A lightness adjustment method and system

Abstract

The application provides a bright chroma adjusting method and system, and belongs to the technical field of display control. The method comprises the following steps: converting a brightness estimation value of a target color pigment measured and obtained into a gray scale estimation value, obtaining a fourth three-stimulus value of the target pixel in a state of displaying the gray scale estimation value, and calculating a three-stimulus value error between the fourth three-stimulus value and a target three-stimulus value; adjusting the brightness estimation value according to the three-stimulus value error to generate a new brightness estimation value for iteration; iteratively adjusting the brightness estimation value and converting the last generated target brightness estimation value into a target gray scale estimation value, so as to perform bright chroma adjustment of a display device according to the target gray scale estimation value. The light source used in the application is a display device. The calculation control device performs feedback correction of bright chroma output in a closed loop iteration mode through the measurement data of the three-stimulus value of the three-stimulus value measurement device, realizes accurate output of the surface array bright chroma, and has low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display control, and in particular to a brightness chromaticity adjustment method and system. BACKGROUND

[0002] CIE1931 summarizes a large number of experimental and scientific research results, and proposes that the visual perception of the human eye to brightness and color can be described by three stimulus values XYZ. In practical applications, if the XYZ values of two targets are equal, it is considered that the human eye cannot distinguish the difference between the two. This feature is widely used in various fields, such as camera calibration, medical imaging, lighting, display, art, photography, visual psychology research, and printing. These fields usually require a surface array light source, and the brightness chromaticity of the light source is adjustable to display the color required by artificial setting. Due to the professional characteristics of these fields, the brightness chromaticity deviation of the light source is usually required to be high. For example, the backlighting of medical film needs to meet certain requirements, and medical images need a display to accurately restore their brightness chromaticity, otherwise it may lead to misjudgment by doctors; in the high-end lighting field, the appropriate brightness chromaticity of the light source needs to be selected according to the application scene and the object being illuminated, so as to accurately restore the true color of the illuminated object or obtain the best photography or viewing effect.

[0003] The existing scheme mainly realizes precise brightness chromaticity adjustment through a monochromator. The monochromator can accurately output stable narrow-band light (approximately monochromatic) and realize uniform illumination of the light source at the light outlet with an integrating sphere or other devices. However, the monochromator can usually only provide a surface array single brightness chromaticity light source, and cannot realize the output of different brightness chromaticity light at different positions on the surface array. In addition, the light intensity of the monochromator is usually low, because the monochromator needs to select and filter out light of a specific wavelength from a complex light source, and its light intensity is usually low, which is a challenge for some high-brightness scene applications. The monochromator also has a high cost, and is usually composed of optical elements with high precision and high stability, making its cost relatively high. In situations where only the visual perception of the human eye needs to be considered without strict requirements on the specific spectral waveform (i.e., allowing the same spectrum but different colors), the monochromator lacks competitiveness. Another solution is a tunable laser, which has the disadvantages of narrow wavelength adjustment range, difficulty in using a single light source to achieve full coverage of visible light wavelengths, and high device cost.

[0004] In summary, it can be seen that the existing technical solutions are difficult to achieve high-precision and full-range adjustment of brightness chromaticity while maintaining a low cost. SUMMARY

[0005] The present application provides a brightness chromaticity adjustment method and system to solve the problem that it is difficult to achieve high-precision and full-range adjustment of brightness chromaticity while maintaining a low cost in the prior art.

[0006] In a first aspect, the present application provides a lightness adjustment method, comprising:

[0007] Step 1: Obtain the first, second and third tristimulus values of a target pixel of a display device in the states of displaying a first, second and third single-channel pure color chart respectively; wherein the gray scale value of the R channel of the first single-channel pure color chart is a preset gray scale value, and the gray scale values of the G and B channels are 0; the gray scale value of the G channel of the second single-channel pure color chart is a preset gray scale value, and the gray scale values of the R and B channels are 0; the gray scale value of the B channel of the third single-channel pure color chart is a preset gray scale value, and the gray scale values of the R and G channels are 0;

[0008] Step 2: Convert the target tristimulus value of the target pixel into a luminance estimate value by using a conversion matrix; the conversion matrix is a 3x3 matrix composed of the first, second and third tristimulus values as column vectors in turn;

[0009] Step 3: Convert the luminance estimate value into a gray scale estimate value, obtain the fourth tristimulus value of the target pixel in the state of displaying the gray scale estimate value, and calculate the tristimulus value error between the fourth tristimulus value and the target tristimulus value;

[0010] Step 4: Adjust the luminance estimate value according to the tristimulus value error to generate a new luminance estimate value for participating in iteration;

[0011] Step 5: Iteratively execute steps 3 and 4 until a preset stop condition is met, and convert the last generated target luminance estimate value into a target gray scale estimate value to adjust the lightness of the display device according to the target gray scale estimate value.

[0012] According to the lightness adjustment method provided by the present application, the conversion of the luminance estimate value into the gray scale estimate value comprises: in the case that the target pixel displays a single-channel pure color chart with different gray scale values, obtaining the stimulus value measurement value corresponding to the color channel of the current sub-pixel displaying the gray scale value; according to the different gray scale values of the current sub-pixel and the one-to-one corresponding stimulus value measurement values, obtaining the gamma value of the current sub-pixel by using the least square fitting slope of the logarithmic scale; and converting the luminance estimate value into the gray scale estimate value according to the gamma value of each sub-pixel.

[0013] According to the lightness adjustment method provided by the present application, the adjustment of the luminance estimate value according to the tristimulus value error to generate a new luminance estimate value for participating in iteration comprises: calculating the adjustment increment of the luminance estimate value by using the inverse matrix of the conversion matrix and the tristimulus value error; and adjusting the current luminance estimate value according to the adjustment increment to generate a new luminance estimate value.

[0014] According to the bright chroma adjustment method provided by the application, the preset stop condition is determined to be met in the case that the iteration number reaches the preset iteration number, or the preset stop condition is determined to be met in the case that the three-stimulus value error is less than the preset three-stimulus value error threshold.

[0015] According to the bright chroma adjustment method provided by the application, the target gray scale estimation value is subjected to dithering processing, and then gray scale output is performed in the case that the display device works in the single-color output mode.

[0016] According to the bright chroma adjustment method provided by the application, the target gray scale estimation value is subjected to rounding processing, and then gray scale output is performed in the case that the display device works in the multi-color output mode.

[0017] According to the bright chroma adjustment method provided by the application, the gamma value of the current sub-pixel is obtained by using the least square fitting slope of the logarithmic scale according to the different gray scale values of the current sub-pixel and the one-to-one corresponding stimulus value measurement values, specifically: a gray scale value vector is constructed according to the different gray scale values of the current sub-pixel, and a logarithmic operation is performed on the gray scale value vector to generate a gray scale value logarithmic vector; and a stimulus value measurement value vector is constructed according to the different gray scale value corresponding stimulus value measurement values, and a logarithmic operation is performed on the stimulus value measurement value vector to generate a stimulus value measurement value logarithmic vector; covariance operation between the gray scale value logarithmic vector and the stimulus value measurement value logarithmic vector is performed to obtain a covariance calculation result; and variance operation is performed on the gray scale value logarithmic vector to obtain a variance calculation result; the ratio of the covariance calculation result to the variance calculation result is taken as the gamma value of the current sub-pixel; wherein the current sub-pixel is any one of the three sub-pixels of the target pixel.

[0018] According to the bright chroma adjustment method provided by the application, the preset gray scale value is the maximum gray scale value of the target pixel configured in advance.

[0019] In a second aspect, the application further provides a bright chroma adjustment system, comprising: a three-stimulus value measurement device, a display device, and a calculation control device; the three-stimulus value measurement device is used to measure the three-stimulus value of the target pixel of the display device and feed back the measurement data to the calculation control device; the calculation control device is in communication connection with the display device and the three-stimulus value measurement device respectively, so as to realize the bright chroma adjustment method in any one of the above aspects.

[0020] According to the bright chroma adjusting system provided by the application, the three-stimulus value measuring device is a surface array or a single-point bright chroma meter.

[0021] In a third aspect, the application provides an electronic device, comprising 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 bright chroma adjusting method according to any one of the above aspects when executing the program.

[0022] In a fourth aspect, the application further provides a non-transitory computer readable storage medium, which stores a computer program, wherein the computer program is executable on a processor to implement the steps of the bright chroma adjusting method according to any one of the above aspects.

[0023] The bright chroma adjusting method and system provided by the application use a display device (display screen) as a light source, and correct the output of bright chroma through the measurement data of the stimulus value of the stimulus value measuring device, so as to realize the accurate output of the surface array bright chroma, fully utilize the advantages of the existing display screen technology (high brightness, high pixel density, wide color gamut, high resolution, etc.), and provide a new high-precision and low-cost implementation scheme for the lighting and display fields. Moreover, the bright chroma adjusting method and system provided by the application have the following advantages:

[0024] (1) The bright chroma adjusting method and system provided by the application are low in cost and simple and convenient to implement. For example, the bright chroma adjusting system provided by the application comprises a display device, a stimulus value measuring device, and a computing control device, and the three components are all mature products available on the market. The system is simple in structure, and the components are independent of each other, detachable, and simple to assemble. When not in use, the system can be easily disassembled, and the components can be used separately according to the original purpose, so the system is low in cost.

[0025] (2) The bright chroma adjusting method and system provided by the application are high in accuracy and adjustable in bright chroma. The user inputs the required monochromatic or multicolor bright chroma value (three-stimulus value XYZ or color coordinate brightness xyY) into the computer, and the system can provide a light source according to the set parameters. The bright chroma accuracy of the device is the accuracy of the used surface array bright chroma meter, and the typical value is color coordinate xy±0.003 and brightness Y±3%.

[0026] (3) The bright chroma adjusting method and system provided by the application can realize the output of monochromatic light and the output of multicolor light.

[0027] (4) The bright chroma adjustment method and system provided by the application can utilize various existing display screen technologies. Typical examples include LCD, OLED, mini-LED, micro-LED, etc. These screens have their own advantages in terms of large area, wide color gamut, high brightness, high resolution, high refresh rate, etc. The application can select the best type of display screen according to actual needs.

[0028] (5) The application uses a closed-loop error iteration method to achieve high-precision output of chroma, and has good robustness for the gray scale-brightness deviation power function model and the pressure drop problem caused by large current of RGB lamp beads. The theoretical precision is the measurement precision of the colorimeter.

[0029] (6) In the application, the gamma value of the RGB sub-pixel uses CIE-X, Y and Z values instead of the traditional method of using CIE-Y value. It is better matched with the power function characteristics of the chroma and gray scale of the RGB sub-pixel. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0031] Figure 1 is a flowchart of the bright chroma adjustment method provided by the application;

[0032] Figure 2 is a flowchart of the method for converting the brightness estimate value into the gray scale estimate value provided by the application;

[0033] Figure 3 is a structural diagram of the bright chroma adjustment system provided by the application;

[0034] Figure 4 is a structural diagram of the electronic device provided by the application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the application clearer, the technical solutions in the application will be described clearly and completely in combination with the drawings in the application. Obviously, the described embodiments are some embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the application.

[0036] It should be noted that in the description of the embodiments of the present application, the terms "comprising", "containing" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0037] The terms "first", "second", and the like in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally a class, and do not limit the number of objects, for example, the first object can be one or more.

[0038] In order to more clearly describe the technical solutions of the present application, the basic principles followed by the present application will be briefly described.

[0039] The light emitting element of the surface light source used in the present application uses the existing display device (display screen). The conventional display screen on the market generally has RGB three primary color sub-pixels, and each type of pixel can be considered as an independent light source. Generally, for the same display screen, the spectral characteristics of the same color sub-pixels at different positions are similar, but not absolutely the same; for the same RGB sub-pixel, when its brightness is changed, it is generally considered that its color coordinates are basically unchanged or only slightly changed. According to Grassmann's law, the color ultimately seen by the human eye is the superposition of the colors of the RGB sub-pixels. Therefore, the color gamut displayed by the display screen is the triangular area surrounded by the RGB three primary color sub-pixels in the CIE1931 color gamut diagram.

[0040] Further, the brightness of the display screen sub-pixel is controlled by the input gray scale value, and the typical gray scale bit width of each color channel is 8 bits and 10 bits. The relationship between the gray scale value and the brightness is generally a power function relationship, and the exponent in it is generally called gamma value gamma. The gamma values of the RGB three sub-pixels, and the gamma values between different pixels generally have certain small differences, and the typical value is generally 2.2. The power function relationship is shown in the following formula:

[0041]

[0042] Wherein, XYZ represents the current output XYZ value, X C Y C Z CX, Y, Z) measurement, where X, Y, Z represent XYZ values of the maximum brightness of the current primary color light bead, L is the current gray scale value, N is the single-channel gray scale bit width, gammaC represents the gamma value of the current channel, and C represents a three-primary color channel (taking one of RGB).

[0043] It should be noted that the power function is only an ideal model of the gray scale-brightness, and therefore it is difficult to obtain high-precision brightness accuracy in practice only by using this model.

[0044] Therefore, the core function of the present application is to calculate the appropriate gray scale data to be input to the display screen through an external device, so that the actual brightness value displayed by each pixel of the display screen is consistent with the value required by the user. The high precision of the present application depends on the measurement accuracy of the brightness meter and the continuous correction of errors by the iterative algorithm. The following will be described in combination with Figures 1-4 The brightness adjustment method and system provided by the embodiment of the present application.

[0045] Figure 1 The flowchart of the brightness adjustment method provided by the present application is shown in FIG. 1, which includes but is not limited to the following steps: Figure 1

[0046] Step 1: Obtain the first three stimulus values, the second three stimulus values and the third three stimulus values corresponding to the target pixel of the display device in the state of displaying the first pure color image, the second pure color image and the third pure color image respectively.

[0047] The gray scale value of the R channel of the first pure color image is a preset gray scale value, and the gray scale values of the G channel and the B channel are 0; the gray scale value of the G channel of the second pure color image is a preset gray scale value, and the gray scale values of the R channel and the B channel are 0; and the gray scale value of the B channel of the third pure color image is a preset gray scale value, and the gray scale values of the R channel and the G channel are 0.

[0048] It can be understood that the first pure color image, the second pure color image and the third pure color image are R, G and B single-channel pure color images respectively.

[0049] Optionally, the display device can be an LCD, an OLED, a mini-LED, a micro-LED or the like display screen; and the preset gray scale value can be the maximum gray scale value 2 N -1 of the target pixel configured in advance.

[0050] Specifically, the target pixel of the display screen displays the first pure color image (2 N -1, 0, 0), the second pure color image (0, 2 N -1, 0) and the third pure color image (0, 0, 2 N -1) respectively.

[0051] The present application can measure the first three stimulus values (X​Rmax , Y Rmax , Z Rmax ), the second tristimulus value (X Gmax , Y Gmax , Z Gmax ) and the third tristimulus value (X Bmax , Y Bmax , Z Bmax ).

[0052] Optionally, the preset gray scale value in the present application can also be the gray scale value in the neighborhood of the gray scale estimation empirical value, such as 0.8, 0.9, 1.0, 1.1, 1.2 times the value. The gray scale estimation empirical value (R, G, B) is the value obtained in step 3 in the historical operation process of the same display panel.

[0053] Step 2: converting the target tristimulus value of the target pixel into a luminance estimation value by using a conversion matrix; the conversion matrix is a 3x3 matrix composed of the first tristimulus value, the second tristimulus value and the third tristimulus value as column vectors in turn.

[0054] It can be understood that the target tristimulus value is the target chrominance value used to represent the bright chrominance to be adjusted in the present application (X targ , Y targ , Z targ ), and the main function of the conversion matrix in the present application is to convert the luminance estimation value into a normalized luminance estimation value (r, g, b).

[0055] The conversion process is shown in the following formula:

[0056]

[0057] Wherein, inv is the matrix inversion.

[0058] Step 3: converting the luminance estimation value into a gray scale estimation value, obtaining the fourth tristimulus value of the target pixel in the state of displaying the gray scale estimation value, and calculating the tristimulus value error between the fourth tristimulus value and the target tristimulus value.

[0059] Specifically, the formula for converting the luminance estimation value (r, g, b) into a gray scale estimation value (R, G, B) is:

[0060]

[0061] Wherein, gammaR is the gamma value corresponding to the R channel sub-pixel, gammaG is the gamma value corresponding to the G channel sub-pixel, and gammaB is the gamma value corresponding to the B channel sub-pixel.

[0062] Let the fourth tristimulus value of the target pixel be (X meas , Ymeas meas If the fourth tristimulus value is not equal to the target tristimulus value, then calculate a tristimulus value error (X dif dif dif

[0063]

[0064] Step 4: Adjust the luminance estimate value according to the tristimulus value error to generate a new luminance estimate value for participating in iteration.

[0065] Step 5: Iteratively perform steps 3 and 4 until a preset stop condition is met, and convert the last generated target luminance estimate value into a target gray scale estimate value, so as to adjust the luminance of the display device according to the target gray scale estimate value.

[0066] Optionally, the preset stop condition includes: determining that the preset stop condition is met in a case where the number of iterations reaches a preset number of iterations; or determining that the preset stop condition is met in a case where the tristimulus value error is less than a preset tristimulus value error threshold. For example, the preset number of iterations is set to 3 times, and the preset tristimulus value error threshold is set to 1% of the target tristimulus value.

[0067] The present application provides a luminance adjustment method, which uses a display device (display screen) as a light source, and performs feedback correction on the luminance output by measuring the stimulus value of the stimulus value measuring device, so as to realize accurate output of the surface array luminance, fully utilize the advantages of the existing display screen technology (high brightness, high pixel density, wide color gamut, high resolution, etc.), and provide a new high-precision low-cost implementation scheme for the lighting and display fields.

[0068] Based on the content of the above embodiment, as an optional embodiment, Figure 2 is a flowchart of the method for converting the luminance estimate value into the gray scale estimate value provided by the present application, as shown in Figure 2 , including the following steps:

[0069] Step 201: In a case where the target pixel displays a single-channel pure color image with different gray scale values, obtain the stimulus value measurement value corresponding to the color channel of the current sub-pixel performing gray scale value display.

[0070] Wherein, the single-channel pure color image is an image in which the sub-pixels of a single channel have gray scale values, and the gray scale values of the sub-pixels of other channels are 0, such as the first pure color image, the second pure color image and the third pure color image.

[0071] ​​​​Step 202: According to the different gray scale values of the current sub-pixel and the one-to-one corresponding stimulus value measurement, the gamma value of the current sub-pixel is obtained by using the least square fitting slope of the logarithmic scale.

[0072] Step 203: According to the gamma value of each sub-pixel, the luminance estimation value is converted into the gray scale estimation value.

[0073] The steps 201 to 203 are described below by taking the gamma value of the RGB sub-pixel of the target pixel P as an example.

[0074] The P pixel of the display screen controls the display of different gray scale values of the RGB pure color picture respectively Wherein k=1, 2..., K, wherein K is usually taken as 8 or 16; and the three stimulus value measurements corresponding to the P pixel are measured by the area array colorimeter as (X Ck , Y Ck , Z Ck ), wherein C is one of RGB, and k is the previous gray scale number.

[0075] For example, for the R sub-pixel, the color channel where it is located is R. When the R sub-pixel displays different gray scale values L k , the stimulus value measurement is the R channel corresponding stimulus value measurement X Rk in the measured three stimulus values. The implementation of other channels is not described here.

[0076] Further, the step of obtaining the gamma value by using the step 202 comprises:

[0077] According to the different gray scale values of the current sub-pixel, a gray scale value vector (for example, vector form L k ) is constructed, so as to generate a gray scale value logarithmic vector (for example, lg(L k )) by performing logarithmic operation on the gray scale value vector; and according to the different gray scale values corresponding stimulus value measurements, a stimulus value measurement vector (for example, vector form X Rk ) is constructed, so as to generate a stimulus value measurement logarithmic vector (for example, lg(X Rk )) by performing logarithmic operation on the stimulus value measurement vector; the covariance operation between the gray scale value logarithmic vector and the stimulus value measurement logarithmic vector is performed, so as to obtain the covariance calculation result (for example, cov(lg(L k ), lg(X Rk )); and the variance operation of the gray scale value logarithmic vector is performed, so as to obtain the variance calculation result (for example, cov(lg(L k ), lg(X Rkthe ratio of the covariance calculation result to the variance calculation result as the gamma value of the current sub-pixel; wherein the current sub-pixel is any one of the three sub-pixels of the target pixel.

[0078] Specifically, it can be known that the formula for calculating the gamma value of the R, G and B sub-pixels is:

[0079]

[0080] wherein lg is the logarithm function with base 10, cov is the covariance function, and var is the variance function.

[0081] For step 203, refer to the formula for converting the luminance estimation value (r, g, b) into the gray scale estimation value (R, G, B) in the above embodiment, which will not be repeated here.

[0082] Based on the above embodiment, as an optional embodiment, the present application provides a luminance and chrominance adjustment method, which adjusts the luminance estimation value according to the tristimulus value error to generate a new luminance estimation value for participating in iteration, comprising: calculating an adjustment increment of the luminance estimation value by using the inverse matrix of the conversion matrix and the tristimulus value error; and adjusting the current luminance estimation value according to the adjustment increment to generate the new luminance estimation value.

[0083] In the calculation, the tristimulus value error can be set as a column vector of 3 rows, and the expression of the adjustment increment is:

[0084]

[0085] The formula for adjusting the current luminance estimation value to generate the new luminance estimation value can be expressed as:

[0086]

[0087] It should be noted that (r t ,g t ,b t ) is the current luminance estimation value, (r t+1 ,g t+1 ,b t+1 ) is the generated new luminance estimation value, and the subscripts t and t+1 are used to distinguish the current luminance estimation value and the new luminance estimation value.

[0088] Based on the above embodiment, as an optional embodiment, the present application provides a luminance and chrominance adjustment method, which adjusts the luminance and chrominance of the display device according to the target gray scale estimation value, comprising: in the case that the display device works in the single-color output mode, performing dithering processing on the target gray scale estimation value before performing the gray scale output.

[0089] The monochrome output mode is configured to output the same bright chrominance light by the display area of the display device, that is, the bright chrominance of all display areas of the screen body is the same. Assuming that the target gray scale estimation value is (R0, G0, B0), the dither processing is performed on the target gray scale estimation value (R0, G0, B0), and the generated output gray scale value (R1, G1, B1) is specifically as follows:

[0090] R1=floor(R0+rand(0,1))

[0091] G1=floor(G0+rand(0,1))

[0092] B1=floor(B0+rand(0,1))

[0093] Wherein, floor is the down rounding operation, and rand(0,1) is a random number uniformly distributed between 0 and 1.

[0094] Based on the content of the above embodiment, as an optional embodiment, the present application provides a bright chrominance adjusting method, wherein the bright chrominance of the display device is adjusted according to the target gray scale estimation value, and the method comprises: performing rounding processing on the target gray scale estimation value, and then performing gray scale output when the display device works in a multi-color output mode.

[0095] The multi-color output mode is configured to output different bright chrominance light by the display area of the display device, that is, different positions of the display area of the screen body can have different bright chrominance.

[0096] Figure 3 is a structural schematic diagram of the bright chrominance adjusting system provided by the present application, as shown in Figure 3 The system comprises a tristimulus value measuring device, a display device and a computing control device. The tristimulus value measuring device is used to measure the tristimulus value of the target pixel of the display device and feed back the measurement data to the computing control device. The computing control device is in communication connection with the display device and the tristimulus value measuring device respectively, so as to realize the bright chrominance adjusting method as described in any one of the above embodiments.

[0097] Specifically, the tristimulus value measuring device can be a surface array or a single-point bright chrominance meter, the display device can be various models of display screens, and the computing control device can be a computer.

[0098] The display screen is the output light source of the system, the bright chrominance meter is used to measure the bright chrominance of the display screen, the measured bright chrominance data is transmitted to the computer for comparison with the target bright chrominance (target tristimulus value), and then the gray scale value output to the display is adjusted according to the comparison result.

[0099] It should be noted that the bright chroma adjusting system provided by the embodiment of the present application can execute the bright chroma adjusting method of any of the above-mentioned embodiments in specific operation, and the embodiment will not be described here.

[0100] In summary, the bright chroma adjusting method and system provided by the present application use a display device (display screen) as a light source, and the feedback correction of the bright chroma output is performed through the measurement data of the stimulus value of the stimulus value measurement device, so as to realize the accurate output of the surface array bright chroma, fully utilize the advantages of the existing display screen technology (high brightness, high pixel density, wide color gamut, high resolution, etc.), and provide a new high-precision low-cost implementation scheme for the lighting and display fields. Moreover, the present application has the following advantages:

[0101] (1) The present application uses a commercially available display screen as a light source at the present stage, so as to realize a high-precision surface light source with adjustable bright chroma;

[0102] (2) The present application uses independent components, so as to have low cost;

[0103] (3) The present application can realize the single-color and multi-color high-precision light source output of the surface array at the same time;

[0104] (4) Since the display screen as a light source can be disassembled, the present application can select a suitable display screen according to actual needs to meet various requirements, such as large area, wide color gamut, high brightness, high resolution and high refresh rate, etc.;

[0105] (5) The present application uses a closed-loop error iteration method, so as to realize the high-precision output of the chroma, and has good robustness for the gray scale-brightness deviation power function model and the voltage drop problem caused by the large current of the RGB lamp bead, and the theoretical precision is the measurement precision of the colorimeter;

[0106] (6) In the present application, the Gamma value of the RGB sub-pixel uses CIE-X, Y and Z values respectively instead of the traditional method using CIE-Y value, and the power function characteristic matching degree of the RGB sub-pixel chroma and the gray scale is better.

[0107] Figure 4 is a structural schematic diagram of an electronic device provided by the present application, such as Figure 4As shown, the electronic device can include a processor 410, a communications interface 420, a memory 430, and a communications bus 440, wherein the processor 410, the communications interface 420, and the memory 430 complete mutual communication through the communications bus 440. The processor 410 can invoke a logical instruction in the memory 430 to execute a bright chroma adjustment method, which includes: step 1: obtaining first tristimulus values, second tristimulus values, and third tristimulus values corresponding to a target pixel of a display device in states of displaying a first pure color chart, a second pure color chart, and a third pure color chart, respectively; wherein the gray scale value of the R channel of the first pure color chart is a preset gray scale value, and the gray scale values of the G channel and the B channel are 0; the gray scale value of the G channel of the second pure color chart is a preset gray scale value, and the gray scale values of the R channel and the B channel are 0; the preset gray scale value of the B channel of the third pure color chart is a preset gray scale value, and the gray scale values of the R channel and the G channel are 0; step 2: converting the target tristimulus values of the target pixel into a luminance estimate value by using a conversion matrix; the conversion matrix is a 3*3 matrix composed of the first tristimulus values, the second tristimulus values, and the third tristimulus values as column vectors in turn; step 3: converting the luminance estimate value into a gray scale estimate value, obtaining fourth tristimulus values of the target pixel in a state of displaying the gray scale estimate value, and calculating a tristimulus value error between the fourth tristimulus values and the target tristimulus values; step 4: adjusting the luminance estimate value according to the tristimulus value error to generate a new luminance estimate value for participating in iteration; step 5: iteratively executing steps 3 and 4 until a preset stop condition is met, and converting the last generated target luminance estimate value into a target gray scale estimate value to adjust the bright chroma of the display device according to the target gray scale estimate value.

[0108] In addition, the logical instruction in the memory 430 described above can be realized in the form of a software function unit and sold or used as an independent product, which can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0109] In yet another aspect, the present application also provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the bright chroma adjustment method provided by any of the above embodiments, the method comprising: step 1: obtaining first tristimulus values, second tristimulus values and third tristimulus values corresponding to a target pixel of a display device respectively in states of displaying a first solid color chart, a second solid color chart and a third solid color chart; wherein the gray scale value of the R channel of the first solid color chart is a preset gray scale value, and the gray scale values of the G channel and the B channel are 0; the gray scale value of the G channel of the second solid color chart is the preset gray scale value, and the gray scale values of the R channel and the B channel are 0; the gray scale value of the B channel of the third solid color chart is the preset gray scale value, and the gray scale values of the R channel and the G channel are 0; step 2: converting the target tristimulus values of the target pixel into a luminance estimate value by using a conversion matrix; the conversion matrix is a 3x3 matrix composed of the first tristimulus values, the second tristimulus values and the third tristimulus values as column vectors in turn; step 3: converting the luminance estimate value into a gray scale estimate value, obtaining fourth tristimulus values of the target pixel in a state of displaying the gray scale estimate value, and calculating a tristimulus value error between the fourth tristimulus values and the target tristimulus values; step 4: adjusting the luminance estimate value according to the tristimulus value error to generate a new luminance estimate value for participating in iteration; step 5: iteratively performing steps 3 and 4 until a preset stop condition is met, and converting the finally generated target luminance estimate value into a target gray scale estimate value to adjust the bright chroma of the display device according to the target gray scale estimate value.

[0110] Those skilled in the art can clearly understand that the embodiments can be implemented by means of software plus necessary universal hardware platforms, and of course can also be implemented by hardware, through the above description of the embodiments. Based on such understanding, the above technical solutions, essentially or in the sense of contribution to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0111] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some technical features thereof; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for adjusting brightness and chromaticity, characterized in that, include: Step 1: Obtain the first tristimulus value, second tristimulus value, and third tristimulus value of the target pixel of the display device under the state of displaying the first pure color image, the second pure color image, and the third pure color image at the preset grayscale value, respectively; wherein, the first pure color image, the second pure color image, and the third pure color image are R, G, and B single-channel pure color images, respectively; Step 2: Use a transformation matrix to convert the target tristimulus value of the target pixel into a luminance estimate; the transformation matrix is ​​constructed from the first tristimulus value, the second tristimulus value, and the third tristimulus value; Step 3: Convert the brightness estimate into a grayscale estimate, obtain the fourth tristimulus value of the target pixel when it is displayed with the grayscale estimate, and calculate the tristimulus value error between the fourth tristimulus value and the target tristimulus value. Step 4: Adjust the brightness estimate based on the tristimulus value error to generate a new brightness estimate for use in the iteration; Step 5: Iterate through steps 3 and 4 until the preset stop condition is met, and convert the final generated target brightness estimate into a target grayscale estimate to adjust the brightness and color of the display device.

2. The brightness and chromaticity adjustment method according to claim 1, characterized in that, The step of converting the brightness estimate into a grayscale estimate includes: When the target pixel displays a single-channel solid color image with different grayscale values, obtain the stimulus value measurement value corresponding to the color channel of the current sub-pixel that is displaying grayscale values; Based on the different grayscale values ​​of the current sub-pixel and the corresponding stimulus values, the gamma value of the current sub-pixel is obtained by using the least squares fitting slope of the logarithmic scale. The luminance estimate is converted into a grayscale estimate based on the gamma value of each sub-pixel.

3. The brightness and chromaticity adjustment method according to claim 1, characterized in that, The step of adjusting the brightness estimate based on the tristimulus value error to generate a new brightness estimate for use in the iteration includes: The adjustment increment of the brightness estimate is calculated using the inverse matrix of the transformation matrix and the tristimulus value error. Based on the adjustment increment, the current brightness estimate is adjusted to generate a new brightness estimate.

4. The brightness and chromaticity adjustment method according to claim 1, characterized in that, Determine if the preset stop conditions are met, including: If the preset number of iterations is reached, the preset stopping condition is determined to be met; or, If the error of the tristimulus value is less than the preset tristimulus value error threshold, the preset stopping condition is determined to be met.

5. The brightness and chromaticity adjustment method according to claim 1, characterized in that, The step of adjusting the brightness and color saturation of the display device based on the target grayscale estimate includes: When the display device is operating in monochrome output mode, the target grayscale estimate is dithered before grayscale output. The monochrome output mode is configured so that the display area of ​​the display device outputs light of the same brightness and chromaticity.

6. The brightness and chromaticity adjustment method according to claim 1, characterized in that, The step of adjusting the brightness and color saturation of the display device based on the target grayscale estimate includes: When the display device is operating in multi-color output mode, the target grayscale estimate is rounded before grayscale output. The multi-color output mode is configured to output different brightness levels of light to the display area of ​​the display device.

7. The brightness and chromaticity adjustment method according to claim 2, characterized in that, Based on the different grayscale values ​​of the current sub-pixel and the corresponding stimulus values, the gamma value of the current sub-pixel is obtained using the least squares fitting slope of the logarithmic scale, specifically: Based on the different grayscale values ​​of the current sub-pixel, a grayscale value vector is constructed, and a logarithmic operation is performed on the grayscale value vector to generate a grayscale value logarithmic vector; and based on the stimulus value measurement values ​​corresponding to different grayscale values, a stimulus value measurement value vector is constructed, and a logarithmic operation is performed on the stimulus value measurement value vector to generate a stimulus value measurement value logarithmic vector. Perform covariance calculation on the logarithmic vector of grayscale values ​​and the logarithmic vector of stimulus measurement values ​​to obtain the covariance calculation result; and perform variance calculation on the logarithmic vector of grayscale values ​​to obtain the variance calculation result. The ratio of the covariance calculation result to the variance calculation result is used as the gamma value of the current sub-pixel; Here, the current sub-pixel is any one of the three sub-pixels of the target pixel.

8. The brightness and chromaticity adjustment method according to claim 1, characterized in that, The preset grayscale value is the maximum grayscale value of the target pixel that has been pre-configured.

9. A brightness and chromaticity adjustment system, characterized in that, include: Tristimulus value measurement equipment, display equipment, and calculation and control equipment; The tristimulus value measuring device is used to measure the tristimulus values ​​of the target pixels of the display device and feed the measurement data back to the computing control device; the computing control device is communicatively connected to the display device and the tristimulus value measuring device to implement the brightness and color adjustment method as described in any one of claims 1 to 8.

10. The brightness and chromaticity adjustment system according to claim 9, characterized in that, The tristimulus value measuring device is an area array or single-point luminance colorimeter.

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