[0072] Optionally, the homography matrix is ​​a perspective transformation matrix used to describe the perspective projection mapping relationship between the two grid coordinate systems and the image coordinate system.

[0073] Optionally, based on the physical resolution of the display module, a standard grid representing the ideal arrangement is constructed, with each grid intersection corresponding to a pixel unit of the display module. The corner information of the first pixel unit is obtained to determine the actual positions of the pixel units in the four corner regions of the display module within the image. A correspondence is established between the coordinates of the four corner points of the standard grid and the image corner coordinates obtained from the corner information of the first pixel unit. The homography matrix (i.e., the perspective transformation matrix) is calculated using the principle of perspective transformation, thus describing the mapping relationship from the standard grid coordinate system to the image coordinate system.

[0074] Step S114: Based on the homography matrix, map the grid intersections in the standard grid to the image coordinate system to obtain the initial optical center coordinates.

[0075] In one feasible embodiment, since there may be tilt, rotation or translation between the display module and the image acquisition device used to acquire the first image, there may be perspective distortion between the ideal coordinates in the standard grid and the position in the actual captured first image. The homography matrix is ​​a mathematical tool used to describe and correct this distortion. Then, based on the homography matrix, the grid intersections in the standard grid are mapped to the image coordinate system to obtain the initial optical center coordinates.

[0076] In this embodiment, a standard grid corresponding to the physical resolution of the display module is constructed, and the homography matrix is ​​calculated using the corner information of the first pixel unit. Then, all grid intersections of the standard grid are mapped to the image coordinate system, achieving a global one-time estimation of the initial optical center coordinates of all pixel units. Compared to the pixel-by-pixel unit search and positioning scheme, this embodiment does not require individual processing of each pixel unit; only one matrix multiplication is needed to complete the coordinate mapping of millions of pixel units across the entire screen, resulting in high computational efficiency. Furthermore, since the homography matrix is ​​solved based on corner information with sub-pixel precision, it can effectively correct perspective distortion and relative pose deviation between the image acquisition device and the display module, ensuring good global consistency of the mapped initial optical center coordinates and providing reliable initial values ​​for subsequent sub-pixel precision positioning. This embodiment significantly reduces the computational complexity of obtaining the initial optical center coordinates and improves the processing efficiency of brightness uniformity correction while maintaining positioning accuracy.

[0077] In one feasible implementation, step S112, the step of obtaining the corner information of the first pixel unit of the display module, includes: Step A10: Obtain the second image of the display module.

[0078] In the second image, the display module displays a preset sparse dot matrix pattern, which includes illuminated pixel units arranged at preset intervals, and each corner area of ​​the display module includes at least one illuminated pixel unit.

[0079] In one feasible embodiment, the display module is controlled to display a preset sparse dot matrix pattern, and an image acquisition device is used to acquire images of the display module to obtain a second image.

[0080] Optionally, a sparse dot matrix refers to an image in which only a portion of the pixel units in the display module are illuminated, and these illuminated pixel units are called lit pixel units. The lit pixel units are arranged at preset fixed intervals, for example, one is illuminated every N pixel units (N is an integer greater than 1), forming a sparsely distributed grid-like array of bright spots. In the sparse dot matrix, sufficient spacing is maintained between the lit pixel units so that each bright spot is separated from the others in the camera image and does not interfere with each other, facilitating subsequent image recognition and localization. Furthermore, in the four corner areas of the display module, the sparse dot matrix is ​​designed to contain at least one illuminated pixel unit to ensure that even if the pixel unit at the corner is damaged, the corner position can still be deduced from the nearby bright spots.

[0081] Step A20: Determine the corner information of the first pixel unit of the display area of ​​the display module based on the effective bright spots in the second image.

[0082] Among them, the effective bright spots correspond to the lit pixel units in the display module.

[0083] In one feasible embodiment, when the display module displays a sparse dot matrix, each lit pixel unit forms a light spot with a certain brightness distribution in the second image, which is an effective bright spot. Effective bright spots differ from noise points or background interference in the image; their brightness is significantly higher than the surrounding area, and their shape is usually approximately circular or Gaussian distributed. Therefore, each effective bright spot can be identified from the second image and its center position determined using image processing algorithms (such as binarization, connected component analysis, centroid calculation, etc.). This center position corresponds to the optical center coordinates of the corresponding lit pixel unit, and based on this, the corner information of the first pixel unit in the display area of ​​the display module is obtained.

[0084] Optionally, the corner information of the first pixel unit includes the coordinate information of the pixel units at the four corners (i.e., the top left, top right, bottom left, and bottom right) of the display area of ​​the display module in the image coordinate system. For example, it includes the coordinate values ​​of the four corner points.

[0085] Optionally, after obtaining the corner information of the first pixel unit, the second image can be adaptively cropped based on the corner information of the first pixel unit to reduce the amount of data in subsequent processing.

[0086] Optionally, the corner point interest region (ROI) of the first image can be determined based on the corner point information of the first pixel unit for subsequent processing, avoiding the computational overhead of full-image search and improving the processing efficiency of the brightness uniformity correction method.

[0087] Optionally, by combining the identification of sparse dot matrix with the global mapping of homography matrix, the positioning method effectively avoids the interference of defects such as dead screen lights and weak light on the positioning of screen corner points, so that the embodiments of this application can accurately and stably establish a global coordinate system and maintain high reliability under complex process defects.

[0088] For example, in order to efficiently and accurately determine the target optical center coordinates of each pixel unit of the display module, optical center positioning can be performed, referring to... Figure 2 The optical center localization steps include: Step A101, controlling the display module to display a preset sparse dot matrix, and acquiring a second image of the display module through an image acquisition device; Step A102, based on the second image, determining whether the corners of the display module are dead corners; if not, proceeding to Step A103; if so, proceeding to Step A104; Step A103, since the corners of the display module are not dead corners in the second image, the corner information of the first pixel unit of the display module can be directly located based on the first image to obtain the coordinates of each corner of the display module; Step A104, although the corners of the display module are dead corners in the second image, since the lit pixel units in the sparse dot matrix are arranged according to a preset interval, the corner area can be identified. Step A105: Based on the corner information of the first pixel unit of the display module, the corner information of other effective bright spots in the vicinity of the domain is calculated in combination with the known geometric interval relationship; Step A106: Based on the corner information of the first pixel unit and the standard grid, the homography matrix is ​​calculated; Step A107: The display module is controlled to display a full-bright image under the reference gray level, and the first image of the display module is acquired by the image acquisition device; Step A108: Based on the homography matrix, the grid intersections in the standard grid are mapped to the image coordinate system; Step A109: The initial optical center coordinates of each pixel unit of the display module are determined in parallel; Step A109: Based on the local gray level centroid method, the initial optical center coordinates are corrected in parallel to obtain the target optical center coordinates under the reference gray level, and the optical center positioning is completed.

[0089] In this embodiment, the illuminated pixel units in the sparse dot matrix are arranged at preset intervals, ensuring that each effective bright spot is separated from the others in the image, thus avoiding interference with positioning accuracy caused by light spot aliasing. Simultaneously, each corner region of the display module contains at least one illuminated pixel unit. Even if a pixel unit at a corner becomes a dead point (completely unlit) due to manufacturing defects, the position of the pixel unit in the corner region can still be robustly calculated by identifying other effective bright spots near the corner region and combining them with known geometric interval relationships. This achieves highly robust positioning of pixel units in the corner regions of the display modules. Compared to methods that directly detect corner points in a fully illuminated image, this embodiment does not rely on the integrity of the corner pixel units and is robust to dead points. Compared to pixel-by-pixel search positioning methods, this embodiment utilizes the regularity and sparsity of the sparse dot matrix, significantly reducing the complexity of image processing and enabling rapid corner positioning with sub-pixel accuracy.

[0090] Based on any of the above embodiments, a third embodiment of the brightness uniformity correction method of this application is proposed. In this embodiment, step S10, which determines the target optical center coordinates of the pixel units of the display module under a preset grayscale based on the first image of the display module, includes: Step S13: When the preset grayscale is a non-reference grayscale, obtain the corner information of the second pixel unit of the display module under the preset grayscale.

[0091] In one feasible embodiment, when the preset grayscale is a non-reference grayscale, the corner information of the second pixel unit of the display module under the non-reference grayscale is obtained.

[0092] Optionally, non-reference grayscale refers to other preset grayscale values ​​besides the reference grayscale.

[0093] Optionally, the reference gray level can be the highest gray level (such as 255 gray level) to obtain high-precision reference optical center coordinates, while non-reference gray levels include other gray levels that need to be observed and compensated for brightness, such as 240 gray level, 224 gray level, ..., 16 gray level, etc.

[0094] Optionally, the target optical center coordinates of the pixel unit at the reference gray level can be determined first, and then the target optical center coordinates of the pixel unit at the non-reference gray level can be determined based on the target optical center coordinates at the reference gray level, so as to improve processing efficiency.

[0095] Optionally, the control display module first displays a fully bright image at the reference grayscale to determine the target optical center coordinates at the reference grayscale; then the control display module sequentially displays fully bright images at other non-reference grayscales to determine the target optical center coordinates at other non-reference grayscales.

[0096] Optionally, the second pixel unit corner information refers to the position coordinates of the pixel units in the four corner areas of the display module in the camera image under non-reference grayscale.

[0097] Step S14: Calculate the corner offset between the corner information of the second pixel unit and the corner information of the pixel unit under the reference grayscale.

[0098] In one feasible embodiment, since the image acquisition device may experience jitter during the acquisition of the first image at different gray levels, it is necessary to calculate the corner offset between the corner information of the second pixel unit and the corner information of the pixel unit at the reference gray level.

[0099] Optionally, the corner offset reflects the overall positional change of the display module at the current grayscale acquisition time relative to the reference grayscale acquisition time, which is usually caused by minor jitter or displacement of the image acquisition device.

[0100] Step S15: If the corner offset is less than the preset offset threshold, the target optical center coordinates under the reference gray level are determined as the target optical center coordinates under the preset gray level.

[0101] In one feasible embodiment, if the corner offset is less than a preset offset threshold, it indicates that the image acquisition device is in a stable state. At this time, the target optical center coordinates under the reference grayscale can be directly reused without any additional calculation.

[0102] Optionally, the preset offset threshold can be set according to the actual situation, for example, the preset offset threshold is 1 pixel.

[0103] Step S16: If the corner offset is greater than or equal to the preset offset threshold, offset compensation is performed on the target optical center coordinates under the reference gray level according to the corner offset to obtain the target optical center coordinates under the preset gray level.

[0104] In one feasible embodiment, if the corner offset is greater than or equal to a preset offset threshold, it indicates that there is a slight jitter in the image acquisition device. At this time, the target optical center coordinates under the current gray level (i.e., non-reference gray level) can be obtained simply by uniformly translating the target optical center coordinates under the reference gray level according to the corner offset.

[0105] Understandably, as the requirements for calibration accuracy continue to increase, positioning algorithms have gradually evolved from simple binarization methods to complex sub-pixel iterative algorithms. However, the increased algorithm complexity has also significantly increased the processing time for a single frame image. In multi-grayscale (e.g., 16 levels or higher) calibration, performing highly complex positioning operations on each frame would cause the overall processing time to exceed the production line's cycle time requirements, thus limiting the detection throughput. The embodiments of this application, through the aforementioned coordinate reuse mechanism based on dynamic displacement correction, only require full-screen high-precision optical center positioning in the first frame during multi-grayscale calibration. Subsequent frames can achieve rapid global coordinate correction by detecting corner offsets. This method effectively addresses image acquisition device jitter while avoiding the repeated execution of complex positioning operations frame by frame, reducing the overall processing time from approximately 500 ms to 150 ms, an efficiency improvement of approximately 3.3 times, matching the cycle time requirements of high-speed production lines.

[0106] For example, to improve the efficiency of the multi-grayscale calibration process, coordinate reuse can be performed, referring to... Figure 3 The coordinate reuse steps include: Step B101, determining the target optical center coordinates and pixel unit corner information under the reference grayscale for subsequent reuse; Step B102, obtaining the second pixel unit corner information of the display module under the current grayscale, calculating the corner offset between the second pixel unit corner information and the pixel unit corner information under the reference grayscale, and determining whether the corner offset is greater than or equal to a preset offset threshold. If not, proceed to Step B103; if yes, proceed to Step B104; Step B103, determining the target optical center coordinates under the reference grayscale as the target optical center coordinates under the current grayscale; Step B104, performing offset compensation on the target optical center coordinates under the reference grayscale based on the corner offset; Step B105, outputting the target optical center coordinates under the current grayscale to end coordinate reuse.

[0107] In this embodiment, compared to the scheme of re-performing the complete coarse positioning and sub-pixel fine positioning for each non-reference gray level, this embodiment reduces the computational cost of single optical center positioning from the gray-level centroid method processing of millions of pixels in the entire screen to the detection of only four corner points and one overall translation by using corner offset detection and coordinate reuse mechanism, effectively improving computational efficiency; at the same time, by setting an offset threshold, frequent corrections caused by small noise are avoided, further optimizing the processing flow while ensuring positioning accuracy.

[0108] In one feasible implementation, step S13, obtaining the corner information of the second pixel unit of the display module under a preset grayscale, includes: Step S131: Perform edge recognition in the corner interest region of the first image to obtain physical corner information.

[0109] The region of interest for corner points is determined based on the corner information of pixel units under the reference grayscale.

[0110] In one feasible embodiment, the region of interest (ROI) for corner points is determined based on the corner point information of pixel units at a reference grayscale, and edge recognition is performed within the ROI of the first image to obtain physical corner point information. This eliminates the need to search the entire image for corner points in fully bright images at non-reference grayscale levels; instead, detection is performed directly within a pre-defined small area (i.e., the ROI), effectively improving processing efficiency.

[0111] Optionally, the region of interest at the corner is pre-defined and stored based on the corner information of the pixel unit at the reference gray level.

[0112] Optionally, physical corner information refers to the coordinates of the boundary vertices of the screen display area, that is, the intersection of two adjacent edges among the four edges of the screen. For example, the physical corner of the upper left corner is the intersection of the left and upper boundaries of the screen.

[0113] Optionally, within a pre-stored local search area for corner points, the first image is binarized, and the edges of connected regions are extracted from the region of interest of corner points in the binarized first image. The intersection of the horizontal edge line and the vertical edge line is calculated to obtain the physical corner point.

[0114] Step S132: Determine the corner information of the second pixel unit under the preset grayscale based on the imaging radius and physical corner information of the pixel unit.

[0115] In one feasible embodiment, the physical corner point is shifted inward by a radius based on the imaging radius of the pixel unit to obtain the corner point information of the second pixel unit under a preset gray level (i.e., non-reference gray level).

[0116] In this embodiment, the region of interest for corner points can be pre-determined based on the corner point information of pixel units under the reference grayscale, thereby reducing the detection range under non-reference grayscale from the entire image to four local small regions, significantly reducing the computational load of image processing, and avoiding false detections or missed detections that may be introduced by full-image search; then, physical corner points are obtained through edge recognition, and the physical corner points are translated inward using the imaging radius of the pixel unit, accurately locating the center of the actual lit pixel unit in the corner point region, and obtaining the corner point information of the second pixel unit, effectively improving the processing efficiency of multi-grayscale correction.

[0117] Based on any of the above embodiments, a fourth embodiment of the brightness uniformity correction method of this application is proposed. In this embodiment, step S20, the step of determining the brightness observation value of a pixel unit at a preset gray level based on the target optical center coordinates and the gray value of the pixel in the first image, includes: Step S21: Construct a sampling window centered on the target optical center coordinates.

[0118] The size of the sampling window is matched with the size of the pixel unit.

[0119] In one feasible embodiment, after determining the target optical center coordinates of the pixel unit, a continuous rectangular sampling window is constructed with those coordinates as the center.

[0120] Optionally, the sampling window is a virtual geometric region with continuous boundaries whose size matches the imaging size of the pixel unit in the image (e.g., 5×5 pixels or 7×7 pixels).

[0121] It is understandable that the light emitted by a pixel unit forms a light spot with a certain area in the first image, rather than an infinitely small point. In order to accurately measure the brightness of the pixel unit, it is necessary to collect the light energy across the entire light spot range, and the role of the sampling window is to define which area of ​​light energy is collected to represent the brightness of the pixel unit.

[0122] Step S22: Determine the brightness weight associated with each pixel in the first image based on the overlap area between each pixel in the first image and the sampling window.

[0123] Among them, there is a positive correlation between brightness weight and overlapping area.

[0124] In one feasible embodiment, the sampling window is a continuous rectangle whose boundary coordinates can be decimals, and the first image is composed of a discrete integer pixel grid, where each pixel is a 1×1 square area. Therefore, the sampling window will cover multiple integer pixels, but may not be completely aligned with the pixel boundaries. Thus, for each integer pixel that intersects with the sampling window, the area of ​​the overlapping part of the pixel and the sampling window (i.e., the overlapping area) is calculated, and the brightness weight of the pixel is determined by the overlapping area.

[0125] Optionally, if an integer pixel falls entirely within the sampling window, the overlap area = 1 (pixel area), and the weight = 1; if an integer pixel partially falls within the sampling window, the overlap area = the area of ​​the actual overlap (e.g., 0.3, 0.7, etc.), and the weight = that area value (between 0 and 1); if an integer pixel has no intersection with the sampling window, the overlap area = 0, and the weight = 0 (not included in the calculation).

[0126] Step S23: Determine the brightness observation value based on the grayscale value of each pixel in the first image and its associated brightness weight.

[0127] In one feasible embodiment, the weight of each pixel is calculated by weighting the corresponding pixel's grayscale value to obtain the brightness observation value of the pixel unit at the current grayscale.

[0128] Optionally, the sampling error caused by the phase mismatch between the optical centers of image pixels and pixel units is eliminated by the above method, thereby obtaining brightness data with high signal-to-noise ratio and high consistency.

[0129] For example, refer to Figure 4 The brightness extraction steps include: Step C101, traversing the target optical center coordinates of each pixel unit in the display module; Step C102, constructing a sampling window centered on the target optical center coordinates; Step C103, traversing the pixels in the first image; Step C104, determining the brightness weight associated with each pixel in the first image based on the overlap area between each pixel in the first image and the sampling window; Step C105, determining whether all pixels in the first image have been traversed; if yes, proceed to Step C106; otherwise, proceed to Step C103; Step C106, determining the brightness observation value based on the grayscale value of each pixel in the first image and its associated brightness weight; Step C107, determining whether all pixel units in the display module have been traversed; if yes, ending the brightness extraction; otherwise, proceeding to Step C101.

[0130] It is understandable that the image acquisition device and the display module are independent discrete pixel arrays, with an inherent geometric misalignment between them. Traditional methods typically use simple mean calculations of integer pixel regions to extract brightness. However, when the optical center of the LED falls within the pixel gap of the camera (i.e., there is a sub-pixel phase shift), its light energy is dispersed to adjacent pixels. This causes LEDs with similar actual brightness to be extracted with significantly different brightness values ​​due to positional phase differences, reducing the signal-to-noise ratio of the data and thus affecting the accuracy of subsequent fitting and correction.

[0131] In this embodiment, the size of the sampling window matches the size of the pixel unit, thereby ensuring that the light energy of the spot area can be completely collected without introducing interference from adjacent pixel units. Furthermore, the overlapping area is used as the brightness weight and a weighted average is used for calculation, so that the contribution of each pixel to the brightness observation value is proportional to the area actually covered by the spot, and edge pixels are included proportionally when partially covered. Compared with the rounding method, this embodiment effectively eliminates the step jump in brightness value caused by the sub-pixel offset of the optical center, so that the brightness observation value changes continuously with the continuous movement of the optical center position, thereby obtaining mathematically continuous, smooth response and clear physical meaning brightness data, laying a reliable data foundation for subsequent grayscale response parameter fitting and grayscale compensation mapping relationship construction.

[0132] In one feasible implementation, step S30, determining the grayscale response parameters of a pixel unit based on its brightness observations at different grayscale levels, includes: Step S31: Construct a grayscale response model for the pixel unit based on the brightness observation values ​​of the pixel unit at different grayscale levels.

[0133] Among them, the grayscale response model is used to indicate the mapping relationship between grayscale and brightness observation values.

[0134] In one feasible embodiment, for each pixel unit in the display module, after the aforementioned processing steps, the brightness observation values ​​of that pixel unit at multiple different gray levels have been obtained. For example, 16 gray levels (such as 255, 240, 224, ..., 16) are collected, each gray level corresponding to a brightness observation value, forming a set of data pairs: (G1, L1), (G2, L2), ..., (G 16 L 16 Furthermore, based on the brightness observations of pixel units at different gray levels, a gray level response model of the pixel unit is constructed to describe the mapping relationship between the input gray level and the output brightness (i.e., the brightness observation).

[0135] Optionally, the grayscale response model is a mathematical function used to describe the photoelectric conversion characteristics of a pixel unit, that is, how the input grayscale determines the output brightness, which can be expressed as a power function.

[0136] Optionally, the input to the grayscale response model is grayscale values, and the output is the observed brightness value at that grayscale. The process of constructing a grayscale response model is essentially about finding a curve that best fits all the observed data points through mathematical methods (such as regression analysis).

[0137] Step S32: Determine the grayscale response parameters based on the grayscale response model.

[0138] In one feasible embodiment, the grayscale response model typically adopts a specific functional form, which contains several undetermined parameters. Therefore, it is necessary to extract the specific values ​​of these parameters from the constructed grayscale response model to obtain the grayscale response parameters.

[0139] Optionally, the grayscale response parameters, i.e., photoelectric response parameters, may include: a gain coefficient, which reflects the overall luminous efficiency of the pixel unit; a grayscale response index γ, which reflects the nonlinearity of brightness change with grayscale; and a bias term b, which reflects the minimum brightness in the dark state.

[0140] Alternatively, a set of parameter values ​​can be found using regression analysis methods (such as least squares) that minimizes the sum of squared errors between the brightness values ​​predicted by the grayscale response model and the actual observed values. This set of parameter values ​​that minimizes the fitting error is the desired grayscale response parameter.

[0141] In this embodiment, a grayscale response model is constructed by acquiring the brightness observation values ​​of pixel units at different grayscale levels, and grayscale response parameters are determined based on the model, thereby achieving accurate quantitative characterization of the photoelectric response characteristics (i.e., grayscale response features) of each pixel unit.

[0142] In one feasible implementation, step S40, the step of constructing the grayscale compensation mapping relationship of the display module based on the grayscale response parameters, includes: Step S41: Determine the target brightness corresponding to each input gray level based on the standard gray level response curve associated with the display module.

[0143] In one feasible embodiment, after obtaining the grayscale response parameters of each pixel unit, it is necessary to determine a unified target standard, that is, the ideal brightness response curve that all pixel units should follow, i.e., the standard grayscale response curve. Then, for each possible input grayscale value (e.g., 0 to 255), the corresponding target brightness value is calculated according to the standard grayscale response curve.

[0144] Alternatively, the standard grayscale response curve can be expressed in the following form: L target =A std ×G 2.2 ; Among them, L target G is the target brightness value, and A is the input grayscale. std 2.2 is the standard gain coefficient, and 2.2 is the standard grayscale response index.

[0145] Step S42: Based on the grayscale response parameters, determine the driving grayscale required for each pixel unit to achieve its target brightness, and construct the grayscale compensation mapping relationship.

[0146] In one feasible embodiment, based on the grayscale response parameters, the number of grayscale levels (i.e., driving grayscale levels) required for a pixel unit to output brightness equal to the target brightness is calculated in reverse. The driving grayscale level is then obtained, and a grayscale compensation mapping relationship is constructed based on the driving grayscale level and the input grayscale level.

[0147] Optionally, a standard grayscale response curve that the display module must follow is preset. For each possible input grayscale, a uniform target brightness is first calculated using the standard grayscale response curve; then, this brightness value is substituted into the inverse function corresponding to the grayscale response model to solve for the driving grayscale required for the pixel unit to achieve the target brightness. By traversing all pixel units and all input grayscales across the entire screen, a full-screen grayscale compensation mapping relationship (i.e., a De-Mura lookup table) containing the mapping relationship of "input grayscale – actual driving grayscale" is finally generated for the display driver chip to call in real time. When the display module is working, the driver chip queries this mapping relationship based on the current input grayscale and pixel unit position, converts the input grayscale into the actual driving grayscale corresponding to the pixel unit, and outputs it, so that the actual output brightness of each pixel unit approaches the standard target brightness, achieving accurate correction of brightness non-uniformity.

[0148] In this embodiment, the target brightness corresponding to each input gray level is determined by the standard gray level response curve, and then the actual driving gray level required to achieve the target brightness is solved in reverse based on the gray level response parameters of each pixel unit, thus constructing a full-screen gray level compensation mapping relationship and realizing accurate correction of brightness non-uniformity.

[0149] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the brightness uniformity correction method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0150] This application provides an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the brightness uniformity correction method in the above embodiments.

[0151] The following is for reference. Figure 5 The diagrams show structural schematics of electronic devices suitable for implementing the embodiments of this application. The electronic devices in the embodiments of this application may include, but are not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 5 The electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0152] like Figure 5As shown, the electronic device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage device 1003 into a random access memory (RAM) 1004. The RAM 1004 also stores various programs and data required for the operation of the electronic device. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touchscreen, touchpad, keyboard, mouse, camera, microphone, accelerometer, gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; storage devices 1003 including, for example, magnetic tape, hard disk, etc.; and communication devices 1009. Communication device 1009 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. While electronic devices with various systems are shown in the figures, it should be understood that implementation or possession of all the systems shown is not required. More or fewer systems may be implemented alternatively.

[0153] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in 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 flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0154] The electronic device provided in this application, employing the brightness uniformity correction method described in the above embodiments, can effectively solve the problem of uneven brightness in the display module. Compared with the prior art, the beneficial effects of the electronic device provided in this application are the same as those of the brightness uniformity correction method provided in the above embodiments, and other technical features of this electronic device are the same as those disclosed in the method of the previous embodiment, and will not be repeated here.

[0155] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0156] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0157] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, which are used to execute the brightness uniformity correction method in the above embodiments.

[0158] The computer-readable storage medium provided in this application embodiment may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0159] The aforementioned computer-readable storage medium may be included in an electronic device or may exist independently without being assembled into an electronic device.

[0160] The aforementioned computer-readable storage medium carries one or more programs. When the aforementioned one or more programs are executed by an electronic device, the electronic device causes the electronic device to: determine the target optical center coordinates of the pixel units of the display module at a preset grayscale based on the first image of the display module; determine the brightness observation value of the pixel units at the preset grayscale based on the target optical center coordinates and the grayscale value of the pixels in the first image; determine the grayscale response parameters of the pixel units based on the brightness observation values ​​of the pixel units at different grayscales; construct the grayscale compensation mapping relationship of the display module based on the grayscale response parameters; determine the actual driving grayscale corresponding to each pixel unit at the current input grayscale based on the grayscale compensation mapping relationship, and drive the display module to display based on the actual driving grayscale.

[0161] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0162] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation 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 consecutively indicated blocks may actually be executed substantially in parallel, and 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 function or operation, or using a combination of dedicated hardware and computer instructions.

[0163] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0164] The readable storage medium provided in this application embodiment is a computer-readable storage medium. This computer-readable storage medium stores computer-readable program instructions (i.e., a computer program) for executing the above-described brightness uniformity correction method, effectively solving the problem of uneven brightness in the display module. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application embodiment are the same as the beneficial effects of the brightness uniformity correction method provided in the above embodiments, and will not be repeated here.

[0165] The above are only some embodiments of this application and do not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for correcting brightness uniformity, characterized in that, The method includes: With a preset grayscale as the reference grayscale, the initial optical center coordinates of the pixel units of the display module under the preset grayscale are determined according to the first image of the display module. The initial optical center coordinates are then corrected to obtain the target optical center coordinates. In the first image, the display module displays a fully bright image under the preset grayscale. Based on the target optical center coordinates and the grayscale values ​​of the pixels in the first image, the brightness observation value of the pixel unit at the preset grayscale is determined; The grayscale response parameters of the pixel unit are determined based on the observed brightness values ​​of the pixel unit at different grayscale levels. Based on the grayscale response parameters, a grayscale compensation mapping relationship for the display module is constructed, wherein the grayscale compensation mapping relationship is used to indicate the driving grayscale corresponding to each pixel unit of the display module under different input grayscale levels; Based on the grayscale compensation mapping relationship, the actual driving grayscale corresponding to each pixel unit under the current input grayscale is determined, and the display module is driven to display based on the actual driving grayscale. The step of determining the initial optical center coordinates of the pixel units of the display module at a preset grayscale based on the first image of the display module includes: Based on the physical resolution of the display module, a standard grid associated with the display module is constructed, wherein the corner points of the standard grid correspond to the pixel units of the display module; A second image of the display module is obtained, wherein the display module displays a preset sparse dot matrix pattern in the second image, the sparse dot matrix pattern includes illuminated pixel units arranged at preset intervals, and each corner area of ​​the display module includes at least one illuminated pixel unit. Based on the second image, determine whether there are any dead angles at the corners of the display module; If there are dead corners in the corner of the display module, the corner information of the first pixel unit of the display area of ​​the display module is determined based on other effective bright spots near the corner area and the geometric spacing relationship of the lit pixel units in the sparse dot matrix. If there are no dead corners in the corners of the display module, the corner information of the first pixel unit of the display area of ​​the display module is determined according to the effective bright spots in the second image, wherein the effective bright spots correspond to the lit pixel units in the display module; Based on the corner information of the first pixel unit and the standard grid, a homography matrix is ​​determined, wherein the homography matrix is ​​used to indicate the mapping relationship between the grid system coordinates of the standard grid and the image coordinate system of the first image of the display module; Based on the homography matrix, the grid intersections in the standard grid are mapped to the image coordinate system to obtain the initial optical center coordinates.

2. The method as described in claim 1, characterized in that, The step of correcting the initial optical center coordinates to obtain the target optical center coordinates includes: Based on the local gray-level centroid method, the initial optical center coordinates are corrected to obtain the target optical center coordinates under the preset gray level.

3. The method as described in claim 1, characterized in that, When the preset grayscale is a non-reference grayscale, the step of determining the target optical center coordinates of the pixel unit of the display module at the preset grayscale includes: Obtain the corner information of the second pixel unit of the display module under the preset grayscale; Calculate the corner offset between the corner information of the second pixel unit and the corner information of the pixel unit under the reference gray level; If the corner offset is less than a preset offset threshold, the target optical center coordinates under the reference gray level are determined as the target optical center coordinates under the preset gray level. If the corner offset is greater than or equal to a preset offset threshold, the target optical center coordinates under the reference grayscale are offset compensated according to the corner offset to obtain the target optical center coordinates under the preset grayscale.

4. The method as described in claim 3, characterized in that, The step of obtaining the corner information of the second pixel unit of the display module under the preset grayscale includes: Edge recognition is performed in the corner interest region of the first image to obtain physical corner information, wherein the corner interest region is determined based on the pixel unit corner information under the reference gray level; Based on the imaging radius of the pixel unit and the physical corner information, the corner information of the second pixel unit under the preset grayscale is determined.

5. The method as described in claim 1, characterized in that, The step of determining the brightness observation value of the pixel unit at the preset grayscale based on the target optical center coordinates and the grayscale value of the pixel in the first image includes: A sampling window is constructed with the target optical center coordinates as the center, wherein the size of the sampling window matches the size of the pixel unit; Based on the overlap area between each pixel in the first image and the sampling window, the brightness weight associated with each pixel in the first image is determined, wherein the brightness weight is positively correlated with the overlap area; The brightness observation value is determined based on the grayscale value of each pixel in the first image and its associated brightness weight.

6. The method as described in claim 1, characterized in that, The step of determining the grayscale response parameters of the pixel unit based on the brightness observation values ​​of the pixel unit at different grayscale levels includes: Based on the brightness observation values ​​of the pixel unit at different gray levels, a gray level response model of the pixel unit is constructed, wherein the gray level response model is used to indicate the mapping relationship between gray levels and brightness observation values; The grayscale response parameters are determined based on the grayscale response model.

7. The method as described in claim 1, characterized in that, The step of constructing the grayscale compensation mapping relationship of the display module based on the grayscale response parameters includes: Based on the standard grayscale response curve associated with the display module, determine the target brightness corresponding to each input grayscale. Based on the grayscale response parameters, the driving grayscale required for the pixel unit to achieve each of the target brightnesses is determined, and the grayscale compensation mapping relationship is constructed.

8. An electronic device, characterized in that, The electronic device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the brightness uniformity correction method as described in any one of claims 1 to 7.

9. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the brightness uniformity correction method as described in any one of claims 1 to 7.

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