White balance correction method and device, equipment and storage medium

Abstract

The invention discloses a white balance correction method, device and equipment and a storage medium, and belongs to the technical field of display, and the method comprises the steps: obtaining the chromaticity coordinate of a first white point displayed by a display system, the chromaticity coordinate being determined by the proportion of the output brightness of red, green and blue channels corresponding to the first white point; predicting a characteristic curve of a red channel, a green channel and a blue channel of the display system, wherein the characteristic curve indicates a mapping relation between the input gray level and the output brightness; based on the color coordinates of the first white point, the target color coordinates and the characteristic curve, first gain values corresponding to the red channel, the green channel and the blue channel respectively are obtained; and adjusting the output brightness of the red, green and blue channels according to the first gain values respectively corresponding to the red, green and blue channels so as to correct the white balance of the display system. The method can improve the white balance correction efficiency.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a method, apparatus, device and storage medium for white balance correction. Background Technology

[0002] In the field of display technology, due to the inherent differences in the luminous efficiency of red, green, and blue sub-pixels, and the existence of manufacturing deviations in the panel's driving circuitry, if the display system directly outputs the same grayscale level, the mixed white light cannot achieve the standard white point, resulting in color temperature deviation. Therefore, performing white balance correction on the display system to bring the white point color coordinates close to the standard color coordinates, ensuring accurate color display and a neutral, unbiased image, is a crucial step in improving the color consistency and image quality of the display system. Summary of the Invention

[0003] This application provides a method, apparatus, device, and storage medium for white balance correction, which can achieve rapid white balance correction.

[0004] In a first aspect, a method for white balance correction is provided, the method comprising: Obtain the color coordinates of the first white point displayed by the display system. The color coordinates are determined by the proportion of the output brightness of the red, green, and blue channels corresponding to the first white point. Predict the characteristic curves of the red, green, and blue channels of the display system, wherein the characteristic curves indicate the mapping relationship between the input gray level and the output brightness; Based on the color coordinates of the first white point, the target color coordinates, and the characteristic curve, the first gain values ​​corresponding to the red, green, and blue channels are obtained respectively, and the target color coordinates are the color coordinates of the white point corresponding to the target color temperature; The output brightness of the red, green, and blue channels is adjusted according to the first gain values ​​corresponding to red, green, and blue, respectively, in order to correct the white balance of the display system.

[0005] In one possible implementation, after adjusting the output brightness of the red, green, and blue channels according to the first gain values ​​corresponding to the red, green, and blue channels respectively, the method further includes: Obtain the color coordinates of the second white point after adjusting the output brightness displayed by the display system; If the color coordinates of the second white point do not match the target color coordinates, the first gain values ​​corresponding to the red, green, and blue channels are adjusted based on the color coordinates of the second white point and the color coordinates of the first white point to obtain the second gain values ​​corresponding to the red, green, and blue channels respectively. The output brightness of the red, green, and blue channels is adjusted according to the second gain values ​​corresponding to the red, green, and blue channels, respectively.

[0006] In one possible implementation, adjusting the first gain values ​​corresponding to the red, green, and blue channels based on the color coordinates of the second white point and the first white point includes: Based on the positional relationship between the color coordinates of the second white point and the color coordinates of the first white point on the color coordinate diagram, the first gain values ​​corresponding to the red, green, and blue channels are adjusted respectively; Wherein, the color coordinates are two-dimensional coordinates, the color coordinate graph is a two-dimensional chart with the two-dimensional coordinates as the coordinate axes, the color coordinate graph is divided into N regions, the N regions include the target region where the target color coordinates are located, and N-1 regions surrounding the target region and symmetrical about the center of the target region, where N is a positive integer greater than 3.

[0007] In one possible implementation, adjusting the first gain values ​​corresponding to the red, green, and blue channels based on the positional relationship between the color coordinates of the second white point and the first white point on the color coordinate graph includes: Based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are located in diagonally opposite regions on the color coordinate diagram, the first gain values ​​corresponding to the red, green, and blue channels are multiplied by the power of b, where b is a natural number less than 1.

[0008] In one possible implementation, adjusting the first gain values ​​corresponding to the red, green, and blue channels based on the positional relationship between the color coordinates of the second white point and the first white point on the color coordinate graph includes: Based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are adjacent in the region on the color coordinate map, the minimum value of the first gain value corresponding to the red, green and blue channels is increased by c, where c is a natural number.

[0009] In one possible implementation, before predicting the characteristic curves of the red, green, and blue channels of the display system, the method further includes: The storage unit is used to record the historical gain values ​​of the red, green and blue channels corresponding to the color coordinates of the first white point. The output brightness of the red, green, and blue channels is adjusted according to the historical gain values ​​corresponding to the red, green, and blue channels, respectively, and the color coordinates of the third white point after the output brightness adjustment are obtained by the display system. The prediction of the characteristic curves of the red, green, and blue channels of the display system includes: If the color coordinates of the third white point do not match the target color coordinates, predict the characteristic curves of the red, green, and blue channels of the display system.

[0010] Secondly, a white balance correction device is provided, the device comprising: The first acquisition module is used to acquire the color coordinates of the first white point displayed by the display system. The color coordinates are determined by the proportion of the output brightness of the red, green and blue channels corresponding to the first white point. The prediction module is used to predict the characteristic curves of the red, green and blue channels of the display system, wherein the characteristic curves indicate the mapping relationship between the input gray level and the output brightness; The second acquisition module is used to acquire the first gain values ​​corresponding to the red, green and blue channels respectively based on the color coordinates of the first white point, the target color coordinates and the characteristic curve, wherein the target color coordinates are the color coordinates of the white point corresponding to the target color temperature; The adjustment module is used to adjust the output brightness of the red, green, and blue channels according to the first gain values ​​corresponding to the red, green, and blue channels, respectively, so as to correct the white balance of the display system.

[0011] In one possible implementation, the first acquisition module is further configured to acquire the color coordinates of the second white point after the output brightness is adjusted as displayed by the display system; The adjustment module is also used to adjust the first gain values ​​corresponding to the red, green, and blue channels respectively, based on the color coordinates of the second white point and the target color coordinates, when the color coordinates of the second white point do not match the color coordinates of the first white point, to obtain the second gain values ​​corresponding to the red, green, and blue channels respectively; and to adjust the output brightness of the red, green, and blue channels according to the second gain values ​​corresponding to the red, green, and blue channels respectively.

[0012] In one possible implementation, the adjustment module is used to adjust the first gain values ​​corresponding to the red, green, and blue channels respectively based on the positional relationship between the color coordinates of the second white point and the color coordinates of the first white point on the color coordinate diagram; Wherein, the color coordinates are two-dimensional coordinates, the color coordinate graph is a two-dimensional chart with the two-dimensional coordinates as the coordinate axes, the color coordinate graph is divided into N regions, the N regions include the target region where the target color coordinates are located, and N-1 regions surrounding the target region and symmetrical about the center of the target region, where N is a positive integer greater than 3.

[0013] In one possible implementation, the adjustment module is used to multiply the first gain values ​​corresponding to the red, green, and blue channels by a power of a, where a is a natural number greater than 1, based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are located in the same region on the color coordinate map.

[0014] In one possible implementation, the adjustment module is used to multiply the first gain values ​​corresponding to the red, green, and blue channels by powers of b, where b is a natural number less than 1, based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are located in diagonally opposite regions on the color coordinate graph.

[0015] In one possible implementation, the adjustment module is used to increase the minimum value of the first gain values ​​corresponding to the red, green, and blue channels by c, where c is a natural number, based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are adjacent in the color coordinate graph.

[0016] In one possible implementation, the device further includes: a third acquisition module, configured to acquire from the storage unit the historical gain values ​​corresponding to the red, green, and blue channels respectively, based on the color coordinates of the first white point; the storage unit is configured to record the historical gain values ​​after white balance correction. The adjustment module is also used to adjust the output brightness of the red, green and blue three channels according to the historical gain values ​​corresponding to the red, green and blue channels respectively, and to obtain the color coordinates of the third white point after the adjusted output brightness is displayed by the display system; The prediction module is used to predict the characteristic curves of the red, green, and blue channels of the display system when the color coordinates of the third white point do not match the target color coordinates.

[0017] Thirdly, a display device is also provided, the display device including a processor and a memory, the memory storing at least one piece of program code, the at least one piece of program code being loaded and executed by the processor to enable the display device to implement the white balance correction method described in any of the above claims.

[0018] In one possible implementation, the display device has the functionality to implement the behavior described in the method embodiments above. The display device may also be a component of a display device (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functionality of the method. The functionality of the display device can be implemented in hardware or by hardware executing corresponding software, the hardware or software including one or more modules or units corresponding to the above-described functionality.

[0019] Fourthly, a computer-readable storage medium is also provided, wherein at least one piece of program code is stored therein, the at least one piece of program code being loaded and executed by a processor of a display device to enable the display device to implement the white balance correction method described in the first aspect above.

[0020] Fifthly, a computer program product or computer program is also provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a display device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the display device to perform the white balance correction method described in the first aspect.

[0021] The technical solution provided in this application can bring at least the following beneficial effects: This method can quickly calculate reasonable gain values ​​for the red, green, and blue channels by predicting the characteristic curve of the display system when the display system characteristic curve is unknown. The calculated gain values ​​of the red, green, and blue channels can then be used to accelerate the white balance correction speed, simplify the white balance correction process, shorten the white balance correction time, and reduce the time cost of white balance correction. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the implementation environment of a white balance correction method provided in an embodiment of this application; Figure 2 This is a flowchart of a white balance correction method provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a color coordinate diagram provided in an embodiment of this application; Figure 4 This is a schematic diagram of the overall framework of a white balance correction process provided in an embodiment of this application; Figure 5 This is a schematic diagram of a white balance correction device provided in an embodiment of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0025] In screen image display, the color temperature of the white point is an important indicator for evaluating color reproduction performance. However, due to fluctuations in the consistency between backlight and LCD screen, the color temperature of each display device cannot be guaranteed to be consistent during the manufacturing process. Since the performance of products within the same batch needs to be consistent, it is necessary to correct the color temperature of the white point, also known as white balance correction. The color temperature of the white point refers to the blackbody radiation temperature corresponding to the color coordinates of white light (i.e., white point color coordinates, also called white dot color coordinates) when the monitor displays a full white image. The unit is Kelvin (K), and it is used to describe the warm or cool tone of white light.

[0026] Color coordinates (x, y) are two-dimensional coordinates used in the CIE standard colorimetric system to quantitatively describe color attributes. They are determined by the relative luminance contributions of the red (R), green (G), and blue (B) channels. Increasing the luminance proportion of the R channel shifts the white point color coordinates towards the red region, decreasing the color temperature; increasing the luminance proportion of the G channel shifts the white point color coordinates towards the green region; and increasing the proportion of the B channel shifts the white point color coordinates towards the blue region, increasing the color temperature. Therefore, by adjusting the proportions of the output luminance of the R, G, and B channels in the output signal, the white point color coordinates can be made closer to the target color coordinates, thus making the white point color temperature closer to the target white point color temperature.

[0027] In a display system, the displayed white point is formed by the mixture of light emitted from three sub-pixels: R, G, and B. The light emitted by these three sub-pixels is determined by the output brightness of the R, G, and B channels, which are obtained by converting the grayscale levels of these three channels. Grayscale level, also known as digital grayscale, ranges from 0 to 255 in an 8-bit environment, where 0 represents the darkest level (e.g., black) and 255 represents the brightest level (e.g., white). For example, in white balance correction, the grayscale level of the R, G, and B channels input to the display system is 255.

[0028] In this embodiment, the curve representing the mapping relationship between the grayscale level of the input display system and the output brightness is called the display system characteristic curve. This curve reflects the overall conversion characteristics from digital signal to optical output. Typically, the display system characteristic curve is not a straight line, but rather an upward-curving curve; for example, it is a gamma curve. In one possible case, the gamma curve has the form: L=L max (gray / 255) γ Where gray represents gray level, γ represents Gamma coefficient, and L max L represents the maximum brightness of the display system, and L represents the output brightness corresponding to the grayscale level.

[0029] In related technologies, when the characteristic curve of the display system is unknown, for a certain input grayscale level (the grayscale levels of the R, G, and B channels are the same), the output R and G components are first adjusted to make the brightness of the output graph close to the target brightness. Then, the current color coordinates are compared with the target color coordinates (i.e., the color coordinates corresponding to the target color temperature). If both the x and y values ​​of the current color coordinates are greater than the target color coordinates, the B component is increased; conversely, if both the x and y values ​​of the current color coordinates are less than the target color coordinates, the B component is decreased. Thus, by continuously comparing the x and y values ​​of the current color coordinates, the value of the B component is continuously corrected until the current color coordinates reach the target color coordinates.

[0030] The method for adjusting the R, G, and B components involves adjusting the gain values ​​of R, G, and B. Taking the Gamma curve above as an example, after adjusting the gain value of the B component, L... B =Bgain L max (Bgray / 255) γ Bgain represents the gain value of the B component, L B The brightness representing the B component is the output brightness of the B channel. However, the methods in related technologies require continuous color coordinate measurement and adjustment attempts, resulting in numerous attempts and a slow correction speed, which increases the time cost of white balance correction and thus raises the mass production cost of the product.

[0031] This application provides a method for white balance correction, which simplifies the white balance correction process, shortens the white balance correction time, and improves the white balance correction efficiency. This white balance correction method can be applied to any implementation environment that includes a display device, which is an electronic device that converts electrical signals into a visible optical image. For example… Figure 1 As shown, the implementation environment of this white balance correction method includes: display device 101, such as a monitor, screen, or terminal display screen.

[0032] For example, the terminal can be any electronic product that can interact with the user through one or more means such as a keyboard, touchpad, touch screen, remote control, voice interaction or handwriting device, such as a personal computer (PC), smartphone, personal digital assistant (PDA), wearable device, handheld PC (PPC), tablet computer, smart car system, etc.

[0033] Those skilled in the art should understand that the above-described display device 101 is merely an example, and other existing or future display devices may also be applicable to this application and should be included within the scope of protection of this application, and are hereby incorporated by reference.

[0034] See Figure 2 , Figure 2 This is a flowchart illustrating a white balance correction method provided in an embodiment of this application. Exemplarily, this method can be applied to the above-described... Figure 1 In the implementation environment shown, for example, by Figure 1 The display device 101 shown executes this method. For example... Figure 2 As shown, the white balance correction method provided in this application embodiment includes, but is not limited to, the following steps 201-204.

[0035] Step 201: Obtain the color coordinates of the first white point displayed by the display system. The color coordinates are determined by the proportion of the output brightness of the red, green and blue channels corresponding to the first white point.

[0036] In this embodiment, the display system can be any complete system that converts digital signals into visual images, text, or graphics and displays them on a screen to provide visual information to the user. In this case, inputting a digital signal (e.g., grayscale level 255) to the display system for displaying white enables the display system to display a white point (i.e., the first white point, also known as the initial white point) on the screen. The method of obtaining the color coordinates of the first white point is not limited in this embodiment; for example, it can be measured using a colorimeter.

[0037] As mentioned above, by measuring whether the color coordinates of the first white point match the target color coordinates, it can be determined whether the display system needs white balance correction. The target color coordinates are the color coordinates of the white point corresponding to the target color temperature, or the color coordinates of the white point corresponding to the target white point color temperature, and can be obtained through configuration.

[0038] Optionally, whether the color coordinates of the first white point match the target color coordinates can refer to whether the color coordinates of the first white point are within the allowable error range of the target color coordinates. For example, whether the distance between the color coordinates of the first white point and the target color coordinates is less than a distance threshold. The distance threshold can be set empirically or adjusted flexibly according to the application scenario. If the distance between the color coordinates of the first white point and the target color coordinates is less than the distance threshold, white balance correction of the display system is required; if the distance between the color coordinates of the first white point and the target color coordinates is greater than or equal to the distance threshold, white balance correction of the display system is not required.

[0039] Exemplarily, if the target color temperature is a color temperature range, the target color coordinates are allowed to fluctuate within a certain error range. Taking the target color coordinates as (target_x, target_y) and the error ranges as x_range and y_range as an example, when the white point color coordinates (correction_x, correction_y) displayed by the measured display system satisfy |correction_x – target_x| < x_range and |correction_y – target_y| < y_range, it is considered that the white field color temperature of the display system is accurate and no white balance correction is required.

[0040] After obtaining the color coordinates of the first white point displayed by the display system, first determine whether the color coordinates of the first white point match the target color coordinates; if the color coordinates of the first white point match the target color coordinates, then steps 202 - step 204 do not need to be executed; if the color coordinates of the first white point do not match the target color coordinates, then continue to execute steps 202 - step 204.

[0041] Step 202, predict the characteristic curves of the red, green, and blue channels of the display system, and the characteristic curves indicate the mapping relationship between the input gray level and the output brightness.

[0042] Since the display characteristics of the display system are close to the Gamma curve, therefore, predicting the characteristic curves of the R, G, and B channels can be understood as predicting the Gamma coefficient (γ) of the Gamma curve. Exemplarily, it is predicted that γ = 2.2. In a possible case, the characteristic curves of the red, green, and blue channels are the same, that is, it is predicted that the Gamma coefficients of the R, G, and B channels are all 2.2.

[0043] In a possible implementation manner, before predicting the characteristic curves of the red, green, and blue channels of the display system, it further includes: obtaining the historical gain values corresponding to the red, green, and blue channels respectively corresponding to the color coordinates of the first white point from the storage unit, and the storage unit is used to record the gain values after historical white balance correction; adjusting the output brightness of the red, green, and blue channels according to the historical gain values corresponding to the red, green, and blue respectively, and obtaining the color coordinates of the third white point after adjusting the output brightness displayed by the display system. In this way, predicting the characteristic curves of the red, green, and blue channels of the display system includes: predicting the characteristic curves of the red, green, and blue channels of the display system when the color coordinates of the third white point do not match the target color coordinates.

[0044] Step 203, based on the color coordinates of the first white point, the target color coordinates, and the characteristic curves, obtain the first gain values corresponding to the red, green, and blue channels respectively.

[0045] After measuring the color coordinates of the first white point and predicting the characteristic curves of the red, green, and blue channels, the output brightness of the red, green, and blue channels can be calculated based on the relationship of the Gamma curve. Based on the difference between the color coordinates of the first white point and the target color coordinates, it can be determined which of the three channels has a lower or higher output brightness. Thus, the first gain value corresponding to the R, G, and B channels can be calculated.

[0046] In this embodiment, considering that the human eye is most sensitive to the brightness of the G channel, the first gain value (Ggain) of the G channel is set to the maximum value, for example, Ggain=1 or 0xFF. This ensures the maximum brightness at the target white point.

[0047] Step 204: Adjust the output brightness of the red, green, and blue channels according to the first gain values ​​corresponding to red, green, and blue respectively, in order to correct the white balance of the display system.

[0048] In one possible implementation, after adjusting the output brightness of the red, green, and blue channels according to the first gain values ​​corresponding to red, green, and blue respectively, the method further includes: obtaining the color coordinates of the second white point displayed by the display system after adjusting the output brightness; if the color coordinates of the second white point do not match the target color coordinates, adjusting the first gain values ​​corresponding to the red, green, and blue channels based on the color coordinates of the second white point and the color coordinates of the first white point to obtain the second gain values ​​corresponding to the red, green, and blue channels respectively; and adjusting the output brightness of the red, green, and blue channels according to the second gain values ​​corresponding to red, green, and blue respectively.

[0049] Optionally, after adjusting the output brightness of the red, green, and blue channels according to the second gain values ​​corresponding to red, green, and blue respectively, the method further includes: obtaining the color coordinates of the fourth white point after adjusting the output brightness as displayed by the display system; if the color coordinates of the fourth white point do not match the target color coordinates, adjusting the second gain values ​​corresponding to the red, green, and blue channels based on the color coordinates of the fourth white point and the second white point to obtain the third gain values ​​corresponding to the red, green, and blue channels respectively; adjusting the output brightness of the red, green, and blue channels according to the third gain values ​​corresponding to red, green, and blue respectively. This process continues until the color coordinates of the white point after adjusting the output brightness as displayed by the display system match the target color coordinates.

[0050] It is understandable that the method of adjusting the second gain values ​​corresponding to the red, green, and blue channels based on the color coordinates of the fourth and second white points can be found in the method of adjusting the first gain values ​​corresponding to the red, green, and blue channels based on the color coordinates of the second and first white points. This application's embodiment uses the adjustment of the first gain values ​​corresponding to the red, green, and blue channels based on the color coordinates of the second and first white points as an example to explain the adjustment method.

[0051] In one possible implementation, the first gain values ​​corresponding to the red, green, and blue channels are adjusted based on the color coordinates of the second white point and the first white point. This includes adjusting the first gain values ​​corresponding to the red, green, and blue channels based on the positional relationship between the color coordinates of the second and first white points on a color coordinate graph. Here, the color coordinates are two-dimensional coordinates, such as the aforementioned color coordinates (x, y). The color coordinate graph is a two-dimensional chart with two-dimensional coordinates as the coordinate axes. The color coordinate graph is divided into N regions, including the target region where the target color coordinates are located, and N-1 regions surrounding the target region and symmetrical about the center of the target region. N is a positive integer greater than 3.

[0052] For example, see Figure 3 The diagram shown illustrates the CIE color coordinate system. The x-axis represents the x-axis in the color coordinate system (x, y), and the y-axis represents the y-axis. Taking N as 5 and the target color coordinates as (0.3127, 0.3290) as an example, the CIE color coordinate system is divided into five regions: Region 0 (the target region), Region 1, Region 2, Region 3, and Region 4. Region 0 represents the area where the target color coordinates are within the error range. If the measured color coordinates of the white point displayed on the system are within Region 0, then the white balance correction is complete.

[0053] In this embodiment of the application, based on the positional relationship between the color coordinates of the second white point and the color coordinates of the first white point on the color coordinate diagram, the first gain values ​​corresponding to the red, green, and blue channels are adjusted, including but not limited to the following three methods.

[0054] Method 1: Based on the fact that the color coordinates of the second white point and the first white point are located in the same region on the color coordinate diagram, the first gain values ​​corresponding to the red, green, and blue channels are multiplied by a power of 'a', where 'a' is a natural number greater than 1. Here, the magnitude of 'a' represents the step size of each γ adjustment. This embodiment does not limit the specific value of 'a'; it can be set based on experience or flexibly adjusted according to the application scenario. Typically, 'a' is a value slightly greater than 1.

[0055] For example, the color coordinates of the second white point and the color coordinates of the first white point are both located on the color coordinate graph. Figure 3Regions 1, 2, 3, or 4 indicate that the predicted γ is too large. Therefore, adjust the new Rgain` = Rgain^a, Ggain` = Ggain^a, and Bgain` = Bgain^a. Rgain represents the first gain value of the R channel, and Rgain` represents the second gain value of the R channel; Ggain represents the first gain value of the G channel, and Ggain` represents the second gain value of the G channel; Bgain represents the first gain value of the B channel, and Bgain` represents the second gain value of the B channel.

[0056] Method 2: Based on the fact that the color coordinates of the second white point and the first white point are located diagonally on the color coordinate graph, the first gain values ​​corresponding to the red, green, and blue channels are multiplied by a power of b, where b is a natural number less than 1. Here, b represents the step size of each γ adjustment. This embodiment does not limit the specific value of b; it can be set based on experience or flexibly adjusted according to the application scenario. Typically, b is a value slightly less than 1.

[0057] For example, the color coordinates of the second white point and the color coordinates of the first white point are located on the color coordinate graph. Figure 3 Regions 2 and 4 shown, or the color coordinates of the second white point and the first white point, are located on the color coordinate diagram. Figure 3 Regions 3 and 1 are shown. At this point, it indicates that the adjustment of the gain value is too large, exceeding the target region 0, and also indicates that the predicted γ of the display system is too small. Therefore, adjust the new Rgain`=Rgain^b, Ggain`=Ggain^b, Bgain`=Bgain^b.

[0058] Method 3: Based on the fact that the color coordinates of the second white point and the first white point are adjacent in the color coordinate graph, the minimum value of the first gain value corresponding to the red, green, and blue channels is increased by c, where c is a natural number. Here, the value of c represents the step size for each single-channel adjustment. This embodiment does not limit the specific value of c; it can be set based on experience or flexibly adjusted according to the application scenario. Typically, c is a decimal less than 1 and greater than 0.

[0059] For example, the color coordinates of the second white point and the color coordinates of the first white point are located on the color coordinate graph. Figure 3 Regions 1 and 2 shown, or the color coordinates of the second white point and the first white point, are located on the color coordinate diagram. Figure 3 Regions 2 and 3 shown, or the color coordinates of the second white point and the first white point, are located on the color coordinate diagram. Figure 3 Regions 3 and 4 shown, or the color coordinates of the second white point and the first white point, are located on the color coordinate diagram. Figure 3Regions 4 and 1 are shown. This indicates that the gamma values ​​of the R, G, and B channels are not consistent. Therefore, it is necessary to adjust the gain value of the single channel with the lowest gain among the R, G, and B channels. For example, if the first gain value of channel B is the lowest among the first gain values ​​corresponding to the R, G, and B channels, then adjust the second gain value of channel B to Bgain` = Bgain + c, while keeping the second gain values ​​of channels R and G the same as their respective first gain values.

[0060] Below, in conjunction with Figure 4 The flowchart shown illustrates the overall white balance correction process, providing an example of the white balance correction method provided in this application. Figure 4 As shown, firstly, the color coordinates of the initial white point (the white point displayed before correction) and the color coordinates of the target white point (i.e., the color coordinates of the target white point mentioned above) are obtained. For example, the white point is displayed based on the input white point grayscale level, and the color coordinates of the displayed white point are measured using a colorimeter to obtain the color coordinates of the initial white point; the color coordinates of the target white point can be obtained through configuration.

[0061] Then, based on the color coordinates of the initial white point and the target white point, the first gain values ​​of the R, G, and B components are obtained. Based on these first gain values, the initial white point undergoes a first white balance correction to obtain the second white point, and its color coordinates are then obtained. The white balance correction process is as follows: the luminance data (Rcode, Gcode, and Bcode) of the R, G, and B components output from the display system characteristic curve of the initial white point are multiplied by the first gain values ​​(Rgian, Ggian, and Bgian) of these components to obtain the luminance data (Rdata, Gdata, and Bdata) of the second white point after display system correction. That is, Rdata = Rcode. Rgian, Gdata=Gcode Ggian, Bdata=Bcode Bgian. Therefore, the luminance data of the three components R, G, and B can be adjusted by changing the gain values ​​of the three components. The change in the luminance data of the three components R, G, and B causes the color coordinates of the white point to change accordingly, and the change in the color coordinates of the white point causes the color temperature of the white point to change accordingly.

[0062] Optionally, based on the color coordinates of the initial white point and the target white point, the first gain values ​​of the R, G, and B components are obtained, including: determining whether the color coordinates of the initial white point are within the error range of the color coordinates of the target white point; if the color coordinates of the initial white point are not within the error range of the color coordinates of the target white point, the first gain values ​​of the R, G, and B components (i.e., the first gain values ​​corresponding to the R, G, and B channels respectively) are obtained; if the color coordinates of the initial white point are within the error range of the color coordinates of the target white point, no white balance correction is required, and the process ends.

[0063] The first gain values ​​of the R, G, and B components can be obtained from a storage unit. In this embodiment, the storage unit stores pre-configured gain values ​​of the R, G, and B components, or gain values ​​of the R, G, and B components recorded during historical white balance correction processes. For example, the storage unit stores multiple sets of gain values ​​of the R, G, and B components corresponding to the color coordinates of the initial white point and the color coordinates of the target white point, respectively. Each set of gain values ​​of the R, G, and B components corresponding to the color coordinates of the initial white point and the target white point is a set of gain values ​​of the R, G, and B components obtained by historically correcting the color coordinates of the initial white point to the color coordinates of the target white point using the method of this embodiment.

[0064] After obtaining the color coordinates of the second white point, it is determined whether the color coordinates of the second white point are within the preset range of the color coordinates of the target white point. If the color coordinates of the second white point are not within the preset range of the color coordinates of the target white point, the display system characteristic curves corresponding to the R, G, and B components are predicted, for example, predicting γ=2.2; based on the predicted display system characteristic curves corresponding to the R, G, and B components, the second gain values ​​of the R, G, and B components are obtained; based on the second gain values ​​of the R, G, and B components, a second white balance correction is performed on the initial white point to obtain the second white point, and the color coordinates of the second white point are obtained.

[0065] After obtaining the color coordinates of the second white point, it is determined whether the color coordinates of the second white point are within the preset range of the color coordinates of the target white point. If the color coordinates of the second white point are not within the preset range of the color coordinates of the target white point, the second gain values ​​of the R, G, and B components are adjusted according to the positional relationship between the color coordinates of the second white point and the color coordinates of the initial white point on the color coordinate graph, resulting in the third gain values ​​of the R, G, and B components. Based on the third gain values ​​of the R, G, and B components, white balance correction is performed on the second white point to obtain the third white point, and the color coordinates of the third white point are obtained.

[0066] In this case, the color coordinates of the second white point and the color coordinates of the initial white point are different in position on the CIE color coordinate diagram, so the way to adjust the second gain value of the three components R, G, and B is also different. Optionally, it includes, but is not limited to, the three adjustment methods mentioned above.

[0067] In summary, the method in this application primarily replaces the traditional method of continuously adjusting the RGB color components with continuously adjusting the RGB gamma values. Since the adjustment range of gamma is relatively small, generally around gamma 2.2, this shortens the calibration time and improves calibration efficiency. By adjusting the different RGB output data, the display system can display different white screen effects, and a colorimeter can be used to measure the adjusted display image to confirm whether it meets the desired target color temperature.

[0068] See Figure 5 This application provides a white balance correction device, which includes: The first acquisition module 501 is used to acquire the color coordinates of the first white point displayed by the display system. The color coordinates are determined by the proportion of the output brightness of the red, green and blue channels corresponding to the first white point. The prediction module 502 is used to predict the characteristic curves of the red, green and blue channels of the display system. The characteristic curves indicate the mapping relationship between the input gray level and the output brightness. The second acquisition module 503 is used to acquire the first gain values ​​corresponding to the red, green and blue channels respectively based on the color coordinates of the first white point, the target color coordinates and the characteristic curve, where the target color coordinates are the color coordinates of the white point corresponding to the target color temperature; The adjustment module 504 is used to adjust the output brightness of the red, green and blue channels according to the first gain values ​​corresponding to red, green and blue, respectively, in order to correct the white balance of the display system.

[0069] In one possible implementation, the first acquisition module 501 is further configured to acquire the color coordinates of the second white point after the output brightness is adjusted as displayed by the display system; The adjustment module 504 is also used to adjust the first gain values ​​corresponding to the red, green, and blue channels respectively, based on the color coordinates of the second white point and the target color coordinates, when the color coordinates of the second white point and the first white point do not match, to obtain the second gain values ​​corresponding to the red, green, and blue channels respectively; and to adjust the output brightness of the red, green, and blue channels according to the second gain values ​​corresponding to the red, green, and blue channels respectively.

[0070] In one possible implementation, the adjustment module 504 is used to adjust the first gain values ​​corresponding to the red, green and blue channels respectively based on the positional relationship between the color coordinates of the second white point and the color coordinates of the first white point on the color coordinate diagram; Wherein, color coordinates are two-dimensional coordinates, and the color coordinate graph is a two-dimensional chart with two-dimensional coordinates as coordinate axes. The color coordinate graph is divided into N regions. The N regions include the target region where the target color coordinates are located, and N-1 regions surrounding the target region and symmetrical about the center of the target region. N is a positive integer greater than 3.

[0071] In one possible implementation, the adjustment module 504 is used to multiply the first gain values ​​corresponding to the red, green, and blue channels by a power of a, where a is a natural number greater than 1, based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are located in the same area on the color coordinate diagram.

[0072] In one possible implementation, the adjustment module 504 is used to multiply the first gain values ​​corresponding to the red, green, and blue channels by powers of b, where b is a natural number less than 1, based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are located in diagonally opposite regions on the color coordinate diagram.

[0073] In one possible implementation, the adjustment module 504 is used to increase the minimum value of the first gain values ​​corresponding to the red, green, and blue channels by c, where c is a natural number, based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are adjacent in the color coordinate diagram.

[0074] In one possible implementation, the device further includes: a third acquisition module, used to acquire from the storage unit the historical gain values ​​corresponding to the red, green and blue channels corresponding to the color coordinates of the first white point, respectively, and the storage unit is used to record the gain values ​​after historical white balance correction; The adjustment module 504 is also used to adjust the output brightness of the three channels (red, green, and blue) according to the historical gain values ​​corresponding to red, green, and blue respectively, and to obtain the color coordinates of the third white point after the output brightness is adjusted and displayed by the display system. The prediction module 502 is used to predict the characteristic curves of the red, green and blue channels of the display system when the color coordinates of the third white point do not match the target color coordinates.

[0075] It should be understood that the apparatus provided in the above embodiments is only illustrated by the division of the above functional modules when implementing its functions. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0076] In an exemplary embodiment, a display device is also provided, comprising a processor and a memory storing at least one line of program code. This at least one line of program code is loaded and executed by one or more processors to enable the display device to implement any of the white balance correction methods described above.

[0077] In an exemplary embodiment, a computer-readable storage medium is also provided, which stores at least one piece of program code that is loaded and executed by a processor of a display device to enable the display device to implement any of the white balance correction methods described above.

[0078] Optionally, the aforementioned computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, floppy disk, and optical data storage device, etc.

[0079] In an exemplary embodiment, a computer program product or computer program is also provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a display device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the display device to perform any of the white balance correction methods described above.

[0080] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0081] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals involved in this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0082] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A method for white balance correction, characterized in that, The method includes: Obtain the color coordinates of the first white point displayed by the display system. The color coordinates are determined by the proportion of the output brightness of the red, green, and blue channels corresponding to the first white point. Predict the characteristic curves of the red, green, and blue channels of the display system, wherein the characteristic curves indicate the mapping relationship between the input gray level and the output brightness; Based on the color coordinates of the first white point, the target color coordinates, and the characteristic curve, the first gain values ​​corresponding to the red, green, and blue channels are obtained respectively, and the target color coordinates are the color coordinates of the white point corresponding to the target color temperature; The output brightness of the red, green, and blue channels is adjusted according to the first gain values ​​corresponding to red, green, and blue, respectively, in order to correct the white balance of the display system.

2. The method according to claim 1, characterized in that, After adjusting the output brightness of the red, green, and blue channels according to the first gain values ​​corresponding to red, green, and blue respectively, the method further includes: Obtain the color coordinates of the second white point after adjusting the output brightness displayed by the display system; If the color coordinates of the second white point do not match the target color coordinates, the first gain values ​​corresponding to the red, green, and blue channels are adjusted based on the color coordinates of the second white point and the color coordinates of the first white point to obtain the second gain values ​​corresponding to the red, green, and blue channels respectively. The output brightness of the red, green, and blue channels is adjusted according to the second gain values ​​corresponding to the red, green, and blue channels, respectively.

3. The method according to claim 2, characterized in that, The adjustment of the first gain values ​​corresponding to the red, green, and blue channels based on the color coordinates of the second white point and the first white point includes: Based on the positional relationship between the color coordinates of the second white point and the color coordinates of the first white point on the color coordinate diagram, the first gain values ​​corresponding to the red, green, and blue channels are adjusted respectively; Wherein, the color coordinates are two-dimensional coordinates, the color coordinate graph is a two-dimensional chart with the two-dimensional coordinates as the coordinate axes, the color coordinate graph is divided into N regions, the N regions include the target region where the target color coordinates are located, and N-1 regions surrounding the target region and symmetrical about the center of the target region, where N is a positive integer greater than 3.

4. The method according to claim 3, characterized in that, The adjustment of the first gain values ​​corresponding to the red, green, and blue channels based on the positional relationship between the color coordinates of the second white point and the color coordinates of the first white point on the color coordinate graph includes: Based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are located in the same region on the color coordinate diagram, the first gain values ​​corresponding to the red, green, and blue channels are multiplied by a power of a, where a is a natural number greater than 1.

5. The method according to claim 3, characterized in that, The adjustment of the first gain values ​​corresponding to the red, green, and blue channels based on the positional relationship between the color coordinates of the second white point and the color coordinates of the first white point on the color coordinate graph includes: Based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are located in diagonally opposite regions on the color coordinate diagram, the first gain values ​​corresponding to the red, green, and blue channels are multiplied by the power of b, where b is a natural number less than 1.

6. The method according to claim 3, characterized in that, The adjustment of the first gain values ​​corresponding to the red, green, and blue channels based on the positional relationship between the color coordinates of the second white point and the color coordinates of the first white point on the color coordinate graph includes: Based on the fact that the color coordinates of the second white point and the color coordinates of the first white point are adjacent in the region on the color coordinate map, the minimum value of the first gain value corresponding to the red, green and blue channels is increased by c, where c is a natural number.

7. The method according to any one of claims 1-6, characterized in that, Before predicting the characteristic curves of the red, green, and blue channels of the display system, the method further includes: The storage unit is used to record the historical gain values ​​of the red, green and blue channels corresponding to the color coordinates of the first white point. The output brightness of the red, green, and blue channels is adjusted according to the historical gain values ​​corresponding to the red, green, and blue channels, respectively, and the color coordinates of the third white point after the output brightness adjustment are obtained by the display system. The prediction of the characteristic curves of the red, green, and blue channels of the display system includes: If the color coordinates of the third white point do not match the target color coordinates, predict the characteristic curves of the red, green, and blue channels of the display system.

8. A white balance correction device, characterized in that, The device includes: The first acquisition module is used to acquire the color coordinates of the first white point displayed by the display system. The color coordinates are determined by the proportion of the output brightness of the red, green and blue channels corresponding to the first white point. The prediction module is used to predict the characteristic curves of the red, green and blue channels of the display system, wherein the characteristic curves indicate the mapping relationship between the input gray level and the output brightness; The second acquisition module is used to acquire the first gain values ​​corresponding to the red, green and blue channels respectively based on the color coordinates of the first white point, the target color coordinates and the characteristic curve, wherein the target color coordinates are the color coordinates of the white point corresponding to the target color temperature; The adjustment module is used to adjust the output brightness of the red, green, and blue channels according to the first gain values ​​corresponding to the red, green, and blue channels, respectively, so as to correct the white balance of the display system.

9. A display device, characterized in that, The display device includes a processor and a memory, the memory storing at least one computer program or instruction, the at least one computer program or instruction being loaded and executed by the processor to enable the display device to implement the white balance correction method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one piece of program code, which is loaded and executed by a processor in the display device to enable the display device to implement the white balance correction method as described in any one of claims 1 to 7.

11. A computer program product, characterized in that, The computer program product includes: computer instructions, which are loaded and executed by the processor of the display device to cause the display device to implement the white balance correction method according to any one of claims 1-7.

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