Gamma tuning method, computer-readable storage medium, and computer program product

Abstract

The disclosure provides a gamma debugging method, a computer readable storage medium and a computer program product. The gamma debugging method comprises: detecting whether the bright chroma of a display module when displaying by using a first gamma register value meets a first bright chroma index, the first gamma register value being a current value of a gamma register of the display module; if the detection result is no, calculating a first difference value between the first gamma register value and a reference gamma register value, obtaining an initial correction coefficient and correcting the first difference value by using the initial correction coefficient to obtain a first adjustment amount, the initial correction coefficient being used to represent the correlation between an actual adjustment amount and a theoretical adjustment amount; adjusting the first gamma register value by using the first adjustment amount, and writing a second gamma register value obtained after the adjustment into the gamma register; and repeatedly executing the step of detecting whether the bright chroma of the display module when displaying by using the first gamma register value meets the first bright chroma index until the detection result is yes.

Description

Technical Field

[0001] This disclosure relates to the field of display technology. More specifically, it relates to a gamma debugging method, a computer-readable storage medium, and a computer program product. Background Technology

[0002] Organic light-emitting diode (OLED) displays are characterized by vibrant colors, high contrast, faster response, and greater energy efficiency, and are widely used in an increasing number of electronic products.

[0003] In OLED displays, brightness and color performance are crucial indicators, and related technologies utilize gamma tuning to ensure these performance metrics. Gamma tuning schemes require adjusting the display to obtain the target gamma register value; however, conventional gamma tuning methods involve numerous adjustments and are time-consuming. Summary of the Invention

[0004] The purpose of this disclosure is to provide a gamma debugging method, a computer-readable storage medium, and a computer program product to solve the technical problems of numerous gamma debugging operations and long debugging times in related technologies.

[0005] To achieve the above objectives, the present disclosure adopts the following technical solution:

[0006] The first aspect of this disclosure provides a gamma debugging method, including the following steps:

[0007] When the display module uses the first gamma register value for display, it is determined whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index. The first gamma register value is the current value of the gamma register of the display module.

[0008] If the detection result is negative, calculate the first difference between the first gamma register value and the reference gamma register value, obtain an initial correction coefficient, and use the initial correction coefficient to correct the first difference to obtain a first adjustment amount. The reference gamma register value is the theoretical gamma register value calculated based on the reference luminance and chrominance. The initial correction coefficient is used to represent the correlation between the actual adjustment amount and the theoretical adjustment amount. The actual adjustment amount is the amount of change required to adjust the first gamma register value to the target gamma register value. The theoretical adjustment amount is the amount of change required to adjust the first gamma register value to the reference gamma register value. The reference gamma register value is the theoretical gamma register value calculated based on the reference luminance and chrominance. The target gamma register value is the actual gamma register value when the luminance and chrominance of the display module meet the first luminance and chrominance index.

[0009] The first adjustment amount is used to adjust the value of the first gamma register, and the adjusted value of the second gamma register is written into the gamma register. The step of detecting whether the brightness and color of the display module meet the first brightness and color index when the display module displays using the first gamma register value is repeated until the detection result is yes.

[0010] Optionally, the steps of obtaining the initial correction coefficients may include:

[0011] Determine whether the adjustment step size of the gamma register is too small or too large;

[0012] If the adjustment step size is too small, the initial correction coefficient is adjusted using the first weighting coefficient. When the adjusted initial correction coefficient is used to correct the first difference, the first adjustment amount increases.

[0013] If the adjustment step size is too large, the initial correction coefficient is adjusted using the second weighting coefficient. When the adjusted initial correction coefficient corrects the first difference, the first adjustment amount decreases.

[0014] Optionally, the step of determining whether the adjustment step size of the gamma register is too small or too large includes:

[0015] The brightness and chromaticity are obtained from multiple consecutive measurements, and each brightness and chromaticity is the brightness and chromaticity of the display module after adjusting the value of the first gamma register once;

[0016] Determine whether the brightness and chromaticity of the multiple consecutive measurements continue to increase or decrease. If they continue to increase or decrease, it is determined that the adjustment step size is too small.

[0017] Determine whether the brightness and chromaticity measured in multiple consecutive measurements fluctuate around the reference brightness and chromaticity. If the determination result is yes, it is determined that the adjustment step size is too large.

[0018] Optionally, the display module includes multiple display brightness ranges, each display brightness range includes multiple bound-point grayscales, each bound-point grayscale corresponds to an initial correction coefficient, and the step of detecting whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index when the display module displays using the first gamma register value further includes:

[0019] For any display brightness range, pre-adjust the grayscale of each bound point within the display brightness range sequentially to determine the initial correction coefficient corresponding to the grayscale of that bound point.

[0020] Optionally, for any bound point grayscale within any display brightness range, the step of pre-adjusting the bound point grayscale to determine the initial correction coefficient corresponding to the bound point grayscale includes:

[0021] When the display module uses the third gamma register value for display, it is determined whether the brightness and chromaticity of the display module meet the second brightness and chromaticity index. The third gamma register value is the current value of the gamma register.

[0022] If the detection result is yes, the third gamma register value is output, and the initial correction coefficient is calculated using the third gamma register value, the previous register value of the gamma register, and the reference gamma register value.

[0023] If the detection result is negative, calculate the second difference between the third gamma register value and the reference gamma register value, obtain a preset correction coefficient, and use the preset correction coefficient to correct the second difference to obtain the second adjustment amount;

[0024] The third gamma register value is adjusted using the second adjustment amount, and the fourth gamma register value obtained after adjustment is written into the gamma register. The step of detecting whether the brightness and color of the display module meets the second brightness and color index when the display module displays using the third gamma register value is repeated until the detection result is yes.

[0025] Optionally, after the step of outputting the third gamma register value, the method further includes:

[0026] Determine if the current number of debug attempts is equal to the first value;

[0027] If the current number of debugging attempts is greater than the first value, execute the step of calculating the initial correction coefficient using the third gamma register value, the previous register value of the gamma register, and the reference gamma register value;

[0028] If the current number of debugging attempts is equal to the first value, the initial correction coefficient is calculated using the third gamma register value and the reference gamma register value, or the initial correction coefficient of the grayscale of the current binding point is obtained by interpolation using the initial correction coefficients of the grayscale of the current binding point adjacent to the grayscale of the current binding point.

[0029] Optionally, after the step of pre-adjusting the grayscale of each bounding point within any display brightness range to determine the initial correction coefficient corresponding to that bounding point grayscale, the method further includes:

[0030] Check whether the initial correction coefficient corresponding to the grayscale of each binding point is an outlier;

[0031] When the initial correction coefficient corresponding to any binding point gray level is an outlier, the initial correction coefficient corresponding to the binding point gray level is calculated using the linear interpolation method, and the initial correction coefficient of the binding point gray level is updated to the linear interpolation calculation result.

[0032] Optionally, the step of calculating the first difference between the first gamma register value and the reference gamma register value includes:

[0033] Obtain the current brightness and chromaticity of the display module when it uses the first gamma register value for display;

[0034] According to the first conversion relationship, the current luminance and chromaticity are converted into the current spectral tristimulus value, and the reference luminance and chromaticity are converted into the reference spectral tristimulus value. The first conversion relationship represents the conversion relationship between luminance and chromaticity and spectral tristimulus value.

[0035] The difference between the current spectral tristimulus value and the reference spectral tristimulus value is calculated, and the difference is converted into the first difference using a second conversion relationship, wherein the second conversion relationship represents the conversion relationship between the gamma register value and the spectral tristimulus value.

[0036] Optionally, the step of detecting whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index when the display module uses the first gamma register value for display includes:

[0037] The measurement and display module uses the first gamma register value to display the current brightness and chromaticity, and converts the current brightness and chromaticity into the current spectral tristimulus value according to the first conversion relationship;

[0038] Determine whether the error between the current spectral tristimulus value and the reference spectral tristimulus value is less than a first error threshold. If the determination result is yes, determine that the brightness and chromaticity of the display module meet the first brightness and chromaticity index.

[0039] Optionally, the display module includes multiple display brightness ranges, each display brightness range corresponds to a second conversion relationship, and each display brightness range includes multiple bound-point grayscale levels. The gamma adjustment method includes:

[0040] For any display brightness range, the first gamma register value of each bound point grayscale is adjusted sequentially using the second conversion relationship corresponding to the display brightness range to obtain the first gamma register value of each bound point grayscale that makes the brightness and color of the display module meet the first brightness and color index.

[0041] Optionally, the step of calculating the first difference between the first gamma register value and the reference gamma register value further includes:

[0042] Write the fifth gamma register value into the gamma register to obtain the spectral tristimulus value of the display module when the display module displays using the fifth gamma register value. The brightness of the display module when displaying using the fifth gamma register value is greater than the brightness of the display module when displaying using the maximum grayscale.

[0043] The second conversion relationship is determined based on the fifth gamma register value and the spectral tristimulus value.

[0044] A second aspect of this disclosure provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the gamma debugging method as described above.

[0045] A third aspect of this disclosure provides a computer program product including a computer program that, when executed by a processor, implements the steps of the gamma debugging method as described above.

[0046] The beneficial effects of this disclosure are as follows:

[0047] The gamma adjustment method of this disclosure adds a correction coefficient during the gamma adjustment process. This correction coefficient can represent the correlation between the actual adjustment amount and the theoretical adjustment amount. During the gamma adjustment process, the theoretical adjustment amount is corrected in real time using this correction coefficient, so that the theoretical adjustment amount changes in the direction of the actual adjustment amount. This can prevent the problem of large deviations in the gamma register value due to the influence of uncertain factors such as optical equipment errors and ambient light. This allows the gamma register value to approach the target gamma register value more quickly and accurately, reducing the number of gamma adjustments, shortening the adjustment cycle, and improving production line capacity. Attached Figure Description

[0048] The specific embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0049] Figure 1 A flowchart illustrating the gamma adjustment method provided in this embodiment of the present disclosure for pre-adjusting any grayscale of a bound point within any display brightness range to determine the initial correction coefficient corresponding to the grayscale of that bound point;

[0050] Figure 2 A flowchart of another embodiment for determining the initial correction coefficient corresponding to any binding point gray level;

[0051] Figure 3 The relationship curve between the grayscale of the binding point and the initial correction coefficient m0 ​​provided in the embodiments of this disclosure;

[0052] Figure 4 This is a flowchart for outlier detection of the initial correction coefficient m0 ​​for each binding point grayscale.

[0053] Figure 5 This is a flowchart for performing gamma adjustment on any display brightness range during the second debugging phase. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0055] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0056] In related technologies, during the gamma calibration of display modules, due to the influence of uncertain factors such as optical equipment errors and ambient light, the gamma register value calculated according to the theoretical formula may deviate significantly from the target gamma register value of the display module. This results in a large number of calibrations and a long calibration time. The target gamma register value here represents the actual gamma register value required for the display module to meet the customer's brightness and color requirements when displaying.

[0057] To address the aforementioned technical problems, this disclosure provides a gamma debugging method, a computer-readable storage medium, and a computer program product, which are described below in conjunction with various specific embodiments.

[0058] In this embodiment of the disclosure, the display module includes multiple display brightness bands, and each display brightness band includes multiple bound grayscale levels. The display brightness of the display module is different when displaying different grayscale images under the same display brightness band, and the display brightness is also different when displaying the same grayscale image under different display brightness bands. Therefore, when performing gamma debugging on a display module, it is necessary to debug each bound grayscale level under each display brightness band of the display module in turn to obtain the gamma register value corresponding to each bound grayscale level under each display brightness band.

[0059] Correspondingly, the customer standard (SPEC) has different luminance and chromaticity requirements for different display brightness ranges and different grayscale levels. In other words, the baseline luminance and chromaticity to be achieved are different for different display brightness ranges and different grayscale levels. Luminance and chromaticity are usually represented by luminance and chromaticity coordinates (L,x,y), where L represents luminance, usually in nits, and x and y are used to describe the hue and saturation of the display.

[0060] In this context, the bound-point grayscale is a selection of representative grayscale levels (typically 15-35) chosen from all grayscale levels. These bound-point grayscale levels are used as the primary target for gamma calibration during display module debugging. For example, for an 8-bit deep display module, there are 19 bound-point grayscale levels: 3, 7, 11, 19, 23, 31, 39, 47, 55, 63, 79, 95, 111, 144, 173, 205, 226, 247, and 255. During gamma calibration of the display module, the gamma register values ​​corresponding to these 19 bound-point grayscale levels need to be obtained for each display brightness range. It is understood that the bound-point grayscale levels can also be other numbers or other grayscale values; this disclosure does not limit their use.

[0061] For a display module, if a pixel includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel, then the display module includes four gamma registers, denoted as gamma register W. reg R reg G reg B reg Among them, the gamma register R reg The register value (R, 0, 0) used to store the red sub-pixel, and the gamma register G. reg Register values ​​(0, G, 0) used to store the green sub-pixel, and gamma register B. reg Register value (0,0,B) used to store the blue sub-pixel, and gamma register W. reg Register values ​​(R, G, B) are used to store the red, green, and blue sub-pixels.

[0062] The gamma debugging method provided in this disclosure is mainly divided into two stages: a first debugging stage and a second debugging stage.

[0063] The first debugging phase is the pre-debugging phase, which can also be understood as the training phase for the initial correction coefficients. During the pre-debugging phase, the display module needs to be initially debugged to ensure its brightness and color saturation meet customer standards. After the first debugging phase, the initial gamma register value and the initial correction coefficient m0 ​​are obtained. This initial correction coefficient m0 ​​is related to the screen characteristics of the display module. The initial gamma register value and the initial correction coefficient m0 ​​serve as the basis for the second debugging phase. Specifically, the initial correction coefficient m0 ​​represents the correlation between the actual adjustment amount and the theoretical adjustment amount. The actual adjustment amount is the change required to adjust the first gamma register value to the target gamma register value. The theoretical adjustment amount is the change required to adjust the first gamma register value to the reference gamma register value. The reference gamma register value is the theoretical gamma register value calculated based on the reference brightness and color saturation. The target gamma register value is the actual gamma register value when the brightness and color saturation of the display module meet the first brightness and color saturation index.

[0064] In practice, the first debugging stage involves debugging sample display modules within a batch of display modules. The initial gamma register value and initial correction coefficient m0 ​​obtained from the debugging are then written into each display module in this batch. Afterward, each display module enters the second debugging stage. Since the initial correction coefficient m0 ​​is obtained from the actual debugging of the sample display modules, it can characterize the correlation between the actual adjustment amount and the theoretical adjustment amount of the display modules in this batch. Therefore, when using the initial correction coefficient m0 ​​for debugging, it can more quickly and accurately approach the target gamma register value. Furthermore, for different display brightness ranges, correction coefficients suitable for each display brightness range are trained separately, which are more consistent with the characteristics of each display brightness range. Therefore, the gamma debugging speed for each display brightness range can be accelerated.

[0065] Understandably, due to numerous uncertainties during the debugging process, such as errors in the optical equipment used to measure the brightness and color of the display modules, variations in the influence of ambient light, and inter-module differences, although the first debugging stage can enable the display modules to meet customer standards, after writing the initial gamma register values ​​to each display module, the brightness and color of each display module may still not meet customer standards when it is displayed. Therefore, a second debugging stage is required. In the second debugging stage, the gamma register values ​​of the display modules are adjusted again to obtain the gamma register values ​​that enable the brightness and color of the display modules to meet customer standards.

[0066] The gamma tuning method of this disclosure requires pre-determining two conversion relationships before tuning: a first conversion relationship and a second conversion relationship. The first conversion relationship represents the conversion between luminance and chromaticity and the spectral tristimulus values, while the second conversion relationship represents the conversion between the gamma register value and the spectral tristimulus values.

[0067] For the display module, the first conversion relationship between luminance and chromaticity and spectral tristimulus values ​​can be expressed as: Y = L, X = (x / y)*Y, Z = ((1-xy) / y)*Y, where L, x, and y represent luminance and chromaticity coordinates, and X, Y, and Z represent spectral tristimulus values.

[0068] For display modules, the maximum brightness that can be achieved in different display brightness ranges is different. Even if the gamma register value is the same, the optical data (such as luminance, chromaticity or spectral tristimulus values) of the display module may be different in different display brightness ranges. Please refer to Table 1, which shows the luminance and chromaticity data measured in different display brightness ranges when the gamma register value is the same.

[0069] Table 1. Luminance and chromaticity data for different bands with the same gamma register value.

[0070]

[0071] In Table 1, band1, band2, and band3 represent three different display brightness ranges, and the gamma register W... reg The corresponding luminance and chrominance data are represented using the gamma register W. reg The brightness and color gamut of the display module are measured when the register values ​​(R, G, B) are turned on. Similarly, the gamma register R... reg The corresponding luminance and chrominance data are represented using the gamma register R. reg The register value (R,0,0) represents the brightness and color saturation of the display module measured when the display module is lit; the gamma register G... reg The corresponding luminance and chrominance data are represented using the gamma register G. reg The register value (0, G, 0) is the brightness and color saturation of the display module measured when the display module is lit; the gamma register B... reg The corresponding luminance and chrominance data are represented using the gamma register B. reg The brightness and color of the display module are measured when the register value (0,0,B) is turned on.

[0072] As can be seen from Table 1, even if the gamma register value is the same, the luminance and chromaticity measured in different display brightness ranges are different. Therefore, it is necessary to determine the second conversion relationship between the gamma register value and the spectral tristimulus value for each display brightness range.

[0073] Optionally, the process of determining the second transformation relationship includes the following steps (11) and (12).

[0074] (11) Write the fifth gamma register value into the gamma register to obtain the spectral tristimulus value of the display module when the display module uses the fifth gamma register value for gamma adjustment. The brightness of the display module when displaying using the fifth gamma register value is greater than the brightness of the display module when displaying using the maximum gray level.

[0075] (12) Determine the second conversion relationship based on the fifth gamma register value and the spectral tristimulus value.

[0076] The selection of the fifth gamma register value needs to meet certain conditions. Specifically, when the display module is lit using the fifth gamma register value, the brightness of the display module is greater than the brightness of the highest grayscale level. For example, the fifth gamma register value is represented as reg = ((2 depth -1) / 5)*4, where reg is a decimal and is rounded down to the nearest integer, and depth represents the number of bits in the gamma register value, for example, depth = 8, 10, 12, 14, etc. At this time, the four gamma registers W reg R reg G reg B reg The gamma register values ​​are represented as Reg- W =(reg,reg,reg),Reg- R =(reg,0,0),Reg- G =(0,reg,0),Reg- B = (0,0,reg), four sets of luminance and chromaticity are obtained by plotting (i.e., lighting up the display module). The four sets of luminance and chromaticity are converted into corresponding spectral tristimulus values ​​according to the first conversion relationship, which are represented as XYZ respectively. W =(X w ,Y w Z w ), XYZ R =(X R ,Y R Z R ), XYZ G =(X G ,Y G Z G ), XYZ B =(X B ,Y B Z B ), where XYZ W This indicates the use of the gamma register value Reg- W =(reg,reg,reg) displays the spectral tristimulus values ​​of the module when plotting. Similarly, XYZ R This indicates the use of the gamma register value Reg- R=(reg,0,0) displays the spectral tristimulus values ​​of the module when plotting, and so on, to determine XYZ. G and XYZ B .

[0077] The second transformation relationship can be represented in matrix form. For example, the second transformation relationship is represented by the intermediate transformation matrix T1, the four sets of gamma register values ​​are represented by matrix A, and the four sets of spectral tristimulus values ​​are represented by matrix B.

[0078]

[0079] Then the intermediate transformation matrix T1 = (A T *A) -1 *A T *B(Formula 1)

[0080] Where A T Let A be the transpose of matrix A, (A T *A) -1 Indicates (A) T The inverse matrix of *A), (A) T *A) -1 *A T T1 represents the pseudo-inverse of matrix A, and T2 represents the transformation of matrix B using the pseudo-inverse to obtain the projection of matrix B onto the column space of matrix A or the least squares solution.

[0081] Multiply both sides of the above formula 1 by A*T1. -1 Formula 1 can be transformed into Formula 2:

[0082] A = B * T1 -1 (Formula 2)

[0083] As can be seen from Formula 2, the inverse matrix T1 of the intermediate transformation matrix T1 is used. -1 It can convert the spectral tristimulus values ​​XYZ into gamma register values ​​Reg.

[0084] The aforementioned fifth gamma register value and the calculated spectral tristimulus values ​​XYZ W XYZ R XYZ G XYZ B The data is saved to a CSV file, and can be used to obtain the intermediate transformation matrix T1 representing the second transformation relationship when training the initial correction coefficients m0 in the first debugging phase.

[0085] During gamma debugging, assume the gamma register value written to the gamma register for the i-th time is represented as Reg. i The luminance and chromaticity of the display module, measured using optical equipment during this display process, are represented as Lxy. i=(L i ,x i ,y i According to the first transformation relationship, the value obtained is related to the luminance Lxy. i The corresponding spectral tristimulus is represented as XYZ i =(X i ,Y i Z i Similarly, suppose the gamma register value written to the gamma register for the (i+1)th time is represented as Reg. i+1 The luminance and chromaticity of the display module, measured using optical equipment during this display process, are represented as Lxy. i+1 =(L i+1 ,x i+1 ,y i+1 According to the first transformation relationship, the value obtained is related to the luminance Lxy. i+1 The corresponding spectral tristimulus is represented as XYZ i+1 =(X i+1 ,Y i+1 Z i+1 The reference spectral tristimulus values ​​can be obtained based on the first transformation relationship and the reference luminance and chromaticity. The reference spectral tristimulus values ​​are represented as XYZ. t =(X t ,Y t Z t ,).

[0086] During the debugging process, assuming the current debugging is the i-th debugging, the measured spectral tristimulus values ​​XYZ i Compared with the reference spectral tristimulus values ​​XYZ t The difference between XYZ D Represented as:

[0087]

[0088] According to Formula 3, the current gamma register value Reg i Compared with the reference gamma register value Reg t RGB difference D It can be represented as:

[0089] RGB D =XYZ D *T1 -1 (Formula 4)

[0090] The (i+1)th debugging iteration of the gamma register value Reg i+1 With the i-th debug gamma register value Reg i The difference Reg error Represented as:

[0091] Reg error=Reg i+1 -Reg i ;

[0092] In theory, setting Reg i+1 =Reg i +RGB D At that time, the gamma register value Reg can be directly set. i Adjust to the reference gamma register value Reg t At this point, the brightness and color saturation of the display module can be directly adjusted to meet the customer's standards. The reference gamma register value Reg here... t It is based on the reference spectral tristimulus values ​​XYZ t The theoretical value is calculated based on the second conversion relationship. However, during actual debugging, due to uncertainties such as optical equipment errors and ambient light, the reference gamma register value Reg... t There will be some deviation from the target gamma register value; directly setting Reg... i+1 =Reg i +RGB D It will not be successful in one go, and may even cause the adjusted gamma register value Reg to change. i+1 The large deviation from the target gamma register value leads to more debugging attempts and a longer debugging cycle. The target gamma register value here refers to the actual gamma register value required by the display module, which is the gamma register value that ensures the brightness and color of the display module meet the customer's standard. The gamma debugging process is the process of continuously adjusting the gamma register value to gradually approach the target gamma register value.

[0093] To solve the problem of directly using Reg i+1 =Reg i +RGB D When debugging the formula, there are problems such as a large deviation between the adjusted gamma register value and the target gamma register value, numerous debugging attempts, and a long debugging cycle. In this embodiment, a correction coefficient m is set to correct the gamma adjustment process. Specifically, the correction coefficient is used to correct the change in the gamma register value during the gamma debugging process. The approximation algorithm model (i.e., the gamma register value debugging model) is represented by the following formula 5:

[0094] Reg i+1 =Reg i +RGB D / m (Formula 5)

[0095] Further transformation of formula 5 yields the following formula 6:

[0096] Reg i+1 -Reg i=RGB D / m(Formula 6)

[0097] Multiply both sides of Formula 6 by (RGB) D ) T We can obtain the following formula 7:

[0098] (Reg i+1 -Reg i )*(RGB D ) T =RGB D *(RGB D ) T / m (Formula 7)

[0099] Multiply both sides of Formula 7 by (RGB) D *(RGB D ) T ) -1 We can obtain the following formula 8:

[0100] (Reg i+1 -Reg i )*(RGB D ) T *(RGB D *(RGB d ) T ) -1 = 1 / m (Formula 8)

[0101] According to Formula 8, the correction coefficient m can be expressed as:

[0102]

[0103] According to Formula 9, the correction coefficient m is based on the gamma register values ​​Reg from two consecutive intervals. i+1 ,Reg i Previous gamma register value Reg i Compared with the reference gamma register value Reg t RGB difference D The value was determined jointly, including the previous gamma register value Reg. i Compared with the reference gamma register value Reg t RGB difference D This can be achieved through the intermediate transformation matrix T1 and the previous spectral tristimulus values ​​XYZ. i Compared with the reference spectral tristimulus values ​​XYZ t Calculated.

[0104] At the end of the first debugging phase, based on the last gamma register value Reg i+1 The previous gamma register value Regi RGB difference D The calculated correction coefficient m is the initial correction coefficient m0, which represents the correlation between the actual adjustment and the theoretical adjustment. Specifically, at the end of the first adjustment phase, the final gamma register value Reg is obtained. i+1 This can be understood as the target gamma register value in the first debugging phase, Reg i This represents the gamma register value before adjustment, therefore Reg i+1 -Reg i It can represent the difference between the target gamma register value and the gamma register value before adjustment, that is, the actual adjustment amount, and RGB... D The initial correction factor m0 can represent the difference between the reference gamma register value and the gamma register value before adjustment, i.e., the theoretical adjustment amount. Therefore, the initial correction factor m0 can represent the actual adjustment amount and the theoretical adjustment amount (i.e., RGB) required to adjust from the gamma register value before adjustment to the target gamma register value. D The ratio or correlation between them.

[0105] The first adjustment stage of the gamma tuning method will be described in detail below.

[0106] In this embodiment of the disclosure, the display module includes multiple display brightness ranges, each display brightness range includes multiple bound point gray levels, and each bound point gray level corresponds to an initial correction coefficient m0. Therefore, before entering the second debugging stage, the gamma debugging method includes: for any display brightness range, performing pre-debugging on each bound point gray level in the display brightness range to determine the initial correction coefficient m0 ​​corresponding to the bound point gray level. That is, before entering the second stage of debugging, pre-debugging is required to determine the initial correction coefficient m0.

[0107] Optional, such as Figure 1 As shown, for any grayscale point within any display brightness range, the steps for pre-adjusting and determining the initial correction coefficient corresponding to that grayscale point include:

[0108] Step S101: When the display module uses the third gamma register value for display, it is detected whether the brightness and chromaticity of the display module meet the second brightness and chromaticity index. The third gamma register value is the current value of the gamma register. If the detection result is yes, step S102 is executed. If the detection result is no, step S104 is executed.

[0109] In this embodiment of the disclosure, when the debugging personnel perform pre-debugging on the display module, they do not know any data beforehand, that is, they do not know the initial gamma register value and the initial correction coefficient m0. At this time, the debugging personnel can randomly write a value into the gamma register, which can be, for example, (0,0,0) or an arbitrary value set by the debugging personnel based on experience, and then perform pre-debugging based on this value. In order to distinguish it from the second debugging stage, this embodiment of the disclosure refers to the current value in the gamma register during the pre-debugging stage (i.e., the first debugging stage) as the third gamma register value.

[0110] The second luminance / chromaticity index is determined according to customer standards. Specifically, the customer standards specify the reference luminance / chromaticity of the display module at different grayscale levels under different display brightness ranges. In practice, when the error between the luminance / chromaticity of the display module and the reference luminance / chromaticity is within a certain range, the display module can be considered to meet the customer standards. For example, the second luminance / chromaticity index indicates that the error between the luminance / chromaticity of the display module and the reference luminance / chromaticity is within 1%. That is, if the error between the luminance / chromaticity of the display module and the reference luminance / chromaticity is within 1%, the display module is considered to meet the customer standards; if the error exceeds 1%, it does not meet the customer standards.

[0111] Since step S101 requires the use of the second luminance index for judgment, the customer standard needs to be preprocessed before step S101 is executed to determine the baseline luminance and the second luminance index.

[0112] Step S102: Output the value of the third gamma register.

[0113] Step S103: Calculate the initial correction coefficient using the third gamma register value, the previous gamma register value, and the difference between the previous gamma register value and the reference gamma register value.

[0114] Specifically, the formula for calculating the correction factor m can be found in Formula 9.

[0115] For example, assuming the display module's luminance and chrominance meet the second luminance and chrominance index and the current value of the gamma register is Reg9, that is, the third gamma register value is Reg9, then the gamma debugging method outputs the gamma register value Reg9, and obtains the previous gamma register value Reg8, the difference between the previous gamma register value Reg8 and the reference gamma register value (RGB). D Then, the initial correction coefficient m0 ​​can be calculated according to Formula 9, for example:

[0116]

[0117] RGB D＝ XYZ D *T1 -1XYZ D =XYZ t -XYZ8.

[0118] Step S104: Calculate the second difference between the third gamma register value and the reference gamma register value, obtain a preset correction coefficient, and use the preset correction coefficient to correct the second difference to obtain a second adjustment amount. Use the second adjustment amount to adjust the third gamma register value, and write the adjusted fourth gamma register value into the gamma register. Repeat the step of detecting whether the brightness and color of the display module meets the second brightness and color index when the display module displays using the third gamma register value until the detection result is yes.

[0119] In step S104, the preset correction coefficient is a value randomly set by the debugger for the correction coefficient m. For example, if the debugger sets the preset correction coefficient to 10, the algorithm for adjusting the value of the third gamma register can be expressed as: Reg i+1 =Reg i +RGB D / m (m=10), where RGB D This is the second difference between the third gamma register value and the base gamma register value, Reg i+1 This represents the adjusted gamma register value, Reg. i This indicates the gamma register value before adjustment.

[0120] After the first debugging phase, the input data for the initial correction coefficient m0 ​​of each binding point grayscale calculation under each display brightness range can be obtained. For details, please refer to Table 2, which shows the grayscale data of each binding point obtained by debugging one of the display brightness ranges.

[0121] Table 2 Input data for the initial training correction coefficient m0

[0122]

[0123] In the first debugging stage, which is the training stage of the initial correction coefficient m0, if the brightness and chromaticity of the display module meet the second brightness and chromaticity index in the first debugging, then there is only one gamma register value. At this time, the gamma register values ​​R, G, and B before and after adjustment in Table 2 are the same, and the brightness and chromaticity L, x, and y before and after adjustment are also the same, which will cause the denominator in Formula 9 to be 0. At this time, the calculated initial correction coefficient m0 ​​is infinite, which is a singularity. In this case, the debugging program will be interrupted.

[0124] To solve this problem, after step S102 (outputting the third gamma register value), the following can also be done: Figure 2As shown, it includes steps S105 and S106.

[0125] Step S105: Determine whether the current number of debugging attempts is equal to the first value. If the determination result is that the current number of debugging attempts is equal to the first value, proceed to step S106. If the determination result is that the current number of debugging attempts is greater than the first value, proceed to the step of calculating the initial correction coefficient using the third gamma register value, the previous register value of the gamma register, and the reference gamma register value, which is to proceed to step S103, where the first value is 1.

[0126] Step S106: Calculate the initial correction coefficient using the third gamma register value and the reference gamma register value, or interpolate using the initial correction coefficients of the adjacent gray levels of the current gray level to obtain the initial correction coefficient of the current gray level.

[0127] Step S106 includes two options, a and b:

[0128] a. Calculate the initial correction coefficient using the third gamma register value and the reference gamma register value.

[0129] At this point, the gamma register value Reg in Formula 9 i This is the current value of the gamma register, which is also the output value of the third gamma register. The gamma register value Reg... i+1 Replace with the baseline gamma register value Reg t Reference gamma register value Reg t Based on Formula 2, using the intermediate transformation matrix T1 and the reference spectral tristimulus values ​​XYZ t The calculation is performed. Due to the inherent measurement errors in optical equipment, the gamma register value Reg obtained during debugging is... i Compared with the reference gamma register value Reg t They are usually not exactly the same, thus avoiding the situation where the denominator is 0.

[0130] b. The initial correction coefficient of the gray level of the current binding point is obtained by interpolation using the initial correction coefficients of the gray levels of the adjacent binding points.

[0131] In practice, when the number of debugging attempts is 1, the initial correction coefficient m0 ​​of the grayscale of this binding point can be set to a temporary value, such as 0. After all the grayscales of the binding points in the current display brightness range have been debugged, the grayscale can be obtained by interpolation using the initial correction coefficient m0 ​​of the grayscales of the binding points adjacent to this binding point.

[0132] In this embodiment of the disclosure, when calculating the initial correction coefficient m0, a step to determine the number of debugging attempts is added to check if the number of debugging attempts is 1. When the number of debugging attempts is greater than 1, the initial correction coefficient m0 ​​can be directly calculated according to Formula 9. When the number of debugging attempts is equal to 1, the initial correction coefficient m0 ​​needs to be calculated through step S106, that is, by interpolation or by using the reference gamma register value. This can solve the problem that the initial correction coefficient m0 ​​is infinite and is a singularity.

[0133] In one possible implementation, after the step of pre-adjusting each grayscale point within the display brightness range to determine the initial correction coefficient corresponding to the grayscale point, the method further includes the following steps: detecting whether the initial correction coefficient corresponding to each grayscale point is an outlier; when the initial correction coefficient corresponding to any grayscale point is an outlier, calculating the initial correction coefficient corresponding to the grayscale point using linear interpolation and updating the initial correction coefficient of the grayscale point to the linear interpolation calculation result.

[0134] In this embodiment of the disclosure, after analyzing the initial correction coefficients m0 corresponding to the grayscale values ​​of each bound point under the same display brightness range of the display module, the debugging personnel found that the value of the initial correction coefficient m0 ​​is positively correlated with the grayscale value of the bound point; the larger the grayscale value of the bound point, the larger its corresponding initial correction coefficient m0 ​​is usually. Please refer to... Figure 3 , Figure 3 This is the curve showing the relationship between the grayscale of the binding point and the initial correction coefficient m0. Figure 3 The horizontal axis represents the grayscale value of the bound point grayscale, and the vertical axis represents the initial correction coefficient m0. In order to improve the accuracy of the initial correction coefficient m0 ​​obtained in the first debugging stage, this embodiment adds an outlier judgment step after obtaining the initial correction coefficient m0 ​​of each bound point grayscale in a certain displayed brightness range. The outlier judgment step judges whether each initial correction coefficient m0 ​​is an outlier by the positive correlation between the initial correction coefficient m0 ​​and the bound point grayscale.

[0135] Optionally, assuming the total number of grayscale points is N, and the grayscale points are sorted in ascending order of their grayscale values, with the indices of each grayscale point being 1, 2, 3, ..., N, then the process of outlier detection for each grayscale point is as follows: Figure 4 As shown, it includes the following steps:

[0136] Step S201: Take the grayscale of the i-th binding point.

[0137] Step S202: Determine whether i is less than or equal to N-2. If the result is yes, proceed to step S203. If the result is no, proceed to step S210.

[0138] Step S203: Take the grayscale values ​​of the i-th, (i+1)-th, and (i+2)-th binding points and the initial correction coefficient m0 ​​corresponding to the grayscale values ​​of the binding points, where the initial correction coefficient m0 ​​corresponding to the grayscale value of the i-th binding point is denoted as m i .

[0139] Step S204: Calculate the derivatives at the gray levels of the i-th binding point and the (i+1)-th binding point, denoted as Δ. i Δ i+1 , respectively represented as:

[0140] Step S205, determine Δ i and Δ i+1 Are all greater than 0? If the result is Δ i and Δ i+1 If all values ​​are greater than 0, it indicates that the initial correction coefficients for the i-th, (i+1)-th, and (i+2)-th binding point grayscales meet the requirements, and step S206 is executed. Otherwise, it indicates that an outlier has occurred. Specifically, if Δ i >0 and Δ i+1 If Δ < 0, it indicates that the initial correction coefficient m0 ​​of the grayscale of the (i+2)th binding point is an outlier. Execute step S207. i <0 and Δ i+1 If Δ < 0, it indicates that the initial correction coefficient m0 ​​of the grayscale of the (i+1)th binding point is an outlier. Execute step S208. i <0 and Δ i+1 If the value is >0, it indicates that the initial correction coefficient m0 ​​of the gray level of the i-th binding point is an outlier. Execute step S209. After steps S207 to S209, jump to step S206.

[0141] Step S206, i = i + 1, return to step S201.

[0142] Step S207: Calculate the initial correction coefficient m for the grayscale of the (i+2)th binding point using linear interpolation. i+2 .

[0143] Assume the grayscale value of the i-th binding point is represented as gray. i Then the initial correction coefficient m of the gray level of the (i+2)th binding point i+2 Represented as:

[0144]

[0145] Step S208: Calculate the initial correction coefficient m for the grayscale of the (i+1)th binding point using linear interpolation. i+1 It is represented as:

[0146]

[0147] Step S209: Calculate the initial correction coefficient m for the grayscale of the i-th binding point using linear interpolation. i It is represented as:

[0148]

[0149] Steps S207 to S209 indicate that when the initial correction coefficient m0 ​​of a certain gray level of a binding point is an outlier, the initial correction coefficient m0 ​​of the gray level of the binding point is calculated using the linear interpolation method, and the original initial correction coefficient is replaced by the calculation result of the linear interpolation.

[0150] Step S210: End the inspection.

[0151] The above combination Figures 1 to 4 The process of obtaining the initial correction coefficient m0 ​​by pre-adjusting each bound point grayscale in each display brightness range in the first debugging stage is described. Then, the display module is debugged in the second stage. The display module includes multiple display brightness ranges, each display brightness range corresponds to a second conversion relationship, and each display brightness range includes multiple bound point grayscales. The gamma debugging method includes: for any display brightness range, using the second conversion relationship corresponding to the display brightness range, adjusting the first gamma register value of each bound point grayscale in the display brightness range in turn to obtain the first gamma register value of each bound point grayscale that makes the brightness and chromaticity of the display module meet the first brightness and chromaticity index.

[0152] Optional, please refer to Figure 5 , Figure 5 A flowchart for gamma adjustment of any display brightness range during the second debugging phase, such as... Figure 5 As shown, the gamma debugging method provided in this embodiment includes the following steps:

[0153] Step S301: Set the customer standard for this display brightness range. The customer standard includes, but is not limited to, the reference luminance and chromaticity of each grayscale point under this display brightness range, and the allowable error threshold during the debugging process, that is, the first luminance and chromaticity index or the second luminance and chromaticity index.

[0154] Step S302: Take the grayscale of the i-th binding point and write it into the gamma register value.

[0155] Step S303: When the display module uses the first gamma register value for display, it is detected whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index. The first gamma register value is the current value of the gamma register of the display module. If the detection result is yes, proceed to step S306; if the detection result is no, proceed to step S304.

[0156] The current value of the gamma register refers to the value currently written to the gamma register. During the first debugging in the second debugging phase, the first gamma register value is the initial gamma register value, which is the register value that was written to the gamma register for the first time. During the i-th debugging, the first gamma register value is the register value that was written to the i-th time.

[0157] In practice, the initial gamma register value can be either a value randomly set by the debugger or the gamma register value output from the first debugging phase. Typically, to speed up the debugging process and shorten the debugging cycle, the initial gamma register value is the gamma register value output from the first debugging phase.

[0158] Assuming this embodiment of the disclosure is for debugging a bound grayscale level 3 within a certain display brightness range, then the value of the first gamma register at this time represents the value currently written to the bound grayscale level 3 in the gamma register. Assuming the value of the first gamma register is the value written to the gamma register for the i-th time, the first gamma register value Reg... i Represented as Reg i =(R i G i B i If the current first gamma register value meets the customer's standard, the display module uses the first gamma register value (R) to determine whether it meets the customer's standard. i G i B i The display module is lit up, and the brightness and color saturation of the display module are measured using optical equipment. Then, it is determined whether the measured brightness and color saturation meet the first brightness and color saturation index.

[0159] The first luminance and chromaticity index is determined according to customer standards. Specifically, the customer standards specify the reference luminance and chromaticity of the display module at different grayscale levels under different display brightness ranges. In practice, when the error between the luminance and chromaticity of the display module and the reference luminance and chromaticity is within a certain range, the display module can be judged to meet the customer standards.

[0160] Optionally, the step of detecting whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index when the display module uses the first gamma register value for display includes:

[0161] (21) Measure the current brightness and chromaticity of the display module when it displays using the first gamma register value;

[0162] (22) Determine whether the error between the current brightness and the reference brightness is less than the first error threshold. If the determination result is yes, determine that the brightness of the display module meets the first brightness index.

[0163] For example, the first brightness index indicates that the error between the brightness of the display module and the reference brightness is within 10%, that is, the first error threshold is 10%. If the error is within 10%, it meets the customer standard; if the error exceeds 10%, it does not meet the customer standard.

[0164] In this embodiment of the disclosure, the second luminance and chromaticity index in the pre-debugging stage is more stringent than the first luminance and chromaticity index in the second debugging stage. For example, when the first luminance and chromaticity index indicates that the error between the luminance and chromaticity of the display module and the reference luminance and chromaticity is within 10%, the second luminance and chromaticity index may be that the error between the luminance and chromaticity of the display module and the reference luminance and chromaticity is within 1%. This is because in the pre-debugging stage, the measurement environment is more stable, and the display module can be considered to be working in a standard test environment. Therefore, the index requirements are more stringent at this time. In the second debugging stage, the measurement environment (e.g., optical measurement equipment, display module temperature, etc.) has a larger error compared to the pre-debugging stage, so the index requirements are more lenient at this time.

[0165] Step S304: Calculate the first difference between the first gamma register value and the reference gamma register value, obtain an initial correction coefficient, and use the initial correction coefficient to correct the first difference to obtain a first adjustment amount. The initial correction coefficient is used to represent the correlation between the actual adjustment amount and the theoretical adjustment amount. The actual adjustment amount is the amount of change required to adjust the first gamma register value to the target gamma register value. The theoretical adjustment amount is the amount of change required to adjust the first gamma register value to the reference gamma register value. The reference gamma register value is the theoretical gamma register value calculated based on the reference luminance and chrominance. The target gamma register value is the actual gamma register value when the luminance and chrominance of the display module meet the first luminance and chrominance index.

[0166] Among them, the reference gamma register value Reg t These are theoretical values ​​calculated using the first and second transformation relationships, as well as the reference luminance and chromaticity values ​​required by the client. Specifically, the reference luminance and chromaticity are first converted into reference spectral tristimulus values ​​XYZ based on the first transformation relationship. t Then, based on the second transformation relationship, the reference spectral tristimulus values ​​XYZ are... t Convert to base gamma register value Reg t First gamma register value Reg i Compared with the reference gamma register value Reg t First difference RGB D =XYZ D *T1 -1 =(XYZ) t -XYZ i )*T1 -1 Using the initial correction coefficient m0 ​​to adjust the first difference RGB DThe process of obtaining the first adjustment amount 'a' through correction is expressed as a = RGB D / m0. In practice, the initial correction coefficient m0 ​​is obtained during the first debugging phase and written into the display module. During the second debugging phase, the initial correction coefficient m0 ​​is used to adjust the first difference RGB. D Make corrections.

[0167] Step S305: Adjust the first gamma register value using the first adjustment amount, and write the adjusted second gamma register value into the gamma register. Repeat the step of detecting whether the brightness and chromaticity of the display module meets the first brightness and chromaticity index when the display module displays using the first gamma register value until the detection result is yes, that is, return to step S303. At this time, the first gamma register value is the adjusted first gamma register value. The adjustment of the first gamma register value using the first adjustment amount a can be represented as Reg. i+1 =Reg i +RGB D / m0.

[0168] Step S306: The gamma debugging of the grayscale of this binding point is completed, and the current gamma register value is output.

[0169] Step S307: Determine whether i is less than the total number of gray levels of the binding points N. If the determination result is yes, proceed to step S308. If the determination result is no, proceed to step S309.

[0170] Step S308: Set i = i + 1, return to step S302, that is, take the next binding point grayscale, continue to adjust the next binding point grayscale, until the gamma adjustment of all binding point grayscales in the display brightness range is completed.

[0171] Step S309: The grayscale adjustment of each binding point in the brightness range of this display is completed.

[0172] Compared with related technologies, the gamma adjustment method of this disclosure adds a correction coefficient during the gamma adjustment process. This correction coefficient can represent the correlation between the actual adjustment amount and the theoretical adjustment amount. During the gamma adjustment process, the theoretical adjustment amount is corrected in real time using this correction coefficient, so that the theoretical adjustment amount changes in the direction of the actual adjustment amount. This can prevent the problem of large deviations in the gamma register value due to the influence of uncertain factors such as optical equipment errors and ambient light. This allows the gamma register value to approach the target gamma register value more quickly and accurately, reducing the number of gamma adjustments, shortening the adjustment cycle, and improving production line capacity.

[0173] In one possible implementation, step S303, which involves detecting whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index when the display module uses the first gamma register value for display, includes:

[0174] (31) The current brightness and chromaticity of the measurement display module when it displays using the first gamma register value are converted into the current spectral tristimulus value according to the first conversion relationship.

[0175] (32) Determine whether the error between the current spectral tristimulus value and the reference spectral tristimulus value is less than the first error threshold. If the determination result is yes, determine that the brightness and chromaticity of the display module meet the first brightness and chromaticity index.

[0176] In this embodiment, when determining whether a display module meets customer standards, the judgment is not made on the luminance and chromaticity dimension, but rather by converting luminance and chromaticity into spectral tristimulus values ​​and making the judgment on the spectral tristimulus value dimension. This setting can improve the judgment accuracy and reduce the judgment error. Specifically, the luminance L value of the display module is relatively large, while the chromaticity coordinates x and y are usually very small (see Table 1). If the judgment is made on the luminance and chromaticity dimension, it is easy to produce a large calculation error. However, on the spectral tristimulus value dimension, the values ​​of spectral tristimulus X, Y, and Z are relatively large and close. Making the judgment on this dimension can reduce the calculation error and thus improve the judgment accuracy.

[0177] In one possible implementation, before the step of obtaining the initial correction coefficient and using the initial correction coefficient to correct the first difference to obtain the first adjustment amount, the method further includes:

[0178] Step S401: Determine whether the adjustment step size of the gamma register is too small or too large. If the determination result is that the adjustment step size is too small, proceed to step S402. If the determination result is that the adjustment step size is too large, proceed to step S403.

[0179] Here, the first adjustment amount 'a' can represent the adjustment step size of the gamma register. During one adjustment process, the larger the value of the first adjustment amount 'a', the longer the adjustment step size 'a'; the smaller the value of the first adjustment amount 'a', the smaller the adjustment step size 'a'.

[0180] When debugging a specific grayscale level, the goal is to find a set of gamma register values ​​that bring the display module's luminance and chromaticity close to the reference luminance and chromaticity. If, during debugging, the luminance and chromaticity measurements repeatedly (e.g., N times, where N is a natural number, typically 2, 3, 4, etc.) change in the same direction (constantly decreasing or increasing), it indicates that the adjustment step size is too small and needs to be increased. Conversely, if the luminance and chromaticity measurements consistently fluctuate around the reference luminance and chromaticity, it indicates that the adjustment step size is too large and needs to be decreased. This allows for real-time assessment of whether the adjustment step size is too small or too large during debugging, and adjustments can be made based on these assessments. This enables the debugged gamma register values ​​to approach the reference gamma register values ​​more quickly, accelerating the adjustment speed and shortening the adjustment cycle.

[0181] Optionally, the step of determining whether the adjustment step size of the gamma register is too small or too large includes:

[0182] (41) Obtain the brightness and chromaticity of multiple consecutive measurements. Each brightness and chromaticity is the brightness and chromaticity of the display module after adjusting the value of the first gamma register once.

[0183] (42) Determine whether the brightness and color intensity of the multiple consecutive measurements continue to increase or decrease. If they continue to increase or decrease, determine that the adjustment step size is too small, and then execute step S402.

[0184] (43) Determine whether the brightness and chromaticity measured in multiple consecutive measurements are fluctuating around the reference brightness and chromaticity. If the determination result is yes, it is determined that the adjustment step size is too large, and step S403 is executed.

[0185] For any grayscale point, the debugging process involves finding the gamma register value, which can be represented as follows: write the initial gamma register value, plot and measure the luminance and chromaticity. Assuming the first measured luminance and chromaticity is represented as Lxy-1, if this luminance and chromaticity Lxy-1 does not meet the first luminance and chromaticity index, then adjust the gamma register value and rewrite it into the gamma register, and then measure the luminance and chromaticity again. The second measured luminance and chromaticity is represented as Lxy-2. If this luminance and chromaticity Lxy-2 does not meet the first luminance and chromaticity index, then adjust the gamma register value again, measure the luminance and chromaticity again, and repeat the above steps until the luminance and chromaticity meet the first luminance and chromaticity index.

[0186] During the debugging process, when it is determined that the brightness and chromaticity of the display module do not meet the first brightness and chromaticity index, a step of real-time judgment of adjustment step size is added, that is, step (41) to step (43) are added. By judging whether the adjustment step size is too large or too small and fine-tuning the adjustment step size in real time, the reference gamma register value can be approached faster, the adjustment speed can be accelerated, and the adjustment cycle can be shortened.

[0187] Step S402: Adjust the initial correction coefficient using the first weighting coefficient. When the adjusted initial correction coefficient corrects the first difference, the first adjustment amount increases.

[0188] For example, the first weighting coefficient is denoted as d1 (d1<1). Adjusting the initial correction coefficient m0 ​​using the first weighting coefficient d1 can be expressed as m0=m0*d1. At this time, the first adjustment amount a will increase, that is, the adjustment step size will increase.

[0189] Step S403: Adjust the initial correction coefficient using the second weighting coefficient. When the adjusted initial correction coefficient corrects the first difference, the first adjustment amount decreases.

[0190] For example, the second weighting coefficient is denoted as d2 (d2>1). Adjusting the initial correction coefficient m0 ​​using the second weighting coefficient d2 can be expressed as m0=m0*d2. At this time, the first adjustment amount a will decrease, that is, the adjustment step size will decrease.

[0191] It is understandable that during the first debugging phase, the first weighting coefficient and the second weighting coefficient shown in steps S401 to S403 can be used to adjust the preset correction coefficient in real time to speed up the debugging process and shorten the debugging cycle.

[0192] In one possible implementation, the step of calculating the first difference between the first gamma register value and the reference gamma register value includes:

[0193] (51) Obtain the current brightness and chromaticity of the display module when the display module uses the first gamma register value for display;

[0194] (52) Convert the current luminance and chromaticity into the current spectral tristimulus value according to the first conversion relationship, and convert the reference luminance and chromaticity into the reference spectral tristimulus value. The first conversion relationship represents the conversion relationship between luminance and chromaticity and spectral tristimulus value.

[0195] (53) Calculate the difference between the current spectral tristimulus value and the reference spectral tristimulus value and convert the difference into the first difference using the second conversion relationship, wherein the second conversion relationship represents the conversion relationship between the gamma register value and the spectral tristimulus value.

[0196] The specific implementation scheme for calculating the first difference can be found in the calculation process shown in Formulas 3 and 4, which will not be described in detail here.

[0197] Optionally, the gamma debugging method in this embodiment can be applied to the driving unit of a display module. The driving unit includes a gamma register for storing gamma register values. The gamma debugging method in this embodiment is used to debug and obtain a target gamma register value that meets the requirements and store it in the gamma register.

[0198] In one possible implementation, different display modules may have different numbers of bits in their gamma registers, such as 8 bits, 10 bits, or 14 bits. To ensure that the gamma debugging method of this embodiment is compatible with display modules of different bit lengths, the gamma register values ​​can be normalized during the debugging process. For example, gamma register values ​​of different bit lengths can be normalized to 8-bit gamma register values. The normalization formula can be expressed as:

[0199]

[0200] Here, depth represents the number of bits in the gamma register value of the display module. Correspondingly, after the gamma register values ​​of each grayscale point under each display brightness range of the display module are obtained through debugging, the gamma register values ​​need to be converted back to the corresponding number of bits of the display module.

[0201] Please refer to Table 3. Table 3 is a comparison table of the number of adjustments required to obtain the target gamma register value when adjusting the grayscale of each bound point in a certain display brightness range of the display module using the gamma adjustment method (with correction coefficient) of the present invention and the conventional gamma adjustment method (without correction coefficient).

[0202] Table 3 compares the number of times a band is debugged with and without a correction factor for gamma debugging.

[0203]

[0204]

[0205] As shown in Table 3, after adding the correction coefficient m to the gamma debugging method, the total number of debugging times for each binding point grayscale in a certain band decreased by 21 times. Based on an average of 300ms per time, this can save 6.3s of time. Assuming that there are a total of 25 bands, the total debugging time for each display module can be reduced by 157.5s.

[0206] Furthermore, the gamma debugging process of three OLED display modules was measured, and the comparison table of debugging times shown in Table 4 was obtained.

[0207] Table 4 Comparison of the number of debugging sessions for multiple display modules with and without correction coefficients for gamma debugging.

[0208] Each debugging session includes writing a gamma register value, measuring the optical data, and performing other procedures for judgment and calculation. Assuming that writing a gamma register value takes 102ms and measuring the optical data takes 25ms, Table 4 shows that, compared with the conventional gamma debugging scheme, the gamma debugging method implemented in this disclosure reduces the number of debugging sessions for display module 1 by 396, saving 396 * (102ms + 25ms) = 50292ms; reduces the number of debugging sessions for display module 2 by 220, saving 220 * (102ms + 25ms) = 27940ms; and reduces the number of debugging sessions for display module 3 by 182, saving 182 * (102ms + 25ms) = 23114ms.

[0209] Based on the same inventive concept, a second aspect of this disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the gamma debugging method described above. In specific implementations, the computer storage medium may include various storage media capable of storing program code, such as a Universal Serial Bus Flash Drive (USB), a portable hard drive, Read-Only Memory (ROM), Random Access Memory (RAM), a magnetic disk, or an optical disk.

[0210] Based on the same inventive concept, a third aspect of this disclosure provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the gamma debugging method described above. Since the principle by which the above computer program solves the problem is similar to the principle of the display driver method, the implementation of the above computer program can be found in the implementation of the display driver method, and repeated details will not be elaborated further.

[0211] Computer program products may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CDROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0212] In this embodiment, the display module can be an organic light-emitting diode (OLED) display module. It is understood that the display module can also be of other types depending on actual needs; for example, it can be a quantum dot light-emitting diode (QLED) display module or a micro light-emitting diode (Micro LED) display module, etc.

[0213] Obviously, the above embodiments of this disclosure are merely examples for clearly illustrating this disclosure, and are not intended to limit the implementation of this disclosure. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all implementation methods here. Any obvious variations or modifications derived from the technical solutions of this disclosure are still within the protection scope of this disclosure.

Claims

1. A gamma debugging method, characterized in that, Includes the following steps: When the display module uses the first gamma register value for display, it is determined whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index. The first gamma register value is the current value of the gamma register of the display module. If the detection result is negative, calculate the first difference between the first gamma register value and the reference gamma register value, obtain an initial correction coefficient, and use the initial correction coefficient to correct the first difference to obtain a first adjustment amount. The initial correction coefficient is used to represent the correlation between the actual adjustment amount and the theoretical adjustment amount. The actual adjustment amount is the amount of change required to adjust the first gamma register value to the target gamma register value. The theoretical adjustment amount is the amount of change required to adjust the first gamma register value to the reference gamma register value. The reference gamma register value is the theoretical gamma register value calculated based on the reference luminance and chrominance. The target gamma register value is the actual gamma register value when the luminance and chrominance of the display module meet the first luminance and chrominance index. The first adjustment amount is used to adjust the value of the first gamma register, and the adjusted value of the second gamma register is written into the gamma register. The step of detecting whether the brightness and color of the display module meet the first brightness and color index when the display module displays using the first gamma register value is repeated until the detection result is yes.

2. The gamma debugging method according to claim 1, characterized in that, The steps preceding the acquisition of the initial correction coefficients also include: Determine whether the adjustment step size of the gamma register is too small or too large; If the adjustment step size is too small, the initial correction coefficient is adjusted using the first weighting coefficient. When the adjusted initial correction coefficient is used to correct the first difference, the first adjustment amount increases. If the adjustment step size is too large, the initial correction coefficient is adjusted using the second weighting coefficient. When the adjusted initial correction coefficient corrects the first difference, the first adjustment amount decreases.

3. The gamma debugging method according to claim 2, characterized in that, The steps for determining whether the adjustment step size of the gamma register is too small or too large include: The brightness and chromaticity are obtained from multiple consecutive measurements, and each brightness and chromaticity is the brightness and chromaticity of the display module after adjusting the value of the first gamma register once; Determine whether the brightness and chromaticity of the multiple consecutive measurements continue to increase or decrease. If they continue to increase or decrease, it is determined that the adjustment step size is too small. Determine whether the brightness and chromaticity measured in multiple consecutive measurements fluctuate around the reference brightness and chromaticity. If the determination result is yes, it is determined that the adjustment step size is too large.

4. The gamma debugging method according to any one of claims 1 to 3, characterized in that, The display module includes multiple display brightness ranges, each display brightness range includes multiple bound grayscale levels, and each bound grayscale level corresponds to an initial correction coefficient. Before the step of detecting whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index when the display module uses the first gamma register value for display, the following steps are also included: For any display brightness range, pre-adjust the grayscale of each bound point within the display brightness range sequentially to determine the initial correction coefficient corresponding to the grayscale of that bound point.

5. The gamma debugging method according to claim 4, characterized in that, For any bounding grayscale within any display brightness range, the steps for pre-adjusting and determining the initial correction coefficient corresponding to the bounding grayscale include: When the display module uses the third gamma register value for display, it is determined whether the brightness and chromaticity of the display module meet the second brightness and chromaticity index. The third gamma register value is the current value of the gamma register. If the detection result is yes, the third gamma register value is output, and the initial correction coefficient is calculated using the third gamma register value, the previous register value of the gamma register, and the reference gamma register value. If the detection result is negative, calculate the second difference between the third gamma register value and the reference gamma register value, obtain a preset correction coefficient, and use the preset correction coefficient to correct the second difference to obtain the second adjustment amount; The third gamma register value is adjusted using the second adjustment amount, and the fourth gamma register value obtained after adjustment is written into the gamma register. The step of detecting whether the brightness and color of the display module meets the second brightness and color index when the display module displays using the third gamma register value is repeated until the detection result is yes.

6. The gamma debugging method according to claim 5, characterized in that, The step of outputting the third gamma register value is followed by: Determine if the current number of debug attempts is equal to the first value; If the current number of debugging attempts is greater than the first value, execute the step of calculating the initial correction coefficient using the third gamma register value, the previous register value of the gamma register, and the reference gamma register value; If the current number of debugging attempts is equal to the first value, the initial correction coefficient is calculated using the third gamma register value and the reference gamma register value, or the initial correction coefficient of the grayscale of the current binding point is obtained by interpolation using the initial correction coefficients of the grayscale of the current binding point adjacent to the grayscale of the current binding point.

7. The gamma debugging method according to claim 5, characterized in that, For any display brightness range, after the step of pre-adjusting the grayscale of each bounding point within the display brightness range to determine the initial correction coefficient corresponding to the grayscale of that bounding point, the following is also included: Check whether the initial correction coefficient corresponding to the grayscale of each binding point is an outlier; If the initial correction coefficient corresponding to any gray level of a binding point is an outlier, the initial correction coefficient corresponding to the gray level of that binding point is calculated using linear interpolation, and the initial correction coefficient of the gray level of that binding point is updated to the result of linear interpolation.

8. The gamma debugging method according to claim 1, characterized in that, The steps for calculating the first difference between the first gamma register value and the reference gamma register value include: Obtain the current brightness and chromaticity of the display module when it uses the first gamma register value for display; According to the first conversion relationship, the current luminance and chromaticity are converted into the current spectral tristimulus value, and the reference luminance and chromaticity are converted into the reference spectral tristimulus value. The first conversion relationship represents the conversion relationship between luminance and chromaticity and spectral tristimulus value. The difference between the current spectral tristimulus value and the reference spectral tristimulus value is calculated, and the difference is converted into the first difference using a second conversion relationship, wherein the second conversion relationship represents the conversion relationship between the gamma register value and the spectral tristimulus value.

9. The gamma debugging method according to claim 8, characterized in that, The steps for detecting whether the brightness and chromaticity of the display module meet the first brightness and chromaticity index when the display module uses the first gamma register value for display include: The measurement and display module uses the first gamma register value to display the current brightness and chromaticity, and converts the current brightness and chromaticity into the current spectral tristimulus value according to the first conversion relationship; Determine whether the error between the current spectral tristimulus value and the reference spectral tristimulus value is less than a first error threshold. If the determination result is yes, determine that the brightness and chromaticity of the display module meet the first brightness and chromaticity index.

10. The gamma debugging method according to claim 8, characterized in that, The display module includes multiple display brightness ranges, each display brightness range corresponds to a second conversion relationship, and each display brightness range includes multiple bound-point grayscale levels. The gamma adjustment method includes: For any display brightness range, the first gamma register value of each bound point grayscale is adjusted sequentially using the second conversion relationship corresponding to the display brightness range to obtain the first gamma register value of each bound point grayscale that makes the brightness and color of the display module meet the first brightness and color index.

11. The gamma debugging method according to claim 8, characterized in that, The steps preceding the calculation of the first difference between the first gamma register value and the reference gamma register value also include: Write the fifth gamma register value into the gamma register to obtain the spectral tristimulus value of the display module when the display module displays using the fifth gamma register value. The brightness of the display module when displaying using the fifth gamma register value is greater than the brightness of the display module when displaying using the maximum grayscale. The second conversion relationship is determined based on the fifth gamma register value and the spectral tristimulus value.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the gamma debugging method as described in any one of claims 1 to 11.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the gamma debugging method as described in any one of claims 1 to 11.

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