White balance adjustment method, spliced screen, storage medium and computer program product

Abstract

The invention provides a white balance adjustment method, a spliced screen, a storage medium and a computer program product, and the method comprises the steps: determining a reference sub-display screen from all sub-display screens of the spliced screen, taking the display brightness of the reference sub-display screen when displaying a target white picture as the target display brightness, the display chromaticity of the reference sub-display screen when the reference sub-display screen displays a target white picture is used as a target display chromaticity, and the sub-display screens except the reference sub-display screen in the spliced screen are to-be-adjusted sub-display screens; acquiring a brightness characteristic parameter of each to-be-adjusted sub display screen, wherein the brightness characteristic parameter comprises a first coefficient corresponding to each color channel of the to-be-adjusted sub display screen; for any to-be-adjusted sub display screen, searching an adjustment value meeting a first brightness condition and a first constraint condition from a pre-stored lookup table according to the target display brightness, the target display chromaticity and the brightness characteristic parameters, and taking the adjustment value as a target adjustment value; and setting the first adjustment layer of each to-be-adjusted sub display screen according to the target adjustment value.

Description

Technical Field

[0001] The present disclosure relates to the field of computer technology, and more specifically, to a white balance adjustment method, a spliced ​​screen, a storage medium, and a computer program product. Background Art

[0002] The splicing screen is an integrated display device formed by splicing and coordinating multiple independent display screens. It can achieve ultra-large display images by seamlessly splicing multiple high-definition display screens. It is widely used in supermarkets, airports, entertainment and leisure venues, education, medical care, government and other scenarios.

[0003] White balance is one of the important indicators that affect the display properties of the spliced ​​screen. The relevant technology discloses a solution of adding a mask layer above the spliced ​​screen UI layer and adjusting the white balance by setting the mask layer parameters. However, this solution has the problems of low efficiency and poor accuracy. Summary of the invention

[0004] The purpose of the present disclosure is to provide a white balance adjustment method, a spliced ​​screen, a storage medium and a computer program product to solve the problems of low efficiency and poor accuracy of white balance adjustment of spliced ​​screens in related technologies.

[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present disclosure provides a white balance adjustment method, which is applicable to a spliced ​​screen, wherein the spliced ​​screen includes at least two sub-display screens, each of which is provided with a first adjustment layer, and the first adjustment layer has a color channel corresponding to each color channel of the sub-display screen in a one-to-one manner; the white balance adjustment method includes the following steps:

[0007] Determine a reference sub-display screen from each sub-display screen of the spliced ​​screen, take the display brightness of the reference sub-display screen when displaying a target white screen as the target display brightness, take the display chromaticity of the reference sub-display screen when displaying a target white screen as the target display chromaticity, and the sub-display screens other than the reference sub-display screen in the spliced ​​screen are sub-display screens to be adjusted;

[0008] Acquire brightness characteristic parameters of each sub-display screen to be adjusted, wherein the brightness characteristic parameters include first coefficients corresponding to each color channel of the sub-display screen to be adjusted, and the first coefficients are used to represent the influence weight of the brightness of the corresponding color channel on the display brightness of the sub-display screen to be adjusted;

[0009] For any sub-display screen to be adjusted, searching a pre-stored lookup table for an adjustment value that satisfies a first brightness condition and a first constraint condition as a target adjustment value according to the target display brightness, target display chromaticity and brightness characteristic parameters, wherein the lookup table includes brightness chromaticity data, and the brightness chromaticity data includes sub-brightness and display chromaticity when each color channel of the sub-display screen to be adjusted displays a target monochrome picture and the first adjustment layer is set to different adjustment values, the target monochrome picture is a sub-picture of the target white picture on the corresponding color channel, the first brightness condition includes that when the first adjustment layer is set to the target adjustment value, a weighted sum of the sub-brightness of each color channel of the sub-display screen to be adjusted and the first coefficient is equal to the target display brightness, and the first constraint condition includes that a chromaticity offset between the display chromaticity corresponding to the target adjustment value and the target display chromaticity is less than a first chromaticity offset threshold;

[0010] The first adjustment layer of each sub-display screen to be adjusted is set according to the target adjustment value.

[0011] Optionally, the step of determining a reference sub-display screen from each sub-display screen of the spliced ​​screen includes:

[0012] Get the display brightness of each sub-display screen when the spliced ​​screen displays the target white screen;

[0013] The sub display screen with the lowest display brightness is determined as the reference sub display screen.

[0014] Optionally, the first adjustment layer includes multiple transparencies, the lookup table includes multiple groups of brightness and chromaticity data, and each group of brightness and chromaticity data corresponds to one transparency;

[0015] Searching for an adjustment value satisfying a first brightness condition and a first constraint condition as a target adjustment value from a pre-stored lookup table according to the target display brightness, the target display chromaticity and the brightness characteristic parameter specifically includes:

[0016] According to the target display brightness, target display chromaticity and brightness characteristic parameters, searching from the plurality of sets of brightness and chromaticity data for transparency and adjustment values ​​of each color channel that satisfy a first brightness condition and a first constraint condition as target transparency and target adjustment value;

[0017] The step of setting the first adjustment layer of each sub-display screen to be adjusted according to the target adjustment value specifically includes: setting the first adjustment layer of each sub-display screen to be adjusted according to the target adjustment value and the target transparency.

[0018] Optionally, before the step of obtaining the brightness characteristic parameters of each sub-display screen to be adjusted, the step further includes:

[0019] For any sub-display screen to be adjusted, measuring the display brightness and the brightness of each color channel when the transparency of the first adjustment layer corresponding to the sub-display screen to be adjusted is a first value and the sub-display screen to be adjusted displays a plurality of reference grayscale white images;

[0020] A first coefficient corresponding to each color channel is calculated according to the measured multiple groups of display brightness and sub-brightness, and a weighted sum of the first coefficient and the sub-brightness of the corresponding color channel is the display brightness.

[0021] Optionally, the plurality of reference grayscale white pictures include at least a low grayscale white picture, a medium grayscale white picture and a high grayscale white picture.

[0022] Optionally, for any sub-display screen to be adjusted, a method for measuring any set of brightness and chromaticity data includes:

[0023] Setting the transparency of the first adjustment layer corresponding to the sub-display screen to be adjusted to a first transparency, where the first transparency is one of the multiple transparencies;

[0024] For any color channel, the adjustment value of the color channel in the first adjustment layer is sequentially set to one of the preset adjustment value ranges, the sub-display screen to be adjusted is controlled to display the target monochrome picture of the color channel and the current display brightness and display chromaticity of the sub-display screen to be adjusted are measured, the display brightness is used as the sub-brightness corresponding to the color channel, the display chromaticity is used as the display chromaticity corresponding to the color channel, and the sub-brightness and display chromaticity corresponding to each color channel constitute a set of brightness and chromaticity data.

[0025] Optionally, the first adjustment layer corresponds to a first transparency range, and the multiple transparencies are arranged at equal intervals within the first transparency range.

[0026] Optionally, the first constraint condition also includes:

[0027] The sum of the target adjustment values ​​corresponding to the color channels in the first adjustment layer is the smallest; and / or

[0028] Among the sub-brightnesses of the target adjustment values ​​of the color channels in the first adjustment layer, the sub-brightness of the first color channel is the largest, and the first color channel is the color channel with the largest first coefficient.

[0029] Optionally, the color channels of the first adjustment layer include a red color channel, a green color channel and a blue color channel, and the first color channel is the green color channel; and the first constraint condition further includes:

[0030] The brightness of the red color channel and the blue color channel in the first adjustment layer corresponding to the target adjustment value is not 0.

[0031] A second aspect of the present disclosure provides a spliced ​​screen, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the white balance adjustment method as described above when executing the program.

[0032] A third aspect of the present disclosure provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the white balance adjustment method described above when the program is executed by a processor.

[0033] A fourth aspect of the present disclosure provides a computer program product, including a computer program, which implements the steps of the white balance adjustment method described above when executed by a processor.

[0034] The beneficial effects of the present disclosure are as follows:

[0035] The white balance adjustment method of the disclosed embodiment determines a reference sub-display screen and a sub-display screen to be adjusted from each sub-display screen of the spliced ​​screen by pre-measuring the brightness characteristic parameters of each sub-display screen and the lookup table of the first adjustment layer under different parameter values, and uses the display brightness of the reference sub-display screen as the target display brightness, and the display chromaticity as the target display chromaticity. When performing white balance adjustment thereafter, for each sub-display screen to be adjusted, the target display brightness, the target display chromaticity and the brightness characteristic parameters are directly used to search for an adjustment value that satisfies a first brightness condition and a first constraint condition from a pre-stored lookup table as a target adjustment value. Such a setting can improve the debugging efficiency of the target adjustment value compared with manual debugging, save time, and the target adjustment value found has high accuracy, which can make the brightness and chromaticity of each sub-display screen in the spliced ​​screen highly consistent and have a better white balance effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The specific implementation methods of the present disclosure are further described in detail below with reference to the accompanying drawings.

[0037] Figure 1 A schematic diagram of the structure of a spliced ​​screen provided in an embodiment of the present disclosure;

[0038] Figure 2 A schematic diagram of a mask parameter setting interface provided by an embodiment of the present disclosure;

[0039] Figure 3 The present invention is a flowchart of a white balance adjustment method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] 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.

[0041] 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.

[0042] In the related art, a mask layer is added above the UI layer. When adjusting the white balance of the spliced ​​screen by adjusting the mask layer parameters, repeated debugging is required due to the large differences among the sub-display screens in the spliced ​​screen. This is very time-consuming and has poor accuracy.

[0043] In order to solve the above technical problems, the present disclosure provides a white balance adjustment method, which is applicable to spliced ​​screens. Figure 1 , Figure 1 A schematic diagram of the structure of the spliced ​​screen provided in the embodiment of the present disclosure is shown in FIG. Figure 1 As shown, the spliced ​​screen includes at least two sub-display screens (such as Figure 1 In which A11, A12, A21 and A22 represent a sub display screen respectively), each of the sub display screens is provided with a first adjustment layer, and the first adjustment layer is used to adjust the brightness, chromaticity and other characteristics of the sub display screens. By setting different parameter values ​​for the first adjustment layers of the sub display screens, the brightness and chromaticity of the entire spliced ​​screen can be adjusted, so that the white balance state of the entire spliced ​​screen is as uniform as possible, so that the overall spliced ​​screen obtains a better display effect.

[0044] In one implementation, the first adjustment layer is a mask layer, which is superimposed on the UI layer in the form of a floating window. The mask layer has the same color channel as the sub-display screen, and the brightness, chromaticity and other characteristics of the sub-display screen are adjusted through the mask layer, which can also be understood as adjusting the pixel values ​​of different color channels of the white screen. For example, for the sub-display screen of the RGB color channel, the mask layer is used to adjust the white balance of the sub-display screen, that is, the R, G, B values ​​of the white screen displayed on the sub-display screen are adjusted using the adjustment values ​​of the R, G, B color channels of the mask layer, which is equivalent to superimposing an adjustment screen composed of adjustment values ​​on the white screen. The adjustment screen is the mask layer. For example, Figure 1 As shown, for the sub-display screen A22, assuming that the RGB value of the white screen is (R1, G1, B1), and the adjustment value on the mask is (R2, G2, B2), then the white screen after white balance adjustment can be understood as the effect of the superposition of (R1, G1, B1) and (R2, G2, B2). In addition, the setting parameters of the mask also include transparency, which can indicate the degree of superposition of the mask. When the transparency of the mask is 0, it is equivalent to that the mask is not effective at this time, which is equivalent to that the mask is not superimposed on the UI layer of the sub-display screen. The greater the transparency of the mask, the greater the impact of the mask on the sub-display screen, and the lower the brightness of the sub-display screen. Figure 2 As shown, when adjusting the white balance, you need to set the mask layer's transparency, R gain, G gain, B gain and other parameters on the mask layer parameter setting interface. R gain is the adjustment value of the R color channel, G gain is the adjustment value of the G color channel, and B gain is the adjustment value of the B color channel.

[0045] Combine the following Figure 3 The white balance adjustment method provided by the embodiment of the present disclosure is introduced. Figure 3 As shown, the white balance adjustment method comprises the following steps:

[0046] Step S101, determining a reference sub-display screen from each sub-display screen of the spliced ​​screen, taking the display brightness of the reference sub-display screen when displaying a target white screen as the target display brightness, taking the display chromaticity of the reference sub-display screen when displaying a target white screen as the target display chromaticity, and the sub-display screens other than the reference sub-display screen in the spliced ​​screen are sub-display screens to be adjusted.

[0047] In a possible implementation, the step of determining a reference sub-display screen from among the sub-display screens of the spliced ​​screen includes: (1) acquiring the display brightness of each sub-display screen when the spliced ​​screen displays a target white screen; and (2) determining the sub-display screen with the lowest display brightness as the reference sub-display screen.

[0048] In the embodiment of the present disclosure, the spliced ​​screen is first controlled to display the target white screen, that is, each sub-display screen displays the target white screen, and then the display brightness of each sub-display screen is measured by a measuring instrument, and the sub-display screen with the lowest display brightness is determined as the reference sub-display screen, and the remaining sub-display screens are determined as sub-display screens to be adjusted. Figure 1 In the spliced ​​screen shown, when each sub-display screen displays the target white screen, the display brightness of sub-display screen A22 is the lowest. In this case, sub-display screen A22 can be set as the reference sub-display screen, and the remaining sub-display screens A11, A12, and A21 are determined as sub-display screens to be adjusted. When adjusting the white balance, the display brightness of the reference sub-display screen is used as the target display brightness, and the display chromaticity of the reference sub-display screen is used as the target display chromaticity. By setting the parameters of the first adjustment layer in the sub-display screen to be adjusted, the display brightness of each sub-display screen to be adjusted is adjusted to the target display brightness, and the display chromaticity of each sub-display screen to be adjusted is offset from the target display chromaticity within a certain range.

[0049] The target display chromaticity includes the display chromaticity of each color channel when the reference sub-display screen displays the target white screen. For example, for an RGB display screen, the target display chromaticity includes the display chromaticity of the R, G, and B color channels when the reference sub-display screen displays the target white screen, wherein the display chromaticity includes two parameters, chromaticity x and chromaticity y, and chromaticity x and chromaticity y represent the hue and chromaticity (or saturation) of the color, respectively. During specific measurement, for the R color channel, the reference sub-display screen can be controlled to display a red screen (255, 0, 0), and then the current display chromaticity is measured as the chromaticity x(r) and y(r) of the R color channel; similarly, for the G color channel, the reference sub-display screen can be controlled to display a green screen (0, 255, 0), and then the current display chromaticity is measured as the chromaticity x(g) and y(g) of the G color channel. For the B color channel, the reference sub-display screen can be controlled to display a blue screen (0, 0, 255), and then the current display chromaticity is measured as the chromaticity x(b) and y(b) of the B color channel. The x(r), y(r), x(g), y(g), x(b), and y(b) measured by the above steps are used as the target display chromaticity. In the disclosed embodiment, the target white screen is formed by superimposing the monochrome screens of each color channel (i.e., the target monochrome screen). The display chromaticity of each color channel when the reference sub-display screen displays the target white screen specifically refers to the display chromaticity when each color channel of the reference sub-display screen displays the corresponding monochrome screen.

[0050] Optionally, the target white screen is a white screen with a grayscale of 255, that is, the RBG value of the target white screen is (255, 255, 255). In digital image processing, the grayscale of 255 represents the grayscale level at which the brightness value reaches the maximum. At this grayscale, since the brightness of the image reaches the highest, any slight color deviation may become obvious. Therefore, adjusting the white balance at this grayscale can ensure the white balance effect at other grayscales. In addition, when the target white screen is a white screen with a grayscale of 255, since the display brightness of each sub-display screen is the maximum value and cannot be further increased, when adjusting the white balance of the entire spliced ​​screen, it is necessary to set the sub-display screen with the lowest display brightness as the reference sub-display screen, and then adjust the display brightness of other sub-display screens to be close to the lowest display brightness. If a larger display brightness is set as the target display brightness, the sub-display screen with the lowest display brightness cannot reach the target display brightness, and the adjustment effect is poor.

[0051] Step S102, obtaining brightness characteristic parameters of each sub-display screen to be adjusted, wherein the brightness characteristic parameters include first coefficients corresponding to each color channel of the sub-display screen to be adjusted, and the first coefficients are used to represent the influence weight of the brightness of the corresponding color channel on the display brightness of the sub-display screen to be adjusted.

[0052] In the embodiment of the present disclosure, each sub-display screen to be adjusted has a corresponding brightness characteristic parameter, and the brightness characteristic parameter can be obtained by pre-measurement.

[0053] For any sub-display, taking the RGB display as an example, the relationship between its display brightness Y and the brightness of each color channel can be expressed as: Y = a*Y r +b*Y g +c*Y b , where Y r , Y g , Y b Respectively represent the display brightness of the R, G, and B color channels, that is, the sub-brightness, and a, b, and c are the first coefficients. For different sub-display screens, the a, b, and c values ​​will be different to a certain extent. In the embodiment of the present disclosure, the a, b, and c values ​​of each sub-display screen are pre-measured and stored as brightness characteristic parameters.

[0054] Step S103: for any sub-display screen to be adjusted, an adjustment value satisfying a first brightness condition and a first constraint condition is searched from a pre-stored lookup table as a target adjustment value according to the target display brightness, the target display chromaticity and the brightness characteristic parameter, wherein the lookup table includes brightness and chromaticity data, and the brightness and chromaticity data includes sub-brightness and display chromaticity when each color channel of the sub-display screen to be adjusted displays a target monochrome picture and the first adjustment layer is set to different adjustment values, the target monochrome picture is a sub-picture of the target white picture on the corresponding color channel, the first brightness condition includes that when the first adjustment layer is set to the target adjustment value, a weighted sum of the sub-brightness of each color channel of the sub-display screen to be adjusted and the first coefficient is equal to the target display brightness, and the first constraint condition includes that a chromaticity offset between the display chromaticity corresponding to the target adjustment value and the target display chromaticity is less than a first chromaticity offset threshold.

[0055] In the embodiment of the present disclosure, for any sub-display screen to be adjusted, a lookup table (i.e., LUT table) is measured in advance, and the lookup table is subsequently used to automatically find an adjustment value that meets the conditions as a target adjustment value. Optionally, the first adjustment layer includes multiple transparencies, and the lookup table includes multiple groups of brightness and chromaticity data, each group of brightness and chromaticity data corresponds to a transparency, and each group of brightness and chromaticity data includes the sub-brightness and display chromaticity when each color channel of the sub-display screen to be adjusted displays a target monochrome image and the first adjustment layer is set to different adjustment values, wherein the first adjustment layer is a different adjustment value means that the R gain, B gain, and G gain in the first adjustment layer are different adjustment values, for example, for the R color channel, the brightness and chromaticity data include the sub-brightness Y of the sub-display screen to be adjusted when the sub-display screen to be adjusted displays an R monochrome image and the R gain (i.e., R-adjustment value) in the first adjustment layer is set to different adjustment values ​​(e.g., 0-255). r Similarly, for the G color channel, the bright chromaticity data includes the brightness Y of the sub-display screen to be adjusted when the sub-display screen to be adjusted displays the G monochrome picture and the G gain (i.e., the G-adjustment value) in the first adjustment layer is set to different adjustment values ​​(e.g., 0-255). g and display chromaticity; for the B color channel, the bright chromaticity data includes the brightness Y of the sub-display screen to be adjusted when the sub-display screen to be adjusted displays the B monochrome picture and the B gain (ie, the B-adjustment value) in the first adjustment layer is set to different adjustment values ​​(e.g., 0-255) b Please refer to Table 1, which is a lookup table corresponding to transparency T1.

[0056] Table 1 - Transparency TI corresponding lookup table

[0057]

[0058] As shown in Table 1, the adjustment value of each color channel of the first adjustment layer in the lookup table ranges from [0, 255]. For transparency T1, its corresponding brightness and chromaticity data includes 256*3=768 records in total, and each record includes at least transparency T1 of the first adjustment layer, adjustment value of the R color channel, adjustment value of the G color channel, adjustment value of the B color channel, brightness Y, chromaticity x, and chromaticity y.

[0059] Among them, brightness Y is Y in the spectral tristimulus values ​​X, Y, and Z. Specifically, the spectral tristimulus values ​​are proposed based on the theory of three primary colors and are used to quantitatively describe the three basic stimulus values ​​of color. In the CIEXYZ color space, the Y value represents the stimulus amount of the green primary color, and together with the red primary color stimulus amount X and the blue primary color stimulus amount Z, it constitutes the tristimulus value of the color. However, since the Y value is related to the light efficiency function V(λ) of the human eye's bright vision spectrum, it can intuitively represent the brightness characteristics of the color. Therefore, the Y value can not only represent the amount of the green primary color, but also the brightness. In specific implementation, the spectral tristimulus values ​​of the sub-display can be measured by a colorimeter (or colorimeter).

[0060] Chroma x and chroma y represent the hue and chroma (or saturation) of the color, respectively, and x and y can be obtained by normalizing the three stimulus values ​​X, Y, and Z. Specifically, chroma x can be expressed as: x=X / (X+Y+Z), and chroma y can be expressed as: y=Y / (X+Y+Z).

[0061] In Table 1, for the R color channel, the sub-display to be adjusted displays the R monochrome picture, that is, displays the (255,0,0) monochrome picture. In the process of the adjustment value of the R color channel of the first adjustment layer changing from 0 to 255, since the values ​​of the G color channel and the B color channel are both 0, the brightness Y measured at this time can also represent the brightness Y of the R color channel. r , the chromaticity x and chromaticity y measured at this time can also represent the display chromaticity of the R color channel; similarly, for the G color channel, the sub-display to be adjusted displays the G monochrome picture, that is, displays the (0,255,0) monochrome picture. In the process of the adjustment value of the G color channel of the first adjustment layer changing from 0 to 255, since the values ​​of the R color channel and the B color channel are both 0, the brightness Y measured at this time can also represent the brightness Y of the G color channel. g , the chromaticity x and chromaticity y measured at this time can also represent the display chromaticity of the G color channel; for the B color channel, the sub-display to be adjusted displays the B monochrome picture, that is, displays the (0,0,255) monochrome picture. In the process of the adjustment value of the B color channel of the first adjustment layer changing from 0 to 255, since the values ​​of the R color channel and the G color channel are both 0, the brightness Y measured at this time can also represent the brightness Y of the B color channel. bAt this time, the measured chromaticity x and chromaticity y can also represent the display chromaticity of the B color channel.

[0062] In the embodiment of the present disclosure, the first brightness condition includes that when the first adjustment layer is set to the target adjustment value, the weighted sum of the sub-brightness of each color channel of the sub-display screen to be adjusted and the first coefficient is equal to the target display brightness, that is, the target adjustment value found from the lookup table satisfies: when the R gain, B gain and G gain in the first adjustment layer are set to the target adjustment value, the weighted sum of the sub-brightness of the R, G, and B color channels when the sub-display screen to be adjusted displays the target white screen is equal to the target display brightness, which can be expressed by the formula: Y = a*Y r +b*Y g +c*Y b For any sub-display screen to be adjusted, the known variables in the formula are a, b, c and Y, where Y is the target display brightness determined in step S101, and then the Y that satisfies the formula is searched from the lookup table. r , Y g , Y b , usually we can get multiple groups of Y r , Y g , Y b , where each group Y r , Y g , Y b Corresponding to a group of adjustment values ​​of each color channel of the first adjustment layer, multiple groups of adjustment values ​​of each color channel can be obtained, so the search result is further constrained by the first constraint condition.

[0063] Optionally, the first constraint condition includes a chromaticity constraint condition, that is, the chromaticity offset between the display chromaticity corresponding to the target adjustment value and the target display chromaticity is less than a first chromaticity offset threshold, that is, for each color channel, under each color channel, the chromaticity offset between the display chromaticity corresponding to the target adjustment value and the target display chromaticity of the color channel is less than the first chromaticity offset threshold.

[0064] Assume that the target display chromaticity is expressed as x(r), y(r), x(g), y(g), x(b), y(b), and for any set of adjustment values ​​found, the corresponding display chromaticity is expressed as x1(r), y1(r), x1(g), y1(g), x1(b), y1(b), then it is necessary to satisfy: the absolute value of the difference between x(r) and x1(r) is less than Δx, the absolute value of the difference between y(r) and y1(r) is less than Δy; and the absolute value of the difference between x(g) and x1(g) is less than Δx, and the absolute value of the difference between y(g) and y1(r) is less than Δy. 1(g) has an absolute value less than Δy; and the absolute value of the difference between x(b) and x1(b) is less than Δx, and the absolute value of the difference between y(b) and y1(b) is less than Δy, wherein Δx and Δy are first chromaticity shift thresholds. Exemplarily, the value of the first chromaticity shift threshold is 0.003, that is, the chromaticity shift is within ±0.003 during white balance adjustment. In this way, it can be ensured that the difference between the display chromaticity of each sub-display screen after adjustment and the target display chromaticity is within a certain range, so that the display chromaticity of each sub-display screen after adjustment is relatively consistent.

[0065] Step S104, setting the first adjustment layer of each sub-display screen to be adjusted according to the target adjustment value, wherein the process of setting the first adjustment layer of each sub-display screen is the process of achieving white balance adjustment of the spliced ​​screen. For example, for the sub-display screen A11 to be adjusted, the adjustment values ​​of the R, G, and B color channels found in the LUT table are R11, G11, and B11, respectively, then the R gain, G gain, and B gain in the first adjustment layer of the sub-display screen A11 to be adjusted are set to R11, G11, and B11, respectively, and other sub-display screens to be adjusted are set similarly, and each sub-display screen in the final spliced ​​screen can achieve highly consistent display brightness and display chromaticity, and the white balance effect is better. In addition, after finding the target adjustment value corresponding to each sub-display screen to be adjusted, each target adjustment value can also be stored in the Soc module of the spliced ​​screen, and the data can be directly used to set the first adjustment layer of each sub-display screen later.

[0066] Compared with the related art, the white balance adjustment method of the embodiment of the present disclosure determines a reference sub-display screen and a sub-display screen to be adjusted from each sub-display screen of the spliced ​​screen by pre-measuring the brightness characteristic parameters of each sub-display screen and the lookup table of the first adjustment layer under different parameter values, and uses the display brightness of the reference sub-display screen as the target display brightness, and the display chromaticity as the target display chromaticity. When performing white balance adjustment thereafter, for each sub-display screen to be adjusted, the target display brightness, target display chromaticity and brightness characteristic parameters are directly used to search for an adjustment value that satisfies the first brightness condition and the first constraint condition from a pre-stored lookup table as the target adjustment value. With such a setting, the debugging efficiency of the target adjustment value can be improved compared with manual debugging, the time consumption is short, and the target adjustment value found is highly accurate, which can make the brightness and chromaticity of each sub-display screen in the spliced ​​screen highly consistent and have a better white balance effect.

[0067] In a possible implementation, the transparency of the mask layer ranges from 0 to 128. When the transparency of the mask layer is greater than 0, the mask layer takes effect, and the R gain, G gain, and B gain in the mask layer take effect. However, the transparency of the mask layer will affect the display brightness of the sub-display screen, which is specifically manifested in that the display brightness of the sub-display screen decreases as the transparency of the mask layer increases. For example, when the transparency of the mask layer reaches a maximum value of 128, the display brightness of the sub-display screen decreases to 50% of the original brightness. Therefore, considering the effect of transparency on brightness, when the embodiment of the present disclosure adjusts the white balance of the spliced ​​screen, it is necessary to set a transparency range (recorded as the first transparency range), and the transparency of the first adjustment layer needs to be selected within the range.

[0068] Optionally, the first transparency range is [0,30]. If 128 is used as the maximum transparency, the first transparency range expressed in percentage is 0-23%. Correspondingly, the pre-measured lookup table also needs to include brightness and chromaticity data at different transparency levels, as shown in Table 1. Table 1 only illustrates the format of brightness and chromaticity data corresponding to any transparency T1, while the brightness and chromaticity data at other transparency levels are the same as Table 1.

[0069] In order to simplify the measurement process, in a possible implementation, multiple transparencies are uniformly selected from the first transparency range as typical values, and then the brightness and chromaticity data corresponding to the typical values ​​are measured, that is, multiple transparencies are arranged at equal intervals within the first transparency range. Exemplarily, 10 transparencies are selected from the first transparency range [0,30] with an interval of 3 for measurement to obtain 10 sets of brightness and chromaticity data. For example, 10 transparencies, 1, 4, 7, 10, 13, 16, 19, 21, 24, and 27, are selected as typical values, and the brightness and chromaticity data corresponding to these 10 transparencies are measured, as shown in Table 1. At this time, for each transparency, the brightness and chromaticity data includes 256*3=768 data. It can be understood that the transparency interval can also be other values. The smaller the interval, the higher the accuracy, but the larger the data volume. Therefore, the transparency interval can be reasonably set according to the data volume limit and accuracy requirements. For example, the transparency interval can be 3, 4, or 5.

[0070] Correspondingly, step S103 searches for target adjustment values ​​of each color channel that satisfy the first brightness condition and the first constraint condition from a pre-stored lookup table according to the target display brightness, target display chromaticity and brightness characteristic parameters, including: searching for transparency and adjustment values ​​of each color channel that satisfy the first brightness condition and the first constraint condition from the multiple sets of brightness and chromaticity data as the target transparency and target adjustment value according to the target display brightness, target display chromaticity and brightness characteristic parameters.

[0071] Correspondingly, performing white balance adjustment on the splicing screen according to the target adjustment value is specifically as follows: performing white balance adjustment on the splicing screen according to the target adjustment value and the target transparency, that is, setting the R gain, G gain, and B gain of the first adjustment layer to the target adjustment value, and setting the transparency of the first adjustment layer to the target transparency.

[0072] In a possible implementation, for any sub-display screen to be adjusted, a method for measuring any set of brightness and chromaticity data includes:

[0073] Step S201 : setting the transparency of the first adjustment layer corresponding to the sub-display screen to be adjusted to a first transparency, where the first transparency is one of the multiple transparencies.

[0074] Step S202: for any color channel, sequentially set the adjustment value of the color channel in the first adjustment layer to one of the preset adjustment value ranges, control the sub-display screen to be adjusted to display the target monochrome image of the color channel and measure the current display brightness and display chromaticity of the sub-display screen to be adjusted, use the display brightness as the sub-brightness corresponding to the color channel, use the display chromaticity as the display chromaticity corresponding to the color channel, and the sub-brightness and display chromaticity corresponding to each color channel constitute a set of brightness and chromaticity data. The preset adjustment value range is the value range of the adjustment value. For example, for an image with a bit depth of 8 bits, the value range of the adjustment value is [0, 255].

[0075] The above steps S201 and S202 can be used to measure the brightness and chromaticity data at any transparency. For example, taking transparency T1 as an example, the process of measuring the brightness and chromaticity data corresponding to the transparency T1 can include the following steps (1) to (4).

[0076] (1) Set the transparency of the first adjustment layer to T1.

[0077] (2) For the R color channel, the adjustment value of the R color channel in the first adjustment layer is set to one of 0-255, and the adjustment values ​​of the G color channel and the B color channel in the first adjustment layer are set to 0, and the sub-display screen to be adjusted is controlled to display the target monochrome image corresponding to the R color channel (i.e., the R monochrome image) and the display brightness and display chromaticity of the sub-display screen to be adjusted are measured, and a total of 256 records are obtained, wherein the measured display brightness and display chromaticity can also be understood as the sub-brightness and display chromaticity of the R color channel, wherein the R monochrome image is the sub-image (255,0,0) of the target white image (255,255,255) on the R color channel.

[0078] (3) For the G color channel, the adjustment value of the G color channel in the first adjustment layer is set to one of 0-255, and the adjustment values ​​of the R color channel and the B color channel in the first adjustment layer are set to 0, and the sub-display screen to be adjusted is controlled to display the target monochrome image corresponding to the G color channel (i.e., the G monochrome image) and the display brightness and display chromaticity of the sub-display screen to be adjusted are measured, and a total of 256 records are obtained, wherein the measured display brightness and display chromaticity can also be understood as the sub-brightness and display chromaticity of the G color channel. Among them, the G monochrome image is the sub-image (0,255,0) of the target white image (255,255,255) on the G color channel.

[0079] (4) For the B color channel, the adjustment value of the B color channel in the first adjustment layer is set to one of 0-255, and the adjustment values ​​of the R color channel and the G color channel in the first adjustment layer are set to 0, and the sub-display screen to be adjusted is controlled to display the target monochrome image corresponding to the B color channel (i.e., the B monochrome image) and the display brightness and display chromaticity of the sub-display screen to be adjusted are measured, and a total of 256 records are obtained, wherein the measured display brightness and display chromaticity can also be understood as the sub-brightness and display chromaticity of the B color channel. Among them, the B monochrome image is the sub-image (0,0,255) of the target white image (255,255,255) on the B color channel.

[0080] In a possible implementation manner, before the step of acquiring the brightness characteristic parameters of each sub-display screen to be adjusted, the step further includes: measuring the brightness characteristic parameters corresponding to each sub-display screen to be adjusted.

[0081] For any sub-display to be adjusted, the measurement process of the brightness characteristic parameters includes:

[0082] (1) measuring the display brightness and the brightness of each color channel when the transparency of the first adjustment layer corresponding to the sub-display screen to be adjusted is a first value and the sub-display screen to be adjusted displays a plurality of reference grayscale white images, that is, measuring the display brightness and the brightness of each color channel of the sub-display screen to be adjusted under a plurality of groups of specific display scenes, wherein the transparency of the first adjustment layer corresponding to the sub-display screen to be adjusted is a first value and the sub-display screen to be adjusted displays a reference grayscale white image.

[0083] Optionally, the multiple reference grayscale white pictures include at least a low grayscale white picture, a medium grayscale white picture and a high grayscale white picture.

[0084] Among them, the first value is 0, and the transparency of the first adjustment layer is set to 0, indicating that the first adjustment layer is not effective at this time. At this time, the measured display brightness and sub-brightness are not affected by the first adjustment layer, and the measurement results can be used to calculate the brightness characteristics of the sub-display. If the transparency of the first adjustment layer is not 0, the measured display brightness and sub-brightness are not only related to the sub-display itself, but also affected by the first adjustment layer, and the measurement results will have a large deviation.

[0085] For example, for a white picture with an 8-bit bit depth, its grayscale range is [0, 255]. At this time, 64, 128, and 192 grayscales can be selected as representatives of low grayscale, medium grayscale, and high grayscale, respectively. At this time, the RGB value of the low grayscale white picture is (64, 64, 64), the RGB value of the medium grayscale white picture is (128, 128, 128), and the RGB value of the high grayscale white picture is (192, 192, 192); for a white picture with a 10-bit bit depth, its grayscale range is [0, 1023]. At this time, 256, 512, and 768 grayscales can be selected as representatives of low grayscale, medium grayscale, and high grayscale, respectively. At this time, the RGB value of the low grayscale white picture is (256, 256, 256), the RGB value of the medium grayscale white picture is (512, 512, 512), and the RGB value of the high grayscale white picture is (768, 768, 768). In the implementation of the present disclosure, taking an 8-bit white screen as an example, in the process of measuring the brightness characteristic parameters, it is necessary to measure the display brightness and the brightness of each color channel when the sub-display to be adjusted displays the reference grayscale white screen (64, 64, 64), (128, 128, 128), and (192, 192, 192). The measurement data are shown in Table 2, where Y w1、 Y w2、 Y w3 They represent the display brightness of the sub-display to be adjusted when it displays a low grayscale white image, a medium grayscale white image, and a high grayscale white image, respectively. r1 , Y r2 , Y r3 They represent the brightness of the R color channel when the sub-display to be adjusted displays a low grayscale white image, a medium grayscale white image, and a high grayscale white image, respectively. g1 , Y g2 , Y g3 They represent the brightness of the G color channel when the sub-display to be adjusted displays a low grayscale white image, a medium grayscale white image, and a high grayscale white image, respectively. b1 , Y b2 , Y b3 They respectively represent the brightness of the B color channel when the sub-display screen to be adjusted displays a low grayscale white image, a medium grayscale white image, and a high grayscale white image. r1 The measurement process is as follows: control the sub-display to be adjusted to display a low grayscale monochrome image, for example (64,0,0), and measure the display brightness of the sub-display to be adjusted as the brightness Y of the R color channel. r1 Similarly, the brightness of other grayscales and other color channels in Table 2 can be measured.

[0086] Table 2 Measurement data

[0087] Reference grayscale white screen Y <![CDATA[Y r ]]> <![CDATA[Y g ]]> <![CDATA[Y b ]]> (64,64,64) <![CDATA[Y w1 ]]> <![CDATA[Y r1 ]]> <![CDATA[Y g1 ]]> <![CDATA[Y b1 ]]> (128,128,128) <![CDATA[Y w2 ]]> <![CDATA[Y r2 ]]> <![CDATA[Y g2 ]]> <![CDATA[Y b2 ]]> (192,192,192) <![CDATA[Y w3 ]]> <![CDATA[Y r3 ]]> <![CDATA[Y g3 ]]> <![CDATA[Y b3 ]]>

[0088] (2) A first coefficient corresponding to each color channel is obtained by fitting according to the multiple groups of display brightness and sub-brightness obtained by measurement, and a weighted sum of the first coefficient and the sub-brightness of the corresponding color channel is the display brightness.

[0089] Specifically, using the three sets of data measured in Table 2, according to the formula Y = a*Y r +b*Y g +c*Y b Establish the equation system, the equation system is as follows:

[0090] Y w1 =a*Y r1 +b*Y g1 +c*Y b1 ;

[0091] Y w2 =a*Y r2 +b*Y g2 +c*Y b2 ;

[0092] Y w3 =a*Y r3 +b*Y g3 +c*Y b3 .

[0093] Solving the above equations can get the values ​​of a, b, and c. Specifically, the values ​​of a, b, and c are expressed in matrices as follows:

[0094]

[0095] Since different sub-display screens have certain differences, the brightness characteristic parameters calculated for different sub-display screens may be different.

[0096] In a possible implementation manner, the first constraint condition further includes:

[0097] (1) the sum of the target adjustment values ​​corresponding to the color channels in the first adjustment layer is the smallest; and / or

[0098] (2) The first color channel has the largest sub-brightness among the sub-brightnesses of the target adjustment values ​​of the color channels in the first adjustment layer, and the first color channel is the color channel with the largest first coefficient.

[0099] Optionally, the color channels of the first adjustment layer include a red color channel (R color channel), a green color channel (i.e., G color channel), and a blue color channel (i.e., B color channel), and the first color channel is the green color channel. gThe white brightness accounts for the largest proportion in the overall display brightness (ie, white brightness), accounting for about 60%. Therefore, when there are multiple groups of adjustment values ​​that meet the first brightness condition, the brightness Y is preferred. g The largest set of adjustment values ​​can ensure that the display brightness after adjustment is maximum.

[0100] In the embodiment of the present disclosure, the first constraint condition may include the constraint conditions shown in (1) and (2) above in addition to the chromaticity constraint condition (i.e., the chromaticity offset between the display chromaticity corresponding to the target adjustment value and the target display chromaticity is less than the first chromaticity offset threshold). Among them, the sum of the target adjustment values ​​corresponding to each color channel in the first adjustment layer is the smallest, that is, the sum of the R gain, G gain, and B gain in the first adjustment layer is the smallest, which corresponds to the situation where the adjustment amount is the smallest during the white balance adjustment process, that is, white balance is achieved through the minimum adjustment.

[0101] In addition, the first constraint condition may also include: the brightness of the red color channel and the blue color channel in the first adjustment layer corresponding to the target adjustment value is not zero.

[0102] Based on the same inventive concept, the second aspect of the present disclosure provides a spliced ​​screen, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the white balance adjustment method as described above when executing the program.

[0103] 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. When the program is executed by a processor, the steps of the white balance adjustment method described above are implemented.

[0104] In the specific implementation process, the computer storage medium may include: Universal Serial Bus Flash Drive (USB), mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, and other storage media that can store program codes.

[0105] 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 white balance adjustment 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 white balance adjustment method, the implementation of the above computer program can refer to the implementation of the white balance adjustment method, and the repeated parts will not be repeated.

[0106] 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 thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more conductors, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0107] 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 white balance adjustment method, characterized in that: The white balance adjustment method is applicable to a spliced ​​screen, wherein the spliced ​​screen includes at least two sub-display screens, each of which is provided with a first adjustment layer, and the white balance adjustment method includes the following steps: Determine a reference sub-display screen from each sub-display screen of the spliced ​​screen, take the display brightness of the reference sub-display screen when displaying a target white screen as the target display brightness, take the display chromaticity of the reference sub-display screen when displaying a target white screen as the target display chromaticity, and the sub-display screens other than the reference sub-display screen in the spliced ​​screen are sub-display screens to be adjusted; Acquire brightness characteristic parameters of each sub-display screen to be adjusted, wherein the brightness characteristic parameters include first coefficients corresponding to each color channel of the sub-display screen to be adjusted, and the first coefficients are used to represent the influence weight of the brightness of the corresponding color channel on the display brightness of the sub-display screen to be adjusted; For any sub-display screen to be adjusted, searching a pre-stored lookup table for an adjustment value that satisfies a first brightness condition and a first constraint condition as a target adjustment value according to the target display brightness, target display chromaticity and brightness characteristic parameters, wherein the lookup table includes brightness chromaticity data, and the brightness chromaticity data includes sub-brightness and display chromaticity when each color channel of the sub-display screen to be adjusted displays a target monochrome picture and the first adjustment layer is set to different adjustment values, the target monochrome picture is a sub-picture of the target white picture on the corresponding color channel, the first brightness condition includes that when the first adjustment layer is set to the target adjustment value, a weighted sum of the sub-brightness of each color channel of the sub-display screen to be adjusted and the first coefficient is equal to the target display brightness, and the first constraint condition includes that a chromaticity offset between the display chromaticity corresponding to the target adjustment value and the target display chromaticity is less than a first chromaticity offset threshold; The first adjustment layer of each sub-display screen to be adjusted is set according to the target adjustment value.

2. The white balance adjustment method according to claim 1, characterized in that: The step of determining a reference sub-display screen from each sub-display screen of the spliced ​​screen comprises: Get the display brightness of each sub-display screen when the spliced ​​screen displays the target white screen; The sub display screen with the lowest display brightness is determined as the reference sub display screen.

3. The white balance adjustment method according to claim 1, characterized in that: The first adjustment layer includes multiple transparency levels, the lookup table includes multiple groups of brightness and chromaticity data, and each group of brightness and chromaticity data corresponds to a transparency level; Searching for an adjustment value satisfying a first brightness condition and a first constraint condition as a target adjustment value from a pre-stored lookup table according to the target display brightness, the target display chromaticity and the brightness characteristic parameter specifically includes: According to the target display brightness, target display chromaticity and brightness characteristic parameters, searching from the plurality of sets of brightness and chromaticity data for transparency and adjustment values ​​of each color channel that satisfy a first brightness condition and a first constraint condition as target transparency and target adjustment value; The step of setting the first adjustment layer of each sub-display screen to be adjusted according to the target adjustment value specifically includes: setting the first adjustment layer of each sub-display screen to be adjusted according to the target adjustment value and the target transparency.

4. The white balance adjustment method according to claim 1, characterized in that: Before the step of obtaining the brightness characteristic parameters of each sub-display screen to be adjusted, the following steps are also included: For any sub-display screen to be adjusted, measuring the display brightness and the brightness of each color channel when the transparency of the first adjustment layer corresponding to the sub-display screen to be adjusted is a first value and the sub-display screen to be adjusted displays a plurality of reference grayscale white images; A first coefficient corresponding to each color channel is calculated according to the measured multiple groups of display brightness and sub-brightness, and a weighted sum of the first coefficient and the sub-brightness of the corresponding color channel is the display brightness.

5. The white balance adjustment method according to claim 4, characterized in that: The plurality of reference grayscale white pictures at least include a low grayscale white picture, a middle grayscale white picture and a high grayscale white picture.

6. The white balance adjustment method according to claim 3, characterized in that: For any sub-display to be adjusted, the measurement method of any set of brightness and chromaticity data includes: Setting the transparency of the first adjustment layer corresponding to the sub-display screen to be adjusted to a first transparency, where the first transparency is one of the multiple transparencies; For any color channel, the adjustment value of the color channel in the first adjustment layer is sequentially set to one of the preset adjustment value ranges, the sub-display screen to be adjusted is controlled to display the target monochrome picture of the color channel and the current display brightness and display chromaticity of the sub-display screen to be adjusted are measured, the display brightness is used as the sub-brightness corresponding to the color channel, the display chromaticity is used as the display chromaticity corresponding to the color channel, and the sub-brightness and display chromaticity corresponding to each color channel constitute a set of brightness and chromaticity data.

7. The white balance adjustment method according to claim 6, characterized in that: The first adjustment layer corresponds to a first transparency range, and the multiple transparencies are arranged at equal intervals within the first transparency range.

8. The white balance adjustment method according to claim 1, characterized in that: The first constraint condition also includes: The sum of the target adjustment values ​​corresponding to the color channels in the first adjustment layer is the smallest; and / or Among the sub-brightnesses of the target adjustment values ​​of the color channels in the first adjustment layer, the sub-brightness of the first color channel is the largest, and the first color channel is the color channel with the largest first coefficient.

9. The white balance adjustment method according to claim 8, characterized in that: The color channels of the first adjustment layer include a red color channel, a green color channel and a blue color channel, and the first color channel is the green color channel; the first constraint condition also includes: The brightness of the red color channel and the blue color channel in the first adjustment layer corresponding to the target adjustment value is not 0.

10. A spliced ​​screen, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the white balance adjustment method according to any one of claims 1 to 9 are implemented.

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 white balance adjustment method as described in 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 white balance adjustment method according to any one of claims 1 to 9 are implemented.

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