Screen Compensation Method, Device and Display Device

Abstract

The present invention provides a method and apparatus for picture compensation and a display device, belonging to the field of display technology. The picture compensation method includes: obtaining a first compensation formula when the brightness of the display screen is greater than a first preset brightness, the first compensation formula being a relational expression between the target gray scale value and the actual gray scale value of a pixel; obtaining a second compensation formula when the brightness of the display screen is less than a second preset brightness, the second compensation formula being a relational expression between the target gray scale value and the actual gray scale value of a pixel, and the second preset brightness being less than or equal to the first preset brightness; obtaining a third compensation formula according to the first compensation formula and the second compensation formula, the third compensation formula being a relational expression between the target gray scale value and the actual gray scale value of a pixel on the display screen at any brightness; inputting the target gray scale value of the pixel into the third compensation formula, calculating the corresponding actual gray scale value, and controlling the pixel to display according to the actual gray scale value. The present invention can improve the picture quality of the display device at low brightness.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and particularly to a method and device for image compensation and a display device. Background Art

[0002] In existing OLED (organic light-emitting diode) panels, at extremely low brightness (about 0.02 nit), the image quality display is generally poor. As Figure 1 shown, it can be seen that the image uniformity is poor. Even after compensating the image, as Figure 2 shown, the image uniformity has not been significantly improved. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method and device for image compensation and a display device, which can improve the image quality of the display device at low brightness.

[0004] To solve the above technical problem, the embodiments of the present invention provide the following technical solutions:

[0005] On the one hand, a method for image compensation is provided, including:

[0006] Obtaining a first compensation formula when the brightness of the display screen is greater than a first preset brightness, where the first compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel;

[0007] Obtaining a second compensation formula when the brightness of the display screen is less than a second preset brightness, where the second compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel, and the second preset brightness is less than or equal to the first preset brightness;

[0008] Obtaining a third compensation formula according to the first compensation formula and the second compensation formula, where the third compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel on the display screen at any brightness;

[0009] Inputting the target gray scale value of a pixel into the third compensation formula, calculating the corresponding actual gray scale value, and controlling the pixel to display according to the actual gray scale value.

[0010] In some embodiments, the obtaining of the first compensation formula when the brightness of the display screen is greater than the first preset brightness includes:

[0011] Controlling the display screen to display a pure white screen, and the brightness of the display screen is greater than the first preset brightness;

[0012] Input a test gray level value to the test pixel of the display screen, take a picture of the display screen, obtain the actual gray level value of the test pixel according to the taken picture, and obtain a set of first test data. The first test data includes the test gray level value of the test pixel and the corresponding actual gray level value;

[0013] Use at least three different sets of first test data to obtain the first compensation formula:

[0014] Y = a*X 2 +b*X + c;

[0015] Wherein, Y is the target gray level value, X is the actual gray level value, and a, b, and c are compensation coefficients.

[0016] In some embodiments, the second compensation formula when the obtained brightness of the display screen is less than a second preset brightness includes:

[0017] Control the display screen to display a pure white screen, and the brightness of the display screen is less than the second preset brightness;

[0018] Input a test gray level value to the test pixel of the display screen, take a picture of the display screen, obtain the actual gray level value of the test pixel according to the taken picture, and obtain a set of second test data. The second test data includes the test gray level value of the test pixel and the corresponding actual gray level value;

[0019] Use the second test data to obtain the second compensation formula:

[0020] Y = X + O;

[0021] Wherein, Y is the target gray level value, X is the actual gray level value, and O is a compensation coefficient.

[0022] In some embodiments, the third compensation formula is:

[0023] Y = a*X 2 +b*X + c + k*O;

[0024] Wherein, k is an adjustment coefficient, and the value of k is inversely proportional to the brightness of the display screen. When the brightness of the display screen is greater than the first preset brightness, k = 0. When the brightness of the display screen is less than the second preset brightness, k = 1.

[0025] In some embodiments, the second preset brightness is 0.02 nit.

[0026] An embodiment of the present invention also provides a picture compensation device, including:

[0027] The first processing module is used to obtain a first compensation formula when the brightness of the display screen is greater than a first preset brightness, and the first compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel;

[0028] The second processing module is used to obtain a second compensation formula when the brightness of the display screen is less than a second preset brightness, and the second compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel, and the second preset brightness is less than or equal to the first preset brightness;

[0029] The third processing module is used to obtain a third compensation formula according to the first compensation formula and the second compensation formula, and the third compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel on the display screen at any brightness;

[0030] The compensation module is used to input the target gray level value of a pixel into the third compensation formula, calculate the corresponding actual gray level value, and control the pixel to display according to the actual gray level value.

[0031] In some embodiments, the first processing module includes:

[0032] The first control unit is used to control the display screen to display a pure white screen, and the brightness of the display screen is greater than a first preset brightness;

[0033] The first test unit is used to input a test gray level value into the test pixel of the display screen, take a picture of the display screen, obtain the actual gray level value of the test pixel according to the taken picture, and obtain a set of first test data, and the first test data includes the test gray level value of the test pixel and the corresponding actual gray level value;

[0034] The first processing unit is used to obtain the first compensation formula by using at least three groups of different first test data:

[0035] Y = a*X 2 +b*X + c;

[0036] where Y is the target gray level value, X is the actual gray level value, and a, b, and c are compensation coefficients.

[0037] In some embodiments, the second processing module includes:

[0038] The second control unit is used to control the display screen to display a pure white screen, and the brightness of the display screen is less than a second preset brightness;

[0039] A second test unit, configured to input a test gray level value to a test pixel of the display screen, take a picture of the display screen, obtain an actual gray level value of the test pixel according to the taken picture, and obtain a set of second test data, where the second test data includes the test gray level value of the test pixel and the corresponding actual gray level value;

[0040] A second processing unit, configured to obtain the second compensation formula by using the second test data:

[0041] Y = X + O;

[0042] Wherein, Y is the target gray level value, X is the actual gray level value, and O is the compensation coefficient.

[0043] In some embodiments, the third compensation formula is:

[0044] Y = a*X 2 + b*X + c + k*O;

[0045] Wherein, k is an adjustment coefficient, and the value of k is inversely proportional to the brightness of the display screen. When the brightness of the display screen is greater than a first preset brightness, k = 0. When the brightness of the display screen is less than a second preset brightness, k = 1.

[0046] An embodiment of the present invention further provides a display device, including the picture compensation device as described above.

[0047] The embodiment of the present invention has the following beneficial effects:

[0048] In the above solution, the first compensation formula when the brightness of the display screen is greater than the first preset brightness and the second compensation formula when the brightness of the display screen is less than the second preset brightness are obtained. The first compensation formula and the second compensation formula are integrated to obtain the third compensation formula. The actual gray level value can be obtained according to the third compensation formula, and the display screen is controlled to display by using the actual gray level value. It can not only compensate for the high-brightness picture quality but also take into account the low-brightness picture quality, and can significantly improve the picture quality of the display device at low brightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of a picture at ultra-low brightness;

[0050] Figure 2 It is a schematic diagram after compensating the ultra-low brightness picture by the prior art;

[0051] Figure 3 It is a schematic flowchart of the picture compensation method according to the embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram after compensating the ultra-low brightness picture according to the embodiment of the present invention;

[0053] Figure 5 This is a schematic structural diagram of the screen compensation device according to an embodiment of the present invention. Detailed implementation manners

[0054] To make the technical problems, technical solutions and advantages to be solved by the embodiments of the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0055] There are two main reasons for the poor picture quality at ultra-low brightness: 1. The delay of the loading and signal conduction of the display panel at low brightness is completely different from that at high brightness; 2. The existing demura compensation technology compensates based on the mura characteristics at high brightness, which will cause the algorithm to not match the mura characteristics at low brightness, resulting in poor compensation effect.

[0056] The embodiments of the present invention provide a screen compensation method, device and display device, which can improve the picture quality of the display device at low brightness.

[0057] The embodiments of the present invention provide a screen compensation method, as Figure 3 shown, including:

[0058] Step 101: Obtain a first compensation formula when the brightness of the display screen is greater than a first preset brightness, and the first compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel;

[0059] Step 102: Obtain a second compensation formula when the brightness of the display screen is less than a second preset brightness, and the second compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel, and the second preset brightness is less than or equal to the first preset brightness;

[0060] Step 103: Obtain a third compensation formula according to the first compensation formula and the second compensation formula, and the third compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel on the display screen at any brightness;

[0061] Step 104: Input the target gray scale value of the pixel into the third compensation formula, calculate the corresponding actual gray scale value, and control the pixel to display according to the actual gray scale value.

[0062] In this embodiment, by obtaining the first compensation formula when the brightness of the display screen is greater than the first preset brightness and the second compensation formula when the brightness of the display screen is less than the second preset brightness, integrating the first compensation formula and the second compensation formula to obtain the third compensation formula, the actual gray scale value can be obtained according to the third compensation formula, and the display screen is controlled to display by using the actual gray scale value, which can not only compensate the picture quality at high brightness but also take into account the picture quality at low brightness, and can significantly improve the picture quality of the display device at low brightness.

[0063] In some embodiments, the first compensation formula when the obtained brightness of the display screen is greater than a first preset brightness includes:

[0064] Control the display screen to display a pure white screen, and the brightness of the display screen is greater than the first preset brightness. The value of the first preset brightness can be set as needed. For example, it can be above 10 nit;

[0065] Input a test gray scale value to the test pixel of the display screen, take a picture of the display screen, obtain the actual gray scale value of the test pixel according to the taken image, and obtain a set of first test data. The first test data includes the test gray scale value of the test pixel and the corresponding actual gray scale value. Taking a picture of the display screen can obtain the actual brightness of the test pixel, and the actual gray scale value of the test pixel can be obtained according to the actual brightness of the test pixel;

[0066] Use at least three different sets of first test data to obtain the first compensation formula:

[0067] Y = a*X 2 +b*X + c;

[0068] Wherein, Y is the target gray scale value, X is the actual gray scale value, and a, b, and c are compensation coefficients.

[0069] In some embodiments, the second compensation formula when the obtained brightness of the display screen is less than a second preset brightness includes:

[0070] Control the display screen to display a pure white screen, and the brightness of the display screen is less than the second preset brightness. The value of the second preset brightness can be set as needed. For example, it can be below 10 nit, specifically 0.02 nit;

[0071] Input a test gray scale value to the test pixel of the display screen, take a picture of the display screen, obtain the actual gray scale value of the test pixel according to the taken image, and obtain a set of second test data. The second test data includes the test gray scale value of the test pixel and the corresponding actual gray scale value. Specifically, use an industrial camera that can shoot ultra-low brightness images to take a picture of the display screen, extract the mura morphology of the display screen at ultra-low brightness. Taking a picture of the display screen can obtain the actual brightness of the test pixel, and the actual gray scale value of the test pixel can be obtained according to the actual brightness of the test pixel;

[0072] Use the second test data to obtain the second compensation formula:

[0073] Y = X + O;

[0074] Wherein, Y is the target gray scale value, X is the actual gray scale value, and O is the compensation coefficient.

[0075] In this embodiment, a second compensation formula can be obtained by using a set of second test data, or a second compensation formula can be obtained by fitting multiple sets of second test data.

[0076] In some embodiments, the third compensation formula is:

[0077] Y = a*X 2 +b*X + c + k*O;

[0078] Where k is an adjustment coefficient, and the value of k is inversely proportional to the brightness of the display screen. When the brightness of the display screen is greater than the first preset brightness, k = 0. When the brightness of the display screen is less than the second preset brightness, k = 1. In this way, when the display screen is in a high-brightness state, k = 0, and the third compensation formula can be used to compensate the display screen in the high-brightness state; when the display screen is in a low-brightness state, k = 1, and the third compensation formula can be used to compensate the display screen in the low-brightness state; when the display screen is in other states, the value of k is adjusted to compensate the display screen in different states. The k values corresponding to different brightness levels can be stored in the register of the IC (driving circuit) in the form of a LUT (Look-Up-Table).

[0079] After obtaining the compensation coefficient and the k value, a whole hexadecimal file can be generated using the compensation coefficient and the k value and stored in the IC. When the display screen is displaying, the brightness of the display screen is obtained, the corresponding k value is determined according to the brightness of the display screen, and then the corresponding third compensation formula is determined. The image quality is compensated according to the third compensation formula. Through the technical solution of this embodiment, the image quality of the display device at low brightness can be improved. Figure 4 It is a schematic diagram after the embodiment of the present invention compensates the ultra-low brightness picture. It can be seen that the picture uniformity is significantly improved.

[0080] The color brightness uniformity (△E) can be used to evaluate the low-brightness image quality effect of the display screen. As shown in Table 1, in a specific example, the display screen is divided into 9*15 display areas. The values in the table are the color brightness uniformity values of each display area. The color brightness uniformity value of each display area can be calculated using the brightness and chromaticity coordinates of the display area. Among them, the color brightness uniformity value of the center area of the display screen is 0. The greater the difference between the color brightness uniformity values of other display areas and 0, the worse the picture uniformity. The smaller the color brightness uniformity value, the better the low-gray-scale image quality of the display screen. Table 1 shows the color brightness uniformity values of the low-brightness display picture without picture compensation. It can be seen that the picture uniformity is poor.

[0081] Table 1

[0082]

[0083] Table 2 shows the color and luminance uniformity values after compensating for the ultra-low brightness screen in the prior art. It can be seen that the screen uniformity has not been significantly improved.

[0084] Table 2

[0085]

[0086] Table 3 shows the color and luminance uniformity values after compensating for the ultra-low brightness screen in the embodiments of the present invention. It can be seen that the screen uniformity has been significantly improved.

[0087] Table 3

[0088]

[0089]

[0090] An embodiment of the present invention further provides a screen compensation device, as Figure 5 shown, including:

[0091] The first processing module 21 is configured to obtain a first compensation formula when the brightness of the display screen is greater than a first preset brightness, and the first compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel;

[0092] The second processing module 22 is configured to obtain a second compensation formula when the brightness of the display screen is less than a second preset brightness, and the second compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel, and the second preset brightness is less than or equal to the first preset brightness;

[0093] The third processing module 23 is configured to obtain a third compensation formula according to the first compensation formula and the second compensation formula, and the third compensation formula is a relational expression between the target gray scale value and the actual gray scale value of a pixel on the display screen at any brightness;

[0094] The compensation module 24 is configured to input the target gray scale value of a pixel into the third compensation formula, calculate the corresponding actual gray scale value, and control the pixel to be displayed according to the actual gray scale value.

[0095] In this embodiment, by obtaining the first compensation formula when the brightness of the display screen is greater than the first preset brightness and the second compensation formula when the brightness of the display screen is less than the second preset brightness, integrating the first compensation formula and the second compensation formula to obtain the third compensation formula, the actual gray scale value can be obtained according to the third compensation formula, and the display screen can be controlled to be displayed by using the actual gray scale value, which can not only compensate for the high-brightness picture quality but also take into account the low-brightness picture quality, and can significantly improve the picture quality of the display device at low brightness.

[0096] In some embodiments, the first processing module 21 includes:

[0097] A first control unit for controlling the display screen to display a pure white screen, and the brightness of the display screen is greater than a first preset brightness. The value of the first preset brightness can be set as needed. For example, it can be above 10 nit;

[0098] A first test unit for inputting a test gray scale value to a test pixel of the display screen, taking a picture of the display screen, obtaining the actual gray scale value of the test pixel according to the taken picture, and obtaining a set of first test data. The first test data includes the test gray scale value of the test pixel and the corresponding actual gray scale value. Taking a picture of the display screen can obtain the actual brightness of the test pixel, and the actual gray scale value of the test pixel can be obtained according to the actual brightness of the test pixel;

[0099] A first processing unit for obtaining the first compensation formula by using at least three groups of different first test data:

[0100] Y = a*X 2 +b*X + c;

[0101] Wherein, Y is the target gray scale value, X is the actual gray scale value, and a, b, and c are compensation coefficients.

[0102] In some embodiments, the second processing module 22 includes:

[0103] A second control unit for controlling the display screen to display a pure white screen, and the brightness of the display screen is less than a second preset brightness. The value of the second preset brightness can be set as needed. For example, it can be below 10 nit, specifically 0.02 nit;

[0104] A second test unit for inputting a test gray scale value to a test pixel of the display screen, taking a picture of the display screen, obtaining the actual gray scale value of the test pixel according to the taken picture, and obtaining a set of second test data. The second test data includes the test gray scale value of the test pixel and the corresponding actual gray scale value. Specifically, an industrial camera capable of shooting ultra-low brightness pictures is used to take pictures of the display screen, and the mura morphology of the display screen at ultra-low brightness is extracted. Taking a picture of the display screen can obtain the actual brightness of the test pixel, and the actual gray scale value of the test pixel can be obtained according to the actual brightness of the test pixel;

[0105] A second processing unit for obtaining the second compensation formula by using the second test data:

[0106] Y = X + O;

[0107] Wherein, Y is the target gray scale value, X is the actual gray scale value, and O is a compensation coefficient.

[0108] In this embodiment, a second compensation formula can be obtained using a set of second test data, or a second compensation formula can be obtained by fitting multiple sets of second test data.

[0109] In some embodiments, the third compensation formula is:

[0110] Y = a*X 2 +b*X + c + k*O;

[0111] Where k is an adjustment coefficient, and the value of k is inversely proportional to the brightness of the display screen. When the brightness of the display screen is greater than the first preset brightness, k = 0. When the brightness of the display screen is less than the second preset brightness, k = 1. In this way, when the display screen is in a high-brightness state, k = 0, and the third compensation formula can be used to compensate the display screen in the high-brightness state; when the display screen is in a low-brightness state, k = 1, and the third compensation formula can be used to compensate the display screen in the low-brightness state; when the display screen is in other states, the value of k is adjusted to compensate the display screen in different states. The k values corresponding to different brightnesses can be stored in the register of the IC (driving circuit) in the form of a LUT (Look-Up-Table).

[0112] After obtaining the compensation coefficient and the k value, a whole hexadecimal file can be generated using the compensation coefficient and the k value and stored in the IC. When the display screen is displaying, the brightness of the display screen is obtained, the corresponding k value is determined according to the brightness of the display screen, and then the corresponding third compensation formula is determined. The image quality is compensated according to the third compensation formula. Through the technical solution of this embodiment, the picture quality of the display device in low brightness can be improved. Figure 4 This is a schematic diagram of the ultra-low brightness picture compensated by the embodiment of the present invention. It can be seen that the picture uniformity is significantly improved.

[0113] The embodiment of the present invention also provides a display device, including the picture compensation device as described above.

[0114] The display device includes but is not limited to: a radio frequency unit, a network module, an audio output unit, an input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, and a power supply, etc. Those skilled in the art can understand that the structure of the above display device does not constitute a limitation on the display device. The display device may include more or fewer components as described above, or combine some components, or have different component arrangements. In the embodiment of the present invention, the display device includes but is not limited to a display, a mobile phone, a tablet computer, a television, a wearable electronic device, a navigation display device, etc.

[0115] The display device may be: a TV, a monitor, a digital photo frame, a mobile phone, a tablet computer, or any product or component with a display function. Among them, the display device further includes a flexible circuit board, a printed circuit board, and a backplane.

[0116] It should be noted that each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the method embodiment, since it is basically similar to the product embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the product embodiment.

[0117] Unless otherwise defined, the technical terms or scientific terms used in this disclosure should have the ordinary meanings understood by those of ordinary skill in the art to which this disclosure belongs. The "first", "second", and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or items appearing before the term cover the elements or items listed after the term and their equivalents, without excluding other elements or items. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right", etc. are only used to represent relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0118] It can be understood that when an element such as a layer, a film, a region, or a substrate is referred to as being "on" or "under" another element, the element can be "directly" on or under the other element, or there may be intermediate elements.

[0119] In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0120] The above is only the specific implementation manner of this disclosure, but the protection scope of this disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by this disclosure can easily think of changes or substitutions, which should all be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be subject to the protection scope of the claims.

Claims

1. A method for image compensation, characterized in that, Including: Obtaining a first compensation formula when the brightness of the display screen is greater than a first preset brightness, where the first compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel; Obtaining a second compensation formula when the brightness of the display screen is less than a second preset brightness, where the second compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel, and the second preset brightness is less than or equal to the first preset brightness; Obtaining a third compensation formula based on the first compensation formula and the second compensation formula, where the third compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel on the display screen at any brightness; Inputting the target gray level value of a pixel into the third compensation formula, calculating the corresponding actual gray level value, and controlling the pixel to display according to the actual gray level value; The third compensation formula is: Y = a*X 2 + b*X + c + k*O; Where Y is the target gray level value, X is the actual gray level value, O, a, b, c are compensation coefficients, k is an adjustment coefficient, and the value of k is determined by the brightness of the display screen.

2. The picture compensation method according to claim 1, characterized in that The obtaining of the first compensation formula when the brightness of the display screen is greater than the first preset brightness includes: Controlling the display screen to display a pure white screen, and the brightness of the display screen is greater than the first preset brightness; Inputting a test gray level value into the test pixel of the display screen, taking a picture of the display screen, obtaining the actual gray level value of the test pixel according to the taken picture, and obtaining a set of first test data, where the first test data includes the test gray level value of the test pixel and the corresponding actual gray level value; Obtaining the first compensation formula by using at least three groups of different first test data; Y = a*X 2 + b*X + c.

3. The picture compensation method according to claim 2, wherein, The obtaining of the second compensation formula when the brightness of the display screen is less than the second preset brightness includes: Controlling the display screen to display a pure white screen, and the brightness of the display screen is less than the second preset brightness; Inputting a test gray level value into the test pixel of the display screen, taking a picture of the display screen, obtaining the actual gray level value of the test pixel according to the taken picture, and obtaining a set of second test data, where the second test data includes the test gray level value of the test pixel and the corresponding actual gray level value; Obtaining the second compensation formula by using the second test data; Y = X + O.

4. The picture compensation method according to claim 3, wherein The value of k is inversely proportional to the brightness of the display screen. When the brightness of the display screen is greater than the first preset brightness, k = 0. When the brightness of the display screen is less than the second preset brightness, k = 1.

5. The method for compensating a picture according to claim 1, characterized in that, The second preset brightness is 0.02 nit.

6. A picture compensation device, characterized in that, Including: A first processing module for obtaining a first compensation formula when the brightness of the display screen is greater than a first preset brightness, where the first compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel; A second processing module for obtaining a second compensation formula when the brightness of the display screen is less than a second preset brightness, where the second compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel, and the second preset brightness is less than or equal to the first preset brightness; A third processing module for obtaining a third compensation formula based on the first compensation formula and the second compensation formula, where the third compensation formula is a relational expression between the target gray level value and the actual gray level value of a pixel on the display screen at any brightness; A compensation module, which is configured to input the target gray scale value of a pixel into the third compensation formula, calculate the corresponding actual gray scale value, and control the pixel to display according to the actual gray scale value; The third compensation formula is: Y = a*X 2 + b*X + c + k*O; where Y is the target gray scale value, X is the actual gray scale value, O, a, b, and c are compensation coefficients, k is an adjustment coefficient, and the value of k is determined by the brightness of the display screen.

7. The picture compensation device according to claim 6, wherein, The first processing module includes: A first control unit, which is configured to control the display screen to display a pure white screen, and the brightness of the display screen is greater than a first preset brightness; A first test unit, which is configured to input a test gray scale value into a test pixel of the display screen, take a picture of the display screen, obtain the actual gray scale value of the test pixel according to the taken picture, and obtain a set of first test data, where the first test data includes the test gray scale value of the test pixel and the corresponding actual gray scale value; A first processing unit, which is configured to obtain the first compensation formula by using at least three different sets of first test data: Y = a*X 2 + b*X + c.

8. The picture compensation device according to claim 7, characterized in that, The second processing module includes: A second control unit, which is configured to control the display screen to display a pure white screen, and the brightness of the display screen is less than a second preset brightness; A second test unit, which is configured to input a test gray scale value into a test pixel of the display screen, take a picture of the display screen, obtain the actual gray scale value of the test pixel according to the taken picture, and obtain a set of second test data, where the second test data includes the test gray scale value of the test pixel and the corresponding actual gray scale value; A second processing unit, which is configured to obtain the second compensation formula by using the second test data: Y = X + O.

9. The picture compensation device according to claim 8, wherein The value of k is inversely proportional to the brightness of the display screen. When the brightness of the display screen is greater than the first preset brightness, k = 0; when the brightness of the display screen is less than the second preset brightness, k = 1.

10. A display device, characterized in that, It includes the screen compensation device according to any one of claims 6-9.

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