CN117153079A

CN117153079A - Color coordinate adjustment method, device, electronic equipment and storage medium

Info

Publication number: CN117153079A
Application number: CN202311084320.5A
Authority: CN
Inventors: 王晓静; 兰博骁; 胡乃威; 吕峰亮; 赵爽; 蒋伟信; 王强; 康皓炜
Original assignee: Beijing Eswin Computing Technology Co Ltd
Current assignee: Beijing Eswin Computing Technology Co Ltd
Priority date: 2023-08-25
Filing date: 2023-08-25
Publication date: 2023-12-01

Abstract

The application provides a color coordinate adjusting method, a device, electronic equipment and a storage medium, and belongs to the technical field of image processing. The method comprises the following steps: obtaining a target white point color coordinate and a target gray scale brightness value of a maximum gray scale L255; judging whether the display module supports a target gray-scale brightness value under the target white point color coordinates; if the display module supports the target gray-scale brightness value, determining different gray-scale brightness values according to the target gray-scale brightness value; and adjusting the color coordinates according to the different gray-scale brightness values and the target white point color coordinates to obtain the color coordinates of different gray scales. Therefore, the scheme can determine the maximum brightness value of the display module under the target white point color coordinates according to the first mapping relation, and further determine whether the display module supports target gray-scale brightness. Further, the brightness values of different gray scales are determined according to the brightness values of the target gray scales, the color coordinates can be accurately adjusted based on the brightness values of the gray scales and the color coordinates of the target white points, and the utilization rate of the display module is improved.

Description

Color coordinate adjustment method, device, electronic equipment and storage medium

Technical Field

The present application relates to the field of image processing technologies, and in particular, to a color coordinate adjustment method, a device, an electronic apparatus, and a storage medium.

Background

The color coordinates of the display modules are different due to different production batches or different modules in the same batch, and the color coordinates also change along with time. The display module is facing different demands of different users on color coordinates, the demands of the users cannot be met through automatic adjustment of the color coordinates, and the utilization rate of the display module is low.

Disclosure of Invention

The application provides a color coordinate adjusting method, a device, electronic equipment, a computer readable storage medium and a computer program product, which are used for solving the problem that the color coordinate cannot be automatically adjusted. The technical scheme of the application is as follows:

according to a first aspect of an embodiment of the present application, there is provided a color coordinate adjustment method including: obtaining a target white point color coordinate and a target gray scale brightness value of a maximum gray scale L255; judging whether the display module supports the target gray-scale brightness value under the target white-point color coordinates; if the display module supports the target gray-scale brightness value, determining different gray-scale brightness values according to the target gray-scale brightness value; and adjusting the color coordinates according to the different gray scale brightness values and the color coordinates of the target white point to obtain the color coordinates of different gray scales.

In one embodiment of the present application, the adjusting the color coordinates according to the different gray-scale luminance values and the target white point color coordinates to obtain the color coordinates of different gray scales includes: acquiring the brightness ratio of the target RGB under the target white point color coordinates; for any gray scale n, determining the brightness value of each RGB color channel under the gray scale n when mixing light according to the gray scale brightness value under the gray scale n and the target RGB brightness ratio; acquiring digital driving values corresponding to the RGB color channels under the gray scale n based on brightness values of the RGB color channels under the gray scale n when light is mixed; and adjusting the color coordinates based on the digital driving values corresponding to the RGB color channels under the gray scale n to obtain the color coordinates of the gray scale n.

In one embodiment of the present application, the determining different gray-scale luminance values according to the target gray-scale luminance value includes: obtaining a minimum gray-scale brightness value; for any gray level n, determining a gray level luminance value of the gray level n based on the target gray level luminance value and the minimum gray level luminance value.

In one embodiment of the present application, the determining the gray-scale luminance value of the gray-scale n based on the target gray-scale luminance value and the minimum gray-scale luminance value includes: acquiring a brightness difference between the target gray-scale brightness value and the minimum gray-scale brightness value; determining a brightness increment value of the gray level n according to the gray level n, the brightness difference and a predetermined input/output characteristic parameter under a specific backlight condition; and obtaining the gray-scale brightness value of the gray-scale n according to the gray-scale brightness value of the minimum gray-scale and the brightness increment value.

In an embodiment of the present application, the obtaining the digital driving value corresponding to each RGB color channel under the gray scale n based on the brightness value when the RGB color channels are mixed, includes: and inputting the brightness value of each RGB color channel under the gray scale n when mixing light into a predetermined RGB tone function, and determining the digital driving value corresponding to each RGB color channel under the gray scale n, wherein the RGB tone function is the mapping relation between the brightness value of each RGB color channel when mixing light and the corresponding digital driving value.

In one embodiment of the present application, the determining whether the display module supports the target gray-scale luminance value under the target white-point color coordinates includes: acquiring a first mapping relation generated in advance, wherein the first mapping relation comprises a mapping relation between candidate white point color coordinates and a maximum gray scale brightness value supported by the candidate white point color coordinates; determining a first maximum gray-scale brightness value with a mapping relation with the target white point color coordinates from the first mapping relation; determining that the display module supports the target gray-scale luminance value under the target white-point color coordinates in response to the first maximum gray-scale luminance value being greater than or equal to the target gray-scale luminance value; and responding to the first maximum gray-scale luminance value being smaller than the target gray-scale luminance value, and determining that the display module does not support the target gray-scale luminance value under the target white point color coordinates.

In one embodiment of the present application, the generating process of the first mapping relationship includes: acquiring a predetermined RGB tone function and a second mapping relation, wherein the second mapping relation is a mapping relation between gray-scale brightness, color coordinates and brightness values of RGB color channels when light is mixed; based on the second mapping relation, calculating the RGB tone function and the candidate white point color coordinates to obtain a maximum gray scale brightness value supported by the candidate white point color coordinates; and generating the first mapping relation based on each candidate white point color coordinate and the maximum gray scale brightness value supported by the candidate white point color coordinate.

In one embodiment of the present application, the calculating the RGB tone function and the candidate white point color coordinates based on the second mapping relationship to obtain the maximum gray level luminance value supported by the candidate white point color coordinates includes: inputting the RGB tone function and the candidate white point color coordinates into the second mapping relation to obtain a third mapping relation between the maximum gray scale brightness and the digital driving values corresponding to the RGB color channels; obtaining a candidate maximum gray scale brightness value under the candidate white point color coordinates based on the third mapping relation and a preset digital driving value of each RGB color channel under the maximum gray scale; and comparing the candidate maximum gray-scale brightness values, obtaining a minimum gray-scale brightness value from the candidate maximum gray-scale brightness values, and taking the minimum gray-scale brightness value as the maximum gray-scale brightness value supported by the candidate white-point color coordinates.

In one embodiment of the application, after obtaining the maximum gray scale luminance value supported by the candidate white point color coordinates, further comprising: inputting the maximum gray-scale brightness value supported by the candidate white-point color coordinates into the third mapping relation to obtain digital driving values corresponding to all RGB color channels under the maximum gray scale; inputting the digital driving value corresponding to each RGB color channel under the maximum gray scale into the RGB tone function to obtain the brightness value of each RGB color channel when mixing light; obtaining RGB brightness ratio under the candidate white point color coordinates based on brightness values of mixed lights on the RGB color channels; and establishing a mapping relation between the candidate white point color coordinates and RGB brightness ratios under the candidate white point color coordinates, and storing the mapping relation in the first mapping relation.

In one embodiment of the present application, obtaining the luminance ratio of RGB corresponding to the target white point color coordinates includes: and inquiring the first mapping relation based on the target white point color coordinate, and acquiring the RGB brightness ratio with the mapping relation with the target white point color coordinate as the brightness ratio of target RGB under the target white point color coordinate.

In one embodiment of the present application, the determining process of the RGB tone function includes: sampling the images to obtain N sampling pictures, and obtaining measurement data of each sampling image, wherein the measurement data comprises a data driving measurement value and a gray scale brightness measurement value; and carrying out least square regression on a preset RGB tone function based on the measurement data to determine characteristic parameters of the RGB tone function and obtain the RGB tone function.

In one embodiment of the present application, the generating process of the second mapping relationship includes: determining a gamut conversion matrix mapped from the RGB gamut to the XYZ gamut; determining a conversion relation between the color coordinates and the XYZ color gamut; and obtaining the second mapping relation based on the color gamut conversion matrix and the conversion relation.

In one embodiment of the application, the method further comprises: dividing the range of all gray scales to obtain different gray scale ranges; generating an RGB tone function of each gray scale range in advance for the gray scale range; and determining digital driving values corresponding to RGB color channels under each gray scale in the gray scale range according to RGB tone functions of the gray scale range in different gray scale ranges, and performing color coordinate adjustment based on the digital driving values.

In one embodiment of the application, the method further comprises: and if the display module does not support the target gray scale brightness under the target white point color coordinates, determining that the display module is an abnormal display module.

According to a second aspect of an embodiment of the present application, there is provided a color coordinate adjusting device including: the acquisition module is used for acquiring target white point color coordinates and a target gray scale brightness value of the maximum gray scale L255; the judging module is used for judging whether the display module supports the target gray-scale brightness value under the target white point color coordinates; the determining module is used for determining different gray-scale brightness values according to the target gray-scale brightness values if the display module supports the target gray-scale brightness values; and the adjusting module is used for adjusting the color coordinates according to the different gray-scale brightness values and the target white point color coordinates to obtain the color coordinates of different gray scales.

In one embodiment of the present application, the adjusting module is further configured to: acquiring the brightness ratio of the target RGB under the target white point color coordinates; for any gray scale n, determining the brightness value of each RGB color channel under the gray scale n when mixing light according to the gray scale brightness value under the gray scale n and the target RGB brightness ratio; acquiring digital driving values corresponding to the RGB color channels under the gray scale n based on brightness values of the RGB color channels under the gray scale n when light is mixed; and adjusting the color coordinates based on the digital driving values corresponding to the RGB color channels under the gray scale n to obtain the color coordinates of the gray scale n.

In one embodiment of the present application, the determining module is further configured to: obtaining a minimum gray-scale brightness value; for any gray level n, determining a gray level luminance value of the gray level n based on the target gray level luminance value and the minimum gray level luminance value.

In one embodiment of the present application, the determining module is further configured to: acquiring a brightness difference between the target gray-scale brightness value and the minimum gray-scale brightness value; determining a brightness increment value of the gray level n according to the gray level n, the brightness difference and a predetermined input/output characteristic parameter under a specific backlight condition; and obtaining the gray-scale brightness value of the gray-scale n according to the gray-scale brightness value of the minimum gray-scale and the brightness increment value.

In one embodiment of the present application, the adjusting module is further configured to: and inputting the brightness value of each RGB color channel under the gray scale n when mixing light into a predetermined RGB tone function, and determining the digital driving value corresponding to each RGB color channel under the gray scale n, wherein the RGB tone function is the mapping relation between the brightness value of each RGB color channel when mixing light and the corresponding digital driving value.

In one embodiment of the present application, the determining module is further configured to: acquiring a first mapping relation generated in advance, wherein the first mapping relation comprises a mapping relation between candidate white point color coordinates and a maximum gray scale brightness value supported by the candidate white point color coordinates; determining a first maximum gray-scale brightness value with a mapping relation with the target white point color coordinates from the first mapping relation; determining that the display module supports the target gray-scale luminance value under the target white-point color coordinates in response to the first maximum gray-scale luminance value being greater than or equal to the target gray-scale luminance value; and responding to the first maximum gray-scale luminance value being smaller than the target gray-scale luminance value, and determining that the display module does not support the target gray-scale luminance value under the target white point color coordinates.

In one embodiment of the present application, the determining module is further configured to: acquiring a predetermined RGB tone function and a second mapping relation, wherein the second mapping relation is a mapping relation between gray-scale brightness, color coordinates and brightness values of RGB color channels when light is mixed; based on the second mapping relation, calculating the RGB tone function and the candidate white point color coordinates to obtain a maximum gray scale brightness value supported by the candidate white point color coordinates; and generating the first mapping relation based on each candidate white point color coordinate and the maximum gray scale brightness value supported by the candidate white point color coordinate.

In one embodiment of the present application, the determining module is further configured to: inputting the RGB tone function and the candidate white point color coordinates into the second mapping relation to obtain a third mapping relation between the maximum gray scale brightness and the digital driving values corresponding to the RGB color channels; obtaining a candidate maximum gray scale brightness value under the candidate white point color coordinates based on the third mapping relation and a preset digital driving value of each RGB color channel under the maximum gray scale; and comparing the candidate maximum gray-scale brightness values, obtaining a minimum gray-scale brightness value from the candidate maximum gray-scale brightness values, and taking the minimum gray-scale brightness value as the maximum gray-scale brightness value supported by the candidate white-point color coordinates.

In one embodiment of the present application, the determining module is further configured to: inputting the maximum gray-scale brightness value supported by the candidate white-point color coordinates into the third mapping relation to obtain digital driving values corresponding to all RGB color channels under the maximum gray scale; inputting the digital driving value corresponding to each RGB color channel under the maximum gray scale into the RGB tone function to obtain the brightness value of each RGB color channel when mixing light; obtaining RGB brightness ratio under the candidate white point color coordinates based on brightness values of mixed lights on the RGB color channels; and establishing a mapping relation between the candidate white point color coordinates and RGB brightness ratios under the candidate white point color coordinates, and storing the mapping relation in the first mapping relation.

In one embodiment of the present application, the determining module is further configured to: and inquiring the first mapping relation based on the target white point color coordinate, and acquiring the RGB brightness ratio with the mapping relation with the target white point color coordinate as the brightness ratio of target RGB under the target white point color coordinate.

In one embodiment of the present application, the determining module is further configured to: sampling the images to obtain N sampling pictures, and obtaining measurement data of each sampling image, wherein the measurement data comprises a data driving measurement value and a gray scale brightness measurement value; and carrying out least square regression on a preset RGB tone function based on the measurement data to determine characteristic parameters of the RGB tone function and obtain the RGB tone function.

In one embodiment of the present application, the determining module is further configured to: determining a gamut conversion matrix mapped from the RGB gamut to the XYZ gamut; determining a conversion relation between the color coordinates and the XYZ color gamut; and obtaining the second mapping relation based on the color gamut conversion matrix and the conversion relation.

In one embodiment of the present application, the adjusting module is further configured to: dividing the range of all gray scales to obtain different gray scale ranges; generating an RGB tone function of each gray scale range in advance for the gray scale range; and determining digital driving values corresponding to RGB color channels under each gray scale in the gray scale range according to RGB tone functions of the gray scale range in different gray scale ranges, and performing color coordinate adjustment based on the digital driving values.

In one embodiment of the present application, the determining module is further configured to: and if the display module does not support the target gray scale brightness under the target white point color coordinates, determining that the display module is an abnormal display module.

According to a third aspect of embodiments of the present application, there is provided an electronic device comprising a processor; a memory for storing processor-executable instructions; wherein the processor is configured to implement the steps of the method of the first aspect of the embodiment of the application.

According to a fourth aspect of embodiments of the present application there is provided a computer readable storage medium having stored thereon computer program instructions which when executed by a processor perform the steps of the method of the first aspect of embodiments of the present application.

According to a fifth aspect of embodiments of the present application there is provided a computer program product comprising a computer program, characterized in that the computer program, when executed by a processor of an electronic device, implements the steps of the method according to the first aspect of embodiments of the present application.

The technical scheme provided by the embodiment of the application at least has the following beneficial effects: after the target white point color coordinates and the target gray scale brightness are obtained, judging whether the display module supports the target gray scale brightness or not so as to exclude part of the display modules which do not support the target gray scale brightness, and improving the selection efficiency of the display modules. Further, the brightness values of different gray scales can be determined according to the brightness values of the target gray scales, the color coordinates can be accurately adjusted based on the brightness values of the gray scales and the color coordinates of the target white points, and the visual effect of the display module is improved. Meanwhile, the automatic adjustment of the color coordinates of different gray scale brightness is realized according to the user requirements, the utilization rate of the display module is improved, and the time cost and the labor cost are saved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

Fig. 1 is a flowchart illustrating a color coordinate adjustment method according to an exemplary embodiment.

Fig. 2 is a flowchart illustrating a color coordinate adjustment method according to another exemplary embodiment.

Fig. 3 is a flowchart illustrating a method for generating a first mapping relationship in a color coordinate adjustment method according to an exemplary embodiment.

Fig. 4 is a flowchart illustrating a method for color coordinate adjustment to obtain a maximum gray scale luminance value supported by candidate white point color coordinates, according to an exemplary embodiment.

Fig. 5 is a flowchart of acquiring RGB luminance ratios at candidate white point color coordinates in a color coordinate adjustment method according to an exemplary embodiment.

Fig. 6 is a flowchart illustrating a method for setting up a first mapping relationship in a color coordinate adjustment method according to an exemplary embodiment.

Fig. 7 is a flowchart illustrating a color coordinate adjustment method according to another exemplary embodiment.

Fig. 8 is a flowchart illustrating a color coordinate adjustment method according to another exemplary embodiment.

Fig. 9 is a flowchart illustrating a color coordinate adjustment method according to another exemplary embodiment.

Fig. 10 is a system configuration block diagram illustrating a color coordinate adjustment method according to an exemplary embodiment.

Fig. 11 is a block diagram showing a structure of a color coordinate adjusting apparatus according to an exemplary embodiment.

Fig. 12 is a block diagram of an electronic device, according to an example embodiment.

Fig. 13 is a block diagram of an electronic device, according to an example embodiment.

Detailed Description

In order to enable a person skilled in the art to better understand the technical solutions of the present application, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. The implementations described in the following exemplary examples do not represent all implementations consistent with the application. Rather, they are merely examples of apparatus and methods consistent with aspects of the application as detailed in the accompanying claims.

The technical scheme of the application obtains, stores, uses, processes and the like the data, which all meet the relevant regulations of national laws and regulations.

The embodiment of the application provides a color coordinate adjusting method. It should be noted that, the execution main body of the color coordinate adjustment method in the embodiment of the application is an electronic device with a display module. The electronic device may be a mobile electronic device or a non-mobile electronic device. By way of example, the mobile electronic device may be a cell phone, tablet computer, notebook computer, palm computer, vehicle mounted electronic device, wearable device, ultra-mobile personal computer (ultra-mobile personal computer, UMPC), netbook or personal digital assistant (personal digital assistant, PDA), etc., and the non-mobile electronic device may be a network attached storage (Network Attached Storage, NAS), personal computer (personal computer, PC), television (TV), teller machine or self-service machine, etc., and the embodiments of the present application are not limited in particular.

As shown in fig. 1, the color coordinate adjustment method provided in the embodiment of the present application is as follows.

S101, obtaining target white point color coordinates and a target gray scale brightness value of a maximum gray scale L255.

In some implementations, the user may input the required white point color coordinates and the required gray scale luminance value of the maximum gray scale L255 into the electronic device, and the electronic device may adjust the color coordinates of the display module according to the user requirement. The required white point color coordinates input by the user on the electronic device can be used as target white point color coordinates, and the input required gray-scale brightness value can be used as the target gray-scale brightness value of the maximum gray-scale L255. For example, the input color coordinates are (0.303,0.304), and the target gray-scale luminance value is 500nit.

S102, judging whether the display module supports the target gray-scale brightness value under the target white point color coordinates.

In some implementations, the display module may include, but is not limited to, a camera module, a display module within a cell phone, and a display module in a Virtual Reality (VR) device.

In some implementations, a first mapping relationship between the white point color coordinates of the display module and the luminance value of the maximum gray level L255 may be pre-established and stored in the memory. After the target white point color coordinates are obtained, the maximum gray-scale brightness value of the display module under the target white point color coordinates can be determined by inquiring the first mapping relation. Further, whether the display module supports the target gray-scale brightness value under the target white point color coordinates can be judged by comparing the maximum gray-scale brightness value with the target gray-scale brightness value.

Optionally, if the maximum gray-scale luminance value is greater than or equal to the target gray-scale luminance value, determining that the display module supports the target gray-scale luminance value under the target white-point color coordinates; if the maximum gray-scale luminance value is smaller than the target gray-scale luminance value, determining that the display module does not support the target gray-scale luminance value under the target white-point color coordinates.

S103, if the display module supports the target gray-scale brightness value, determining different gray-scale brightness values according to the target gray-scale brightness value.

In some implementations, when the display module supports the target gray scale luminance value, the gray scale luminance value of the display module at different gray scales may be determined based on the target gray scale luminance value. Alternatively, the luminance values of different gray scales may be determined according to a functional relationship among the minimum gray scale luminance value, the characteristic parameter, and the target gray scale luminance value. Optionally, the brightness increment of any gray level may be determined according to the brightness difference between the target gray level brightness value and the minimum gray level brightness value and the characteristic parameter, and the brightness increment and the minimum gray level brightness value are added to obtain the brightness value of any gray level.

And S104, adjusting the color coordinates according to the different gray-scale brightness values and the target white point color coordinates to obtain the color coordinates of different gray scales.

In some implementations, the luminance ratio of the target RGB at the target white point color coordinates may be determined from the target white point color coordinates, and optionally, a mapping between the white point color coordinates and the luminance ratio of RGB may also be included in the first mapping. It is understood that the RGB luminance ratio represents the extent to which each channel of RGB contributes to the luminance value. In the embodiment of the application, after the target white point color coordinates are obtained, the first mapping relation can be queried to obtain the RGB brightness ratio with the mapping relation with the target white point color coordinates, and further, the RGB brightness values can be calculated according to different gray scale brightness values and the RGB brightness ratio corresponding to the target white point color coordinates. Alternatively, the gray-scale luminance value may be multiplied by the RGB luminance ratio to obtain the luminance values of RGB, respectively.

In some implementations, the digital drive values corresponding to RGB at different gray levels may be determined based on the luminance values, and further, the color coordinates at the gray level may be determined based on the digital drive values and the gray level luminance values at the same gray level. Wherein different color coordinates can be used to characterize different RGB colors, and the display panel can be driven to display the RGB colors according to the color coordinates based on inputting the color coordinates to the display panel.

In the color coordinate adjusting method provided by the embodiment of the application, after the target white point color coordinate and the target gray scale brightness are obtained, whether the display module supports the target gray scale brightness is judged, so that a part of the display module which does not support the target gray scale brightness is eliminated, and the selection efficiency of the display module can be improved. Further, the brightness values of different gray scales can be determined according to the brightness values of the target gray scales, the color coordinates can be accurately adjusted based on the brightness values of the gray scales and the color coordinates of the target white points, and the visual effect of the display module is improved. Meanwhile, the automatic adjustment of the color coordinates of different gray scale brightness is realized according to the user requirements, the utilization rate of the display module is improved, and the time cost and the labor cost are saved.

Fig. 2 is a flowchart illustrating a color coordinate adjustment method according to an exemplary embodiment, as shown in fig. 2, including, but not limited to, the following steps:

s201, obtaining target white point color coordinates and a target gray scale brightness value of a maximum gray scale L255.

In the embodiment of the present application, the implementation manner of step S201 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S202, determining a first maximum gray-scale brightness value with a mapping relation with the target white point color coordinates from a pre-generated first mapping relation.

In the embodiment of the application, a first mapping relation which is generated in advance is obtained, and a first maximum gray-scale brightness value which has the mapping relation with the target white point color coordinates is determined from the first mapping relation. The first mapping relation comprises a mapping relation between candidate white point color coordinates and maximum gray scale brightness values supported by the candidate white point color coordinates. Optionally, after determining the target white point color coordinate, the first mapping relationship may be queried to determine a first maximum gray scale luminance value corresponding to the display module under the target white point color coordinate.

S203, in response to the first maximum gray-scale luminance value being greater than or equal to the target gray-scale luminance value, determining that the display module supports the target gray-scale luminance value under the target white-point color coordinates.

In some implementations, whether the display module supports the target grayscale luminance value may be determined by comparing the first maximum grayscale luminance value to the target grayscale luminance value. If the first maximum gray-scale luminance value is greater than or equal to the target gray-scale luminance value, determining that the display module supports the target gray-scale luminance value under the target white point color coordinates.

S204, determining different gray-scale brightness values according to the target gray-scale brightness value.

In the embodiment of the present application, the implementation manner of step S204 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S205, according to different gray scale brightness values and target white point color coordinates, the color coordinates are adjusted to obtain the color coordinates of different gray scales.

In the embodiment of the present application, the implementation manner of step S205 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S206, responding that the first maximum gray-scale brightness value is smaller than the target gray-scale brightness value, determining that the display module does not support the target gray-scale brightness value under the target white point color coordinates, and determining that the display module is an abnormal display module.

In some implementations, the magnitudes of the first maximum grayscale luminance value and the target grayscale luminance value are compared, and if the first maximum grayscale luminance value is less than the target grayscale luminance value, it is determined that the display module does not support the target grayscale luminance value under the target white point color coordinates.

It should be noted that, if the display module supports the target gray scale brightness under the target white point color coordinates, the display module can be used for subsequent color coordinate adjustment; if the display module does not support the target gray scale brightness under the target white point color coordinates, determining that the display module is an abnormal display module.

On the basis of the above embodiment, the process of generating the first mapping relationship in the embodiment of the present application may be explained, as shown in fig. 3, where the process of generating the first mapping relationship includes, but is not limited to, the following steps:

s301, a predetermined RGB tone function and a second mapping relation are obtained, wherein the second mapping relation is a mapping relation between gray-scale brightness, color coordinates and brightness values of each RGB color channel when light is mixed.

In the embodiment of the application, the predetermined RGB tone function and the second mapping relation are stored in the memory, and the RGB tone function and the second mapping relation can be read from the memory.

Alternatively, the RGB tone function may be determined from the data-driven measurement and the grayscale luminance measurement of the sampled picture.

Optionally, N sampling pictures can be obtained by sampling the images, measurement data of each sampling image is obtained, and based on the measurement data, least square regression is performed on a preset RGB tone function to determine characteristic parameters of the RGB tone function, so as to obtain the RGB tone function. Wherein the measurement data includes a data driving measurement value and a gray scale luminance measurement value.

In some implementations, since the input and output of the display module are in an exponential trend, the prior art uses a fixed formula to perform color coordinate adjustment, and cannot accurately approximate the characteristic curve of the display module, which affects the accuracy of color coordinate adjustment. In order to improve the accuracy of color coordinate adjustment, the method is used for sampling the picture to obtain an RGB tone function, and the color coordinate is adjusted based on the RGB tone function.

Optionally, taking the logarithm of the exponential model of the display module, and sampling the image based on the logarithmic function, wherein the sampling formula is as follows:

wherein j is the sampling number, n is the sampling number, D _j Is the gray scale value of the jth sampling image, D _max Is the picture gray-scale maximum L255.

TABLE 1

j	0	1	2	3	4	5	6	7	8	9
											D(n＝6)	0	43	95	142	185	222	255
D(n＝7)	0	35	81	123	161	195	226	255
											D(n＝8)	0	29	70	108	142	174	203	230	255
D(n＝9)	0	25	61	95	127	157	184	209	233	255

It will be appreciated that each element in table 1 is independent, and that these elements are illustratively listed in the same table, but do not represent that all elements in the table must exist simultaneously in accordance with what is shown in the table. Wherein the value of each element is independent of any other element value in table 1. It will be appreciated by those skilled in the art that the values of each of the elements in Table 1 are a separate embodiment.

For example, when the sampling number n=6, the gray levels of the first to sixth pictures are 0, 43, 95, 142, 185, 222, 255, respectively.

Optionally, an RGB tone function of the display module may be preset, where the RGB tone function is a relationship between an RGB data driving measurement value and a luminance value when mixing light of each color channel of RGB, and is shown in the following formula:

wherein Y is the brightness measurement value of each RGB color channel when mixing light, and comprises Y _r 、Y _g 、Y _b The method comprises the steps of carrying out a first treatment on the surface of the D is a digital drive value comprising D _r 、D _g 、D _b The method comprises the steps of carrying out a first treatment on the surface of the K is a characteristic parameter, and γ is an input/output characteristic parameter under a specific backlight condition.

In some implementations, the tone function may also be described using a quadratic polynomial in order to improve the accuracy in color coordinate adjustment. The formula is as follows:

Y＝K ₁ D ² -K ₂ D+K ₃ (3)

Wherein Y is the brightness measurement value of each RGB color channel when mixing light, and comprises Y _r 、Y _g 、Y _b The method comprises the steps of carrying out a first treatment on the surface of the D is a digital drive value comprising D _r 、D _g 、D _b The method comprises the steps of carrying out a first treatment on the surface of the K is a characteristic parameter.

Further, taking the logarithm of the RGB tone function to obtain a linear correlation function between the digital driving value and the brightness value of each RGB color channel when mixing light, wherein the linear correlation function is as follows:

LgY _i ＝γ _i Lg(D _i )+Lg(K _i ) (i＝r，g，b) (4)

the measurement data of the N sampled images is (LgD) _r0 ，LgY _r0 )，(LgD _r1 ，LgY _r1 )，(LgD _r2 ，LgY _r2 )，(LgD _r3 ，LgY _r3 )……(LgD _r[N-1] ，LgY _r[N-1] )。

Alternatively, lgD of the jth sample image may be determined based on equation (1) _rj The method comprises the steps of carrying out a first treatment on the surface of the Optionally, the jth sample image is measured based on a color analyzer, such as CA310, to obtain LgY _rj 。

In some implementations, regression analysis may be performed on the preset RGB tone function with the line y=ax+b to determine the characteristic parameters of the RGB tone function. The formula for calculating the characteristic parameters of the RGB tone function is as follows:

wherein,x _i representation LgD _rj ，/>Represents N sample data LgD _rj Average value of y _i Representation LgY _rj ，/>Represents N sample data LgY _rj Average value of (2).

And (3) carrying the measurement data into a formula (4) to obtain values of characteristic parameters gamma and K in the RGB tone function and obtain the RGB tone function.

For example, the RGB tone function may be:

alternatively, a second mapping relationship may be determined according to a conversion matrix and a conversion relationship of the color gamut converted from RGB to XYZ by the candidate white point color coordinates, the second mapping relationship representing a mapping relationship between the gray-scale luminance, the color coordinates, and the luminance values when the RGB color channels are mixed.

In some implementations, a gamut conversion matrix that maps from the RGB gamut to the XYZ gamut is determined, and a conversion relationship between the color coordinates and the XYZ gamut is determined, and a second mapping relationship is derived based on the gamut conversion matrix and the conversion relationship.

In some implementations, Y is converted to Y using a gamut conversion matrix _i Converting from an RGB color gamut to an XYZ color gamut. Alternatively, the gamut conversion matrix may be calculated by a special position method. Setting the color and conversion matrix as matrix A, and calculating the coefficient a of the matrix A by testing the tristimulus values of (128,0,0), (0,128,0) and (0,0,128) or the tristimulus values of (255, 0) (0,255,0) (0,0,255) _ij (i，j＝1,2,3)。

Illustratively, the values of the gamut conversion matrix a may be:

alternatively, in order to adjust the color coordinates, a color space that is independent of the display module, such as an XYZ color gamut space, may be selected to transform the RGB color gamut space into the XYZ color gamut space. Alternatively, it is possible to convert from the RGB color gamut space to the XYZ color gamut space by a conversion formula according to the color gamut conversion matrix. The conversion formula for converting from the RGB color gamut space to the XYZ color gamut space is as follows:

in some implementations, the color coordinates are in a conversion relationship with the XYZ color gamut such that the color coordinates can be converted to XYZ color gamut space. The color coordinates are (x, y), and the conversion relation is as follows:

Wherein L is the luminance value of the maximum gray level L255.

Alternatively, the color gamut conversion matrix and the conversion relationship are substituted into the formula (7), and a mapping relationship between the maximum gray-scale luminance, the color coordinates, and the luminance value when the RGB color channels are mixed can be obtained as the second mapping relationship. The second mapping relationship is as follows:

s302, based on the second mapping relation, the RGB tone function and the candidate white point color coordinates are operated to obtain the maximum gray scale brightness value supported by the candidate white point color coordinates.

In some implementations, the RGB tone function and the candidate white point color coordinates may be input into the second mapping relationship to perform an operation, so as to obtain a third mapping relationship between the maximum gray-scale brightness and the digital driving values corresponding to the RGB color channels. Further, based on the third mapping relation and the preset digital driving value of each RGB color channel under the maximum gray scale, the candidate maximum gray scale brightness value under the candidate white point color coordinates can be obtained, further, the candidate maximum gray scale brightness value is compared, and the minimum maximum gray scale brightness value is used as the candidate maximum gray scale brightness value supported by the candidate white point color coordinates.

S303, generating a first mapping relation based on each candidate white point color coordinate and the maximum gray scale brightness value supported by the candidate white point color coordinate.

In some implementations, the RGB tone function and each candidate white point color coordinate are input into a second mapping relationship for operation, resulting in a maximum grayscale luminance value supported by each candidate white point color coordinate. And storing each candidate white point color coordinate and the supported maximum gray scale brightness value as a lookup table as a first mapping relation.

In the color coordinate adjusting method provided by the embodiment of the application, the data driving measured value and the gray scale brightness measured value of the sampled picture are obtained by sampling the image, so that the RGB tone function is determined, the RGB tone function is obtained according to the color characteristics of the sampled picture, and the accuracy of color coordinate adjustment can be improved. And generating a second mapping relation based on the tone function and the target white point color coordinates, and obtaining a maximum gray scale brightness value supported by the candidate white point color coordinates according to the second mapping relation so as to generate a first mapping relation. The first mapping relation is stored in the memory, and the color coordinates can be automatically adjusted according to the requirements of users on the color coordinates and the maximum brightness value, so that the utilization rate of the display module is improved, and the time cost and the labor cost are saved. After the target white point color coordinates are obtained, whether the display module supports the target gray scale brightness or not can be determined according to the first mapping relation, so that part of the display modules which do not support the target gray scale brightness can be eliminated, and the selection efficiency of the display modules can be improved. Further, the brightness values of different gray scales can be determined according to the brightness values of the target gray scales, accurate adjustment of the color coordinates is achieved based on the brightness values of the gray scales and the color coordinates of the target white points, and the visual effect of the display module is improved.

On the basis of the above embodiment, the process of obtaining the maximum gray-scale luminance value supported by the candidate white-point color coordinates according to the embodiment of the present application may be explained, as shown in fig. 4, and includes, but is not limited to, the following steps:

s401, inputting the RGB tone function and the candidate white point color coordinates into a second mapping relation to obtain a third mapping relation between the maximum gray scale brightness and the digital driving value corresponding to each RGB color channel.

In some implementations, the RGB tone function and the candidate white point color coordinates are input into the above formula (9), so as to obtain a third mapping relationship between the maximum gray-scale brightness and the digital driving values corresponding to the RGB color channels. The third mapping relationship is as follows:

wherein L is the maximum gray scale brightness, D _r 、D _g 、D _b Is the digital driving value corresponding to each RGB color channel, c ₁ 、c ₂ 、c ₃ Is a parameter of the third mapping relation, and parameters corresponding to different white point color coordinates are different.

Illustratively, in the case where the white point color coordinates are (0.3312,0.303), the third mapping relationship may be represented by the following formula (11)

S402, obtaining a candidate maximum gray-scale brightness value under the candidate white point color coordinates based on the third mapping relation and the preset digital driving value of each RGB color channel under the maximum gray scale.

Alternatively, the preset digital driving values of the RGB color channels under the maximum gray level may be substituted into the formula (10), to obtain three candidate maximum gray level luminance values under the candidate white point color coordinates.

S403, comparing the candidate maximum gray-scale brightness values, obtaining a minimum gray-scale brightness value from the candidate maximum gray-scale brightness values, and taking the minimum gray-scale brightness value as the maximum gray-scale brightness value supported by the candidate white point color coordinates.

In some implementations, the minimum gray-scale luminance value is selected from the candidate maximum gray-scale luminance values and is used as the maximum gray-scale luminance value supported by the candidate white-point color coordinates, so that the candidate white-point color coordinates can be ensured to have enough luminance, the expected adjustment requirement is met, and the image distortion caused by overlarge adjusted luminance value is avoided.

Illustratively, assuming that the candidate white point color coordinates are (0.3312,0.303), the third mapping relationship is as shown in formula (11), D in the digital driving value is preset _r Inputting the maximum gray-scale brightness value obtained in the formula (1) in the formula (11) as 1162nit and presetting D in the digital driving value _g Inputting the maximum gray-scale brightness value obtained in the formula (2) in the formula (11) to 1760nit, and presetting D in the digital driving value _g The maximum gray-scale luminance value obtained by inputting the formula (3) in the formula (11) is 1431nit. And comparing the three maximum gray-scale brightness values, wherein the minimum gray-scale brightness value is 1162nit, and taking 1162nit as the maximum gray-scale brightness value supported by the candidate white point color coordinates.

On the basis of the above embodiment, the process of obtaining the RGB luminance ratio in the candidate white point color coordinates according to the embodiment of the present application may be explained, as shown in fig. 5, and includes, but is not limited to, the following steps:

s501, inputting the maximum gray-scale brightness value supported by the candidate white point color coordinates into a third mapping relation to obtain digital driving values corresponding to each RGB color channel under the maximum gray scale.

In some implementations, the first mapping relationship further includes a mapping relationship between the candidate white point color coordinates and the RGB luminance ratios at the candidate white point color coordinates, and the RGB luminance ratios at the candidate white point color coordinates may be determined based on the third mapping relationship and the RGB tone function.

Optionally, inputting the maximum gray-scale brightness value supported by the candidate white-point color coordinates into the third mapping relation, so as to obtain digital driving values corresponding to each RGB color channel under the maximum gray scale, and further obtaining the brightness ratio of RGB according to the digital driving values and the RGB tone function.

S502, inputting the digital driving value corresponding to each RGB color channel under the maximum gray scale into the RGB tone function to obtain the brightness value when each RGB color channel is mixed.

In some implementations, the digital driving values corresponding to the RGB color channels under the maximum gray scale can be input into the RGB tone function (2) to obtain the brightness value Y when the RGB color channels are mixed _r 、Y _g 、Y _b 。

S503, obtaining RGB brightness ratio under the candidate white point color coordinates based on the brightness value of the mixed light on each RGB color channel.

In some implementations, the luminance ratio of each color channel may be obtained by calculating the ratio of the sum of the luminance values of the RGB color channels and the luminance values of the mixing light on each color channel, thereby obtaining the RGB luminance ratio under the candidate white point color coordinates, which is shaped as R: G: B.

The RGB luminance ratios of the different maximum gray-scale luminance values are the same in the same candidate white point color coordinates.

S504, a mapping relation between the candidate white point color coordinates and the RGB brightness ratio under the candidate white point color coordinates is established and stored in a first mapping relation.

Optionally, after the RGB luminance ratio under the candidate white point color coordinate is obtained, the mapping relationship between the established candidate white point color coordinate and the RGB luminance ratio under the candidate white point color coordinate may be set, and the RGB luminance ratio under the candidate white point color coordinate is stored in the first mapping relationship based on the candidate white point color coordinate, so that the first mapping relationship may include the mapping relationship between the candidate white point color coordinate, the maximum gray-scale luminance supported by the candidate white point color coordinate, and the luminance ratio under the candidate white point color coordinate, which is specifically shown in table 2 in the present application. In the color coordinate adjusting method provided by the embodiment of the application, after the target white point color coordinate and the target gray scale brightness are obtained, whether the display module supports the target gray scale brightness is judged, so that a part of the display module which does not support the target gray scale brightness is eliminated, and the selection efficiency of the display module can be improved. Further, the brightness values of different gray scales can be determined according to the brightness values of the target gray scales, the color coordinates can be accurately adjusted based on the brightness values of the gray scales and the color coordinates of the target white points, and the visual effect of the display module is improved. Meanwhile, a first mapping relation formed by the white point color coordinates, the maximum brightness value and the RGB brightness ratio is stored in the memory, so that the color coordinates can be automatically adjusted according to the requirements of users on the color coordinates and the maximum brightness value, the utilization rate of the display module is improved, and the time cost and the labor cost are saved.

On the basis of the above embodiment, the process of establishing the first mapping relationship in the embodiment of the present application may be explained, as shown in fig. 6, and includes, but is not limited to, the following steps:

s601, a predetermined RGB tone function and a second mapping relation are obtained, wherein the second mapping relation is a mapping relation between gray-scale brightness, color coordinates and brightness values of each RGB color channel when light is mixed.

In the embodiment of the present application, the implementation manner of step S601 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S602, based on the second mapping relation, the RGB tone function and the candidate white point color coordinates are operated to obtain the maximum gray scale brightness value supported by the candidate white point color coordinates.

In the embodiment of the present application, the implementation manner of step S602 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S603, inputting the RGB tone function and the candidate white point color coordinates into a second mapping relation to obtain a third mapping relation between the maximum gray scale brightness and the digital driving value corresponding to each RGB color channel.

In the embodiment of the present application, the implementation manner of step S603 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S604, obtaining a candidate maximum gray-scale brightness value under the candidate white point color coordinates based on the third mapping relation and the preset digital driving value of each RGB color channel under the maximum gray scale.

In the embodiment of the present application, the implementation manner of step S604 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S605, comparing the candidate maximum gray-scale brightness values, obtaining a minimum gray-scale brightness value from the candidate maximum gray-scale brightness values, and taking the minimum gray-scale brightness value as the maximum gray-scale brightness value supported by the candidate white point color coordinates.

In the embodiment of the present application, the implementation manner of step S605 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S606, inputting the maximum gray-scale brightness value supported by the candidate white point color coordinates into a third mapping relation to obtain digital driving values corresponding to each RGB color channel under the maximum gray scale.

In the embodiment of the present application, the implementation manner of step S606 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S607, inputting the digital driving value corresponding to each RGB color channel under the maximum gray scale into the RGB tone function to obtain the brightness value when each RGB color channel mixes light.

In the embodiment of the present application, the implementation manner of step S607 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S608, obtaining the RGB brightness ratio under the candidate white point color coordinates based on the brightness value of the mixed light on each RGB color channel.

In the embodiment of the present application, the implementation manner of step S608 may be implemented by any manner of each embodiment of the present application, which is not limited herein, and is not described herein again.

S609, a first mapping relationship is generated based on each candidate white point color coordinate and the maximum gray scale luminance value supported by the candidate white point color coordinate, and the RGB luminance ratio under the candidate white point color coordinate.

After obtaining the maximum gray-scale luminance value supported by each candidate white-point color coordinate and the RGB luminance ratio under the candidate white-point color coordinate, the mapping relationship between the established candidate white-point color coordinate-the maximum gray-scale luminance value supported by the candidate white-point color coordinate-the RGB luminance ratio under the candidate white-point color coordinate may be obtained, and the lookup table shown in table 2 is obtained in the first mapping relationship.

TABLE 2

It will be appreciated that each element in table 2 is independent, and that these elements are illustratively listed in the same table, but do not represent that all elements in the table must exist simultaneously in accordance with what is shown in the table. Wherein the value of each element is independent of any other element value in table 2. It will be appreciated by those skilled in the art that the values of each element in Table 2 are a separate embodiment.

Fig. 7 is a flowchart illustrating a color coordinate adjustment method according to an exemplary embodiment, as shown in fig. 7, including, but not limited to, the following steps:

s701, obtaining a target white point color coordinate and a target gray scale brightness value of a maximum gray scale L255.

In the embodiment of the present application, the implementation manner of step S701 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S702, judging whether the display module supports the target gray-scale brightness value under the target white point color coordinates.

In the embodiment of the present application, the implementation manner of step S702 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S703, if the display module supports the target gray-scale luminance value, determining different gray-scale luminance values according to the target gray-scale luminance value.

In the embodiment of the present application, the implementation manner of step S703 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S704, obtaining the brightness ratio of the target RGB under the target white point color coordinates.

In some implementations, the first mapping includes a mapping between candidate white point color coordinates and RGB luminance ratios corresponding to the candidate white point color coordinates. Optionally, based on the target white point color coordinates, inquiring the first mapping relation, and acquiring the RGB brightness ratio with the mapping relation with the target white point color coordinates as the brightness ratio of the target RGB under the target white point color coordinates.

S705, for any gray level n, determining the brightness value of each RGB color channel in gray level n when mixing light according to the gray level brightness value in gray level n and the target RGB brightness ratio.

It will be appreciated that the RGB luminance ratio represents the contribution of R, G, B color channels to the maximum gray scale luminance value, and determines the size of the luminance value of each color channel at the maximum gray scale luminance value of R, G, B.

In some implementations, the gray-scale luminance value at the gray-scale n may be multiplied by the target RGB luminance ratio to obtain the luminance value when the RGB color channels mix. Let the brightness value of each RGB color channel when mixing light be Y _r 、Y _g 、Y _b 。

S706, based on the brightness value of each RGB color channel under the gray scale n when mixing light, obtaining the digital driving value corresponding to each RGB color channel under the gray scale n.

In some implementations, the predetermined RGB tone function may determine the digital driving value corresponding to each of the RGB color channels based on the luminance value of the RGB color channels when mixing light. Let the digital driving value corresponding to each RGB color channel be D _r 、D _g 、D _b . Wherein, the exponential relation between the digital driving value and the brightness constitutes the RGB tone function.

Optionally, the brightness value of each RGB color channel under the gray level n when mixing light is input into a predetermined RGB tone function, and the digital driving value corresponding to each RGB color channel under the gray level n is determined, wherein the RGB tone function is the mapping relationship between the brightness value of each RGB color channel when mixing light and the corresponding digital driving value.

S707, based on the digital driving values corresponding to the RGB color channels under the gray scale n, the color coordinates are adjusted to obtain the color coordinates of the gray scale n.

In some implementations, the maximum grayscale luminance L of L255 at the grayscale n may be determined based on the digital driving values corresponding to the RGB color channels and based on the third mapping relationship _max Further, L will _max And the brightness value of each RGB color channel under the gray scale n when mixing light is input into a formula (8) to obtain the color coordinates of the adjusted gray scale n.

In the color coordinate adjusting method provided by the embodiment of the application, after the target white point color coordinate and the target gray-scale brightness are obtained, whether the display module supports the target gray-scale brightness or not is judged so as to exclude part of the display module which does not support the target gray-scale brightness, and the selecting efficiency of the display module can be improved. Further, the brightness values of different gray scales can be determined according to the brightness values of the target gray scales, so that accurate adjustment of color coordinates can be realized, and the visual effect of the display module is improved. Meanwhile, a first mapping relation formed by the white point color coordinates, the maximum brightness value and the RGB brightness ratio is stored in the memory, so that the color coordinates can be automatically adjusted according to the requirements of users on the color coordinates and the maximum brightness value, the utilization rate of the display module is improved, and the time cost and the labor cost are saved.

Fig. 8 is a flowchart illustrating a color coordinate adjustment method according to an exemplary embodiment, as shown in fig. 8, including, but not limited to, the following steps:

s801, obtaining a target white point color coordinate and a target gray scale brightness value of a maximum gray scale L255.

In the embodiment of the present application, the implementation manner of step S801 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S802, determining that the display module supports the target gray-scale brightness value under the target white point color coordinates.

In the embodiment of the present application, the implementation manner of step S802 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

S803, obtaining the minimum gray-scale brightness value.

In some implementations, the gray scale ranges from 0 to 255, where 0 represents the darkest black and 255 represents the brightest white. The minimum gray-scale luminance value is a luminance value of 0 gray scale.

S804, for any gray level n, determining the gray level brightness value of the gray level n based on the target gray level brightness value and the minimum gray level brightness value.

In some implementations, for any gray level n, the gray level luminance value of the gray level n may be determined from the luminance difference between the gray level n and the target and minimum gray level luminance values, and the characteristic parameter.

Alternatively, the luminance increment value of the gray level n is determined by acquiring the luminance difference between the target gray level luminance value and the minimum gray level luminance value, based on the gray level n, the luminance difference, and the predetermined input/output characteristic parameter under the specific backlight condition. And obtaining the gray-scale brightness value of the gray-scale n according to the gray-scale brightness value and the brightness increment value of the minimum gray-scale. Wherein, the sum of the gray-scale brightness value and the brightness increment value of the minimum gray-scale is the gray-scale brightness value of the gray-scale n. The calculation formula is as follows:

LVn _n ＝(Ln/255)(Ln/255) ^γ *(LV _P -LV ₀ )+LV ₀ (12)

Wherein LV is _n A gray-scale luminance value of gray-scale n, ln is gray-scale n, gamma is a characteristic parameter, LV _p Is the target gray-scale brightness value, LV ₀ Is the minimum gray scale luminance value.

S805, according to the different gray scale brightness values and the target white point color coordinates, the color coordinates are adjusted to obtain the color coordinates of different gray scales.

In the embodiment of the present application, the implementation manner of step S805 may be implemented by any one of the embodiments of the present application, which is not limited herein, and is not described herein again.

In the color coordinate adjusting method provided by the embodiment of the application, after the target white point color coordinate and the target gray scale brightness are obtained, whether the display module supports the target gray scale brightness is judged, so that a part of the display module which does not support the target gray scale brightness is eliminated, and the selection efficiency of the display module can be improved. Further, the brightness values of different gray scales can be determined according to the brightness values of the target gray scales, so that accurate adjustment of color coordinates can be realized, and the visual effect of the display module is improved. Meanwhile, a first mapping relation formed by the white point color coordinates, the maximum brightness value and the RGB brightness ratio is stored in the memory, so that the color coordinates can be automatically adjusted according to the requirements of users on the color coordinates and the maximum brightness value, the utilization rate of the display module is improved, and the time cost and the labor cost are saved.

Fig. 9 is a flowchart illustrating a color coordinate adjustment method according to an exemplary embodiment, as shown in fig. 9, including, but not limited to, the following steps:

and S901, performing range division on all gray scales to obtain different gray scale ranges.

In some implementations, in order to more precisely adjust the color coordinates, gray scales may be range-divided to obtain different gray scale ranges, each corresponding to an RGB tone function. Alternatively, the value of the segmentation parameter w, w representing the number of divided gray-scale ranges may be set. For example, when w=3, the range division may be performed in accordance with low gray levels (0 to 63), medium gray levels (64 to 191), and high gray levels (192 to 255). Different gray scale ranges can be set by oneself, for example, 0-10 is the first gray scale range, 11-50 is the second gray scale range, and 51-255 is the third gray scale range.

It should be noted that, when the accuracy requirement for color coordinate adjustment is low, w may be set to a smaller value; when the accuracy requirement for color coordinate adjustment is high, w may be set to a larger value.

S902, for each gray scale range, RGB tone functions of the gray scale range are generated in advance.

In some implementations, an RGB tone function as in equation (2) may be preset, for each gray scale range, the images within the gray scale range are sampled, and the data driving measurement and the gray scale luminance measurement for each sampled image are obtained. And carrying out least square regression on a preset RGB tone function based on the data driving measured value and the gray scale brightness measured value so as to determine characteristic parameters of the RGB tone function and obtain the RGB tone function in the gray scale range.

S903, determining digital driving values corresponding to RGB color channels under each gray scale in the gray scale range according to RGB tone functions of the gray scale range in different gray scale ranges, and performing color coordinate adjustment based on the digital driving values.

In some implementations, the luminance value of the minimum gray level in the different gray level ranges is obtained, and the gray level luminance value of any gray level can be determined according to formula (12). And determining the brightness duty ratio of the target RGB from the first mapping relation according to the target white point color coordinates, and further determining the brightness value of each RGB color channel when mixing light according to the gray scale brightness value and the RGB brightness duty ratio. Based on the brightness value of each RGB color channel when mixing light, according to the RGB tone function of different gray scale ranges, the digital driving value corresponding to each RGB color channel under each gray scale in the current gray scale range can be determined, and then the color coordinates under different gray scales can be adjusted.

According to the color coordinate adjusting method provided by the embodiment of the application, different gray scale ranges can be divided according to the requirements for color coordinate precision adjustment, so that tone functions in different gray scale ranges are generated, and the precision of color coordinate adjustment is improved. Based on tone functions in different gray scale ranges, a first mapping relation can be generated, after the color coordinates of a target white point are obtained, the brightness ratio of RGB can be determined according to the first mapping relation, the brightness values of different gray scales are determined, further, the digital driving value corresponding to RGB under each gray scale is obtained, the color coordinates are adjusted based on the digital driving value, and the visual effect of the display module is improved. Meanwhile, a first mapping relation formed by the white point color coordinates, the maximum brightness value and the RGB brightness ratio is stored in the memory, so that the color coordinates can be automatically adjusted according to the requirements of users on the color coordinates and the maximum brightness value, the utilization rate of the display module is improved, and the time cost and the labor cost are saved.

The color coordinate adjustment system shown in fig. 10 is composed of three parts, namely an application processor (Application Processor, AP), a Driver chip (Driver Integrated Circuit, driver IC), and a display panel. The AP comprises a central processing unit (Central Processing Unit, CPU) and application software; the driver chip includes a display serial interface (Display Serial Interface, DSI), a random access memory (Random Access Memory, RAM), a clock control and processing chip. The driving chip comprises a line buffer and a source driver, wherein digital driving values can be buffered in the line buffer, and the display panel is driven by the source driver to realize adjustment of color coordinates.

The CPU and application software input image data to the driver chip through respective interfaces. The DSI Interface (I/F) receives the image data transmitted by the CPU and processes the image data in a chip, wherein the clock control is used for ensuring synchronization, the processing chip can be a field programmable gate array (Field Programmable Gate Array, FPGA), and the processing chip can be applied to the fields of communication, image processing, automobile electronics, industrial control and the like. A Look-Up Table (LUT), i.e., a first mapping relationship, is stored in the RAM, and the LUT is input into the processing chip. The processing chip may determine a numerical driving value corresponding to the image data according to the method in the above embodiment based on the first mapping relationship, and perform real-time color difference adjustment on the image by driving the display panel by using the source, that is, implement automatic and accurate adjustment on the color coordinates by combining with the LUT.

Fig. 11 is a block diagram showing a structure of a color coordinate adjusting apparatus according to an exemplary embodiment. Referring to fig. 11, a color coordinate adjusting apparatus 1100 according to an embodiment of the present application includes: an acquisition module 1101, a judgment module 1102, a determination module 1103 and an adjustment module 1104.

The obtaining module 1101 is configured to obtain a target white point color coordinate and a target gray-scale luminance value of the maximum gray-scale L255.

The judging module 1102 is configured to judge whether the display module supports the target gray-scale luminance value under the target white point color coordinate.

The determining module 1103 is configured to determine different gray-scale luminance values according to the target gray-scale luminance value if the display module supports the target gray-scale luminance value.

The adjustment module 1104 is configured to adjust the color coordinates according to the different gray-scale luminance values and the target white point color coordinates to obtain color coordinates of different gray scales.

In one embodiment of the present application, the adjustment module 1104 is further configured to: acquiring the brightness ratio of the target RGB under the target white point color coordinates; for any gray scale n, determining the brightness value of each RGB color channel under the gray scale n when mixing light according to the gray scale brightness value under the gray scale n and the target RGB brightness ratio; acquiring digital driving values corresponding to the RGB color channels under the gray scale n based on brightness values of the RGB color channels under the gray scale n when light is mixed; and adjusting the color coordinates based on the digital driving values corresponding to the RGB color channels under the gray scale n to obtain the color coordinates of the gray scale n.

In one embodiment of the present application, the determining module 1103 is further configured to: obtaining a minimum gray-scale brightness value; for any gray level n, determining a gray level luminance value of the gray level n based on the target gray level luminance value and the minimum gray level luminance value.

In one embodiment of the present application, the determining module 1103 is further configured to: acquiring a brightness difference between the target gray-scale brightness value and the minimum gray-scale brightness value; determining a brightness increment value of the gray level n according to the gray level n, the brightness difference and a predetermined input/output characteristic parameter under a specific backlight condition; and obtaining the gray-scale brightness value of the gray-scale n according to the gray-scale brightness value of the minimum gray-scale and the brightness increment value.

In one embodiment of the present application, the adjustment module 1104 is further configured to: and inputting the brightness value of each RGB color channel under the gray scale n when mixing light into a predetermined RGB tone function, and determining the digital driving value corresponding to each RGB color channel under the gray scale n, wherein the RGB tone function is the mapping relation between the brightness value of each RGB color channel when mixing light and the corresponding digital driving value.

In one embodiment of the present application, the determining module 1102 is further configured to: acquiring a first mapping relation generated in advance, wherein the first mapping relation comprises a mapping relation between candidate white point color coordinates and a maximum gray scale brightness value supported by the candidate white point color coordinates; determining a first maximum gray-scale brightness value with a mapping relation with the target white point color coordinates from the first mapping relation; determining that the display module supports the target gray-scale luminance value under the target white-point color coordinates in response to the first maximum gray-scale luminance value being greater than or equal to the target gray-scale luminance value; and responding to the first maximum gray-scale luminance value being smaller than the target gray-scale luminance value, and determining that the display module does not support the target gray-scale luminance value under the target white point color coordinates.

In one embodiment of the present application, the determining module 1102 is further configured to: acquiring a predetermined RGB tone function and a second mapping relation, wherein the second mapping relation is a mapping relation between gray-scale brightness, color coordinates and brightness values of RGB color channels when light is mixed; based on the second mapping relation, calculating the RGB tone function and the candidate white point color coordinates to obtain a maximum gray scale brightness value supported by the candidate white point color coordinates; and generating the first mapping relation based on each candidate white point color coordinate and the maximum gray scale brightness value supported by the candidate white point color coordinate.

In one embodiment of the present application, the determining module 1102 is further configured to: inputting the RGB tone function and the candidate white point color coordinates into the second mapping relation to obtain a third mapping relation between the maximum gray scale brightness and the digital driving values corresponding to the RGB color channels; obtaining a candidate maximum gray scale brightness value under the candidate white point color coordinates based on the third mapping relation and a preset digital driving value of each RGB color channel under the maximum gray scale; and comparing the candidate maximum gray-scale brightness values, obtaining a minimum gray-scale brightness value from the candidate maximum gray-scale brightness values, and taking the minimum gray-scale brightness value as the maximum gray-scale brightness value supported by the candidate white-point color coordinates.

In one embodiment of the present application, the determining module 1102 is further configured to: inputting the maximum gray-scale brightness value supported by the candidate white-point color coordinates into the third mapping relation to obtain digital driving values corresponding to all RGB color channels under the maximum gray scale; inputting the digital driving value corresponding to each RGB color channel under the maximum gray scale into the RGB tone function to obtain the brightness value of each RGB color channel when mixing light; obtaining RGB brightness ratio under the candidate white point color coordinates based on brightness values of mixed lights on the RGB color channels; and establishing a mapping relation between the candidate white point color coordinates and RGB brightness ratios under the candidate white point color coordinates, and storing the mapping relation in the first mapping relation.

In one embodiment of the present application, the determining module 1102 is further configured to: and inquiring the first mapping relation based on the target white point color coordinate, and acquiring the RGB brightness ratio with the mapping relation with the target white point color coordinate as the brightness ratio of target RGB under the target white point color coordinate.

In one embodiment of the present application, the determining module 1102 is further configured to: sampling the images to obtain N sampling pictures, and obtaining measurement data of each sampling image, wherein the measurement data comprises a data driving measurement value and a gray scale brightness measurement value; and carrying out least square regression on a preset RGB tone function based on the measurement data to determine characteristic parameters of the RGB tone function and obtain the RGB tone function.

In one embodiment of the present application, the determining module 1102 is further configured to: determining a gamut conversion matrix mapped from the RGB gamut to the XYZ gamut; determining a conversion relation between the color coordinates and the XYZ color gamut; and obtaining the second mapping relation based on the color gamut conversion matrix and the conversion relation.

In one embodiment of the present application, the adjustment module 1104 is further configured to: dividing the range of all gray scales to obtain different gray scale ranges; generating an RGB tone function of each gray scale range in advance for the gray scale range; and determining digital driving values corresponding to RGB color channels under each gray scale in the gray scale range according to RGB tone functions of the gray scale range in different gray scale ranges, and performing color coordinate adjustment based on the digital driving values.

In one embodiment of the present application, the determining module 1102 is further configured to: and if the display module does not support the target gray scale brightness under the target white point color coordinates, determining that the display module is an abnormal display module.

In the color coordinate adjusting device provided by the embodiment of the application, after the target white point color coordinate and the target gray-scale brightness are obtained, whether the display module supports the target gray-scale brightness is judged, so that a part of the display module which does not support the target gray-scale brightness is eliminated, and the selection efficiency of the display module can be improved. Further, the brightness values of different gray scales can be determined according to the brightness values of the target gray scales, the color coordinates can be accurately adjusted based on the brightness values of the gray scales and the color coordinates of the target white points, and the visual effect of the display module is improved. Meanwhile, the automatic adjustment of the color coordinates of different gray scale brightness is realized according to the user requirements, the utilization rate of the display module is improved, and the time cost and the labor cost are saved.

Fig. 12 is a block diagram of an electronic device, according to an example embodiment. The electronic device shown in fig. 12 is only an example and should not be construed as limiting the functionality and scope of use of the embodiments of the application.

As shown in fig. 12, the electronic device 1200 includes a processor 1201, which can perform various appropriate actions and processes according to a program stored in a Read Only Memory (ROM) 1202 or a program loaded from a Memory 1206 into a random access Memory (Random Access Memory, RAM) 1203. In the RAM 1203, various programs and data required for the operation of the electronic apparatus 1200 are also stored. The processor 1201, the ROM 1202, and the RAM 1203 are connected to each other through a bus 1204. An Input/Output (I/O) interface 1205 is also connected to bus 1204.

The following components are connected to the I/O interface 1205: a memory 1206 including a hard disk or the like; and a communication section 1209 including a network interface card such as a local area network (Local Area Network, LAN) card, a modem, or the like, the communication section 1209 performing communication processing via a network such as the internet; the drive 1208 is also connected to the I/O interface 1205 as needed.

In particular, according to embodiments of the present application, the processes described above with reference to flowcharts may be implemented as computer software programs. For example, embodiments of the present application include a computer program embodied on a computer readable medium, the computer program containing program code for performing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication section 1209. The above-described functions defined in the method of the present application are performed when the computer program is executed by the processor 1201.

In an exemplary embodiment, a storage medium is also provided, such as a memory, comprising instructions executable by the processor 1201 of the electronic device 1200 to perform the method described above. Alternatively, the storage medium may be a non-transitory computer readable storage medium, which may be, for example, ROM, random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like.

In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. In the present application, however, the computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, with the computer-readable program code embodied therein. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, fiber optic cable, RF, etc., or any suitable combination of the foregoing.

Fig. 13 is a block diagram of an electronic device, according to an example embodiment. The electronic device shown in fig. 13 is merely an example, and should not impose any limitation on the functionality and scope of use of embodiments of the present application. As shown in fig. 13, the electronic device 1300 includes a processor 1301, a memory 1302. The memory 1302 is used for storing program codes, and the processor 1301 is connected to the memory 1302, and is used for reading the program codes from the memory 1302 to implement the color coordinate adjustment method in the above embodiment.

Alternatively, the number of processors 1301 may be one or more.

Optionally, the electronic device may further include an interface 1303, and the number of the interfaces 1303 may be plural. The interface 1303 may be connected to an application program, and may receive data of an external device such as a sensor, or the like.

Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It is to be understood that the application is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. A color coordinate adjustment method, comprising:

obtaining a target white point color coordinate and a target gray scale brightness value of a maximum gray scale L255;

judging whether the display module supports the target gray-scale brightness value under the target white-point color coordinates;

if the display module supports the target gray-scale brightness value, determining different gray-scale brightness values according to the target gray-scale brightness value;

and adjusting the color coordinates according to the different gray scale brightness values and the color coordinates of the target white point to obtain the color coordinates of different gray scales.

2. The method of claim 1, wherein adjusting the color coordinates to obtain color coordinates of different gray scales based on different gray scale luminance values and the target white point color coordinates comprises:

acquiring the brightness ratio of the target RGB under the target white point color coordinates;

for any gray scale n, determining the brightness value of each RGB color channel under the gray scale n when mixing light according to the gray scale brightness value under the gray scale n and the target RGB brightness ratio;

Acquiring digital driving values corresponding to the RGB color channels under the gray scale n based on brightness values of the RGB color channels under the gray scale n when light is mixed;

and adjusting the color coordinates based on the digital driving values corresponding to the RGB color channels under the gray scale n to obtain the color coordinates of the gray scale n.

3. The method of claim 1, wherein said determining different gray scale luminance values from said target gray scale luminance value comprises:

obtaining a minimum gray-scale brightness value;

for any gray level n, determining a gray level luminance value of the gray level n based on the target gray level luminance value and the minimum gray level luminance value.

4. The method of claim 3, wherein the determining the grayscale luminance value of the grayscale n based on the target grayscale luminance value and the minimum grayscale luminance value comprises:

acquiring a brightness difference between the target gray-scale brightness value and the minimum gray-scale brightness value;

determining a brightness increment value of the gray level n according to the gray level n, the brightness difference and a predetermined input/output characteristic parameter under a specific backlight condition;

and obtaining the gray-scale brightness value of the gray-scale n according to the gray-scale brightness value of the minimum gray-scale and the brightness increment value.

5. The method according to claim 2, wherein the obtaining the digital driving value corresponding to each of the RGB color channels at the gray level n based on the luminance value when the RGB color channels are mixed, includes:

and inputting the brightness value of each RGB color channel under the gray scale n when mixing light into a predetermined RGB tone function, and determining the digital driving value corresponding to each RGB color channel under the gray scale n, wherein the RGB tone function is the mapping relation between the brightness value of each RGB color channel when mixing light and the corresponding digital driving value.

6. The method of any of claims 1-5, wherein the determining whether the display module supports the target gray scale luminance value at the target white point color coordinates comprises:

acquiring a first mapping relation generated in advance, wherein the first mapping relation comprises a mapping relation between candidate white point color coordinates and a maximum gray scale brightness value supported by the candidate white point color coordinates;

determining a first maximum gray-scale brightness value with a mapping relation with the target white point color coordinates from the first mapping relation;

determining that the display module supports the target gray-scale luminance value under the target white-point color coordinates in response to the first maximum gray-scale luminance value being greater than or equal to the target gray-scale luminance value;

And responding to the first maximum gray-scale luminance value being smaller than the target gray-scale luminance value, and determining that the display module does not support the target gray-scale luminance value under the target white point color coordinates.

7. The method of claim 6, wherein the generating of the first mapping relationship comprises:

acquiring a predetermined RGB tone function and a second mapping relation, wherein the second mapping relation is a mapping relation between gray-scale brightness, color coordinates and brightness values of RGB color channels when light is mixed;

based on the second mapping relation, calculating the RGB tone function and the candidate white point color coordinates to obtain a maximum gray scale brightness value supported by the candidate white point color coordinates;

and generating the first mapping relation based on each candidate white point color coordinate and the maximum gray scale brightness value supported by the candidate white point color coordinate.

8. The method of claim 7, wherein the computing the RGB tone function and the candidate white point color coordinates based on the second mapping relationship to obtain a maximum gray scale luminance value supported by the candidate white point color coordinates comprises:

inputting the RGB tone function and the candidate white point color coordinates into the second mapping relation to obtain a third mapping relation between the maximum gray scale brightness and the digital driving values corresponding to the RGB color channels;

Obtaining a candidate maximum gray scale brightness value under the candidate white point color coordinates based on the third mapping relation and a preset digital driving value of each RGB color channel under the maximum gray scale;

and comparing the candidate maximum gray-scale brightness values, obtaining a minimum gray-scale brightness value from the candidate maximum gray-scale brightness values, and taking the minimum gray-scale brightness value as the maximum gray-scale brightness value supported by the candidate white-point color coordinates.

9. The method of claim 7, further comprising, after deriving the maximum gray scale luminance value supported by the candidate white point color coordinates:

inputting the maximum gray-scale brightness value supported by the candidate white-point color coordinates into the third mapping relation to obtain digital driving values corresponding to all RGB color channels under the maximum gray scale;

inputting the digital driving value corresponding to each RGB color channel under the maximum gray scale into the RGB tone function to obtain the brightness value of each RGB color channel when mixing light;

obtaining RGB brightness ratio under the candidate white point color coordinates based on brightness values of mixed lights on the RGB color channels;

and establishing a mapping relation between the candidate white point color coordinates and RGB brightness ratios under the candidate white point color coordinates, and storing the mapping relation in the first mapping relation.

10. The method of claim 9, wherein obtaining the luminance ratio of RGB for the target white point color coordinates comprises:

and inquiring the first mapping relation based on the target white point color coordinate, and acquiring the RGB brightness ratio with the mapping relation with the target white point color coordinate as the brightness ratio of target RGB under the target white point color coordinate.

11. The method of claim 7, wherein the determining of the RGB tone function comprises:

sampling the images to obtain N sampling pictures, and obtaining measurement data of each sampling image, wherein the measurement data comprises a data driving measurement value and a gray scale brightness measurement value;

and carrying out least square regression on a preset RGB tone function based on the measurement data to determine characteristic parameters of the RGB tone function and obtain the RGB tone function.

12. The method of claim 7, wherein the generating of the second mapping relationship comprises:

determining a gamut conversion matrix mapped from the RGB gamut to the XYZ gamut;

determining a conversion relation between the color coordinates and the XYZ color gamut;

and obtaining the second mapping relation based on the color gamut conversion matrix and the conversion relation.

13. The method of claim 7, wherein the method further comprises:

dividing the range of all gray scales to obtain different gray scale ranges;

generating an RGB tone function of each gray scale range in advance for the gray scale range;

and determining digital driving values corresponding to RGB color channels under each gray scale in the gray scale range according to RGB tone functions of the gray scale range in different gray scale ranges, and performing color coordinate adjustment based on the digital driving values.

14. The method according to any one of claims 1-5, further comprising:

and if the display module does not support the target gray scale brightness under the target white point color coordinates, determining that the display module is an abnormal display module.

15. A color coordinate adjusting device, comprising:

the acquisition module is used for acquiring target white point color coordinates and a target gray scale brightness value of the maximum gray scale L255;

the judging module is used for judging whether the display module supports the target gray-scale brightness value under the target white point color coordinates;

the determining module is used for determining different gray-scale brightness values according to the target gray-scale brightness values if the display module supports the target gray-scale brightness values;

And the adjusting module is used for adjusting the color coordinates according to the different gray-scale brightness values and the target white point color coordinates to obtain the color coordinates of different gray scales.

16. The apparatus of claim 15, wherein the adjustment module is further configured to:

17. The apparatus of claim 15, wherein the determining module is further configured to:

obtaining a minimum gray-scale brightness value;

18. The apparatus of claim 17, wherein the means for determining is further configured to:

19. The apparatus of claim 16, wherein the adjustment module is further configured to:

20. The apparatus according to any one of claims 15-19, wherein the determining module is further configured to:

21. The apparatus of claim 20, wherein the determining module is further configured to:

22. The apparatus of claim 21, wherein the determining module is further configured to:

23. The apparatus of claim 21, wherein the determining module is further configured to:

24. The apparatus of claim 23, wherein the determining module is further configured to:

25. The apparatus of claim 21, wherein the determining module is further configured to:

26. The apparatus of claim 21, wherein the determining module is further configured to:

27. The apparatus of claim 21, wherein the adjustment module is further configured to:

dividing the range of all gray scales to obtain different gray scale ranges;

28. The apparatus according to any one of claims 15-19, wherein the determining module is further configured to:

29. An electronic device, comprising:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to implement the steps of the method of any one of claims 1-14.

30. A computer readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the steps of the method of any of claims 1-14.