Brightness compensation method and device, and computer-readable storage medium

Abstract

A brightness compensation method and device, and a computer-readable storage medium, the brightness compensation method comprising: determining a baseline compensation parameter for each sub-pixel in a display panel and a currently displayed brightness segment; determining a brightness segment compensation parameter corresponding to the brightness segment based on the currently displayed brightness segment, the brightness segment compensation parameter being used to adjust the compensation result of the baseline compensation parameter according to a magnification; calculating a compensated grayscale value corresponding to each sub-pixel based on the input grayscale value of the sub-pixel, the baseline compensation parameter, and the brightness segment compensation parameter, and performing brightness compensation on the sub-pixel based on the compensated grayscale value corresponding to the sub-pixel.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to, but are not limited to, display technology, and in particular to a brightness compensation method and device, and a computer-readable storage medium. Background Art

[0002] Organic Light Emitting Diodes (OLEDs) are active light-emitting display devices with advantages such as luminescence, ultra-thinness, wide viewing angles, high brightness, high contrast, low power consumption, and extremely fast response times. OLEDs can be categorized by driving method: Passive Matrix (PM) and Active Matrix (AM). AMOLEDs are current-driven devices that use independent thin-film transistors (TFTs) to control each sub-pixel, allowing each sub-pixel to emit light continuously and independently. Summary of the Invention

[0003] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0004] An embodiment of the present disclosure provides a brightness compensation method, including: determining a baseline compensation parameter for each sub-pixel in a display panel and a currently displayed brightness segment; determining a brightness segment compensation parameter corresponding to the brightness segment based on the currently displayed brightness segment, the brightness segment compensation parameter being used to adjust the compensation result of the baseline compensation parameter according to a magnification; calculating a compensated grayscale value corresponding to the sub-pixel based on an input grayscale value of each sub-pixel, the baseline compensation parameter, and the brightness segment compensation parameter, and performing brightness compensation on the sub-pixel based on the compensated grayscale value corresponding to the sub-pixel.

[0005] An embodiment of the present disclosure further provides a brightness compensation device, comprising: a processor; and a memory storing a computer program, wherein when the computer program is executed by the processor, the brightness compensation method as described in any embodiment of the present disclosure is implemented.

[0006] An embodiment of the present disclosure further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the brightness compensation method as described in any embodiment of the present disclosure is implemented.

[0007] Other aspects will become apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings are used to provide an understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation to the technical solution of the present disclosure.

[0009] Figure 1 A schematic diagram of a brightness compensation method;

[0010] Figure 2 Schematic diagram of compensation curves in different brightness range modes;

[0011] Figure 3A and Figure 3B Schematic diagrams of Mura under over-compensation and under-compensation respectively;

[0012] Figure 4A A schematic flow chart of a brightness compensation method provided in an embodiment of the present disclosure;

[0013] Figure 4B is a schematic diagram of a gamma curve;

[0014] Figure 5 A schematic diagram of a brightness compensation method according to an embodiment of the present disclosure;

[0015] Figure 6 A schematic diagram of a DDIC circuit provided in an embodiment of the present disclosure;

[0016] Figure 7 The present invention provides a schematic structural diagram of a brightness compensation device according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0017] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The embodiments can be implemented in a variety of different forms. A person skilled in the art can easily understand that the method and content can be transformed into other forms without departing from the purpose and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the contents described in the following embodiments. In the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other in any manner.

[0018] In the drawings, the size of one or more components, layer thicknesses, or regions may be exaggerated for clarity. Therefore, one embodiment of the present disclosure is not necessarily limited to these dimensions, and the shapes and sizes of one or more components in the drawings do not reflect true proportions. Furthermore, the drawings schematically illustrate idealized examples, and one embodiment of the present disclosure is not limited to the shapes or values ​​shown in the drawings.

[0019] In this specification, ordinal numbers such as "first," "second," and "third" are provided to avoid confusion among constituent elements, and are not intended to limit the number. "Multiple" in this disclosure means two or more.

[0020] Mura is a common undesirable phenomenon in OLED display technology, primarily caused by differences in the characteristics of each TFT due to immature TFT processes. Demura is a compensation method for mura, which is divided into internal compensation and external compensation. Internal compensation compensates for differences in TFT characteristics through pixel circuits; external compensation detects differences in each pixel through optical or electrical means and compensates for them by changing the drive voltage. Currently, the commonly used demura compensation method is to capture several grayscale images with a high-resolution and high-precision charge coupled device (CCD) camera, analyze the color distribution characteristics of the pixels in the display based on the data collected by the camera, and identify mura based on an algorithm. Mura compensation is then performed based on the demura compensation algorithm corresponding to the mura data level to generate demura data, i.e., mura compensation data.

[0021] like Figure 1 As shown in FIG, a parameter calculation model of a demura compensation algorithm is:

[0022] Y=A*X 2 +B*X+Offset (I)

[0023] Wherein, Y is the target grayscale, X is the input grayscale, A, B and Offset are all reference compensation parameters, A is the first compensation parameter, B is the second compensation parameter, and Offset is the third compensation parameter.

[0024] For the compensation curve of different brightness bands, use the Offset scalar parameter to adjust the gain. The compensation formula for different brightness bands is:

[0025] Y=A*X 2 +B*X+Offset*Offset scalar (II)

[0026] However, this demura compensation method is not flexible enough to meet the demura compensation adjustment requirements. Figure 2As shown in the figure, there is a problem of insufficient adjustment space for the High Brightness Mode (HBM) mode and the Normal9 (N9) mode. Specifically, the following are the problems: 1) In HBM mode, Gray255 is over-compensated, and the Offset scalar parameter is set to 0, but the over-compensation cannot be eliminated; 2) In N9 mode, Gray32 Mura is too heavy, and the Offset scalar parameter is set to a large value, but the improvement effect is still not obvious. Even if further improvement can be made, there is still the risk of over-compensation of high grayscale (Gray128 / Gray255). Figure 3A and Figure 3B As shown in the figure, overcompensation is typically manifested as HBM pitting Mura, and undercompensation is typically manifested as the inability to completely eliminate N9Gray32 vertical stripes.

[0027] like Figure 4A As shown, the embodiment of the present disclosure provides a brightness compensation method, comprising the following steps:

[0028] Step 401: Determine the reference compensation parameter of each sub-pixel in the display panel and the currently displayed brightness segment;

[0029] Step 402: Determine a brightness segment compensation parameter corresponding to the brightness segment according to the currently displayed brightness segment, wherein the brightness segment compensation parameter is used to adjust the compensation result of the reference compensation parameter according to a magnification;

[0030] Step 403: Calculate the compensated grayscale value corresponding to each sub-pixel based on the input grayscale value of each sub-pixel, the reference compensation parameter, and the brightness segment compensation parameter;

[0031] Step 404 : Perform brightness compensation on the sub-pixel according to the compensated grayscale value corresponding to the sub-pixel.

[0032] The disclosed embodiment adjusts the compensation result of the reference compensation parameter by a magnification through the brightness segment compensation parameter, which can greatly improve the flexibility of mura compensation and effectively solve the problems of being unable to eliminate over-compensation in high-brightness mode and unable to improve under-compensation in low-brightness mode.

[0033] In some exemplary embodiments, in step 401, the brightness segment includes at least one of the following: Always On Display (AOD), High Brightness Mode (HBM), and Normal mode. Figure 4BAs shown, the normal mode may include normal mode 1 to normal mode 9. The maximum brightness gradually decreases from normal mode 1 to normal mode 9. For example, the brightness range of normal mode 1 is 0 to 500 nits, the brightness range of normal mode 2 is 0 to 400 nits, the brightness range of normal mode 3 is 0 to 150 nits, ..., and the brightness range of normal mode 9 is 0 to 2 nits.

[0034] In some exemplary embodiments, in step 401, the reference compensation parameters include a first compensation parameter A, a second compensation parameter B, and a third compensation parameter Offset, and compensation is performed using the reference compensation parameters according to the following formula: Y0 = A*X 2 +B*X+Offset, where Y0 is the grayscale value after compensation using the reference compensation parameters, and X is the input grayscale value.

[0035] In some exemplary embodiments, 2 -20 ≤A≤2 -10 ;0.75≤B≤1.25;-8≤Offset≤8.

[0036] It should be noted that the embodiments of the present disclosure do not limit the number of reference compensation parameters and the reference compensation formula. In other exemplary embodiments, other reference compensation parameters or formulas may also be used for compensation, for example, Y0=A*X+Offset, etc.

[0037] In some exemplary embodiments, in step 403, the compensated grayscale value corresponding to each sub-pixel is calculated based on the input grayscale value of each sub-pixel, the reference compensation parameter, and the brightness segment compensation parameter, specifically:

[0038] According to the following functional relationship: Y = Y0 * Scalar, the compensated grayscale value corresponding to the sub-pixel is calculated, where Y0 is the grayscale value compensated using the reference compensation parameter, Y is the grayscale value after sub-pixel compensation, Scalar is the brightness segment compensation parameter, and Scalar is a real number greater than or equal to 0.

[0039] In the disclosed embodiment, when weak compensation is performed on the HBM mode, the value of the brightness segment compensation parameter Scalar is reduced to 0; when compensation is performed on the N9 mode, the value of the brightness segment compensation parameter Scalar is increased, which can multiply the compensation and greatly increase the flexibility of compensation adjustment.

[0040] In some exemplary embodiments, in step 401, the reference compensation parameter is determined as follows:

[0041] In a preset first brightness range, capturing test images of the display panel at a plurality of preset first grayscales;

[0042] Acquire image data of a plurality of test images;

[0043] Data processing and calculation are performed on multiple image data to obtain reference compensation parameters.

[0044] In the embodiment of the present disclosure, under the same brightness range conditions, a CCD camera is used to capture several grayscale images (for example, the several grayscale images can be three white images at grayscales 255, 128, and 31, or three red / green / blue images at grayscales 255, 128, and 31) to obtain Mura information, and a reference compensation parameter is obtained through pre-processing and post-processing, wherein the pre-processing includes extracting the display area, removing particles, rounding corners and hole area processing, etc., and the post-processing mainly refers to calculating the reference compensation parameter through a preset compensation algorithm, storing the reference compensation parameter in a bin file, and storing it in a FLASH IC through a burning process. The compensation curves of the remaining brightness ranges are adjusted based on the reference compensation curve using the brightness range compensation parameter Scalar. Since the brightness range compensation parameter Scalar simultaneously adjusts the gain of A, B, and Offset, the problem of over-compensation of high grayscale or under-compensation of low grayscale can be solved.

[0045] In some exemplary embodiments, the brightness compensation method further includes:

[0046] Pre-storing a plurality of grayscale compensation parameter tables, each grayscale compensation parameter table including grayscale compensation parameters corresponding to a plurality of preset second display grayscales in a brightness range;

[0047] Get the current grayscale of the display panel;

[0048] According to the grayscale compensation parameter table, a value of the grayscale compensation parameter corresponding to the acquired display grayscale is determined.

[0049] In some exemplary embodiments, the compensated grayscale value corresponding to each sub-pixel is calculated based on the input grayscale value of each sub-pixel, the reference compensation parameter, and the brightness segment compensation parameter, specifically:

[0050] According to the following functional relationship: Y = Y0 * Scalar + offset', the compensated grayscale value corresponding to the sub-pixel is calculated, where Y0 is the grayscale value compensated using the reference compensation parameter, Y is the grayscale value of the sub-pixel after compensation, Scalar is the brightness segment compensation parameter, Scalar is a real number greater than or equal to 0, and offset' is the grayscale compensation parameter.

[0051] In the embodiment of the present disclosure, corresponding registers may be added to the data driver to store multiple grayscale compensation parameter tables. For example, the grayscale compensation parameter table for a certain brightness range may be as shown in Table 1.

[0052] Gray8 Gray16 Gray32 Gray64 Gray128 Gray255 R Offset'8 value1 Offset'16 value1 … … … … G Offset'8 value2 Offset'16 value2 … … … … B Offset'8 value3 Offset'16 value3 … … … …

[0053] Table 1

[0054] In some exemplary embodiments, determining a value of a grayscale compensation parameter corresponding to the acquired display grayscale according to a grayscale compensation parameter table includes:

[0055] When the acquired display grayscale is one of a plurality of preset second display grayscales, directly determining a value of a corresponding grayscale compensation parameter from a grayscale compensation parameter table;

[0056] When the acquired display grayscale is not any of a plurality of preset second display grayscales, two second display grayscales closest to the acquired display grayscale are determined, and interpolation calculation is performed based on the values ​​of the grayscale compensation parameters corresponding to the determined two second display grayscales to obtain the values ​​of the grayscale compensation parameters corresponding to the acquired display grayscale.

[0057] In some exemplary embodiments, the values ​​of the plurality of preset second display grayscales are 8, 16, 32, 64, 128, and 255, respectively.

[0058] The embodiment of the present disclosure does not limit the number and value of the preset second display grayscales. Generally speaking, the plurality of preset second display grayscales should include at least one low grayscale, at least one middle grayscale, and at least one high grayscale.

[0059] The current brightness compensation method still has the problem of insufficient independence of compensation for different grayscales. Specifically,

[0060] 1) The compensation coefficient for low-brightness, low-grayscale (N9 Gray32) has been further increased. Even when set to the maximum value, N9 Gray32's mura is significantly improved. However, at this time, N9 Gray16 / Gray8-Gray0 / Gray128-Gray255 are affected and over-compensated.

[0061] 2) HBM Gray255 overcompensation can be improved by reducing Scalar compensation, but HBMGray32 compensation is weakened, resulting in undercompensated vertical mura.

[0062] like Figure 5 As shown, the embodiment of the present disclosure sets grayscale compensation parameters and uses them in conjunction with brightness segment compensation parameters. By adjusting the compensation values ​​for different brightness segments and preset grayscales under different brightness segments, the flexibility of adjusting the demura compensation parameters can be greatly improved, the problem of insufficient independence of compensation for different grayscales can be solved, and the best demura effect can be guaranteed.

[0063] In some exemplary embodiments, the present disclosure performs compensation according to the following functional relationship:

[0064] Y=(A*X 2 +B*X+Offset)*scalar+offset′.

[0065] In some exemplary embodiments, the values ​​of the reference compensation parameters A, B, and Offset may be stored in Flash, and the values ​​of the brightness segment compensation parameter Scalar and the grayscale compensation parameter Offset′ may be stored in registers in a display driver IC (DDIC).

[0066] like Figure 6 As shown, when the module displays, it calls the baseline compensation parameters A, B, and Offset in Flash memory, then calls the Scalar and Offset parameters in the display driver IC (DDIC) registers, overlaying them with the source image data to produce a more perfect image. Importing the Scalar and Offset parameters requires adding corresponding circuit interfaces and registers to the DDIC. After adjusting the Scalar and Offset parameters, they are burned into the corresponding registers using OTP (one-time program) at the gamma station.

[0067] An embodiment of the present disclosure further provides a brightness compensation device, comprising a memory; and a processor coupled to the memory, wherein the processor is configured to execute the steps of the brightness compensation method as described in any embodiment of the present disclosure based on instructions stored in the memory.

[0068] like Figure 7 As shown, in one example, the brightness compensation device may include: a processor 710, a memory 720 and a bus system 730, wherein the processor 710 and the memory 720 are connected via the bus system 730, the memory 720 is used to store instructions, and the processor 710 is used to execute the instructions stored in the memory 720 to determine the baseline compensation parameters of each sub-pixel in the display panel and the currently displayed brightness segment; determine the brightness segment compensation parameters corresponding to the brightness segment according to the currently displayed brightness segment, and the brightness segment compensation parameters are used to adjust the compensation result of the baseline compensation parameters according to the magnification; calculate the compensated grayscale value corresponding to the sub-pixel according to the input grayscale value of each sub-pixel, the baseline compensation parameter and the brightness segment compensation parameter, and perform brightness compensation on the sub-pixel according to the compensated grayscale value corresponding to the sub-pixel.

[0069] It should be understood that the processor 710 may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0070] The memory 720 may include a read-only memory and a random access memory, and provides instructions and data to the processor 710. A portion of the memory 720 may also include a non-volatile random access memory. For example, the memory 720 may also store information about the device type.

[0071] In addition to the data bus, the bus system 730 may also include a power bus, a control bus, and a status signal bus. Figure 7 Various buses are labeled as bus system 730.

[0072] During implementation, the processing performed by the processing device can be completed by the hardware integrated logic circuit in the processor 710 or by instructions in the form of software. That is, the method steps of the embodiment of the present disclosure can be embodied as being executed by a hardware processor, or being executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 720, and the processor 710 reads the information in the memory 720 and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

[0073] An exemplary embodiment of the present disclosure further provides a display panel including the aforementioned brightness compensation device.

[0074] The exemplary embodiments of the present disclosure further provide a display device including the aforementioned display panel. The display device may be a mobile phone, tablet computer, television, display device, laptop computer, digital photo frame, navigation device, or any other product or component with a display function.

[0075] An embodiment of the present disclosure further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the brightness compensation method as described in any embodiment of the present disclosure.

[0076] In some possible implementations, various aspects of the brightness compensation method provided in the present application may also be implemented in the form of a program product, which includes program code. When the program product is run on a computer device, the program code is used to enable the computer device to execute the steps of the brightness compensation method according to various exemplary embodiments of the present application described above in this specification. For example, the computer device may execute the brightness compensation method described in the embodiments of the present application.

[0077] The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0078] The drawings in this disclosure only relate to the structures involved in this disclosure, and other structures may refer to general designs. In the absence of conflict, the embodiments of this disclosure and the features in the embodiments may be combined with each other to obtain new embodiments.

[0079] It should be understood by those skilled in the art that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present disclosure, and all should be included in the scope of the claims of the present disclosure.

Claims

1. A brightness compensation method, characterized in that: include: Determining a reference compensation parameter for each sub-pixel in the display panel and a currently displayed brightness segment; A brightness segment compensation parameter corresponding to the brightness segment currently displayed is determined. The brightness segment compensation parameter is used to adjust the compensation result of the reference compensation parameter according to a magnification. The reference compensation parameter includes a first compensation parameter A, a second compensation parameter B, and a third compensation parameter Offset. The reference compensation parameter is used for compensation according to the following formula: =A*X 2 +B*X+Offset, where is the grayscale value after compensation using the reference compensation parameters, and X is the input grayscale value; Calculating a compensated grayscale value corresponding to each sub-pixel according to the input grayscale value of the sub-pixel, the reference compensation parameter, and the brightness segment compensation parameter; Brightness compensation is performed on the sub-pixel according to the compensated grayscale value corresponding to the sub-pixel.

2. The brightness compensation method according to claim 1, wherein: ； ； 。 3. The brightness compensation method according to claim 1, wherein: The reference compensation parameters are determined as follows: In a preset first brightness range, capturing test images of the display panel at a plurality of preset first grayscales; acquiring image data of a plurality of test images; Data processing and calculation are performed on the plurality of image data to obtain the reference compensation parameters.

4. A brightness compensation method, characterized in that: include: Determining a reference compensation parameter for each sub-pixel in the display panel and a currently displayed brightness segment; Determining, according to the currently displayed brightness segment, a brightness segment compensation parameter corresponding to the brightness segment, wherein the brightness segment compensation parameter is used to adjust the compensation result of the reference compensation parameter according to a magnification; Calculating a compensated grayscale value corresponding to each sub-pixel according to the input grayscale value of the sub-pixel, the reference compensation parameter, and the brightness segment compensation parameter; Performing brightness compensation on the sub-pixel according to the compensated grayscale value corresponding to the sub-pixel; The compensated grayscale value corresponding to each sub-pixel is calculated according to the input grayscale value of each sub-pixel, the reference compensation parameter, and the brightness segment compensation parameter, specifically: According to the following functional relationship: Y= *Scalar, calculates the compensated grayscale value corresponding to the sub-pixel; or: According to the following functional relationship: Y= *Scalar+offset', calculate the compensated grayscale value corresponding to the sub-pixel; in, is the grayscale value after compensation using the reference compensation parameter, Y is the grayscale value of the sub-pixel after compensation, Scalar is the brightness segment compensation parameter, Scalar is a real number greater than or equal to 0, and offset' is the grayscale compensation parameter.

5. The brightness compensation method according to claim 4, characterized in that: The reference compensation parameters are determined as follows: In a preset first brightness range, capturing test images of the display panel at a plurality of preset first grayscales; acquiring image data of a plurality of test images; Data processing and calculation are performed on the plurality of image data to obtain the reference compensation parameters.

6. The brightness compensation method according to claim 5, characterized in that: The values ​​of the first grayscales are 255, 128 and 31 respectively.

7. The brightness compensation method according to claim 4, wherein: The method further comprises: Pre-storing a plurality of grayscale compensation parameter tables, each grayscale compensation parameter table including grayscale compensation parameters corresponding to a plurality of preset second display grayscales in a brightness range; Get the current grayscale of the display panel; According to the grayscale compensation parameter table, a value of the grayscale compensation parameter corresponding to the acquired display grayscale is determined.

8. The brightness compensation method according to claim 7, wherein: The step of determining, according to the grayscale compensation parameter table, a value of the grayscale compensation parameter corresponding to the acquired display grayscale comprises: When the acquired display grayscale is one of a plurality of preset second display grayscales, directly determining a value of the corresponding grayscale compensation parameter from the grayscale compensation parameter table; When the acquired display grayscale is not any of the multiple preset second display grayscales, two second display grayscales closest to the acquired display grayscale are determined, and interpolation calculation is performed based on the values ​​of the grayscale compensation parameters corresponding to the determined two second display grayscales to obtain the values ​​of the grayscale compensation parameters corresponding to the acquired display grayscale.

9. The brightness compensation method according to claim 7, wherein: The plurality of preset values ​​of the second display grayscale are 8, 16, 32, 64, 128 and 255 respectively.

10. A brightness compensation device, characterized in that: include: processor; as well as A memory storing a computer program, wherein when the computer program is executed by a processor, the brightness compensation method according to any one of claims 1 to 9 is implemented.

11. A computer-readable storage medium, characterized in that A computer program is stored, and when the computer program is executed by a processor, the brightness compensation method according to any one of claims 1 to 9 is implemented.

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