Brightness compensation method, electronic device, storage medium and computer program product

Abstract

The invention provides a brightness compensation method, electronic equipment, a storage medium and a computer program product, and the method comprises the steps: obtaining gray values of a first image frame and a second image frame, the second image frame being a to-be-displayed image frame, the first image frame being a previous frame of the to-be-displayed image frame, the gray value of the first image frame being recorded as a first gray value, and the gray value of the second image frame being recorded as a second gray value; the gray value of the second image frame is recorded as a second gray value; voltage compensation parameters corresponding to the first gray value and the second gray value are searched from a lookup table according to the first gray value and the second gray value, the lookup table comprises a plurality of voltage compensation parameters, and each voltage compensation parameter corresponds to a third gray value and a fourth gray value; and acquiring a data voltage of the second image frame, compensating the data voltage through the voltage compensation parameter, and driving the display panel to display the second image frame by using the compensated data voltage.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and more specifically, to a brightness compensation method, electronic device, storage medium, and computer program product. Background Art

[0002] AMOLED (active matrix organic light-emitting diode) displays have been widely used in high-end display devices due to their excellent color performance, high contrast, and low power consumption. However, during the black-and-white screen switching process of the AMOLED display, due to the influence of the driving circuit and device structure, a problem will arise: the brightness of the first frame of the white screen is often lower than the final white brightness value, that is, the first frame brightness is insufficient. For the more sensitive human eye, the phenomenon seen is that there will be a ghosting in the first frame after the screen is switched. FFR (First Frame Ratio) is usually used to characterize this phenomenon. FFR is the first frame refresh rate or the first frame brightness ratio. The lower the FFR value, the more obvious the ghosting. Summary of the invention

[0003] The purpose of the present disclosure is to provide a brightness compensation method, an electronic device, a storage medium and a computer program product to solve the technical problem of insufficient brightness of the first frame when the display screen is switched in the related art.

[0004] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0005] The present disclosure provides a brightness compensation method in a first aspect, comprising the following steps:

[0006] Acquire grayscale values ​​of a first image frame and a second image frame, wherein the second image frame is an image frame to be displayed, the first image frame is a previous frame of the image frame to be displayed, the grayscale value of the first image frame is recorded as a first grayscale value, and the grayscale value of the second image frame is recorded as a second grayscale value;

[0007] searching a pre-stored lookup table for a voltage compensation parameter corresponding to the first gray value and the second gray value according to the first gray value and the second gray value, wherein the lookup table includes a plurality of voltage compensation parameters, each voltage compensation parameter corresponds to a third gray value and a fourth gray value, and the voltage compensation parameter represents a compensation parameter satisfying that a first frame brightness ratio is greater than a preset value when the display panel switches from a display screen of the third gray value to a display screen of the fourth gray value;

[0008] A data voltage of the second image frame is acquired, the data voltage is compensated by the voltage compensation parameter, and the display panel is driven by the compensated data voltage to display the second image frame.

[0009] Optionally, the voltage compensation parameter is a voltage compensation value; and compensating the data voltage by using the voltage compensation parameter includes:

[0010] The sum of the voltage compensation value and the data voltage is used as the compensated data voltage.

[0011] Optionally, the voltage compensation parameter is a voltage compensation coefficient; and compensating the data voltage by using the voltage compensation parameter includes:

[0012] The product of the voltage compensation coefficient and the data voltage is used as the compensated data voltage.

[0013] Optionally, the brightness compensation method further includes:

[0014] Obtaining a voltage compensation parameter when the display panel switches from a first test picture to a second test picture and the proportion of the brightness of the first frame is greater than a preset value, wherein the grayscale value of the first test picture is the third grayscale value, the grayscale value of the second test picture is the fourth grayscale value, and the third grayscale value, the fourth grayscale value and the voltage compensation parameter constitute a set of reference data;

[0015] A plurality of groups of the reference data are obtained, and a lookup table is established according to the plurality of groups of the reference data, wherein the third grayscale values ​​corresponding to the respective groups of the reference data are different and / or the fourth grayscale values ​​corresponding to the respective groups of the reference data are different.

[0016] Optionally, the second test picture includes a plurality of frames, and the step of obtaining a voltage compensation parameter when the brightness ratio of the first frame is greater than a preset value when the display panel switches from the first test picture to the second test picture includes:

[0017] Set multiple voltage compensation parameters;

[0018] For any voltage compensation parameter, the brightness of the display panel when displaying the first test screen is obtained as the original brightness, the brightness of the display panel when displaying the first frame of the second test screen is obtained as the first brightness, and the brightness of the display panel when displaying the second frame of the second test screen is obtained as the second brightness, and the first frame brightness ratio corresponding to the voltage compensation parameter is calculated according to the original brightness, the first brightness, and the second brightness;

[0019] A voltage compensation parameter whose first frame brightness ratio is greater than a preset value is obtained from first frame brightness ratios corresponding to multiple voltage compensation parameters.

[0020] Optionally, the step of searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value includes:

[0021] Searching a third grayscale value closest to the first grayscale value and a fourth grayscale value closest to the second grayscale value from a pre-stored lookup table;

[0022] The voltage compensation parameters corresponding to the third grayscale value and the fourth grayscale value found are used as the voltage compensation parameters corresponding to the first grayscale value and the second grayscale value.

[0023] Optionally, the lookup table includes a plurality of sub-tables, each sub-table corresponding to a brightness level; and the step of searching the pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value comprises:

[0024] Acquire the brightness level currently set on the display panel as a first brightness level;

[0025] According to the first grayscale value and the second grayscale value, voltage compensation parameters corresponding to the first grayscale value and the second grayscale value are searched from the subtable corresponding to the first brightness level.

[0026] Optionally, the step of acquiring the grayscale values ​​of the first image frame and the second image frame includes:

[0027] Divide the first image frame into multiple first image blocks, calculate the grayscale values ​​of the first image blocks as first sub-grayscale values, and a set of the first sub-grayscale values ​​of the first image blocks constitutes the first grayscale value;

[0028] Divide the second image frame into blocks to obtain second image blocks corresponding to the first image blocks one by one, calculate the grayscale values ​​of the second image blocks as second sub-grayscale values, and a set of the second sub-grayscale values ​​of the second image blocks constitutes the second grayscale value;

[0029] The step of searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value comprises:

[0030] For any first image block and corresponding second image block, voltage compensation parameters corresponding to the first sub-grayscale value and the second sub-grayscale value are searched from the lookup table according to the first sub-grayscale value corresponding to the first image block and the second sub-grayscale value corresponding to the second image block.

[0031] Optionally, the step of calculating the grayscale value of the first image block as the first sub-grayscale value includes:

[0032] Calculating an average value of the grayscale value of each pixel in the first image block;

[0033] The average value is used as the first sub-grayscale value corresponding to the first image block.

[0034] A second aspect of the present disclosure provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor is configured to read the program in the memory to implement the steps of the brightness compensation method described above.

[0035] A third aspect of the present disclosure provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the brightness compensation method described above are implemented.

[0036] A fourth aspect of the present disclosure provides a computer program product, including a computer program, which implements the steps of the brightness compensation method described above when executed by a processor.

[0037] The beneficial effects of the present disclosure are as follows:

[0038] The brightness compensation method of the disclosed embodiment measures and stores a lookup table in advance, wherein the lookup table includes a voltage compensation parameter that makes the brightness ratio of the first frame after the switch greater than a preset value when the display panel switches from a picture with a third grayscale value to a picture with a fourth grayscale value. When the display panel switches the picture, the voltage compensation parameter is searched using the grayscale value of the image frame to be displayed and the previous frame of the image frame to be displayed, and the data voltage of the image frame to be displayed is compensated by the found voltage compensation parameter. In this way, the problem of reduced brightness of the first frame when switching the picture caused by IR Drop can be compensated, thereby improving FFR performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The specific implementation methods of the present disclosure are further described in detail below with reference to the accompanying drawings.

[0040] Figure 1 This is a schematic diagram showing that the brightness of the first frame is insufficient when the display screen switches to black and white;

[0041] Figure 2 Schematic diagram of the principle that when switching to black and white images, IR Drop causes the brightness of the first few frames of white images to be lower than the determined value;

[0042] Figure 3 A basic structural diagram of a pixel driving circuit of a display panel;

[0043] Figure 4 A flowchart of a brightness compensation method provided by an embodiment of the present disclosure;

[0044] Figure 5 A schematic diagram of dividing a first image frame into blocks to obtain a plurality of first image blocks;

[0045] Figure 6 A schematic diagram of the operation time when the compensation IP performs inverse compensation on display images with different grayscales;

[0046] Figure 7 It is the display brightness of each frame before and after switching from the G0 screen to the G255 screen in the related art;

[0047] Figure 8 When the G0 screen is switched to the G255 screen in the embodiment of the disclosure, the brightness compensation method is used to compensate for the display brightness of each frame before and after the switching;

[0048] Fig. 9 A flow chart for establishing a lookup table provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0050] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0051] FFR is an important parameter in the optical performance of the display, which affects the smoothness of dynamic images and the visual experience. A high first frame refresh rate means that the screen can update the image more frequently, reducing motion blur and motion smear, and providing a smoother visual experience. Please refer to Figure 1 , Figure 1 This is a schematic diagram showing that the brightness of the first frame is insufficient when the display switches from black to white. Figure 1 The horizontal axis represents time, the vertical axis represents optical response, and the curve represents the current curve. Figure 10 Frame represents a black frame, 1st Frame, 2nd Frame, and 3rd Frame represent the first white frame, the second white frame, and the third white frame after the black frame, respectively. R1, R2, and R0 represent the average brightness of each frame of the 1st Frame, the 2nd Frame, and the 3rd Frame, respectively. The white brightness of the third white frame and subsequent white frames tends to be stable. R0 can also be understood as the average brightness of each frame after the white brightness stabilizes (no longer increases for each frame). Figure 1 It can be seen that when the display switches from a black screen to a white screen, the brightness of the first few frames (especially the first frame) of the white screen is often lower than the final white screen brightness value R0. This phenomenon may be caused by certain factors such as TFT (thin film transistor) hysteresis effect or IR Drop (current reduction).

[0052] Please refer to Figures 2 to 3 , Figure 2 When the black screen switches to the white screen, IR Drop causes the brightness of the first few frames of the white screen to be lower than the predetermined value. Figure 2 As shown, the equivalent resistance of all sub-pixel units in parallel in the display area of ​​the display screen (for example, a sub-pixel unit composed of each R, G, and B sub-pixel can also be understood as a pixel) is defined as Rx, and the resistance of the ELVDD voltage lead excluding the sub-pixel unit is defined as R0, and R0 is a fixed value in the display screen. Figure 2 As shown, Rx and R0 are in series, and the same current I passes through both. Therefore, the resistor R0 occupies part of the voltage, that is, V Drop =I×R0. During the display process, the current I will change with the different display patterns, resulting in V Drop V Drop The influence of IR Drop will cause the voltages allocated to the sub-pixel units in parallel in the display area to change simultaneously, that is, Real ELVDD=ELVDD-I×R0. This phenomenon that the Real ELVDD of sub-pixel units is different due to different display loads (display images) is called IR Drop. Affected by IR Drop, Real ELVDD is variable, so the current I of the sub-pixel unit is affected by both Real ELVDD and V Data Variable influence.

[0053] Combine the following Figure 3 In-depth analysis of the causes of IR Drop, Figure 3The basic structure diagram of the pixel driving circuit of the display panel of the related art is shown in FIG. The pixel driving circuit is a typical 7T1C driving circuit, wherein transistor T1 is a reset transistor, transistor T4 is a data input transistor, transistor T3 is a driving transistor, transistor T2 is a compensation transistor, transistors T5 and T7 are light-emitting control transistors, and transistor T6 is a reset transistor. The control electrodes of transistors T2 and T4 are electrically connected to the row scanning terminal to access the row scanning signal Gate, the control electrode of transistor T1 is electrically connected to the reset control terminal to access the reset control signal RESET, and the drain of transistor T4 is connected to the data voltage V Data EL represents a light emitting diode. The entire light emitting process can be divided into three stages: reset, compensation, and light emitting. Since the 7T1C driving circuit is a mature technology, the embodiments of the present disclosure will not describe the various stages of the light emitting process in detail. In the light emitting stage of EL, a part of the voltage is stored in the parasitic capacitance between the gate and drain of transistor T3, generating a voltage difference ΔVC; when the picture changes, ΔVC will affect the data voltage V at the drain of transistor T3. Data , thus affecting the capacitance C from transistor T2 to the gate of transistor T3 during the compensation phase st , causing the current to change, and the current formula is as follows:

[0054]

[0055] Where, I is the leakage current of transistor T3, that is, the current in EL, μ represents the electron mobility of transistor T3, C ox represents the capacitance coefficient of transistor T3, W represents the channel width of transistor T3, L represents the channel length of transistor T3, V gs represents the gate-source voltage of the transistor T3 , ELVDD represents the first voltage applied to the pixel driving circuit, and ELVSS represents the second voltage applied to the pixel driving circuit.

[0056] When the display screen switches from a black screen with a grayscale of 0 (whose RGB value is represented by (0,0,0)) to a white screen with a grayscale of 255 (whose RGB value is represented by (255,255,255)), the current I1 in EL is expressed as:

[0057]

[0058] When the display screen switches from a 255-grayscale white screen to a 255-grayscale white screen (it can also be understood as a white screen switching to a white screen, or two adjacent frames displayed are the same, both white screens), the current I2 in EL is expressed as:

[0059]

[0060] Where, ΔV C1 Indicates the voltage in the parasitic capacitance between the gate and drain of transistor T3 when the display screen displays a black screen when the black screen of 0 grayscale is switched to the white screen of 255 grayscale, ΔV C2 It means that when the white screen with gray scale of 255 is switched to the white screen with gray scale of 255, the display screen shows the voltage in the parasitic capacitance between the gate and drain of transistor T3 when the white screen before switching is switched. Ideally, I1 and I2 are equal, but due to ΔV C The influence of C1 >ΔV C2 , which will cause I1<I2. Therefore, it is observed on the waveform that the brightness of the first frame decreases when the black screen switches to the white screen, and temporary image adhesion is observed when the image changes (switches). C Therefore, when different grayscale images are switched, the brightness of the first frame decreases to different degrees. In the related art, the brightness of the first frame is usually improved by increasing the complexity of the TFT drive circuit, but this not only increases the manufacturing cost, but also may introduce additional failure points, reducing the reliability and stability of the display. In the embodiment of the present disclosure, the data voltage is compensated by using a voltage compensation parameter to compensate ΔV C This causes the brightness of the first frame to decrease when the screen switches.

[0061] Specifically, the embodiments of the present disclosure provide a brightness compensation method, an electronic device, a storage medium, and a computer program product, which are described below in conjunction with various specific embodiments. The brightness compensation method can be integrated in a control module of a display panel, which can be a Soc (System on Chip) of a display panel, or a DDIC (Dispaly Driver IC), or other control unit. The brightness compensation algorithm can be understood as a compensation IP, which uses a previous frame image to compensate for the data voltage of the next frame image to be displayed.

[0062] Please refer to Figure 4 , Figure 4 A flowchart of a brightness compensation method provided by an embodiment of the present disclosure, such as Figure 4 As shown, it includes the following steps:

[0063] Step S110, obtaining grayscale values ​​of a first image frame and a second image frame, wherein the second image frame is an image frame to be displayed, the first image frame is a previous frame of the image frame to be displayed, the grayscale value of the first image frame is recorded as a first grayscale value, and the grayscale value of the second image frame is recorded as a second grayscale value.

[0064] In the embodiment of the present disclosure, the brightness compensation method is used to solve the problem of insufficient brightness when the display panel switches from the first image frame to the second image frame. n , which is the image frame to be displayed currently, the first image frame is denoted as P n-1 , which is the previous image frame of the current image frame to be displayed. Assume that the video stream in the display panel includes images P1, P2, P3.....P m , then if the second image frame P n is P3, then the first image frame P n-1 is P2, if the second image frame P n is P4, then the first image frame P n-1 is P3, and so on.

[0065] The first image frame and the second image frame each include a plurality of pixels, and in the RGB color space, each pixel corresponds to an RGB value, and the first image frame and the second image frame can be represented by RGB data. After the RGB data of the first image frame and the second image frame are obtained, their respective grayscale values ​​need to be calculated.

[0066] For any pixel, its RGB data is represented as (R, G, B), and the gray value corresponding to the pixel is recorded as Gray. The calculation formula of the gray value can be expressed as:

[0067]

[0068] Here, 2.2 represents the gamma value of the display panel.

[0069] In the embodiment of the present disclosure, when brightness compensation is performed on the second image frame, the data voltage of each pixel can be compensated independently in units of pixels, or the data voltage of each pixel in the entire frame image can be compensated uniformly with the second image frame as a whole. However, when each pixel is compensated independently, although the compensation accuracy is high, it will significantly increase the amount of calculation and storage requirements, the resource consumption is large, and the compensation efficiency is low; and when the entire frame image is compensated uniformly, the compensation accuracy is low and the compensation effect is poor. In order to solve the problems existing in the above two compensation methods, a block compensation method is adopted in the embodiment of the present disclosure. In specific implementation, the second image frame can be divided into multiple image blocks, and then independent compensation is performed on each image block.

[0070] Correspondingly, the steps of obtaining the grayscale values ​​of the first image frame and the second image frame include: (1) dividing the first image frame into blocks to obtain multiple first image blocks, calculating the grayscale values ​​of the first image blocks as the first sub-grayscale values, and the set of the first sub-grayscale values ​​of each first image block constitutes the first grayscale value; (2) dividing the second image frame into blocks to obtain second image blocks corresponding to the first image blocks one by one, calculating the grayscale values ​​of the second image blocks as the second sub-grayscale values, and the set of the second sub-grayscale values ​​of each second image block constitutes the second grayscale value.

[0071] For example, the first image frame may be divided into 4*2 blocks, that is, the first image frame is divided into 4 blocks in the row direction and 2 blocks in the column direction, so as to obtain 8 image blocks in total. Figure 5 , Figure 5 A schematic diagram of dividing the first image frame into multiple first image blocks, wherein the first image blocks are respectively represented as A11, A12, A21, A22, A31, A32, A41, A42, and assuming that their corresponding first sub-grayscale values ​​are respectively recorded as G11, G12, G21, G22, G31, G32, G41, G42, and the first grayscale value corresponding to the first image frame is recorded as G1, then G1 can be expressed as: {G11, G12, G21, G22, G31, G32, G41, G42}.

[0072] Optionally, the step of calculating the grayscale value of the first image block as the first sub-grayscale value includes: (1) calculating the average grayscale value of each pixel in the first image block; (2) using the average grayscale value as the first sub-grayscale value corresponding to the first image block. That is, for any first image block, the average grayscale value of each pixel contained in the first image block is used as the grayscale value of the first image block. The specific process of dividing the second image frame into blocks and calculating the second sub-grayscale value corresponding to each second image block is the same as the calculation process of the first image frame, and will not be repeated here.

[0073] It is understandable that the block division method and the number of blocks for dividing the image frame are not limited to the exemplary 4*2 block division method, but can be set based on the fineness of brightness compensation, the amount of calculation, and the storage requirements, so as to achieve a balance between compensation accuracy and compensation efficiency. In addition, dividing the first image frame and the second image frame into blocks can also effectively simplify the data processing of any complex display screen, which is beneficial to the internal logic algorithm processing of the IC.

[0074] Step S120, searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value, wherein the lookup table includes a plurality of voltage compensation parameters, each voltage compensation parameter corresponds to a third grayscale value and a fourth grayscale value, and the voltage compensation parameter represents a compensation parameter satisfying that a first frame brightness ratio is greater than a preset value when the display panel switches from a display screen with a third grayscale value to a display screen with a fourth grayscale value.

[0075] In the disclosed embodiment, the first frame brightness ratio can be used to indicate the degree of brightness reduction of the first frame display screen after the screen switches. The larger the first frame brightness ratio, the larger the first frame brightness after the screen switches, and the smaller the degree of brightness reduction of the first frame. At this time, the less the image residue of the previous frame, the less obvious the first frame smear phenomenon, and a smooth visual experience can be provided. On the contrary, the smaller the first frame brightness ratio, the lower the brightness of the first frame after the screen switches, and the greater the degree of brightness reduction of the first frame. At this time, the image residue of the previous frame is large, with obvious dynamic blur and motion smear, and the visual experience is poor. The disclosed embodiment compensates for the second image frame, that is, increases the brightness ratio of the first frame after the screen switches.

[0076] In the disclosed embodiment, a look-up table (Look Up Table), referred to as a LUT table, is measured and stored in advance. The LUT table stores voltage compensation parameters that can satisfy the situation where the brightness ratio of the first frame is greater than a preset value when the display panel switches from a display screen with one grayscale value to a display screen with another grayscale value. The preset value can be, for example, 85%, 90%, 92%, etc., and the voltage compensation parameter is obtained by actual measurement of the display panel.

[0077] Assuming that the grayscale value of the display screen before switching in the LUT table is recorded as the third grayscale value, and the grayscale value of the display screen after switching is recorded as the fourth grayscale value, the voltage compensation parameter corresponds to a third grayscale value and a fourth grayscale value, and refers to the voltage compensation parameter for compensating the data voltage of the display screen of the fourth grayscale value when the display screen of the third grayscale value is switched to the display screen of the fourth grayscale value. Please refer to Table 1, which is a schematic diagram of the LUT table.

[0078] Table 1 LUT table

[0079]

[0080] Table 1 P m Represents the image frame after switching, P m-1Represents the image frame before switching, the third grayscale value and the fourth grayscale value both include multiple grayscale values ​​such as G0, G32, G64...G192, G224, G255, among which G0 represents a grayscale value of 0, G32 represents a grayscale value of 32, G64 represents a grayscale value of 64, and so on, G255 represents a grayscale value of 255, and R_Offset01 in Table 1 represents a voltage compensation parameter when a picture with a grayscale value of 32 is switched to a picture with a grayscale value of 0. Similarly, R_Offset10 represents a voltage compensation parameter when a picture with a grayscale value of 0 is switched to a picture with a grayscale value of 32. The meanings of other voltage compensation parameters are similar. NA represents that the voltage compensation parameter is 0, that is, when switching the picture, if the grayscale values ​​before and after the switching are the same, no compensation is required at this time.

[0081] Optionally, the step of searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value includes:

[0082] (1) searching a pre-stored lookup table for a third grayscale value that is closest to the first grayscale value and a fourth grayscale value that is closest to the second grayscale value;

[0083] (2) Using the voltage compensation parameters corresponding to the third grayscale value and the fourth grayscale value found as the voltage compensation parameters corresponding to the first grayscale value and the second grayscale value.

[0084] In the disclosed embodiment, in order to simplify the amount of calculation of the brightness compensation method, the third grayscale value and the fourth grayscale value in the LUT table are discontinuous values, which are several grayscale values ​​selected from the grayscale of 0-255. When the LUT table is used to search for voltage compensation parameters, the nearest grayscale will be selected, that is, the grayscale closest to the nearest distance, where the nearest distance means that the difference in grayscale values ​​is the smallest. For example, the calculated first grayscale value of the first image frame is 20, and the second grayscale value of the second image frame is 62. The third grayscale value closest to the first grayscale value found in the LUT table is 32, and the fourth grayscale value closest to the second grayscale value is 64, and the voltage compensation parameter is R_Offset21. It can be understood that the LUT table shown in Table 1 can add more grayscales according to the compensation accuracy.

[0085] Step S130 , acquiring a data voltage of the second image frame, compensating the data voltage using the voltage compensation parameter, and using the compensated data voltage to drive the display panel to display the second image frame.

[0086] In the embodiment of the present disclosure, the data voltage V Data, that is, Data voltage, which can also be understood as source voltage, which is determined by the display content. For example, for the second image frame represented by RGB data, for any pixel, its data voltage V Data It is determined by the RGB value of the pixel. The corresponding data voltage V can be obtained according to the RGB value of the pixel. Data Specifically, when the second image frame P is obtained n After the RGB data is obtained, the second image frame P can be obtained according to the RGB data. n The data voltage V corresponding to each pixel Data .

[0087] In a possible implementation, the voltage compensation parameter is a voltage compensation value; and compensating the data voltage by using the voltage compensation parameter includes: taking a sum of the voltage compensation value and the data voltage as the compensated data voltage.

[0088] Assume that according to the first image frame P n-1 and the second image frame P n , the voltage compensation value obtained by looking up the table is recorded as ΔV T(n-1) , the second image frame P n The data voltage of each pixel is recorded as V Data(n) , then use the voltage compensation parameter ΔV T(n-1) For the second image frame P n After compensation, the data voltage of each pixel is expressed as: V Data(n) +ΔV T(n-1) At this time, the current corresponding to each pixel is expressed as:

[0089]

[0090] In other implementations, the voltage compensation parameter is a voltage compensation coefficient; and compensating the data voltage by using the voltage compensation parameter includes: taking the product of the voltage compensation coefficient and the data voltage as the compensated data voltage.

[0091] Assume that according to the first image frame P n-1 and the second image frame P n The voltage compensation coefficient obtained by looking up the table is recorded as K T(n-1) , the second image frame P n The data voltage of each pixel is recorded as V Data(n) , then the voltage compensation parameter is used to compensate the second image frame P n After compensation, the data voltage of each pixel is expressed as: K T(n-1) *V Data(n) At this time, the current corresponding to each pixel is expressed as:

[0092]

[0093] In the embodiment of the present disclosure, the voltage compensation value ΔV T(n-1) , voltage compensation coefficient K T(n-1) Both are used to compensate ΔV C Ideally, Real ELVDD-(V Data(n) +ΔV T(n-1) )=ELVDD-V Data(n) -ΔV C , which is ΔV T(n-1) =-ΔV C Similarly, ideally, Real ELVDD-K T(n-1) ×V Data(n) =ELVDD-V Data(n) -ΔV C , that is, K T(n-1) =(V Data(n) +ΔV C ) / V Data(n) It is understandable that the voltage compensation parameter can also be expressed in other forms, as long as it can inversely compensate the data voltage and eliminate ΔV C This can solve the problem of reduced brightness of the first frame when the screen switches.

[0094] Please refer to Figure 7 and Figure 8 , Figure 7 is the display brightness of each frame before and after switching from the G0 screen to the G255 screen in the related art, Figure 8 In the embodiment of the present disclosure, when the G0 screen is switched to the G255 screen, the brightness compensation method is used to compensate, and the display brightness of each frame before and after the switching is as follows: Figure 7 As shown, when no compensation is performed and the screen is switched to G255 white, the brightness of the first frame (first frame) white screen and the second frame white screen is lower than the final brightness value, and the brightness of the first frame accounts for about 72%. Figure 8 As shown, after compensation and switching to the G255 white screen, the brightness of the first frame of the white screen is close to the final brightness value, and the brightness of the first frame accounts for about 91%, which greatly alleviates the first frame ghosting problem.

[0095] Compared with the related art, the brightness compensation method of the embodiment of the present disclosure pre-measures and stores a lookup table, wherein the lookup table includes a voltage compensation parameter that makes the brightness ratio of the first frame after switching greater than a preset value when the display panel switches from a picture of a third grayscale value to a picture of a fourth grayscale value. When the display panel switches the picture, the voltage compensation parameter is searched using the grayscale values ​​of the image frame to be displayed and the previous frame of the image frame to be displayed, and the data voltage of the image frame to be displayed is compensated by the found voltage compensation parameter. In this way, the problem of reduced brightness of the first frame when switching the picture caused by IR Drop can be compensated, and the FFR performance is improved, so that the brightness ratio of the first frame of the image frame to be displayed after switching is greater than the preset value, thereby alleviating the first frame smear phenomenon and reducing the image adhesion caused by the residual image of the previous frame. In addition, the compensation is performed by an algorithm, and the compensation algorithm can be quickly implemented in the driver chips of different display panels without adding a complex TFT driving circuit, avoiding changes to the original driving circuit, and improving the reliability and stability of the display screen. The implementation is simple, practical, low-cost, and high in feasibility.

[0096] The brightness compensation method of the embodiment of the present disclosure obtains a first image frame P n-1 data, and for the first image frame P n-1 Process and calculate the first image frame P n-1 The first gray value corresponding to the first image frame P n-1 During the processing interval, the second image frame P is obtained. n The data of the second image frame P is calculated n The second gray value of the first image frame P n-1 Processing and processing of the second image frame P n Processing, there is an intersection in the timing, so that the delay can be reduced. Among them, for the first image frame P n-1 Processing and processing of the second image frame P n The intersection in the timing can also be understood as: when reading the image frame to be displayed, that is, reading the second image frame P n At the same time as the image data of the first image frame P n-1 Perform operation to calculate its gray value to reduce the second image frame P n of delay.

[0097] Among them, for the image frame to be displayed, when performing IR Drop inverse compensation, it is necessary to use the previous frame image. By reading the previous frame image for compensation, the efficiency of the inverse compensation operation can be improved and the delay can be reduced. Specifically, for the display panel, the current flowing through each pixel will change with the different displayed images, which is specifically manifested as: the current when displaying a black image is smaller than the current when displaying a white image. Therefore, the IR Drop when displaying a black image is weaker than the IR Drop when displaying a white image. And because the operation of the black image is simpler and faster, the algorithm operation time for compensating the IR Drop of the black image is also short.

[0098] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the calculation time when the compensation IP performs inverse compensation on the display screen with different grayscales. Figure 6 In the formula, input represents the processing time of the image data corresponding to the Pattern input into the compensation IP, output represents the processing time of the compensation IP outputting the image data, and σ represents the processing time of the compensation IP compensating the image data. Figure 6 Pattern1 represents a black screen, Pattern2 and Pattern3 represent white screens. Figure 6 It can be seen that the time for the compensation IP to obtain the image data of Pattern1 is 0, and the time for outputting the image data of Pattern1 is 0. When switching from Pattern1 to Pattern2, the time required for the compensation IP to input the image data of Pattern2 is 115, the processing time σ for obtaining the image data of the previous frame (i.e., Pattern1) and using Pattern1 to compensate for Pattern2 is 0 (because the operation of the black screen is simpler and faster), and the time required for the compensation IP to output the image data of Pattern2 is 115; when switching from Pattern2 to Pattern3, the time required for the compensation IP to input the image data of Pattern3 is 115, the processing time σ for obtaining the image data of the previous frame (i.e., Pattern2) and using Pattern2 to compensate for Pattern3 is 25, and the time required for the compensation IP to output the image data of Pattern3 is 140. It should be noted that Figure 6 The specific values ​​of input, output, and σ are only for reference and are used to express the processing time of different patterns, but do not represent the actual processing time. Figure 6 It can be seen that the computation time for compensating the black screen IR Drop is shorter than the computation time for compensating the white screen IR Drop.

[0099] In the embodiment of the present disclosure, the data voltage of the second image frame is compensated by using the first image frame, so that the data voltage of the second image frame can be dynamically adjusted. Data To offset the change in Real ELVDD, that is, to implement IR Drop inverse compensation, the brightness of each pixel can be adjusted quickly and accurately when the display content changes rapidly.

[0100] Optionally, when compensation is performed in a block compensation manner, for any second image block, the voltage compensation parameters of each pixel therein are the same. Specifically, when the second image frame is compensated in a block compensation manner, the step of searching for the voltage compensation parameters corresponding to the first grayscale value and the second grayscale value from a pre-stored lookup table according to the first grayscale value and the second grayscale value includes: for any first image block and the corresponding second image block, searching for the voltage compensation parameters corresponding to the first sub-grayscale value and the second sub-grayscale value from the lookup table according to the first sub-grayscale value corresponding to the first image block and the second sub-grayscale value corresponding to the second image block.

[0101] Correspondingly, the steps of obtaining the data voltage of the second image frame, compensating the data voltage by the voltage compensation parameter, and driving the display panel to display the second image frame by using the compensated data voltage include: for any second image block, obtaining the data voltage of the second image block, and compensating the data voltage of the second image block by using the voltage compensation parameter corresponding to the second image block found.

[0102] Optionally, the brightness compensation method in the embodiment of the present disclosure further includes: establishing a lookup table. The step of establishing the lookup table is as follows: Fig. 9 As shown, including:

[0103] Step S210, obtaining a voltage compensation parameter when the brightness ratio of the first frame is greater than a preset value when the display panel switches from the first test screen to the second test screen, the grayscale value of the first test screen is the third grayscale value, and the grayscale value of the second test screen is the fourth grayscale value, and the third grayscale value, the fourth grayscale value and the voltage compensation parameter constitute a set of reference data.

[0104] Step S220, obtaining a plurality of groups of reference data, and establishing a lookup table according to the plurality of groups of reference data, wherein the third grayscale values ​​corresponding to each group of reference data are different and / or the fourth grayscale values ​​corresponding to each group of reference data are different.

[0105] The lookup table is obtained by actually measuring the display panel. For example, for the LUT table shown in Table 1, the first test picture is P m-1 , the second test screen is P mA set of reference data is a voltage compensation parameter and the third grayscale value and the fourth grayscale value corresponding to the voltage compensation parameter in Table 1. By performing multiple tests to obtain multiple sets of reference data, the voltage compensation parameters when a picture with different grayscales is switched to another picture with different grayscales can be obtained.

[0106] Optionally, the second test screen P m The display panel is obtained by a first test picture P m-1 Switch to the second test screen P m The step of adjusting the voltage compensation parameter when the first frame brightness ratio is greater than the preset value comprises:

[0107] (1) Setting multiple voltage compensation parameters R_Offset;

[0108] (2) For any voltage compensation parameter R_Offset, obtain the first test picture P displayed by the display panel m-1 The brightness at that time is taken as the original brightness L0, and the first frame second test picture P is displayed. m The brightness at the time of displaying the second frame of the second test picture is taken as the first brightness L1, and the brightness of the second frame of the second test picture is taken as the second brightness L2, and the first frame brightness ratio FFR corresponding to the voltage compensation parameter R_Offset is calculated according to the original brightness L0, the first brightness L1 and the second brightness L1. Exemplarily, FFR = (L1-L0) / (L2-L0).

[0109] (3) Obtaining a voltage compensation parameter whose first frame brightness ratio is greater than a preset value from the first frame brightness ratios corresponding to the plurality of voltage compensation parameters.

[0110] In the embodiment of the present disclosure, the second test screen P m At least two frames are included, which are respectively recorded as the first frame and the second test frame P m1 and the second test picture P of the second frame m2 , and the first frame second test picture P m1 and the second test picture P of the second frame m2 The grayscale value is the same as that of the first test picture P m-1 Switch to the second test screen P m When the first frame of the second test picture P is displayed m1 , then display the second frame of the second test picture P m2 If the first frame second test picture P is displayed m1 The display brightness L1 when displaying the second frame of the second test picture P m2 The display brightness L2 is the same as that at the time of ΔV, which is the best state. It can be considered that the first frame brightness accounts for FFR is 100%, and there is no first frame smear at this time. However, due to ΔV CIn general, FFR will be smaller, such as 60%, 70%, etc. In the disclosed embodiment, a plurality of different voltage compensation parameters are set, and the first frame brightness ratio FFR of the display panel when the screen is switched at each voltage compensation parameter is measured, and the voltage compensation parameter when the first frame brightness ratio is greater than the preset value is used as the final voltage compensation parameter to construct the LUT table.

[0111] In a possible implementation, the display brightness of the display panel is not only related to the display content, but also related to the display brightness level currently set on the display panel. For example, the minimum display brightness of the display panel is 0, and the maximum display brightness is L max , the display brightness range of the display panel is expressed as [0,L max 】, the display brightness range can be pre-divided into multiple sub-ranges, each sub-range corresponds to a brightness level, and the user can set the current required brightness level according to the needs. For any picture, the current when it is displayed at different brightness levels is different, and the generated ΔV C In order to achieve a better FFR compensation effect at different brightness levels, in the embodiment of the present disclosure, the lookup table includes a plurality of sub-tables, each of which corresponds to a brightness level.

[0112] Correspondingly, the step of searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value includes:

[0113] (1) obtaining a brightness level currently set on the display panel as a first brightness level;

[0114] (2) searching, according to the first grayscale value and the second grayscale value, for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value from a subtable corresponding to the first brightness level.

[0115] Based on the same inventive concept, the second aspect of the present disclosure provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor is used to read the program in the memory to implement the steps of the brightness compensation method as described above.

[0116] Based on the same inventive concept, the third aspect of the present disclosure provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the brightness compensation method described above are implemented. In the specific implementation process, the computer storage medium may include: a universal serial bus flash drive (USB, Universal Serial Bus Flash Drive), a mobile hard disk, a read-only memory (ROM, Read Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and other storage media that can store program codes.

[0117] Based on the same inventive concept, the fourth aspect of the present disclosure provides a computer program product, including a computer program, which implements the steps of the brightness compensation method described above when executed by a processor. Since the principle of solving the problem by the above computer program is similar to the principle of the brightness compensation method, the implementation of the above computer program can refer to the implementation of the brightness compensation method, and the repeated parts will not be repeated.

[0118] The computer 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 device, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with 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 of the above.

[0119] Among them, the display module in the embodiment of the present disclosure can be an organic light-emitting diode (OLED) display module. It is understandable that the display module can also be set to other types according to actual needs. For example, the display module can also be a quantum dot light emitting diode (QLED) display module or a micro light emitting diode (MicroLED) display module.

[0120] Obviously, the above embodiments of the present disclosure are merely examples for clearly illustrating the present disclosure, and are not limitations on the implementation methods of the present disclosure. For ordinary technicians in this field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present disclosure are still within the protection scope of the present disclosure.

Claims

1. A brightness compensation method, characterized in that: The following steps are involved: Acquire grayscale values ​​of a first image frame and a second image frame, wherein the second image frame is an image frame to be displayed, the first image frame is a previous frame of the image frame to be displayed, the grayscale value of the first image frame is recorded as a first grayscale value, and the grayscale value of the second image frame is recorded as a second grayscale value; searching a pre-stored lookup table for a voltage compensation parameter corresponding to the first gray value and the second gray value according to the first gray value and the second gray value, wherein the lookup table includes a plurality of voltage compensation parameters, each voltage compensation parameter corresponds to a third gray value and a fourth gray value, and the voltage compensation parameter represents a compensation parameter satisfying that a first frame brightness ratio is greater than a preset value when the display panel switches from a display screen of the third gray value to a display screen of the fourth gray value; A data voltage of the second image frame is acquired, the data voltage is compensated by the voltage compensation parameter, and the display panel is driven by the compensated data voltage to display the second image frame.

2. The brightness compensation method according to claim 1, characterized in that: The voltage compensation parameter is a voltage compensation value; and compensating the data voltage by using the voltage compensation parameter includes: The sum of the voltage compensation value and the data voltage is used as the compensated data voltage.

3. The brightness compensation method according to claim 1, characterized in that: The voltage compensation parameter is a voltage compensation coefficient; and compensating the data voltage by using the voltage compensation parameter includes: The product of the voltage compensation coefficient and the data voltage is used as the compensated data voltage.

4. The brightness compensation method according to any one of claims 1 to 3, characterized in that: The brightness compensation method further comprises: Obtaining a voltage compensation parameter when the display panel switches from a first test picture to a second test picture and the proportion of the brightness of the first frame is greater than a preset value, wherein the grayscale value of the first test picture is the third grayscale value, the grayscale value of the second test picture is the fourth grayscale value, and the third grayscale value, the fourth grayscale value and the voltage compensation parameter constitute a set of reference data; A plurality of groups of the reference data are obtained, and a lookup table is established according to the plurality of groups of the reference data, wherein the third grayscale values ​​corresponding to the respective groups of the reference data are different and / or the fourth grayscale values ​​corresponding to the respective groups of the reference data are different.

5. The brightness compensation method according to claim 4, characterized in that: The second test picture includes a plurality of frames, and the step of obtaining a voltage compensation parameter when the display panel switches from the first test picture to the second test picture and the proportion of the brightness of the first frame is greater than a preset value includes: Set multiple voltage compensation parameters; For any voltage compensation parameter, the brightness of the display panel when displaying the first test screen is obtained as the original brightness, the brightness of the display panel when displaying the first frame of the second test screen is obtained as the first brightness, and the brightness of the display panel when displaying the second frame of the second test screen is obtained as the second brightness, and the first frame brightness ratio corresponding to the voltage compensation parameter is calculated according to the original brightness, the first brightness, and the second brightness; A voltage compensation parameter whose first frame brightness ratio is greater than a preset value is obtained from first frame brightness ratios corresponding to multiple voltage compensation parameters.

6. The brightness compensation method according to claim 1, characterized in that: The step of searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value comprises: Searching a third grayscale value closest to the first grayscale value and a fourth grayscale value closest to the second grayscale value from a pre-stored lookup table; The voltage compensation parameters corresponding to the third grayscale value and the fourth grayscale value found are used as the voltage compensation parameters corresponding to the first grayscale value and the second grayscale value.

7. The brightness compensation method according to claim 1, characterized in that: The lookup table includes a plurality of sub-tables, each sub-table corresponds to a brightness level; and the step of searching the pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value comprises: Acquire the brightness level currently set on the display panel as a first brightness level; According to the first grayscale value and the second grayscale value, voltage compensation parameters corresponding to the first grayscale value and the second grayscale value are searched from the subtable corresponding to the first brightness level.

8. The brightness compensation method according to claim 1, characterized in that: The step of acquiring the grayscale values ​​of the first image frame and the second image frame comprises: Divide the first image frame into multiple first image blocks, calculate the grayscale values ​​of the first image blocks as first sub-grayscale values, and a set of the first sub-grayscale values ​​of the first image blocks constitutes the first grayscale value; Divide the second image frame into blocks to obtain second image blocks corresponding to the first image blocks one by one, calculate the grayscale values ​​of the second image blocks as second sub-grayscale values, and a set of the second sub-grayscale values ​​of the second image blocks constitutes the second grayscale value; The step of searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value comprises: For any first image block and corresponding second image block, voltage compensation parameters corresponding to the first sub-grayscale value and the second sub-grayscale value are searched from the lookup table according to the first sub-grayscale value corresponding to the first image block and the second sub-grayscale value corresponding to the second image block.

9. The brightness compensation method according to claim 8, characterized in that: The step of calculating the grayscale value of the first image block as the first sub-grayscale value comprises: Calculating an average value of the grayscale value of each pixel in the first image block; The average value is used as the first sub-grayscale value corresponding to the first image block.

10. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that: The processor is used to read the program in the memory to implement the steps of the brightness compensation method according to any one of claims 1 to 9.

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

12. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the brightness compensation method according to any one of claims 1 to 9 are implemented.

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