CN109817176B

CN109817176B - Pixel signal conversion method, pixel signal conversion device and display device

Info

Publication number: CN109817176B
Application number: CN201910154159.1A
Authority: CN
Inventors: 单剑锋
Original assignee: HKC Co Ltd
Current assignee: HKC Co Ltd
Priority date: 2019-02-28
Filing date: 2019-02-28
Publication date: 2021-08-24
Anticipated expiration: 2039-02-28
Also published as: CN109817176A

Abstract

The application discloses a pixel signal conversion method, a pixel signal conversion device and a display device, wherein the pixel signal conversion method comprises the following steps: acquiring a first initial stimulation value signal of a first sub-pixel, a second initial stimulation value signal of a second sub-pixel and a third initial stimulation value signal of a third sub-pixel in a first pixel unit before conversion; determining a first gain coefficient of a fourth sub-pixel in the converted second pixel unit and second gain coefficients of the first sub-pixel, the second sub-pixel and the third sub-pixel according to the color purity of the first pixel unit; and determining a first conversion gray scale of the first sub-pixel, a second conversion gray scale of the second sub-pixel, a third conversion gray scale of the third sub-pixel and a fourth conversion gray scale of the fourth sub-pixel in the second pixel unit. The technical scheme of the application helps to improve the color display effect.

Description

Pixel signal conversion method, pixel signal conversion device and display device

Technical Field

The present disclosure relates to the field of display technologies, and in particular, to a pixel signal conversion method, a pixel signal conversion device, and a display apparatus.

Background

The statements herein merely provide background information related to the present application and may not necessarily constitute prior art. In the display device, according to the spatial color mixing principle, a plurality of primary colors of light are mixed according to corresponding proportions to realize the display of color pictures. As the resolution is improved, the number of sub-pixels on the display panel of the display device is increased, resulting in a decrease in the transmittance and light efficiency of the display device. By changing the first pixel unit (typically including a first sub-pixel-red (R) sub-pixel, a second sub-pixel-green (G) sub-pixel and a third sub-pixel-blue (B) sub-pixel) on the display panel to a second pixel unit (typically including a first sub-pixel-red (R) sub-pixel, a second sub-pixel-green (G) sub-pixel, a third sub-pixel-blue (B) sub-pixel and a fourth sub-pixel-white (W) sub-pixel), i.e., by adding W sub-pixels in a pixel to compensate for the decrease in transmittance and light efficiency caused by the increase in the number of sub-pixels.

However, since the display device also has a difference in transmittance in different directions, a large viewing angle color shift phenomenon often still exists in the high resolution display device with the second pixel unit, and the color display effect is poor.

Content of application

The present application is directed to a pixel signal conversion method, which achieves a better color display effect while maintaining a high resolution in a display device.

In order to achieve the above object, the present application provides a pixel signal conversion method, including the following steps:

acquiring a first initial stimulation value signal RXo of a first sub-pixel, a second initial stimulation value signal GYo of a second sub-pixel and a third initial stimulation value signal BZo of a third sub-pixel in a first pixel unit before conversion;

determining a first gain coefficient k1 of a fourth sub-pixel in the converted second pixel unit and a second gain coefficient k2 of the first sub-pixel, the second sub-pixel and the third sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit, wherein the first gain coefficient k1 is reduced along with the increase of the color purity, and the second gain coefficient k2 is increased along with the increase of the color purity;

according to the first initial stimulus value signal RXo of the first sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2, the first conversion gray scale Rt of the first sub-pixel in the second pixel unit, the second conversion gray scale Gt of the second sub-pixel, the third conversion gray scale Bt of the third sub-pixel and the fourth conversion gray scale Wt of the fourth sub-pixel are determined.

Optionally, the step of acquiring the first initial stimulation value signal RXo of the first sub-pixel, the second initial stimulation value signal GYo of the second sub-pixel and the third initial stimulation value signal BZo of the third sub-pixel in the first pixel unit before conversion includes:

acquiring a first initial gray scale R of a first sub-pixel, a second initial gray scale G of a second sub-pixel and a third initial gray scale B of a third sub-pixel in the first pixel unit;

according to

Calculating the first sub-imageFirst initial stimulus value signal RXo of element based on

Calculating a second initial stimulus value signal GYo for the second sub-pixel based on

Calculating a third initial stimulus value signal BZo for the third sub-pixel;

wherein N is the maximum gray scale value, γ_RXIs a power function of the first stimulus value signal of the first sub-pixel, gamma_GYIs a power function of the second stimulus value signal of the second sub-pixel, gamma_BZIs a power function of the third stimulus value signal of the third sub-pixel.

Optionally, the step of determining the first gain factor k1 of the fourth sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit comprises:

comparing the color purity of the first pixel unit with a first preset color purity;

when the color purity is smaller than the first preset color purity, determining the value of the first gain coefficient k1 in the range of k1>2 according to the color purity;

when the color purity is greater than or equal to the first preset color purity, comparing the color purity with a second preset color purity;

determining that the first gain coefficient k1 satisfies k1 ═ 2 when the color purity is less than or equal to the second preset color purity;

when the color purity is greater than the second preset color purity, determining that the first gain coefficient k1 takes a value within a range of 1< k1<2 according to the color purity;

wherein the first preset color purity is less than or equal to the second preset color purity.

Optionally, the step of determining the second gain factor k2 of the first sub-pixel, the second sub-pixel and the third sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit includes:

acquiring a first initial stimulus value signal RXo of a first sub-pixel in the first pixel unit, a first minimum value min (RXo, GYo, BZo) and a first maximum value max (RXo, GYo, BZo) of a second initial stimulus value signal GYo of the second sub-pixel and a third initial stimulus value signal BZo of the third sub-pixel;

when max (RXo, GYo, BZo) -k1 × min (RXo, GYo, BZo) is less than or equal to 0, determining that the second gain coefficient k2 satisfies k2 is 2;

when max (RXo, GYo, BZo) -k1 min (RXo, GYo, BZo)>When 0, the second gain coefficient k2 is determined to satisfy

Wherein γ is a scaling factor of the fourth sub-pixel.

Optionally, the step of determining the first conversion gray scale Rt of the first sub-pixel, the second conversion gray scale Gt of the second sub-pixel, the third conversion gray scale Gt of the third sub-pixel, the third conversion gray scale Bt of the third sub-pixel and the fourth conversion gray scale Wt of the fourth sub-pixel according to the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 in the first pixel unit comprises:

determining a first converted stimulus value signal RXt of the first sub-pixel, a second converted stimulus value signal GYt of the second sub-pixel, a third converted stimulus value signal BZt of the third sub-pixel and a second converted stimulus value signal WYt of the fourth sub-pixel in accordance with the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 of the first sub-pixel in the first pixel unit;

determining a first conversion gray scale Rt of a first sub-pixel in the unit of the second pixel according to a first conversion stimulus value signal RXt of the first sub-pixel, determining a second conversion gray scale Gt of the second sub-pixel according to a second conversion stimulus value signal GYt of the second sub-pixel, determining a third conversion gray scale Bt of the third sub-pixel according to a third conversion stimulus value signal BZt of the third sub-pixel, and determining a fourth conversion gray scale Wt of the fourth sub-pixel according to a second conversion stimulus value signal WYt of the fourth sub-pixel.

Optionally, the step of determining the second transformed stimulus value signal WYt of the fourth sub-pixel in the second pixel unit according to the first initial stimulus value signal RXo of the first sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 comprises:

calculating a first intermediate stimulus value signal RXm for a first sub-pixel in said second pixel unit based on RXm-k 2-RXo, a second intermediate stimulus value signal GYm for a second sub-pixel in said second pixel unit based on GYm-k 2-GYo, and a third intermediate stimulus value signal BZm for a third sub-pixel in said second pixel unit based on BZm-k 2-BZo;

acquiring a second minimum value min (RXm, GYm, BZm) of the first intermediate stimulus value signal RXm of the first sub-pixel, the second intermediate stimulus value signal GYm of the second sub-pixel, and the third intermediate stimulus value signal BZm of the third sub-pixel in the second pixel unit;

comparing the second minimum value with a preset stimulus value;

determining the second switching stimulus value signal WYt of the fourth sub-pixel to be the second minimum value when the second minimum value is less than or equal to the preset stimulus value;

when the second minimum value is greater than the preset stimulus value, the second conversion stimulus value signal WYt of the fourth sub-pixel is determined to be the preset stimulus value.

Optionally, the step of determining the first transformed stimulus value signal RXt of the first sub-pixel, the second transformed stimulus value signal GYt of the second sub-pixel and the third transformed stimulus value signal BZt of the third sub-pixel in the second pixel unit according to the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 comprises:

according to

Calculating a fourth conversion gray scale Wt of the fourth sub-pixel;

according to

Calculating a first transformed stimulus value signal WXt for said fourth sub-pixel, based on

Calculating a third converted stimulus value signal WZt for the fourth sub-pixel;

calculating a first converted stimulus value signal RXt for a first sub-pixel in said second pixel unit from RXt-RXm-WXt, a second converted stimulus value signal GYt for a second sub-pixel in said second pixel unit from GYt GYm-WYt, a third converted stimulus value signal BZt for a third sub-pixel in said second pixel unit from BZt-BZm-WZt;

wherein N is the maximum gray scale value, γ_WXIs a power function of the first stimulus value signal of the fourth sub-pixel, gamma_WYIs a power function of the second stimulus value signal of the fourth sub-pixel, gamma_WZIs a power function of the third stimulus value signal of the fourth sub-pixel.

Alternatively, the steps of determining a first conversion gray scale Rt of a first sub-pixel in the second pixel unit according to a first conversion stimulus value signal RXt of the first sub-pixel, determining a second conversion gray scale Gt of the second sub-pixel according to a second conversion stimulus value signal GYt of the second sub-pixel, determining a third conversion gray scale Bt of the third sub-pixel according to a third conversion stimulus value signal BZt of the third sub-pixel, and determining a fourth conversion gray scale Wt of the fourth sub-pixel according to a second conversion stimulus value signal WYt of the fourth sub-pixel include:

according to

Calculating a first converted gray scale Rt of the first sub-pixel according to

Calculating a second conversion gray scale Gt of the second sub-pixel according to

Calculating a third converted gray level Bt of the third sub-pixel according to

Calculating a fourth conversion gray scale Wt of the fourth sub-pixel;

wherein N is the maximum gray scale value, γ_RXIs a power function of the first stimulus value signal of the first sub-pixel, gamma_GYIs a power function of the second stimulus value signal of the second sub-pixel, gamma_BZIs a power function of the third stimulus value signal of the third sub-pixel, gamma_WYAs a power function of the second stimulus value signal of the fourth sub-pixel.

To achieve the above object, the present application also proposes a pixel signal conversion apparatus, which includes a memory, a processor, and a pixel signal conversion program stored on the memory and executable on the processor, the pixel signal conversion program, when executed by the processor, implementing the steps of a pixel signal conversion method, the pixel signal conversion method including the steps of: acquiring a first initial stimulation value signal RXo of a first sub-pixel, a second initial stimulation value signal GYo of a second sub-pixel and a third initial stimulation value signal BZo of a third sub-pixel in a first pixel unit before conversion; determining a first gain coefficient k1 of a fourth sub-pixel in the converted second pixel unit and a second gain coefficient k2 of the first sub-pixel, the second sub-pixel and the third sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit, wherein the first gain coefficient k1 is reduced along with the increase of the color purity, and the second gain coefficient k2 is increased along with the increase of the color purity; according to the first initial stimulus value signal RXo of the first sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2, the first conversion gray scale Rt of the first sub-pixel in the second pixel unit, the second conversion gray scale Gt of the second sub-pixel, the third conversion gray scale Bt of the third sub-pixel and the fourth conversion gray scale Wt of the fourth sub-pixel are determined.

To achieve the above object, the present application further proposes a display apparatus, which includes a display panel and a pixel signal conversion device electrically connected to the display panel, the pixel signal conversion device including a memory, a processor, and a pixel signal conversion program stored in the memory and operable on the processor, the pixel signal conversion program, when executed by the processor, implementing a step of a pixel signal conversion method, the pixel signal conversion method including the steps of: acquiring a first initial stimulation value signal RXo of a first sub-pixel, a second initial stimulation value signal GYo of a second sub-pixel and a third initial stimulation value signal BZo of a third sub-pixel in a first pixel unit before conversion; determining a first gain coefficient k1 of a fourth sub-pixel in the converted second pixel unit and a second gain coefficient k2 of the first sub-pixel, the second sub-pixel and the third sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit, wherein the first gain coefficient k1 is reduced along with the increase of the color purity, and the second gain coefficient k2 is increased along with the increase of the color purity; according to the first initial stimulus value signal RXo of the first sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2, the first conversion gray scale Rt of the first sub-pixel in the second pixel unit, the second conversion gray scale Gt of the second sub-pixel, the third conversion gray scale Bt of the third sub-pixel and the fourth conversion gray scale Wt of the fourth sub-pixel are determined.

In the technical scheme of the application, the pixel signal conversion method comprises the following steps: acquiring a first initial stimulation value signal RXo of a first sub-pixel, a second initial stimulation value signal GYo of a second sub-pixel and a third initial stimulation value signal BZo of a third sub-pixel in a first pixel unit before conversion; determining a first gain coefficient k1 of a fourth sub-pixel in the converted second pixel unit and a second gain coefficient k2 of the first sub-pixel, the second sub-pixel and the third sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit, wherein the first gain coefficient k1 is reduced along with the increase of the color purity, and the second gain coefficient k2 is increased along with the increase of the color purity; the first conversion gray scale Rt of the first sub-pixel, the second conversion gray scale Gt of the second sub-pixel, the third conversion gray scale Gt of the third sub-pixel, the third conversion gray scale Bt of the third sub-pixel and the fourth conversion gray scale Wt of the fourth sub-pixel in the second pixel unit are determined according to the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 in the first pixel unit. In the pixel, the change relationship of the primary color stimulus value signal corresponding to the primary color type of each sub-pixel with respect to the gray scale of the sub-pixel is substantially the same, and therefore, in the present embodiment, the stimulus value signal of the first pixel unit is converted into the gray scale of the second pixel unit based on the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, and the third initial stimulus value signal BZo of the third sub-pixel, so as to drive the display of the screen. Further, the color of the second pixel unit is controlled by the first gain coefficient k1 and the second gain coefficient k 2. Specifically, when the color purity of the first pixel unit is high, a smaller first gain coefficient k1 and a larger second gain coefficient k2 are selected to reduce the ratio of the display effect of the W sub-pixel in the display effect of the second pixel unit, so as to ensure good color; when the color purity of the first pixel unit is low, the requirement on the color is correspondingly low after the first pixel unit is converted into the second pixel unit, so that the larger first gain coefficient k1 and the smaller second gain coefficient k2 are selected to increase the ratio of the display effect of the W sub-pixel in the display effect of the second pixel unit, thereby enhancing the transmittance and the light efficiency. In summary, the pixel signal conversion method of the present application can improve the color display effect of the display device, and particularly, in the high resolution display device, can realize better color display while ensuring the transmittance and the optical efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic diagram showing Y stimulus value signal-gray scale relationship of each sub-pixel of an IPS LCD panel in an example;

FIG. 2 is a schematic diagram showing Y stimulus value signal-gray scale relationship of each sub-pixel of an exemplary VA liquid crystal display panel;

FIG. 3 is a schematic flowchart illustrating a pixel signal conversion method according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram illustrating the relationship between the X stimulus value signal-gray scale of the R sub-pixel, the Y stimulus value signal-gray scale of the G sub-pixel, and the Z stimulus value signal-gray scale of the B sub-pixel according to an embodiment of the pixel signal conversion method of the present application;

FIG. 5 is a schematic diagram illustrating input gray scales of an R sub-pixel, a G sub-pixel and a B sub-pixel of a first pixel unit before conversion according to an embodiment of the pixel signal conversion method of the present application;

fig. 6 is a schematic diagram illustrating output gray levels of the W sub-pixel, the R sub-pixel, the G sub-pixel, and the B sub-pixel of the second pixel unit after conversion when the first gain factor k1 is equal to 2 and the scaling factor γ is equal to 1 according to an embodiment of the pixel signal conversion method of the present application;

fig. 7 is a schematic diagram illustrating output gray levels of the W sub-pixel, the R sub-pixel, the G sub-pixel, and the B sub-pixel of the second pixel unit after conversion according to an embodiment of the pixel signal conversion method of the present application when the first gain coefficient k1 is 1.5;

fig. 8 is a schematic diagram illustrating output gray levels of the W sub-pixel, the R sub-pixel, the G sub-pixel, and the B sub-pixel of the second pixel unit after conversion according to an embodiment of the pixel signal conversion method of the present application when the first gain coefficient k1 is 2.5;

fig. 9 is a schematic diagram of output gray scales of the W sub-pixel of the second pixel unit after conversion when the first gain factor k1 is 1.5, 2, 2.5 according to an embodiment of the pixel signal conversion method of the present application;

fig. 10 is a schematic diagram illustrating output gray levels of the W sub-pixel, the R sub-pixel, the G sub-pixel, and the B sub-pixel of the second pixel unit after conversion according to an embodiment of the pixel signal conversion method when the first gain factor k1 is 2 and the scaling factor γ is 3;

fig. 11 is a schematic diagram illustrating an output gray scale of the W sub-pixel of the second pixel unit after conversion when the first gain factor k1 is 2 and the scaling factor γ is 1, 3 according to an embodiment of the pixel signal conversion method of the present application;

fig. 12 is a schematic structural diagram of an embodiment of a display device according to the present application.

The implementation, functional features and advantages of the objectives of the present application will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that if directional indications (such as up, down, left, right, front, and back … …) are referred to in the embodiments of the present application, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout is to include three juxtapositions, exemplified by "A and/or B" including either scheme A, or scheme B, or a scheme in which both A and B are satisfied. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present application.

In one example, a display apparatus includes a display panel and a driving chip to drive the display panel. The display panel comprises a plurality of pixels, a plurality of data lines and a plurality of scanning lines, the pixels comprise at least three sub-pixels, different sub-pixels can display different primary color lights, and different primary color lights can be mixed according to a certain proportion to display multiple colors according to a spatial color mixing principle. Generally, a pixel at least includes an R sub-pixel, a G sub-pixel and a B sub-pixel, and hereinafter, the technical solution of the present application will be described in detail by taking R as red (R), G as green (G) and B as blue (B) as examples. Of course, those skilled in the art may also select other primary colors to combine without creative work, and adjust the scheme of the present application accordingly to improve the color display effect of the display device, which is not described herein again. Sub-pixels on the display panel are arranged in a rectangular array, wherein the R sub-pixel comprises an R photoresist, the G sub-pixel comprises a G photoresist, the B sub-pixel comprises a B photoresist, and the R photoresist absorbs other visible light except the R light and simultaneously enables the R light to penetrate through; the G photoresist absorbs other visible light except the G light and simultaneously enables the G light to penetrate through; the B photoresist absorbs other visible light except the B light and simultaneously transmits the B light. The data lines and the scan lines are electrically connected to the subpixels in a certain manner. The sub-pixels are respectively turned on under the action of scanning signals on the scanning lines, and when the sub-pixels are in an on state, the sub-pixels are charged under the driving action of driving signals on the data lines, so that certain brightness is displayed, and different colors are displayed under the filtering action of corresponding light resistors. The driving signal can be obtained according to the gray scale of each pixel or sub-pixel in the picture to be displayed. According to the display principle, when white light generated by a backlight source of the display device passes through each sub-pixel, part of the white light is lost due to the filtering effect of the photoresist, and thus the transmittance and the light efficiency of the display device are reduced. In order to solve the above problem, a W sub-pixel is further introduced into the pixel, a first pixel unit originally composed of an R sub-pixel, a G sub-pixel, a B sub-pixel and a W sub-pixel on the display panel is changed into a second pixel unit including the R sub-pixel, the G sub-pixel, the B sub-pixel and the W sub-pixel, and the transmittance and the light efficiency of the display device are improved through the W sub-pixel. In order to ensure the large-viewing-angle display effect of the display device, an In-Plane Switching (IPS) liquid crystal display panel is generally used as the display panel In the display device, and In the IPS liquid crystal display panel, the same or similar transmittance characteristics are provided In a full-wavelength range at a positive viewing angle and a large viewing angle, so that the IPS liquid crystal display panel has a good large-viewing-angle display effect. As shown in fig. 1, in the IPS liquid crystal display panel, the relationship between the gray scale of the R sub-pixel and the Y stimulus value signal RY thereof, the relationship between the gray scale of the G sub-pixel and the Y stimulus value signal GY thereof, and the relationship between the gray scale of the B sub-pixel and the Y stimulus value signal BY thereof are substantially the same, so that when the first pixel unit is converted into the second pixel unit in the IPS liquid crystal display panel, the Y stimulus value signal of each sub-pixel can be used as a basis, and a good conversion effect can be obtained. However, the IPS lcd panel has a relatively high cost, and in a Vertical Alignment (VA) lcd panel with a lower cost and a wider application range, although the W sub-pixel has a higher transmittance, the large viewing angle light leakage phenomenon is more serious, which easily causes a bad effect on the display screen. As shown in fig. 2, in the VA liquid crystal display panel, there is a certain difference in the relationship between the gray scale of the R sub-pixel and the Y stimulus value signal RY thereof, the relationship between the gray scale of the G sub-pixel and the Y stimulus value signal GY thereof, and the relationship between the gray scale of the B sub-pixel and the Y stimulus value signal BY thereof, and if the conversion from the first pixel unit to the second pixel unit is performed based on the Y stimulus value signal of each sub-pixel, the color shift is aggravated. Specifically, in this example, the pixel signal conversion method includes the following steps:

s100 ', acquiring an initial gray scale R' of an R sub-pixel, an initial gray scale G 'of a G sub-pixel and an initial gray scale B' of a B sub-pixel in a first pixel unit;

step S200' according to

Calculating Y initial stimulus value signal RY' of R sub-pixel

Calculating the Y initial stimulus value signal GY' of the G sub-pixel according to

Calculating Y initial stimulus value signal BY 'of B sub-pixel, wherein N' is maximum gray level value, gamma_RY′Is a power function of Y stimulus value signal of R sub-pixel, gamma_GY′Is a power function of the Y stimulus value signal of the G sub-pixel, gamma_BY′Is a power function of the Y stimulus value signal of the B sub-pixel;

it should be noted that each of the stimulus value signals referred to here and hereinafter is a stimulus value signal subjected to normalization processing.

Step S300 ', determining that the gain coefficient k' of the converted second pixel unit is 2, calculating a Y intermediate stimulus value signal RYm 'of the R sub-pixel in the second pixel unit according to RYm', k 'RY', calculating a Y intermediate stimulus value signal GYm 'of the G sub-pixel in the second pixel unit according to GYm', k 'BY', and calculating a Y intermediate stimulus value signal BYm 'of the B sub-pixel in the second pixel unit according to BYm';

the gain coefficient k' is obtained according to parameters such as areas and penetration rates of the W sub-pixel, the R sub-pixel, the G sub-pixel and the B sub-pixel. In general, when the areas of the W sub-pixel, the R sub-pixel, the G sub-pixel and the B sub-pixel are equal to each other two by two, and the transmittance of the W sub-pixel is equal to the sum of the transmittances of the R sub-pixel, the G sub-pixel and the B sub-pixel, the gain coefficient k 'satisfies k' 2, that is, the stimulation value signal of the second pixel unit is twice the stimulation value signal of the original first pixel unit, wherein half of the stimulation value signal is contributed by the W sub-pixel in the second pixel unit, and the other half of the stimulation value signal is contributed by the R sub-pixel, the G sub-pixel and the B sub-pixel in the second pixel unit.

Step S400 ', determining that the Y conversion stimulus value signal WYt' of the W sub-pixel in the second pixel unit is the Y intermediate stimulus value signal RYm 'of the R sub-pixel, the Y intermediate stimulus value signal GYm' of the G sub-pixel, and the minimum value min (RYm ', GYm', BYm ') of the Y intermediate stimulus value signal BYm' of the B sub-pixel, i.e., WYt '═ min (RYm', GYm ', BYm'), calculating the Y conversion stimulus value signal RYt 'of the R sub-pixel in the second pixel unit from RYt' ═ RYm '-WYt', calculating the Y conversion stimulus value signal GYt 'of the G sub-pixel in the second pixel unit from GYt' ═ GYm '-WYt', and calculating the Y conversion stimulus value signal BYt 'of the B sub-pixel in the second pixel unit from BYt' ═ BYm '-WYt';

in order to keep the color displayed by the second pixel unit after conversion the same as or similar to the color displayed by the first pixel unit before conversion, when the Y conversion stimulus value signal WYt 'of the W sub-pixel is determined, it is necessary to further process each Y intermediate stimulus value signal of the R sub-pixel, the G sub-pixel and the B sub-pixel according to the method in step S400' to obtain corresponding Y conversion stimulus value signals.

Step S500' according to

Calculating a conversion gray scale Rt' of the R sub-pixel according to

Calculating the conversion gray scale Gt' of the G sub-pixel according to

Calculating the conversion gray scale Bt' of the B sub-pixel according to

The conversion gray level Wt' of the W sub-pixel is calculated.

Since the data signal on the data line of the display panel is obtained according to the gray scale of each sub-pixel, after the Y-conversion stimulus value signal of each sub-pixel in the second pixel unit after conversion is determined, it is further converted into the corresponding conversion gray scale, and the display of the color picture is realized under the effect of the conversion gray scale.

According to the pixel signal conversion method in the example, due to the light leakage at the large viewing angle of the W sub-pixel on the display panel, the inconsistent relationship between the gray scale of each sub-pixel and the Y stimulus value signal, and the like, the display effect of the second pixel unit obtained by the conversion according to the above method has certain defects.

The present application provides a pixel signal conversion method to improve a color display effect.

In an embodiment of the present application, as shown in fig. 3, the pixel signal conversion method includes the following steps:

step S100, acquiring a first initial stimulation value signal (X initial stimulation value signal) RXo of the R sub-pixel, a second initial stimulation value signal (Y initial stimulation value signal) GYo of the G sub-pixel, and a third initial stimulation value signal (Z initial stimulation value signal) BZo of the B sub-pixel in the first pixel unit before conversion;

according to the color theory, in the R sub-pixel, the first stimulus value signal (X stimulus value signal) has the largest influence on the color obtained by final color mixing; in the G sub-pixel, the second stimulus value signal (Y stimulus value signal) has the largest influence on the color resulting from the final color mixing; in the B sub-pixel, the third stimulus value signal (Z stimulus value signal) has the largest influence on the color resulting from the final color mixing. As shown in fig. 4, the relationship between the gray scale of the R sub-pixel and the X stimulus value signal, the relationship between the gray scale of the G sub-pixel and the Y stimulus value signal, and the relationship between the gray scale of the B sub-pixel and the Z stimulus value signal are shown. As can be seen from comparing fig. 4 and fig. 2, the relationship between the gray scale of the R sub-pixel and the X stimulus value signal, the relationship between the gray scale of the G sub-pixel and the Y stimulus value signal, and the relationship between the gray scale of the B sub-pixel and the Z stimulus value signal are closer to each other, so that in the process of changing the first pixel unit to the second pixel unit and correspondingly converting the pixel signals, the X initial stimulus value signal RXo of the R sub-pixel, the Y initial stimulus value signal GYo of the G sub-pixel, and the Z initial stimulus value signal BZo of the B sub-pixel are used as a conversion basis to reduce color shift caused by the difference between the relationship between the stimulus value signals of different primary colors and the gray scale.

Step S200, determining a first gain coefficient k1 of the W sub-pixel in the converted second pixel unit and a second gain coefficient k2 of the R sub-pixel, the G sub-pixel and the B sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit, wherein the first gain coefficient k1 is reduced along with the increase of the color purity, and the second gain coefficient k2 is increased along with the increase of the color purity;

in the second pixel unit, as the stimulus value contribution of the R sub-pixel, the G sub-pixel and the B sub-pixel to the final second pixel unit is increased, the color displayed by the second pixel unit is generally more vivid, but the brightness is lower; and as the contribution of the W sub-pixel to the stimulus value of the final second pixel cell increases, the luminance of this second pixel cell will increase, but the color will be less vivid. In order to balance the relationship between the color and the brightness of the pixel and realize better display effect, the first gain coefficient k1 and the second gain coefficient k2 in the pixel signal conversion process are determined according to the color purity of the original first pixel unit. Specifically, as the color purity increases, a smaller first gain coefficient k1 and a larger second gain coefficient k2 are selected to reduce the contribution of the W sub-pixel in the second pixel unit, and improve the contributions of the R sub-pixel, the G sub-pixel and the B sub-pixel in the second pixel unit, thereby realizing better color display; with the reduction of the color purity, a larger first gain coefficient k1 and a smaller second gain coefficient k2 are selected to increase the contribution of the W sub-pixel in the second pixel unit and reduce the contribution of the R sub-pixel, the G sub-pixel and the B sub-pixel in the second pixel unit, so that the display brightness of the second pixel unit is improved, and the problems of the reduction of the transmittance and the light efficiency are avoided.

Step S300, determining a first conversion gray scale Rt of the R sub-pixel, a second conversion gray scale Gt of the G sub-pixel, a third conversion gray scale Bt of the B sub-pixel and a fourth conversion gray scale Wt of the W sub-pixel in the second pixel unit according to the X initial stimulus value signal RXo of the R sub-pixel, the Y initial stimulus value signal GYo of the G sub-pixel, the Z initial stimulus value signal BZo of the B sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 in the first pixel unit.

In a display panel of a display device, data signals on data lines for driving the sub-pixels are generally obtained according to the corresponding gray levels of the sub-pixels, and therefore, in order to facilitate driving of a display device including a second pixel unit, it is necessary to obtain converted gray levels of the sub-pixels in the second pixel unit so as to drive the sub-pixels in the second pixel unit according to the corresponding converted gray levels. During the conversion, the first gain coefficient k1 determines the contribution ratio of the W sub-pixel in the second pixel unit, the second gain coefficient k2 determines the contribution ratio of the R sub-pixel, the G sub-pixel and the B sub-pixel in the second pixel unit, and the first conversion gray scale Rt of the R sub-pixel in the second pixel unit, the second conversion gray scale Gt of the G sub-pixel, the third conversion gray scale Bt of the B sub-pixel and the fourth conversion gray scale Wt of the W sub-pixel are obtained after the conversion based on the X initial stimulus value signal RXo of the R sub-pixel, the Y initial stimulus value signal GYo of the G sub-pixel and the Z initial stimulus value signal BZo of the B sub-pixel in the first pixel unit before the conversion.

In this embodiment, the pixel signal conversion method includes the steps of: acquiring an X initial stimulus value signal RXo of an R sub-pixel, a Y initial stimulus value signal GYo of a G sub-pixel and a Z initial stimulus value signal BZo of a B sub-pixel in a first pixel unit before conversion; determining a first gain coefficient k1 of a fourth sub-pixel in the converted second pixel unit and a second gain coefficient k2 of the R, G and B sub-pixels in the converted second pixel unit according to the color purity of the first pixel unit, wherein the first gain coefficient k1 decreases with the increase of the color purity and the second gain coefficient k2 increases with the increase of the color purity; the first conversion gray scale Rt of the R sub-pixel, the second conversion gray scale Gt of the G sub-pixel, the third conversion gray scale Bt of the B sub-pixel, and the fourth conversion gray scale Wt of the fourth sub-pixel in the second pixel unit are determined according to the X initial stimulus value signal RXo of the R sub-pixel, the Y initial stimulus value signal GYo of the G sub-pixel, the Z initial stimulus value signal BZo of the B sub-pixel, the first gain coefficient k1, and the second gain coefficient k2 in the first pixel unit. In the pixel, the change relationship of the primary color stimulus value signal corresponding to the primary color type of each sub-pixel with respect to the gray scale of the sub-pixel is substantially the same, and therefore, in the present embodiment, the stimulus value signal of the first pixel unit is converted into the gray scale of the second pixel unit based on the X initial stimulus value signal RXo of the R sub-pixel, the Y initial stimulus value signal GYo of the G sub-pixel, and the Z initial stimulus value signal BZo of the B sub-pixel, so as to drive the display of the screen. Further, the color of the second pixel unit is controlled by the first gain coefficient k1 and the second gain coefficient k 2. Specifically, when the color purity of the first pixel unit is high, a smaller first gain coefficient k1 and a larger second gain coefficient k2 are selected to reduce the ratio of the display effect of the W sub-pixel in the display effect of the second pixel unit, so as to ensure good color; when the color purity of the first pixel unit is low, the requirement on the color is correspondingly low after the first pixel unit is converted into the second pixel unit, so that the larger first gain coefficient k1 and the smaller second gain coefficient k2 are selected to increase the ratio of the display effect of the W sub-pixel in the display effect of the second pixel unit, thereby enhancing the transmittance and the light efficiency. In summary, the pixel signal conversion method of the present application can improve the color display effect of the display device, and particularly, in the high resolution display device, can realize better color display while ensuring the transmittance and the optical efficiency.

Optionally, step S100 includes:

step S110, acquiring a first initial gray scale R of an R sub-pixel in a first pixel unit, a second initial gray scale G of a G sub-pixel and a third initial gray scale B of a B sub-pixel;

step S120, according to

Calculate the X initial stimulus value signal RXo for the R sub-pixel based on

Calculate the Y initial stimulus value signal GYo for the G sub-pixel based on

Calculating the Z initial stimulus value signal BZo for the B sub-pixel;

wherein N is the maximum gray scale value, γ_RXIs a power function of the X stimulus value signal of the R sub-pixel, gamma_GYIs a power function of the Y stimulus value signal of the G sub-pixel, gamma_BZIs a power function of the Z stimulus value signal of the B sub-pixel.

For each sub-pixel or pixel there is a corresponding tristimulus value signal reflecting the amount of stimulus levels of the three primary colors of a certain color perception by the human retina, which may be calculated for any sub-pixel in the following manner:

x stimulus value signal of R sub-pixel

Y stimulus value signal of R sub-pixel

Z stimulus value signal of R sub-pixel

Wherein, γ_RXIs a power function of the X stimulus value signal of the R sub-pixel, gamma_RYY stimulus for R sub-pixelPower function of value signal, gamma_RZIs a power function of the Z stimulus value signal of the R sub-pixel. Similarly, the X stimulus value signal of the G sub-pixel

Y stimulus value signal of G sub-pixel

Z stimulus value signal of G sub-pixel

Wherein, γ_GXIs a power function of the X stimulus value signal of the G sub-pixel, gamma_GYIs a power function of the Y stimulus value signal of the G sub-pixel, gamma_GZThe power function of the Z stimulus value signal of the G sub-pixel; x stimulus value signal of B sub-pixel

Y stimulus value signal of B sub-pixel

Z stimulus value signal of B sub-pixel

Wherein, γ_BXIs a power function of the X stimulus value signal of the B sub-pixel, gamma_BYIs a power function of Y stimulus value signal of B sub-pixel, gamma_BZIs a power function of the Z stimulus value signal of the B sub-pixel. According to the above relationship, the X initial stimulus value signal of the R sub-pixel

Y initial stimulus value signal of G sub-pixel

Z initial stimulus value signal of B sub-pixel

Wherein N is the maximum gray level of the sub-pixelGenerally, the gray scale value in the display panel is any integer between 0 and 255, and the maximum gray scale value N is 255.

step S211, comparing the color purity of the first pixel unit with a first preset color purity;

step S212, when the color purity is smaller than a first preset color purity, determining the value of a first gain coefficient k1 in the range of k1>2 according to the color purity;

step S213, comparing the color purity with a second preset color purity when the color purity is greater than or equal to the first preset color purity;

step S214, when the color purity is less than or equal to the second preset color purity, determining that the first gain coefficient k1 satisfies k1 ═ 2;

s215, when the color purity is greater than a second preset color purity, determining the value of a first gain coefficient k1 in the range of 1< k1<2 according to the color purity;

Considering that the larger the contribution of the W subpixel to the second pixel unit during conversion, the more the vividness of the displayed color is reduced, the first gain coefficient k1 may be selected to be a constant value k 1-2 when the color purity is within a certain range. In the present embodiment, when the color purity is between the first preset color purity and the second preset color purity, the first gain coefficient k1 satisfies k1 — 2. Of course, when the range of the color purity itself is large, the first gain coefficient k1 may also be adjusted according to the change of the color purity. Specifically, for a picture with low color purity, namely, the color purity is less than a first preset color purity, k1 is selected to be greater than 2; for pictures with high color purity, i.e. with color purity greater than the second predetermined color purity, 1< k1<2 is selected. The first preset color purity and the second preset color purity can be preset according to requirements and stored in the display device, and can also be adjusted by a user in the using process.

Based on the above embodiment, the step of determining the second gain coefficients k2 of the R, G, and B sub-pixels in the converted second pixel unit according to the color purity of the first pixel unit includes:

step S221, acquiring a first minimum value min (RXo, GYo, BZo) and a first maximum value max (RXo, GYo, BZo) of the X initial stimulus value signal RXo, the Y initial stimulus value signal GYo, and the Z initial stimulus value signal BZo of the R sub-pixel, the G sub-pixel, and the B sub-pixel in the first pixel unit;

step S222, when max (RXo, GYo, BZo) -k1 × min (RXo, GYo, BZo) is less than or equal to 0, determining that the second gain coefficient k2 satisfies k2 is 2;

step S223, when max (RXo, GYo, BZo) -k1 min (RXo, GYo, BZo)>When 0, the second gain coefficient k2 is determined to satisfy

Where γ is the scaling factor of the fourth sub-pixel.

In order to ensure the display effect, the sum of the stimulus value signals of the R sub-pixel, the G sub-pixel, the B sub-pixel and the W sub-pixel in the second pixel unit is at most twice the sum of the stimulus value signals of the R sub-pixel, the G sub-pixel and the B sub-pixel in the first pixel unit, in a specific example, the sum of the transmittance of the R sub-pixel, the G sub-pixel and the B sub-pixel in the second pixel unit is equivalent to the transmittance of the W sub-pixel, so that the second gain coefficient k2 is related to the first gain coefficient k1, decreases with the increase of the first gain coefficient k1, and the maximum value of the second gain coefficient k2 is k2 ═ 2. When max (RXo, GYo, BZo) -k1 min (RXo, GYo, BZo)>At 0, the second gain coefficients k2 of the R, G and B sub-pixels are calculated according to the first gain coefficient k1, that is, the first gain coefficient k1

Wherein γ is a scale adjustment factor of the W sub-pixel to control the vividness of the color displayed by the second pixel unit.

The corresponding pixel signal conversion conditions under the selection of several specific first gain coefficients k1, second gain coefficients k2 and scaling factors γ will be explained below. As shown in fig. 5, in the first pixel unit before conversion, the input gray scale of the R sub-pixel is maintained at the maximum gray scale value N of 255, the input gray scale of the G sub-pixel is equivalent to the input gray scale of the B sub-pixel, and the input gray scale is linearly changed from the minimum gray scale value of 0 to the maximum gray scale value N of 255.

As shown in fig. 6, when the first gain factor k1 satisfies k1 ═ 2, the converted output gray scales of the R sub-pixel, G sub-pixel, B sub-pixel and W sub-pixel in the second pixel unit are obtained. As shown in fig. 7, when the first gain factor k1 satisfies the condition that k1 is 1.5, the output gray levels of the R sub-pixel, the G sub-pixel, the B sub-pixel and the W sub-pixel in the second pixel unit are converted. As shown in fig. 8, when the first gain factor k1 satisfies the condition that k1 is 2.5, the output gray levels of the R sub-pixel, the G sub-pixel, the B sub-pixel and the W sub-pixel in the second pixel unit are converted. As shown in fig. 9, the output gray levels of the R sub-pixel, the G sub-pixel, the B sub-pixel and the W sub-pixel in the second pixel unit after conversion are compared under different first gain coefficients k1 in fig. 6 to 8. When the first gain coefficient k1 is decreased, the output gray scale curve of the W sub-pixel is gradually smoothed as the input gray scales of the R sub-pixel, the G sub-pixel and the B sub-pixel in the first pixel unit before conversion are increased, so that the contribution in the second pixel unit after conversion is decreased and the displayed color is more vivid; similarly, when the first gain factor k1 is increased, the output gray scale curve of the W sub-pixel becomes gradually steeper as the input gray scales of the R sub-pixel, the G sub-pixel, and the B sub-pixel in the first pixel unit before conversion increase, so that the contribution in the second pixel unit after conversion increases, the vividness of the displayed color decreases, but it helps to increase the brightness and contrast of the display surface.

As shown in fig. 10, when the first gain factor k1 satisfies k1 ═ 2 and the scaling factor γ satisfies γ ═ 3, the converted output gray scales of the R, G, B, and W sub-pixels in the second pixel unit are obtained. In fig. 6, the scaling factor γ satisfies γ equal to 1. Fig. 11 compares the output gray levels of the R sub-pixel, the G sub-pixel, the B sub-pixel and the W sub-pixel in the second pixel unit after conversion under different scaling factors γ in fig. 6 and 10. When the proportion adjustment factor is increased, the contribution of the W sub-pixel in the second pixel unit is reduced, so that the adverse effect of the W sub-pixel on the color vividness is reduced, and the displayed color is more vivid.

In the above-described embodiment of the present application, step S300 includes:

step S310, determining a first converted stimulus value signal (X converted stimulus value signal) RXt, a second converted stimulus value signal (Y converted stimulus value signal) GYt, a third converted stimulus value signal (Z converted stimulus value signal) BZt and a second converted stimulus value signal (Y converted stimulus value signal) WYt of the R sub-pixel and the fourth sub-pixel in the second pixel unit according to the X initial stimulus value signal RXo of the R sub-pixel, the Y initial stimulus value signal GYo of the G sub-pixel, the Z initial stimulus value signal BZo of the B sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 in the first pixel unit;

step S320, determining a first conversion gray scale Rt of the R sub-pixel according to the X-conversion stimulus value signal RXt of the R sub-pixel in the second pixel unit, determining a second conversion gray scale Gt of the G sub-pixel according to the Y-conversion stimulus value signal GYt of the G sub-pixel, determining a third conversion gray scale Bt of the B sub-pixel according to the Z-conversion stimulus value signal BZt of the B sub-pixel, and determining a fourth conversion gray scale Wt of the fourth sub-pixel according to the Y-conversion stimulus value signal WYt of the fourth sub-pixel.

During the conversion process, the first gain coefficient k1 determines the contribution ratio of the W sub-pixel in the second pixel unit, the second gain coefficient k2 determines the R sub-pixel, and the G sub-pixel and the B sub-pixel in the second pixel unit, and the converted X conversion stimulus value signal RXt of the R sub-pixel, the converted Y conversion stimulus value signal GYt of the G sub-pixel, the converted Z conversion stimulus value signal BZt of the B sub-pixel, and the converted Y conversion stimulus value signal WYt of the W sub-pixel in the second pixel unit are obtained based on the X initial stimulus value signal RXo of the R sub-pixel, the Y initial stimulus value signal GYo of the G sub-pixel, and the converted Z initial stimulus value signal BZo of the B sub-pixel in the first pixel unit before the conversion. Further, a first conversion gray scale Rt of the R sub-pixel is determined according to the X-conversion stimulus value signal RXt of the R sub-pixel in the second pixel unit, a second conversion gray scale Gt of the G sub-pixel is determined according to the Y-conversion stimulus value signal GYt of the G sub-pixel, a third conversion gray scale Bt of the B sub-pixel is determined according to the Z-conversion stimulus value signal BZt of the B sub-pixel, and a fourth conversion gray scale Wt of the fourth sub-pixel is determined according to the Y-conversion stimulus value signal WYt of the fourth sub-pixel. It should be noted that, since the human eye is most sensitive to Y light, the Y conversion stimulus value signal WYt in the tristimulus value signals of the W sub-pixel is selected as the conversion target to achieve a better display effect of the second pixel unit.

Wherein, the step of determining the Y-transformed stimulus value signal WYt of the fourth sub-pixel in the second pixel unit according to the Y initial stimulus value signal RXo of the R sub-pixel in the first pixel unit, the Y initial stimulus value signal GYo of the G sub-pixel, the Z initial stimulus value signal BZo of the B sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 comprises:

step S311, calculating a first intermediate stimulus value signal (X intermediate stimulus value signal) RXm of the R sub-pixel in the second pixel unit from RXm ═ k2 × RXo, calculating a second intermediate stimulus value signal (Y intermediate stimulus value signal) GYm of the G sub-pixel in the second pixel unit from GYm ═ k2 ×) GYo, and calculating a third intermediate stimulus value signal (Z intermediate stimulus value signal) BZm of the B sub-pixel in the second pixel unit from BZm ═ k2 ×) BZo;

step S312, acquiring a second minimum value min (RXm, GYm, BZm) of the X intermediate stimulus value signal RXm of the R sub-pixel, the Y intermediate stimulus value signal GYm of the G sub-pixel, and the Z intermediate stimulus value signal BZm of the B sub-pixel in the second pixel unit;

step S313, comparing the second minimum value with a preset stimulation value;

step S314, when the second minimum value is less than or equal to the preset stimulus value, determining the Y conversion stimulus value signal WYt of the fourth sub-pixel as the second minimum value;

and step S315, when the second minimum value is greater than the preset stimulus value, determining the Y conversion stimulus value signal WYt of the fourth sub-pixel as the preset stimulus value.

Considering that the transmittance of the W sub-pixel is equivalent to the sum of the transmittances of the R, G and B sub-pixels, the preset stimulus value may be set to 1. In general, the X intermediate stimulus value signal RXm of the R sub-pixel, the Y intermediate stimulus value signal GYm of the G sub-pixel, and the second minimum value min (RXm, GYm, BZm) of the Z intermediate stimulus value signal BZm of the B sub-pixel in the second pixel unit are less than or equal to 1, the Y conversion stimulus value signal of the W sub-pixel takes on the second minimum value min (RXm, GYm, BZm), and if the second minimum value min (RXm, GYm, BZm) is greater than 1, the Y conversion stimulus value signal of the W sub-pixel takes on the value 1, so that the contribution ratio of the W sub-pixel in the second pixel unit is about 50%.

Based on the above embodiment, the step of determining the X conversion stimulus value signal RXt of the R sub-pixel, the Y conversion stimulus value signal GYt of the G sub-pixel, and the Z conversion stimulus value signal BZt of the B sub-pixel in the second pixel unit according to the X initial stimulus value signal RXo of the R sub-pixel, the Y initial stimulus value signal GYo of the G sub-pixel, the Z initial stimulus value signal BZo of the B sub-pixel, the first gain coefficient k1, and the second gain coefficient k2 in the first pixel unit includes:

step S316, according to

Calculating a fourth conversion gray scale Wt of the W sub-pixel;

step S317 according to

Calculating the X-transition stimulus value signal WXt of the W sub-pixel based on

Calculating the Z-transformed stimulus value signal WZt for the W sub-pixel;

step S318, calculating an X conversion stimulus value signal RXt of the R sub-pixel in the second pixel unit according to RXt-RXm-WXt, calculating a Y conversion stimulus value signal GYt of the G sub-pixel in the second pixel unit according to GYt GYm-WYt, and calculating a Z conversion stimulus value signal BZt of the B sub-pixel in the second pixel unit according to BZt-BZm-WZt;

wherein N is the maximum gray scale value, γ_WXIs a power function of the X stimulus value signal of the W sub-pixel, gamma_WYIs a power function of Y stimulus value signal of W sub-pixel, gamma_WZIs a power function of the Z stimulus value signal of the W sub-pixel.

In order to keep the color of the second pixel unit after conversion the same as or similar to the color of the first pixel unit before conversion, the converted tristimulus value signal of the W sub-pixel is firstly obtained. Specifically, a fourth conversion gray scale Wt of the W sub-pixel is obtained according to the Y conversion stimulus value signal WYt of the W sub-pixel, and the X conversion stimulus value signal WXt and the Z conversion stimulus value signal WZt of the W sub-pixel are inversely derived according to the fourth conversion gray scale Wt. In the process of calculating the X conversion stimulus value signal RXt of the R sub-pixel, the Y conversion stimulus value signal GYt of the G sub-pixel, and the Z conversion stimulus value signal BZt of the B sub-pixel, they are respectively calculated according to the corresponding primary colors to improve the color-preserving effect of the second pixel unit obtained after conversion.

Optionally, step S320 includes:

step S321, according to

Calculating a first conversion gray scale Rt of the R sub-pixel according to

Calculating a second conversion gray scale Gt of the G sub-pixel according to

Calculating a third converted gray level Bt of the B sub-pixel according to

Calculating a fourth conversion gray scale Wt of the fourth sub-pixel;

wherein N is the maximum gray scale value, γ_RXIs a power function of the X stimulus value signal of the R sub-pixel, gamma_GYIs a power function of the Y stimulus value signal of the G sub-pixel, gamma_BZIs a power function of the Z stimulus value signal of the B sub-pixel, gamma_WYIs a power function of the Y stimulus value signal of the fourth sub-pixel.

Considering that the X stimulus value signal has the greatest influence in the R sub-pixel, the Y stimulus value signal has the greatest influence in the G sub-pixel, and the Z stimulus value signal has the greatest influence in the B sub-pixel, the conversion process is performed based on the X stimulus value signal of the R sub-pixel, the Y stimulus value signal of the G sub-pixel, and the Z stimulus value signal of the B sub-pixel in the conversion process of the conversion stimulus value signal into the conversion gray scale. Meanwhile, considering that human eyes are most sensitive to Y light, when the fourth conversion gray scale Wt of the W sub-pixel is calculated, it is obtained according to the Y conversion stimulus value signal of the W sub-pixel.

The application also provides a pixel signal conversion device which comprises a memory and a processor.

When executed by a processor, a pixel signal conversion program stored on a memory implements the following operations:

acquiring an X initial stimulation value signal RXo of an R sub-pixel in a first pixel unit before conversion, a second initial stimulation value signal GYo of a second sub-pixel and a third initial stimulation value signal BZo of a third sub-pixel;

determining a first gain coefficient k1 of a fourth sub-pixel in the converted second pixel unit and a second gain coefficient k2 of the R sub-pixel, the second sub-pixel and the third sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit, wherein the first gain coefficient k1 decreases with the increase of the color purity, and the second gain coefficient k2 increases with the increase of the color purity;

the first conversion gray scale Rt of the R sub-pixel in the second pixel unit, the second conversion gray scale Gt of the second sub-pixel, the third conversion gray scale Bt of the third sub-pixel, and the fourth conversion gray scale Wt of the fourth sub-pixel are determined according to the X initial stimulus value signal RXo of the R sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1, and the second gain coefficient k 2.

When the pixel signal conversion program stored in the memory is executed by the processor, the operation of obtaining the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel and the third initial stimulus value signal BZo of the third sub-pixel in the first pixel unit before conversion includes:

acquiring a first initial gray scale R of a first sub-pixel, a second initial gray scale G of a second sub-pixel and a third initial gray scale B of a third sub-pixel in a first pixel unit;

according to

Calculating a first initial stimulus value signal RXo for the first sub-pixel based on

Calculating a third initial stimulus value signal BZo for the third sub-pixel;

The operation of determining the first gain factor k1 for the fourth sub-pixel in the converted second pixel cell based on the color purity of the first pixel cell when the pixel signal conversion program stored in the memory is executed by the processor comprises:

when the color purity is smaller than a first preset color purity, determining that the value of a first gain coefficient k1 is within a range of k1>2 according to the color purity;

when the color purity is greater than or equal to a first preset color purity, comparing the color purity with a second preset color purity;

when the color purity is less than or equal to a second preset color purity, determining that the first gain coefficient k1 satisfies k 1-2;

when the color purity is greater than the second preset color purity, determining that the value of the first gain coefficient k1 is within the range of 1< k1<2 according to the color purity;

The operation of determining the second gain factor k2 for the first sub-pixel, the second sub-pixel, and the third sub-pixel in the converted second pixel unit based on the color purity of the first pixel unit when the pixel signal conversion program stored in the memory is executed by the processor includes:

acquiring a first minimum value min (RXo, GYo, BZo) and a first maximum value max (RXo, GYo, BZo) of the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, and the third initial stimulus value signal BZo of the third sub-pixel in the first pixel unit;

Where γ is the scaling factor of the fourth sub-pixel.

The operations of determining the first conversion gray scale Rt of the first sub-pixel in the second pixel unit, the second conversion gray scale Gt of the second sub-pixel, the third conversion gray scale Bt of the third sub-pixel and the fourth conversion gray scale Wt of the fourth sub-pixel according to the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 when the pixel signal conversion program stored in the memory is executed by the processor include:

determining a first transformed stimulus value signal RXt of the first sub-pixel, a second transformed stimulus value signal GYt of the second sub-pixel, a third transformed stimulus value signal BZt of the third sub-pixel and a second transformed stimulus value signal WYt of the fourth sub-pixel in the second pixel unit according to the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 of the first sub-pixel in the first pixel unit;

a first conversion gray scale Rt of the first sub-pixel is determined according to the first conversion stimulus value signal RXt of the first sub-pixel in the unit of the second pixel, a second conversion gray scale Gt of the second sub-pixel is determined according to the second conversion stimulus value signal GYt of the second sub-pixel, a third conversion gray scale Bt of the third sub-pixel is determined according to the third conversion stimulus value signal BZt of the third sub-pixel, and a fourth conversion gray scale Wt of the fourth sub-pixel is determined according to the second conversion stimulus value signal WYt of the fourth sub-pixel.

When the pixel signal conversion program stored in the memory is executed by the processor, the operation of determining the second conversion stimulus value signal WYt of the fourth sub-pixel in the second pixel unit according to the first initial stimulus value signal RXo of the first sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 comprises:

calculating a first intermediate stimulus value signal RXm for a first sub-pixel in the second pixel unit from RXm-k 2-RXo, a second intermediate stimulus value signal GYm for a second sub-pixel in the second pixel unit from GYm-k 2-GYo, and a third intermediate stimulus value signal BZm for a third sub-pixel in the second pixel unit from BZm-k 2-BZo;

comparing the second minimum value with a preset stimulus value;

when the second minimum value is less than or equal to the preset stimulus value, determining the second conversion stimulus value signal WYt of the fourth sub-pixel as the second minimum value;

When the pixel signal conversion program stored in the memory is executed by the processor, the operations of determining the first converted stimulus value signal RXt of the first sub-pixel in the second pixel unit, the second converted stimulus value signal GYt of the second sub-pixel and the third converted stimulus value signal BZt of the third sub-pixel according to the first initial stimulus value signal RXo of the first sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 comprise:

according to

Calculating a fourth conversion gray scale Wt of the fourth sub-pixel;

according to

Calculating a first transformed stimulus value signal WXt for the fourth sub-pixel based on

Calculating a third transformed stimulus value signal WZt for the fourth sub-pixel;

calculating a first transition stimulus value signal RXt for a first sub-pixel in the second pixel unit from RXt-RXm-WXt, a second transition stimulus value signal GYt for a second sub-pixel in the second pixel unit from GYt GYm-WYt, and a third transition stimulus value signal BZt for a third sub-pixel in the second pixel unit from BZt-BZm-WZt;

When the pixel signal conversion program stored in the memory is executed by the processor, the operations of determining the first conversion gray scale Rt of the first sub-pixel according to the first conversion stimulus value signal RXt of the first sub-pixel in the second pixel unit, determining the second conversion gray scale Gt of the second sub-pixel according to the second conversion stimulus value signal GYt of the second sub-pixel, determining the third conversion gray scale Bt of the third sub-pixel according to the third conversion stimulus value signal BZt of the third sub-pixel, and determining the fourth conversion gray scale Wt of the fourth sub-pixel according to the second conversion stimulus value signal WYt of the fourth sub-pixel include:

according to

Calculating a first converted gray scale Rt of the first sub-pixel based on

Calculating a third converted gray level Bt of the third sub-pixel according to

Calculating a fourth conversion gray scale Wt of the fourth sub-pixel;

As shown in fig. 12, the display device includes a display panel 200 and a pixel signal conversion device 100, the pixel signal conversion device 100 is electrically connected to the display panel 200, and the specific structure of the pixel signal conversion device 100 refers to the above embodiments and is not repeated herein. Among them, the display panel 200 may be a VA liquid crystal display panel or the like.

The above description is only an alternative embodiment of the present application, and not intended to limit the scope of the present application, and all modifications and equivalents of the technical solutions that can be directly or indirectly applied to other related fields without departing from the spirit of the present application are intended to be included in the scope of the present application.

Claims

1. A pixel signal conversion method, characterized by comprising the steps of:

acquiring a first initial stimulus value signal RXo of a first sub-pixel, a second initial stimulus value signal GYo of a second sub-pixel and a third initial stimulus value signal BZo of a third sub-pixel in a first pixel unit before conversion;

determining a first gain coefficient k1 of a fourth sub-pixel in the converted second pixel unit and a second gain coefficient k2 of the first sub-pixel, the second sub-pixel and the third sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit; wherein the first gain coefficient k1 decreases with increasing color purity, and the second gain coefficient k2 increases with increasing color purity;

determining a first conversion gray scale Rt of the first sub-pixel, a second conversion gray scale Gt of the second sub-pixel, a third conversion gray scale Gt of the third sub-pixel, a third conversion gray scale Bt of the third sub-pixel and a fourth conversion gray scale Wt of the fourth sub-pixel in the second pixel unit according to the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k 2;

the step of determining a first gain factor k1 for the fourth sub-pixel in the converted second pixel unit based on the color purity of the first pixel unit comprises:

when the color purity is greater than the second preset color purity, determining that the first gain coefficient k1 takes a value within a range of 1< k1<2 according to the color purity; wherein the first preset color purity is less than or equal to the second preset color purity; the second gain factor K2 is related to the first gain factor K1, and the second gain factor K2 decreases as the first gain factor K1 increases.

2. The pixel signal converting method according to claim 1, wherein the step of obtaining the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel and the third initial stimulus value signal BZo of the third sub-pixel in the first pixel unit before conversion comprises:

according to

Calculating a third initial stimulus value signal BZo for the third sub-pixel;

3. The pixel signal converting method according to claim 1, wherein the step of determining the first gain factor k1 of the fourth sub-pixel in the converted second pixel unit according to the color purity of the first pixel unit further comprises:

determining that the first gain coefficient k1 satisfies k1 ═ 2 when the color purity is less than or equal to the second preset color purity.

4. The pixel signal converting method according to claim 3, wherein the step of determining the second gain coefficients k2 of the first sub-pixel, the second sub-pixel, and the third sub-pixel in the converted second pixel unit based on the color purity of the first pixel unit comprises:

Wherein γ is a scaling factor of the fourth sub-pixel.

5. The pixel signal converting method according to any one of claims 1 to 4, wherein the step of determining the first conversion gray scale Rt of the first sub-pixel, the second conversion gray scale Gt of the second sub-pixel, the third conversion gray scale Bt of the third sub-pixel and the fourth conversion gray scale Wt of the fourth sub-pixel in the second pixel unit according to the first initial stimulus value signal RXo of the first sub-pixel, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 comprises:

6. The pixel signal converting method according to claim 5, wherein the step of determining the second conversion stimulus value signal WYt of the fourth sub-pixel in the second pixel unit according to the first initial stimulus value signal RXo of the first sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 comprises:

comparing the second minimum value with a preset stimulus value;

7. The pixel signal converting method according to claim 6, wherein the step of determining the first converted stimulus value signal RXt of the first sub-pixel, the second converted stimulus value signal GYt of the second sub-pixel and the third converted stimulus value signal BZt of the third sub-pixel in the second pixel unit according to the first initial stimulus value signal RXo of the first sub-pixel in the first pixel unit, the second initial stimulus value signal GYo of the second sub-pixel, the third initial stimulus value signal BZo of the third sub-pixel, the first gain coefficient k1 and the second gain coefficient k2 comprises:

according to

Calculating a fourth conversion gray scale Wt of the fourth sub-pixel;

according to

8. The pixel signal converting method according to claim 5, wherein the steps of determining the first conversion gray scale Rt of the first sub-pixel according to the first conversion stimulus value signal RXt of the first sub-pixel in the second pixel unit, determining the second conversion gray scale Gt of the second sub-pixel according to the second conversion stimulus value signal GYt of the second sub-pixel, determining the third conversion gray scale Bt of the third sub-pixel according to the third conversion stimulus value signal BZt of the third sub-pixel, and determining the fourth conversion gray scale Wt of the fourth sub-pixel according to the second conversion stimulus value signal WYt of the fourth sub-pixel comprise:

according to

Calculating a first converted gray scale Rt of the first sub-pixel according to

Calculating a third converted gray level Bt of the third sub-pixel according to

Calculating a fourth conversion gray scale Wt of the fourth sub-pixel;

wherein N is the maximum gray scale value, γ_RXTo the power of the first stimulus value signal of the first sub-pixelFunction, gamma_GYIs a power function of the second stimulus value signal of the second sub-pixel, gamma_BZIs a power function of the third stimulus value signal of the third sub-pixel, gamma_WYAs a power function of the second stimulus value signal of the fourth sub-pixel.

9. A pixel signal conversion apparatus, characterized in that the pixel signal conversion apparatus comprises a memory, a processor and a pixel signal conversion program stored on the memory and executable on the processor, the pixel signal conversion program when executed by the processor implementing the steps of the pixel signal conversion method according to any one of claims 1 to 8.

10. A display device, characterized in that the display device comprises:

a display panel; and the number of the first and second groups,

the pixel signal conversion device according to claim 9, which is electrically connected to the display panel.