A display screen brightness and chrominance joint compensation mapping generation method

Abstract

The application discloses a display screen brightness and chrominance joint compensation mapping generation method, and belongs to the technical field of Micro-LED display correction and optical calibration. The method solves the problem that brightness reproduction and cross-gray-scale chrominance drift are difficult to be considered in existing white field gray-scale correction, and comprises the following steps: acquiring red, green and blue single-channel full-gray-scale first optical measurement data and equivalent white field full-gray-scale second optical measurement data; for a target gray scale, equivalent RGB initial code values are determined according to the second optical measurement data, a limited RGB candidate driving domain is constructed in combination with a preset single-channel search radius and a maximum deviation amount between channels; candidate combined three-stimulus value outputs are estimated based on single-channel three-stimulus value increments and corresponding gray-scale three-stimulus value superposition; a joint target function is constructed by taking the target brightness and a preset reference chrominance as a reference and adding adjacent gray-scale driving code continuity constraints, and an optimal solution is solved as a compensation RGB driving code value; and a gray scale to compensation code lookup table is generated by traversing all the gray scales. The method is used in the field of information display.

Description

Technical Field

[0001] This invention belongs to the field of Micro-LED display calibration and optical calibration technology, and in particular relates to a method for generating a joint compensation mapping for brightness and chromaticity of a display screen. Background Technology

[0002] In the fields of high-end commercial displays, automotive displays, and consumer electronics, Micro-LED display technology has become an important development direction for next-generation display technology due to its advantages such as high brightness, high contrast, and long lifespan. However, due to the tiny size of Micro-LED chips, the unavoidable material growth dispersion, mass transfer process errors, and uneven packaging stress during the manufacturing process result in significant non-uniformity in the photoelectric characteristics of millions or even tens of millions of micron-level light-emitting units on the same panel. This non-uniformity is particularly prominent in white-point grayscale reproduction, directly affecting the quality of the displayed image.

[0003] To improve display consistency, optical feedback and correction technologies are widely used in the industry. Traditional correction methods often rely on Gamma curve fitting or one-dimensional lookup table mapping. These methods typically assume that the red, green, and blue primary color channels are independent and adjust the transfer function to make the output brightness conform to the characteristics of human vision. However, in actual Micro-LED devices, the electro-optical conversion functions of the RGB colors are not a simple linear relationship, and due to differences in quantum well structures, the turn-on voltage, luminous efficiency, and light extraction efficiency of the three color chips are different. When using traditional equal-code-value driving to try to reproduce the white grayscale, the measured brightness often deviates from the ideal target Gamma curve. More problematic is that as the grayscale code value changes, the contribution ratio of the RGB colors to the white brightness drifts, causing the white chromaticity coordinates to produce a visible color shift as the grayscale changes. This phenomenon is particularly severe in the low grayscale region, often manifesting as a bluish or yellowish tint or grainy appearance in dark areas.

[0004] To address the aforementioned issues, existing technologies have attempted to introduce 3D color space lookup table (3D-LUT) technology. This technology establishes a precise mapping relationship from input digital driving values ​​to output light color response by acquiring a large number of non-equivalent color patch samples in the RGB 3D space. While this method can theoretically cover a wide color gamut and correct complex nonlinear couplings, its fatal flaw lies in the extremely time-consuming calibration process. For a conventional 8-bit display system, covering the complete RGB color space requires acquiring more than 16 million data points. Even with sparse sampling and interpolation algorithms, this is insufficient to meet the high-efficiency mass production requirements of modern Micro-LED panel production lines. Furthermore, the massive data storage requirements place stringent demands on the embedded memory resources of the display control system, increasing hardware costs.

[0005] Other technical solutions focus on simple brightness inversion algorithms, which eliminate brightness errors by establishing an inverse mapping model between brightness and driving code values. While these methods can improve brightness consistency to some extent, their optimization target only includes the brightness dimension, lacking a constraint mechanism on the chromaticity coordinates. In practical applications, the algorithm might, in pursuit of perfect brightness matching, provide a set of RGB code values. Although this set of values ​​meets the brightness standard, it causes the chromaticity coordinates to deviate significantly from the standard white field, resulting in a trade-off and ultimately degrading the display effect. Furthermore, some cutting-edge research has introduced temperature sensors or real-time photoelectric feedback loops for dynamic compensation, but this undoubtedly increases the hardware complexity, power consumption, and manufacturing cost of the module, and the accuracy and lifespan of the sensors themselves also become new reliability risks.

[0006] Therefore, in the process of Micro-LED display technology moving towards large-scale commercial application, how to ensure accurate brightness reproduction along the white-field grayscale path while effectively suppressing chromaticity drift across grayscale levels, and significantly reducing the sampling cost and computational complexity of optical calibration, has become a pressing technical challenge in this field. Current technologies lack a low-overhead compensation mapping generation scheme that can simultaneously address both brightness and chromaticity correction objectives and is suitable for rapid deployment on production lines. Summary of the Invention

[0007] In view of this, the present invention aims to propose a method for generating a display screen brightness and chromaticity joint compensation mapping, so as to solve the problem that the existing technology cannot effectively suppress chromaticity drift across gray levels while ensuring accurate brightness reproduction on the white field grayscale path.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a method for generating a display screen brightness and chromaticity joint compensation mapping, the method comprising: Acquire first optical measurement data of the red, green, and blue single channels of the Micro-LED display screen within their respective full grayscale ranges, and second optical measurement data of the display screen within the full grayscale range of the white field of red, green, and blue values. For the target grayscale value, an equivalent RGB initial code value is determined based on the second optical measurement data, and a restricted RGB candidate driving domain is constructed with the equivalent RGB initial code value as the center, combined with the preset single-channel search radius and the maximum deviation between channels; Within the restricted RGB candidate driving domain, the tristimulus value output of each candidate RGB driving combination is estimated by superimposing the single-channel tristimulus value increment in the first optical measurement data with the corresponding grayscale tristimulus value in the second optical measurement data. Based on the target brightness and preset reference chromaticity coordinates corresponding to the target grayscale value, and combined with the continuity constraint of adjacent grayscale driving codes, a joint objective function is constructed. Solve the joint objective function within the restricted RGB candidate driving domain, and determine the optimal solution as the compensated RGB driving code value corresponding to the target grayscale value; Iterate through all target grayscale values ​​and generate a compensation lookup table from grayscale values ​​to compensated RGB driver code values.

[0009] Furthermore, a preferred embodiment is proposed, wherein constructing the restricted RGB candidate driving domain includes: The initial RGB code value is set to the equivalent value. The restricted RGB candidate driving domain for:

[0010] in, r This represents the candidate output code value for the red channel. g This represents the candidate output code value for the green channel. b Indicates the candidate output code value for the blue channel; d D represents the single-channel search radius; D represents the maximum deviation between channels. Indicates the maximum grayscale value; Indicates the first k The equivalent RGB initial code value for grayscale; This represents the maximum value among the candidate output code values ​​for the red, green, and blue channels. This represents the minimum value among the candidate output code values ​​for the red, green, and blue channels.

[0011] Furthermore, a preferred method is proposed, wherein the estimation of the tristimulus values ​​output for each candidate RGB driver combination includes:

[0012] in, Indicates candidate driver combinations d The estimated tristimulus values ​​output, This represents the tristimulus value of the equivalent RGB white field. This represents the tristimulation value of the red single channel. This represents the tristimulus value of the red single channel in the reference grayscale. This indicates the tristimulation value of the green single channel. This represents the tristimulus value of the green single channel under the reference grayscale. This represents the tristimulation value of the blue single channel. This represents the tristimulus value of the blue single channel under the reference grayscale.

[0013] Furthermore, a preferred method is proposed, wherein the preset reference chromaticity coordinates are determined in the following way: Multiple white field chromaticity coordinates within the high grayscale stable range of the second optical measurement data are selected, and their average value is calculated as the preset reference chromaticity coordinates.

[0014] Furthermore, a preferred embodiment is proposed, wherein the high grayscale stable range is defined as a continuous range in which the grayscale code value is greater than a preset threshold, and the chromaticity coordinates are in the CIE 1976 chromaticity coordinate system. u′ and v′ coordinate.

[0015] Furthermore, an optimal approach is proposed, wherein the joint objective function is:

[0016] in, Describe the joint objective function. This represents the normalized error between the candidate output brightness and the target brightness. This indicates the chromaticity deviation between the candidate output chromaticity coordinates and the reference chromaticity coordinates; This represents the continuity cost between the current candidate code value and the determined code values ​​of adjacent gray levels; , and For the corresponding weights.

[0017] Furthermore, a preferred approach is proposed, which further includes verifying whether the estimated brightness of adjacent gray levels satisfies the non-decreasing constraint after solving the joint objective function. If not, the optimal solution for the current gray level is adjusted until it does. ,in, Indicates the first k The optimal estimated brightness for +1 gray level Indicates the first k The optimal estimated brightness for grayscale.

[0018] Furthermore, a preferred method is proposed, wherein both the first optical measurement data and the second optical measurement data include CIE XYZ tristimulus values, luminance value Y, and chromaticity coordinates, and preprocessing steps of dark field subtraction and outlier removal are performed after the data is acquired.

[0019] Furthermore, a preferred method is proposed, in which, after traversing all target grayscale values, the generated compensation lookup table is written into the display control card, FPGA, or display driver chip, and used to call the corresponding RGB output code value when displaying white grayscale content.

[0020] Based on the same inventive concept, the present invention also proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes a display screen brightness and chromaticity joint compensation mapping generation method according to any one of the preceding claims.

[0021] Compared with the prior art, the beneficial effects of the present invention are: The core concept of this invention lies in abandoning the conventional thinking of either isolating brightness correction or exhaustively sampling the entire color gamut in traditional technologies. Instead, it focuses the correction target on the white grayscale path, which is most frequently used in display applications, and constructs a constrained local optimization model in the vicinity of this path. The technical principle is as follows: In the electro-optical conversion characteristics of Micro-LED devices, the light and color response on the equivalent RGB white grayscale path has good continuity and predictability. Based on this, this invention only needs to utilize single-channel full grayscale data of red, green, and blue, as well as equivalent RGB white grayscale data, to accurately simulate any RGB combination output within a small neighborhood near the equivalent path through single-channel incremental superposition. This estimation method avoids building a complex and data-intensive full three-dimensional color model; essentially, it transforms the infinite color space search problem into a neighborhood search problem on a finite path while ensuring accuracy.

[0022] This invention achieves a balance between calibration efficiency and correction accuracy. Traditional 3D lookup table techniques require a massive number of sampling points to support interpolation calculations, while this invention introduces the concept of a restricted RGB candidate driving domain. By setting a reasonable search radius and channel deviation threshold around the equivalent RGB initial solution, the optimization space is strictly limited to the effective support range of the measured data. This not only avoids the risk of physical distortion caused by extrapolation calculations, but more importantly, simplifies the process from traversing millions of color combinations to optimizing only a few thousand local candidate points, greatly shortening the calibration cycle and making it suitable for industrial mass production needs.

[0023] This invention solves the industry problem of mutual constraints between luminance and chromaticity correction. Existing luminance inversion algorithms often sacrifice chromaticity accuracy in pursuit of luminance numerical matching, resulting in significant color shifts at low grayscale levels. The joint objective function constructed in this invention considers luminance error, chromaticity deviation, and the continuity of adjacent grayscale levels on an equal footing. In particular, in the selection of the chromaticity reference value, the average value of the high grayscale stable range is used as the benchmark, effectively avoiding noise interference caused by inconsistent turn-on voltages in the low grayscale region. This optimization mechanism under multiple constraints ensures that while correcting luminance nonlinearity, the white field chromaticity trajectory is forcibly locked, fundamentally eliminating grayscale jumps or color shifts.

[0024] This invention improves the stability and smoothness of display control. In the process of solving for the optimal driving code value step-by-step, this invention introduces a continuity constraint on adjacent grayscale mapping and a non-decreasing brightness constraint. This design cleverly utilizes the human eye's sensitivity to grayscale transitions, preventing drastic jumps in adjacent code values ​​or grayscale reversals caused by algorithm optimization. This makes the generated compensation lookup table physically smoother, ensuring a delicate transition of the displayed image during grayscale switching and avoiding pseudo-contours or flickering phenomena that may occur in traditional correction methods.

[0025] The output of this invention is a standard grayscale-to-RGB driver code lookup table, which is fully compatible with existing mainstream display control system architectures. Whether writing to a Field Programmable Gate Array (FPGA), display control card, or driver chip, no modification to the underlying hardware circuitry or addition of additional sensor components is required. This software algorithm improvement not only reduces the hardware complexity and cost of the system but also enables this invention to serve as a universal firmware upgrade solution, widely applicable to the factory calibration and subsequent maintenance of various Micro-LED display products. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart of a method for generating a display screen brightness and chromaticity joint compensation mapping according to the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0028] Implementation Method 1: This implementation method proposes a method for generating a display screen brightness and chromaticity joint compensation mapping, the method comprising: Acquire first optical measurement data of the red, green, and blue single channels of the Micro-LED display screen within their respective full grayscale ranges, and second optical measurement data of the display screen within the full grayscale range of the white field of red, green, and blue values. For the target grayscale value, an equivalent RGB initial code value is determined based on the second optical measurement data, and a restricted RGB candidate driving domain is constructed with the equivalent RGB initial code value as the center, combined with the preset single-channel search radius and the maximum deviation between channels; Within the restricted RGB candidate driving domain, the tristimulus value output of each candidate RGB driving combination is estimated by superimposing the single-channel tristimulus value increment in the first optical measurement data with the corresponding grayscale tristimulus value in the second optical measurement data. Based on the target brightness and preset reference chromaticity coordinates corresponding to the target grayscale value, and combined with the continuity constraint of adjacent grayscale driving codes, a joint objective function is constructed. Solve the joint objective function within the restricted RGB candidate driving domain, and determine the optimal solution as the compensated RGB driving code value corresponding to the target grayscale value; Iterate through all target grayscale values ​​and generate a compensation lookup table from grayscale values ​​to compensated RGB driver code values.

[0029] In this embodiment, constructing the restricted RGB candidate driving domain includes: The initial RGB code value is set to the equivalent value. The restricted RGB candidate driving domain for:

[0030] in, r This represents the candidate output code value for the red channel. g This represents the candidate output code value for the green channel. b Indicates the candidate output code value for the blue channel; d D represents the single-channel search radius; D represents the maximum deviation between channels. This represents the maximum grayscale value.

[0031] In this embodiment, the estimation of the tristimulus values ​​for each candidate RGB driver combination includes:

[0032] in, Indicates candidate driver combinations d The estimated tristimulus values ​​output, This represents the tristimulus value of the equivalent RGB white field. This represents the tristimulation value of the red single channel. This represents the tristimulus value of the red single channel in the reference grayscale. This indicates the tristimulation value of the green single channel. This represents the tristimulus value of the green single channel under the reference grayscale. This represents the tristimulation value of the blue single channel. This represents the tristimulus value of the blue single channel under the reference grayscale.

[0033] In this embodiment, the preset reference chromaticity coordinates are determined in the following way: Multiple white field chromaticity coordinates within the high grayscale stable range of the second optical measurement data are selected, and their average value is calculated as the preset reference chromaticity coordinates.

[0034] Furthermore, the high grayscale stable range is defined as a continuous range where the grayscale code value is greater than a preset threshold, and the chromaticity coordinates are in the CIE 1976 chromaticity coordinate system. u′ and v′ coordinate.

[0035] In this embodiment, the joint objective function is:

[0036] in, Describe the joint objective function. This represents the normalized error between the candidate output brightness and the target brightness. This indicates the chromaticity deviation between the candidate output chromaticity coordinates and the reference chromaticity coordinates; This represents the continuity cost between the current candidate code value and the determined code values ​​of adjacent gray levels; , and For the corresponding weights.

[0037] In this embodiment, the method further includes, after solving the joint objective function, verifying whether the estimated brightness of adjacent gray levels satisfies the non-decreasing constraint; if not, adjusting the optimal solution of the current gray level until it does. ,in, Indicates the first k The optimal estimated brightness for +1 gray level Indicates the first k The optimal estimated brightness for grayscale.

[0038] In this embodiment, both the first optical measurement data and the second optical measurement data include CIE XYZ tristimulus values, luminance value Y, and chromaticity coordinates, and after acquiring the data, preprocessing steps of dark field subtraction and outlier removal are performed.

[0039] In this embodiment, after traversing all target grayscale values, the generated compensation lookup table is written into the display control card, FPGA, or display driver chip, which is used to call the corresponding RGB output code value when displaying white grayscale content.

[0040] The core of this implementation is not to establish a complete RGB color management model, but to generate a luminance and chromaticity joint compensation mapping for the vicinity of the white point grayscale path. This method can be used for factory calibration of Micro-LED displays, optimization of white point grayscale consistency of display modules, compensation of near-white point display content, low-sampling-cost optical correction processes, and lookup table generation in display control systems.

[0041] In this embodiment, an 8-bit grayscale code value g=0-255 can be used to acquire four full grayscale scan paths: R, G, B single channels, and equivalent RGB white field. Measurement indicators may include CIE XYZ, luminance Y, CIE 1931 xy, and CIE 1976. Evaluation indicators may include average normalized luminance error, maximum luminance error, average, maximum, and error statistics within different grayscale intervals.

[0042] The method proposed in this embodiment differs from ordinary gamma correction in that ordinary gamma correction mainly adjusts the luminance response along the isochannel direction, while this method allows for small-range independent adjustment of the RGB three-channel code values ​​within a limited candidate domain and explicitly introduces chromaticity deviation constraints. The method also differs from a complete 3D-LUT in that it does not require acquiring a complete non-equivalent RGB color mesh; it primarily targets compensation mapping generation near the white point grayscale path.

[0043] Implementation Method 2, see below Figure 1 This embodiment describes a complete implementation of the display screen brightness and chromaticity joint compensation mapping generation method described in Embodiment 1, including: full grayscale optical measurement, white field response analysis, reference chromaticity determination, construction of restricted candidate driving domains, estimation of candidate optical output, solving the joint objective function, generation of compensation lookup table, and writing of display control.

[0044] Specifically, the method includes: Step S1: Full grayscale optical measurement and data preprocessing.

[0045] Input the R, G, B single-channel grayscale scan images and the equivalent RGB white field grayscale scan image sequentially into the display screen to be calibrated. For an 8-bit grayscale system, the grayscale code value k can be from 0 to 255; for other bit depth systems, sampling can be performed according to the corresponding code value range.

[0046] At each grayscale node, the CIE XYZ tristimulus values, luminance Y, and CIE 1931 chromaticity coordinates of the displayed output are collected using a luminance colorimeter, imaging colorimeter, or spectral measurement device. x , y And the CIE 1976 chromaticity coordinates u′ and v′. The measurement data can be expressed as:

[0047] in, , , Let represent the tristimulus value vectors of the red, green, and blue single channels at the grayscale code value k, respectively. This indicates the equivalent RGB white point in grayscale values. k The tristimulus value vector is given below. The above tristimulus value vector can be written as:

[0048] in, , , These represent the scan paths. i In grayscale values k CIE XYZ tristimulus values, It also indicates the corresponding brightness. This indicates the scanning path of the red channel. Indicates the scan path of the green channel. Indicates the scan path of the blue single channel. Indicates the white field scan path. i The index variable represents the scan path.

[0049] Preferably, the measurement data undergoes dark field subtraction, outlier removal, grayscale order checking, and necessary smoothing to reduce the impact of measurement noise on subsequent mapping solutions.

[0050] Step S2: White field luminance response and chromaticity trajectory analysis.

[0051] Based on equivalent RGB white field measurement data Obtain the response curve of white field brightness as a function of grayscale and u′ and v′ Chromaticity trajectory. By comparing the measured white point luminance with the target luminance curve, the luminance nonlinearity error is determined; by comparing the chromaticity coordinates at different gray levels with the reference chromaticity coordinates, the gray-level correlated chromaticity shift is determined.

[0052] The target brightness curve can be represented as:

[0053] in, Represents the target grayscale k The corresponding target brightness, Indicates the maximum grayscale code value. k This represents the grayscale node. The target brightness curve can be determined based on the standard gamma curve, the display system calibration target, or the electro-optical conversion relationship set by the user.

[0054] The reference chromaticity coordinates can be selected as the average chromaticity coordinates of the high grayscale stability range. For example, let the high grayscale stability range be... Then refer to the chromaticity coordinates Represented as:

[0055] in, This represents the number of gray-level nodes within the high-gray-level stable range. and These represent the equivalent RGB white point in grayscale. k The CIE 1976 chromaticity coordinates are shown below. Alternatively, a full white grayscale can be selected as the reference chromaticity coordinates. The chromaticity coordinates at the specified location, or select the chromaticity coordinates of the specified standard white field.

[0056] Step S3: Construction of restricted RGB candidate driving domains.

[0057] For each target gray level k First, determine an initial solution with equivalent RGB values. The initial solution can be obtained through gamma mapping, luminance inversion, or an isochannel initial lookup table. The corresponding initial RGB drive code value... It can be represented as:

[0058] Subsequently, with Constructing a restricted RGB candidate driving domain centered on :

[0059] in, r This represents the candidate output code value for the red channel. g This represents the candidate output code value for the green channel. b Indicates the candidate output code value for the blue channel; d D represents the single-channel search radius; D represents the maximum deviation between channels. This represents the maximum grayscale code value. Using this restricted candidate domain, compensation code values ​​can be searched near the equivalent RGB white field path, while avoiding excessive deviation of the compensation code value from the range supported by the measured data.

[0060] Step S4: Local optical output estimation of candidate RGB driver combinations.

[0061] For candidate driver combination d:

[0062] This implementation method estimates the local optical output using a single-channel tristimulus value increment superposition method. Let... Let k be the initial code value of the equal-channel type corresponding to the target gray level k. Then the tristimulus value estimation of the candidate combination can be expressed as:

[0063] in, This represents the estimated tristimulus values ​​output for the candidate driver combination d. If:

[0064] in, This represents the estimated red tristimulus value corresponding to candidate driver combination d. This represents the estimated green tristimulus value corresponding to candidate driver combination d. This represents the estimated blue tristimulus value corresponding to candidate driver combination d.

[0065] The estimated brightness of the candidate combination is: .

[0066] Its CIE 1976 chromaticity coordinates can be calculated using the following formula: ,

[0067] in, This represents the estimated CIE 1976 chromaticity x-coordinate corresponding to the candidate driving combination d. This represents the estimated CIE 1976 chromaticity ordinate corresponding to the candidate driving combination d.

[0068] This estimation method uses a single-channel incremental response to describe the effect of channel adjustment in a small range near the equivalent RGB white field path, without requiring the establishment of a complete RGB three-dimensional color space model. In practical applications, in addition to the incremental superposition of tristimulus values, local linear models, quadratic response models, piecewise polynomial models, radial basis function models, neural network models, or small-scale 3D-LUT interpolation models can also be used to estimate the optical output of candidate driver combinations.

[0069] Step S5: Solve the joint objective function of luminance and chrominance.

[0070] For each target gray level k In candidate driver domain Internal search for the optimal RGB driver code value. Joint objective function. It simultaneously includes target brightness error, reference chromaticity deviation, and continuity of adjacent grayscale mapping, and can be expressed as:

[0071] in, This represents the normalized error between the candidate output brightness and the target brightness. This indicates the chromaticity deviation between the candidate output chromaticity coordinates and the reference chromaticity coordinates; This represents the continuity cost between the current candidate code value and the determined code values ​​of adjacent gray levels; , and For the corresponding weights.

[0072] Preferably, brightness error It can be represented as:

[0073] in, No. k The target brightness value of the grayscale. This indicates the maximum brightness of the display panel under full white drive conditions. This indicates the minimum non-zero brightness that the display panel can output.

[0074] Color deviation It can be represented as:

[0075] in, This represents the x-axis of the reference white point. This represents the chromaticity ordinate of the reference white field.

[0076] Continuous cost It can be represented as:

[0077] in, This indicates the optimal compensation code value that has been determined for the previous gray level. Let represent the L2 norm. For each gray level, choose one that makes ... The smallest candidate driving combination is used as the compensation output code value for that gray level. :

[0078] To ensure the order of grayscale reproduction, this implementation can also set a non-decreasing brightness constraint, that is, the estimated output brightness of adjacent grayscale levels satisfies:

[0079] in, Indicates the first k The optimal estimated brightness for +1 gray level Indicates the first k The optimal estimated brightness for grayscale.

[0080] This avoids grayscale reversal after compensation.

[0081] Step S6: Compensation mapping generation and display output.

[0082] After completing the search of all grayscale nodes, a grayscale-to-RGB driving code value compensation lookup table (LUT) is generated:

[0083] in, This indicates that the compensation lookup table is in the first position. k Mapping entries at grayscale levels; This indicates that under the white field path, in order to compensate for the first kThe optimal output driving code value is ultimately determined for the grayscale and red channel. This indicates that under the white field path, in order to compensate for the first k The optimal output driving code value ultimately determined for grayscale and green channel. This indicates that under the white field path, in order to compensate for the first k The optimal output driving code value is finally determined for the grayscale and blue channel.

[0084] This lookup table can be written into the display control card, FPGA, display driver chip, or host computer calibration software. When displaying white or near-white grayscale content, the system calls the corresponding RGB output code value based on the input grayscale to achieve joint compensation of brightness and chromaticity. For non-8-bit systems, interpolation, piecewise fitting, or high-depth lookup table expansion can be used. In practical applications, the compensation mapping can be written into the display control card, FPGA, driver chip, receiver card, host computer calibration software, on-chip memory, or cloud calibration system; it can also be implemented through lookup tables, piecewise functions, parametric models, or real-time search methods.

[0085] In a preferred embodiment, a flip-chip COB Micro-LED display module is used as the measurement object, and the model domain is numerically evaluated using R, G, and B single-channel and equivalent RGB white field full grayscale measurement data. Compared with gamma and other channel mappings, the generated joint compensation mapping can significantly reduce brightness error and cross-grayscale chromaticity deviation, indicating that introducing chromaticity constraints in the restricted candidate domain is beneficial to improving chromaticity consistency near the white field grayscale path.

[0086] In this embodiment, in addition to collecting 256 nodes at each gray level, segmented sampling, key gray level sampling combined with interpolation fitting, imaging colorimeter area sampling, or spectrometer sampling can also be used to obtain R / G / B single-channel and white field response data.

[0087] In this embodiment, the candidate domain can be a cube search domain, a spherical or ellipsoidal search domain, an asymmetric search domain weighted by channel sensitivity, or the search radius and channel deviation threshold can be dynamically adjusted according to the grayscale interval.

[0088] Implementation Method 3: This implementation method proposes a computer device, including a memory and a processor. The memory stores a computer program. When the processor runs the computer program stored in the memory, the processor executes a display screen brightness and chromaticity joint compensation mapping generation method according to any one of Implementation Method 1 to Implementation Method 2.

[0089] The specific embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A method for generating a display screen brightness and chromaticity joint compensation mapping, characterized in that, The method includes: Acquire first optical measurement data of the red, green, and blue single channels of the Micro-LED display screen within their respective full grayscale ranges, and second optical measurement data of the display screen within the full grayscale range of the white field of red, green, and blue values; For the target grayscale value, an equivalent RGB initial code value is determined based on the second optical measurement data, and a restricted RGB candidate driving domain is constructed with the equivalent RGB initial code value as the center, combined with the preset single-channel search radius and the maximum deviation between channels; Within the restricted RGB candidate driving domain, the tristimulus values ​​of each candidate RGB driving combination are estimated by superimposing the single-channel tristimulus value increment in the first optical measurement data with the corresponding grayscale tristimulus values ​​in the second optical measurement data. Based on the target brightness and preset reference chromaticity coordinates corresponding to the target grayscale value, and combined with the continuity constraint of adjacent grayscale driving codes, a joint objective function is constructed. Solve the joint objective function within the restricted RGB candidate driving domain, and determine the optimal solution as the compensated RGB driving code value corresponding to the target grayscale value; Iterate through all target grayscale values ​​and generate a compensation lookup table from grayscale values ​​to compensated RGB driver code values.

2. The method for generating a display screen brightness and chromaticity joint compensation mapping according to claim 1, characterized in that, The construction of the restricted RGB candidate driving domain includes: The initial RGB code value is set to the equivalent value. The restricted RGB candidate driving domain for: in, r This represents the candidate output code value for the red channel. g This represents the candidate output code value for the green channel. b Indicates the candidate output code value for the blue channel; d D represents the single-channel search radius; D represents the maximum deviation between channels. Indicates the first k The equivalent RGB initial code value for grayscale; Indicates the maximum grayscale value; This represents the maximum value among the candidate output code values ​​for the red, green, and blue channels. This represents the minimum value among the candidate output code values ​​for the red, green, and blue channels.

3. The method for generating a display screen brightness and chromaticity joint compensation mapping according to claim 1, characterized in that, The estimated tristimulus values ​​for each candidate RGB driver combination are output, including: in, Indicates candidate driver combinations d The estimated tristimulus values ​​output, This represents the tristimulus value of the equivalent RGB white field. This represents the tristimulation value of the red single channel. This represents the tristimulus value of the red single channel in the reference grayscale. This indicates the tristimulation value of the green single channel. This represents the tristimulus value of the green single channel under the reference grayscale. This represents the tristimulation value of the blue single channel. This represents the tristimulus value of the blue single channel under the reference grayscale.

4. The method for generating a display screen brightness and chromaticity joint compensation mapping according to claim 1, characterized in that, The preset reference chromaticity coordinates are determined in the following way: Multiple white field chromaticity coordinates within the high grayscale stable range of the second optical measurement data are selected, and their average value is calculated as the preset reference chromaticity coordinates.

5. The method for generating a display screen brightness and chromaticity joint compensation mapping according to claim 4, characterized in that, The high grayscale stable range is a continuous range where the grayscale code value is greater than a preset threshold, and the chromaticity coordinates are in the CIE 1976 chromaticity coordinate system. u′ and v′ coordinate.

6. The method for generating a display screen brightness and chromaticity joint compensation mapping according to claim 1, characterized in that, The joint objective function is: in, Describe the joint objective function. This represents the normalized error between the candidate output brightness and the target brightness. This indicates the chromaticity deviation between the candidate output chromaticity coordinates and the reference chromaticity coordinates; This represents the continuity cost between the current candidate code value and the determined code values ​​of adjacent gray levels; , and For the corresponding weights.

7. The method for generating a display screen brightness and chromaticity joint compensation mapping according to claim 1, characterized in that, The method further includes, after solving the joint objective function, verifying whether the estimated brightness of adjacent gray levels satisfies the non-decreasing constraint; if not, adjusting the optimal solution of the current gray level until it does. ,in, Indicates the first k The optimal estimated brightness for +1 gray level Indicates the first k The optimal estimated brightness for grayscale.

8. The method for generating a display screen brightness and chromaticity joint compensation mapping according to claim 1, characterized in that, Both the first and second optical measurement data contain CIE XYZ tristimulus values, luminance value Y, and chromaticity coordinates. After acquiring the data, preprocessing steps of dark field subtraction and outlier removal are performed.

9. The method for generating a display screen brightness and chromaticity joint compensation mapping according to claim 1, characterized in that, After traversing all target grayscale values, the generated compensation lookup table is written into the display control card, FPGA, or display driver chip, which is used to call the corresponding RGB output code value when displaying white grayscale content.

10. A computer device, characterized in that: The device includes a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes a display screen brightness and chromaticity joint compensation mapping generation method according to any one of claims 1-9.

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