CN105472364B - The chrominance signal conversion method and device of LCDs - Google Patents

Abstract

The present invention relates to a color signal conversion method and device for a liquid crystal display, wherein the method includes: comparing the grayscale values of the R signal, the G signal and the B signal in the input RGB signal; the B signal in the RGB signal When the grayscale value of the signal is the smallest and the grayscale value of the R signal is greater than the grayscale value of the G signal, the RGB signal is converted into a first RGBY signal and the first RGBY signal is output, wherein the Y signal in the first RGBY signal The gray scale value of the G signal in the RGB signal is the gray scale value of the G signal, the gray scale value of the G signal in the first RGBY signal is the minimum gray scale value, and the gray scale value of the B signal in the first RGBY signal is the gray scale value of the RGB signal. The grayscale value of the B signal, the grayscale value of the R signal in the first RGBY signal is based on the grayscale value of the R signal in the RGB signal, the grayscale value of the Y signal in the first RGBY signal, the maximum grayscale value and The predetermined brightness curve gamma value is determined. According to the present invention, the color of the converted color signal can be made more vivid.

Description

Color signal conversion method and device for liquid crystal display

technical field

The invention relates to the field of liquid crystal display, in particular to a method and device for converting color signals of a liquid crystal display.

Background technique

Among the current mainstream display devices, the pixels of LCD (English: Liquid Crystal Display, Chinese: Liquid Crystal Display Panel) and OLED (English: Organic Light-Emitting Diode, Chinese: Organic Electroluminescent Display Panel) are generally composed of RGB (red, Green, blue) three sub-pixels, however, RGBY (red, green, blue, yellow) four sub-pixels are gradually appearing. Since the Y (yellow) signal is added, the yellow and gold signals are obtained. With better reproduction, the skin tones that often appear in videos will be closer to real-world colors. At the same time, after the yellow that is the complementary color of blue is enhanced, it will also play a very good role in improving the expressiveness of blue.

In general, the pixel signals transmitted by signal transmission interfaces such as VGA (English: Video Graphics Array, Chinese: Video Graphics Array) interface and DVI (English: Digital Visual Interface, Chinese: Digital Video Interface) are all RGB signals. Applying RGB signals directly to an RGBY display will result in image distortion, so it is necessary to convert the RGB signals connected to the RGBY display. In the traditional RGB signal conversion method, if the input color is not yellow, the color of the converted RGB signal may not be vivid enough, and if the input color is yellow, the color of yellow in the converted RGBY signal may not be enough bright.

Contents of the invention

technical problem

In view of this, the technical problem to be solved by the present invention is how to convert the RGB signal so that the color of the converted color signal is more vivid.

solution

In order to solve the above technical problems, according to one aspect of the present invention, a color signal conversion method of a liquid crystal display is provided, including:

Compare the grayscale values of the R signal, G signal and B signal in the input RGB signal;

In the case where the grayscale value of the B signal in the RGB signals is the smallest, comparing the grayscale values of the R signal and the G signal in the RGB signals;

converting the RGB signal into a first RGBY signal and outputting the first RGBY signal when the grayscale value of the R signal in the RGB signal is greater than the grayscale value of the G signal,

Wherein, the gray scale value of the Y signal in the first RGBY signal is the gray scale value of the G signal in the RGB signal,

The grayscale value of the G signal in the first RGBY signal is the minimum grayscale value,

The grayscale value of the B signal in the first RGBY signal is the grayscale value of the B signal in the RGB signal,

The grayscale value of the R signal in the first RGBY signal is based on the grayscale value of the R signal in the RGB signal, the grayscale value of the Y signal in the first RGBY signal, the maximum grayscale value, and a predetermined The luma curve gamma value is determined.

For the above color signal conversion method, in a possible implementation manner, it also includes:

converting the RGB signal into a second RGBY signal and outputting the second RGBY signal in a case where the grayscale value of the R signal in the RGB signal is less than or equal to the grayscale value of the G signal,

Wherein, the gray scale value of the Y signal in the second RGBY signal is the gray scale value of the R signal in the RGB signal,

The grayscale value of the R signal in the second RGBY signal is the minimum grayscale value,

The grayscale value of the B signal in the second RGBY signal is the grayscale value of the B signal in the RGB signal,

The grayscale value of the G signal in the second RGBY signal is based on the grayscale value of the G signal in the RGB signal, the grayscale value of the Y signal in the second RGBY signal, the maximum grayscale value, and the The predetermined brightness curve gamma value is determined.

For the above color signal conversion method, in a possible implementation, when the grayscale value of the R signal in the RGB signal is greater than the grayscale value of the G signal, the first The grayscale value of the R signal in the RGBY signal,

Formula 1

Wherein, R2 is the gray scale value of the R signal in the first RGBY signal, N is the maximum gray scale value, R1 is the gray scale value _of the R signal in the RGB signal, and _Y2 is the first _RGBY signal. The grayscale value of the Y signal in the RGBY signal, and γ is a predetermined gamma value of the brightness curve.

For the above color signal conversion method, in a possible implementation, when the grayscale value of the R signal in the RGB signal is less than or equal to the grayscale value of the G signal, the following formula 2 is used to calculate the the grayscale value of the G signal in the second RGBY signal,

Formula 2

Wherein, G2 is the grayscale value of the G signal in the _second RGBY signal, N is the maximum grayscale value, _G1 is the grayscale value of the G signal in the RGB signal, and _Y2 is the second The grayscale value of the Y signal in the RGBY signal, and γ is a predetermined gamma value of the brightness curve.

Regarding the above color signal conversion method, in a possible implementation manner, the method further includes:

converting the RGB signal into a third RGBY signal and outputting the third RGBY signal when the grayscale value of the B signal in the RGB signal is not the smallest,

Wherein, converting the RGB signal into a third RGBY signal and outputting the third RGBY signal includes:

improving the relative saturation of the RGB signal;

According to the enhanced relative saturation of the RGB signal and the length of the line segment OD in the RGB triangle, the corresponding point D2 in the RGB triangle is obtained, and the RGB triangle is used to represent the color gamut range of the liquid crystal display. ;as well as

Outputting the third RGBY signal according to the chromaticity coordinates of D2, wherein the grayscale value of the Y signal in the third RGBY signal is the minimum grayscale value,

Wherein, in the RGB triangle, the point O is determined by the reference white point coordinates, the point D1 is the point corresponding to the RGB signal in the RGB triangle, and the point D is the intersection point of the ray OD1 and the RGB triangle.

For the above color signal conversion method, in a possible implementation manner, the point D2 corresponding to the third RGBY signal in the RGB triangle is obtained according to the following formula 3,

OD2＝OD*S1 Formula 3

Among them, OD2 is the length of line segment OD2, OD is the length of line segment OD, and S1 is the relative saturation after promotion.

In order to solve the above technical problems, according to another aspect of the present invention, a color signal conversion device for a liquid crystal display is provided, including:

A comparison unit is used to compare the grayscale values of the R signal, the G signal and the B signal in the input RGB signal; and

The conversion output unit is connected with the comparison unit, and the comparison result of the comparison unit is that the gray scale value of the B signal in the RGB signals is the smallest and the gray scale value of the R signal is greater than the gray scale value of the G signal. case, converting the RGB signal into a first RGBY signal and outputting the first RGBY signal,

Wherein, the gray scale value of the Y signal in the first RGBY signal is the gray scale value of the G signal in the RGB signal,

The grayscale value of the G signal in the first RGBY signal is the minimum grayscale value,

The grayscale value of the B signal in the first RGBY signal is the grayscale value of the B signal in the RGB signal,

The grayscale value of the R signal in the first RGBY signal is based on the grayscale value of the R signal in the RGB signal, the grayscale value of the Y signal in the first RGBY signal, the maximum grayscale value, and a predetermined The luma curve gamma value is determined.

For the above color signal conversion device, in a possible implementation manner, the conversion output unit is further configured to obtain the comparison result of the comparison unit that the gray scale value of the B signal in the RGB signals is the smallest and the gray scale value of the R signal is the smallest. When the grayscale value is less than or equal to the grayscale value of the G signal, converting the RGB signal into a second RGBY signal and outputting the second RGBY signal,

Wherein, the gray scale value of the Y signal in the second RGBY signal is the gray scale value of the R signal in the RGB signal,

The grayscale value of the R signal in the second RGBY signal is the minimum grayscale value,

The grayscale value of the B signal in the second RGBY signal is the grayscale value of the B signal in the RGB signal,

The grayscale value of the G signal in the second RGBY signal is based on the grayscale value of the G signal in the RGB signal, the grayscale value of the Y signal in the second RGBY signal, the maximum grayscale value, and the The predetermined brightness curve gamma value is determined.

For the above color signal conversion device, in a possible implementation manner, in the case where the grayscale value of the R signal in the RGB signal is greater than the grayscale value of the G signal, the conversion output unit performs the following formula 1 calculating the grayscale value of the R signal in the first RGBY signal,

Formula 1

Wherein, R2 is the gray scale value of the R signal in the first RGBY signal, N is the maximum gray scale value, R1 is the gray scale value _of the R signal in the RGB signal, and _Y2 is the first _RGBY signal. The grayscale value of the Y signal in the RGBY signal, and γ is a predetermined gamma value of the brightness curve.

For the above color signal conversion device, in a possible implementation manner, in the case where the grayscale value of the R signal in the RGB signal is less than or equal to the grayscale value of the G signal, the conversion output unit is based on the following formula 2 to calculate the grayscale value of the G signal in the second RGBY signal,

Formula 2

Wherein, G2 is the grayscale value of the G signal in the _second RGBY signal, N is the maximum grayscale value, _G1 is the grayscale value of the G signal in the RGB signal, and _Y2 is the second The grayscale value of the Y signal in the RGBY signal, and γ is a predetermined gamma value of the brightness curve.

Regarding the above color signal conversion device, in a possible implementation manner, the conversion and output unit is further configured to be used when the comparison result of the comparison unit is that the grayscale value of the B signal in the RGB signals is not the smallest , converting the RGB signal into a third RGBY signal and outputting the third RGBY signal,

Wherein, converting the RGB signal into a third RGBY signal and outputting the third RGBY signal includes:

improving the relative saturation of the RGB signal;

According to the enhanced relative saturation of the RGB signal and the length of the line segment OD in the RGB triangle, the corresponding point D2 in the RGB triangle is obtained, and the RGB triangle is used to represent the color gamut range of the liquid crystal display. ;as well as

Outputting the third RGBY signal according to the chromaticity coordinates of D2, wherein the grayscale value of the Y signal in the third RGBY signal is the minimum grayscale value,

Wherein, in the RGB triangle, the point O is determined by the reference white point coordinates, the point D1 is the point corresponding to the RGB signal in the RGB triangle, and the point D is the intersection point of the ray OD1 and the RGB triangle.

For the above color signal conversion device, in a possible implementation manner, the conversion output unit acquires the point D2 corresponding to the third RGBY signal in the RGB triangle according to the following formula 3,

OD2＝OD*S1 Formula 3

Among them, OD2 is the length of line segment OD2, OD is the length of line segment OD, and S1 is the relative saturation after promotion.

Beneficial effect

The color signal conversion method and device for a liquid crystal display according to the embodiments of the present invention can convert original RGB signals into RGBY signals. When the input color is yellow, RGBY signals that make yellow more vivid can be output, and when the input color is not yellow, RGB signals that make other colors more vivid can be output. In this way, the color signal conversion method and device according to the embodiments of the present invention can make the color of the converted color signal more vivid.

Other features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 shows a flowchart of a method for converting color signals of a liquid crystal display according to an embodiment of the present invention;

2 shows a flowchart of a method for converting color signals of a liquid crystal display according to another embodiment of the present invention;

3 shows a schematic diagram of determining the chromaticity coordinate points of the new RGB signal from the chromaticity coordinate points of the original RGB signal according to an embodiment of the present invention;

FIG. 4 shows a specific example of a color signal conversion method when the input color is not yellow in an embodiment of the present invention;

Figure 5 shows a schematic diagram of a sine function as a function of increasing the relative saturation of RGB signals;

FIG. 6 shows a structural block diagram of a color signal conversion device for a liquid crystal display according to an embodiment of the present invention.

detailed description

Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the accompanying drawings. The same reference numbers in the figures indicate functionally identical or similar elements. While various aspects of the embodiments are shown in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or better than other embodiments.

In addition, in order to better illustrate the present invention, numerous specific details are given in the specific embodiments below. It will be understood by those skilled in the art that the present invention may be practiced without certain of the specific details. In some instances, methods, means, components and circuits well known to those skilled in the art have not been described in detail in order to highlight the gist of the present invention.

Example 1

FIG. 1 shows a flow chart of a method for converting color signals of a liquid crystal display according to an embodiment of the present invention. As shown in FIG. 1 , the color signal conversion method mainly includes the following steps S100-S130.

Step S100 , comparing the gray scale values of the R signal, the G signal and the B signal among the input RGB signals.

Specifically, firstly, the original RGB signal transmitted in such as VGA interface, DVI interface, etc. is input to the color signal conversion device of the present invention, and then the color signal conversion device compares the R signal and the G signal in the input RGB signal and the size of the grayscale value of the B signal. Wherein, in a possible implementation manner, the minimum gray scale value of the R signal, the G signal and the B signal in the RGB signal is 0, and the maximum gray scale value is 255. In other words, the gray scale values of the R signal, the G signal and the B signal are all in the range of 0-255.

Step S110, when the gray scale value of the B signal in the RGB signal is the smallest, compare the gray scale value of the R signal and the G signal in the RGB signal;

Step S120, in the case that the gray scale value of the R signal in the RGB signal is greater than the gray scale value of the G signal, convert the RGB signal into a first RGBY signal and output the first RGBY signal.

Wherein, the gray scale value of the Y signal in the first RGBY signal is the gray scale value of the G signal in the RGB signal, and the gray scale value of the G signal in the first RGBY signal is the minimum gray scale value, The grayscale value of the B signal in the first RGBY signal is the grayscale value of the B signal in the RGB signal, and the grayscale value of the R signal in the first RGBY signal is based on the R in the RGB signal. The grayscale value of the signal, the grayscale value of the Y signal in the first RGBY signal, the maximum grayscale value, and a predetermined gamma value of the brightness curve are determined.

For example, among the input RGB signals, the grayscale values of the R signal, G signal, and B signal are 150, 100, and 50 respectively, then in the above step S100, it is determined that the grayscale value of the B signal in the RGB signals is The value has the smallest grayscale value. Then, in the above step S110, it is determined that the grayscale value of the R signal is greater than that of the G signal. At this time, in step S120, the input RGB signal is converted into a first RGBY signal and the first RGBY signal is output. Wherein, in the RGBY signal, the grayscale value of the Y signal is the grayscale value of the G signal in the input RGB signal, that is, 100, and the grayscale value of the G signal is the minimum grayscale value, that is, 0, B The grayscale value of the signal remains unchanged, that is, it is still 50, and the grayscale value of the R signal can be based on the grayscale value of the R signal in the input RGB signal, the grayscale value of the Y signal in the first RGBY signal, and the maximum The grayscale value and the predetermined gamma value of the brightness curve are determined. In a possible implementation manner, the predetermined gamma value of the brightness curve is 2.2.

In this way, through the above step S120, the color signal conversion device can convert the input original RGB signal into an RGBY signal and output it to the RGBY display screen to display the color corresponding to the converted signal.

Through the above color signal conversion method of the embodiment of the present invention, the original RGB signal can be converted into an RGBY signal. Moreover, through the above color signal conversion method, the R signal in the converted RGBY signal can be better reflected, and the yellow color is enhanced, so that the color of the output RGBY signal is more vivid.

In a possible implementation manner, the color signal conversion method in the embodiment of the present invention may further include step S130.

Step S130 , in the case that the grayscale value of the R signal in the RGB signal is less than or equal to the grayscale value of the G signal, convert the RGB signal into a second RGBY signal and output the second RGBY signal.

Wherein, the grayscale value of the Y signal in the second RGBY signal is the grayscale value of the R signal in the RGB signal, the grayscale value of the R signal in the second RGBY signal is the minimum grayscale value, and the second RGBY The grayscale value of the B signal in the RGB signal is the grayscale value of the B signal in the RGB signal, and the grayscale value of the G signal in the second RGBY signal is based on the grayscale value of the G signal in the RGB signal, the second RGBY The grayscale value of the Y signal in the signal, the maximum grayscale value and the predetermined gamma value of the brightness curve are determined.

For example, among the input RGB signals, the grayscale values of the R signal, G signal, and B signal are 100, 150, and 50 respectively, then in the above step S100, it is determined that the grayscale value of the B signal in the RGB signals is The value has the smallest grayscale value. Then, in the above step S110, it is determined that the grayscale value of the R signal is smaller than that of the G signal. At this time, in step S130, the input RGB signal is converted into a second RGBY signal. Wherein, in the second RGBY signal, the grayscale value of the Y signal is the grayscale value of the R signal in the input RGB signal, that is, 100, and the grayscale value of the R signal is the minimum grayscale value, that is, 0 , the grayscale value of the B signal remains unchanged, that is, still 50, and the grayscale value of the G signal can be based on the grayscale value of the G signal in the input RGB signal and the grayscale value of the Y signal in the second RGBY signal value, the maximum grayscale value, and the predetermined gamma value of the brightness curve. In a possible implementation manner, the predetermined luminance curve gamma value is the same as the predetermined luminance curve gamma value in the foregoing implementation manner, and is also 2.2.

In this way, through the above step S130, the color signal conversion device can convert the input original RGB signal into an RGBY signal and output it to the RGBY display screen to display the color corresponding to the converted signal.

Through the color signal conversion method in the above embodiments, the original RGB signal can be converted into an RGBY signal. Moreover, through the above color signal conversion method, the G signal in the converted RGBY signal can be better reflected, and the yellow color is enhanced, so that the color of the output RGBY signal is more vivid.

Through the above color signal conversion method of the embodiment of the present invention, among the input RGB signals, when the gray scale value of the B signal is the smallest, it can be determined that the input color is yellow. In this case, compare the grayscale values of the R signal and the G signal in the RGB signal, and then use the step S120 or S130 in the above color signal conversion method to better reflect the R signal or the G signal. If it is determined that the grayscale value of the R signal is greater than that of the G signal, the R signal is better represented through the above step S120; otherwise, the G signal is better represented through the above step S130. Through the above color signal conversion method, the yellow color can be enhanced, thereby making the color of the RGBY signal more vivid.

Example 2

The main difference between this embodiment and the above-mentioned embodiment 1 is that in the above-mentioned step S120, in the case where the gray-scale value of the R signal in the input RGB signal is greater than the gray-scale value of the G signal, it can be specifically calculated according to the following formula 1 to calculate the grayscale value of the R signal in the first RGBY signal,

Formula 1

Wherein, R2 is the grayscale value of the R signal in the first RGBY signal, N is the maximum grayscale value, for example, ₂₅₅ , R1 is the grayscale value _of the R signal in the input RGB signal, and _Y2 is the grayscale value of the first RGBY signal. The grayscale value of the Y signal in an RGBY signal, γ is a predetermined luminance curve gamma value, for example γ=2.2.

Through the above color signal conversion method of the embodiment of the present invention, the original RGB signal can be converted into an RGBY signal. Moreover, through the above color signal conversion method, the color of the R signal in the converted RGBY signal is enhanced, that is, the colors of other colors except yellow are enhanced, so that all colors are more vivid and balanced.

In a possible implementation, in the above step S140, in the case where the grayscale value of the R signal in the input RGB signal is less than or equal to the grayscale value of the G signal, it can be specifically calculated according to the following formula 2 the grayscale value of the G signal in the second RGBY signal,

Formula 2

Wherein, G2 is the grayscale value of the G signal in the _second RGBY signal, N is the maximum grayscale value, for example, 255, _G1 is the grayscale value of the G signal in the input RGB signal, and _Y2 is the grayscale value of the second RGBY signal. The grayscale value of the Y signal in the two RGBY signals, γ is a predetermined gamma value of the luminance curve, for example, γ=2.2.

Through the color signal conversion method in the above embodiments, the original RGB signal can be converted into an RGBY signal. Moreover, the R signal or the G signal can be better reflected, and the yellow color is enhanced, so that the color of the RGBY signal is more vivid.

Example 3

FIG. 2 shows a flow chart of a method for converting color signals of a liquid crystal display according to another embodiment of the present invention. Steps in FIG. 2 with the same numbers as those in FIG. 1 have the same functions, and for the sake of brevity, detailed descriptions of these steps are omitted.

As shown in Figure 2, the main difference between the color signal conversion method shown in Figure 2 and the color signal conversion method shown in Figure 1 is that if the B signal in the input RGB signal is not the smallest, it can be judged that the If the color of the input signal is not yellow, there is no need to activate the Y pixel. At this time, the Y signal can be set to the minimum gray scale value, and the color enhancement can be performed according to the following steps S200 (including steps S2010-S2030).

In other words, in the color signal conversion method of the embodiment of the present invention, in addition to the steps S100-S130 in the above-mentioned embodiment, the following step S200 (including steps S2010-S2030) may be mainly included.

Step S200, if the gray scale value of the B signal in the input RGB signal is not the smallest, convert the input RGB signal into a third RGBY signal and output the third RGBY signal.

Wherein, the above step S200 may mainly include the following steps:

Step S2010, improving the relative saturation of the input RGB signal;

Step S2020, obtain the corresponding point D2 in the RGB triangle according to the enhanced relative saturation of the input RGB signal and the length of the line segment OD in the RGB triangle, wherein, as shown in Figure 3, the RGB triangle is used for Indicates the color gamut range of the LCD, wherein, in the RGB triangle, the O point is determined by the coordinates of the reference white point, and the D1 point is the corresponding point of the input RGB signal in the RGB triangle, and connects OD1, and extends the line segment OD1 along the OD1 direction To form ray OD1, the intersection of ray OD1 and RGB triangle is D; and

Step S2030, outputting a third RGBY signal according to the chromaticity coordinates of D2, wherein the grayscale value of the Y signal in the third RGBY signal is the minimum grayscale value.

Through the above-mentioned color signal conversion method of this embodiment, if the gray scale value of the B signal in the input RGB signal is not the minimum, that is, the input color is not yellow, first determine the color in the RGB triangle that is consistent with the input RGB signal. The chromaticity point D1 corresponding to the signal, and increase the relative saturation of the input RGB signal, and then obtain a new chromaticity point D2 according to the increased relative saturation and the length of the line segment OD. In this way, the hue H of the new chromaticity point D2 is the same as that of the original chromaticity point D1, but the relative saturation of the new chromaticity point D2 relative to the original chromaticity point D1 is improved. Then, some RGB combinations are found according to the new chromaticity point D2, so that their chromaticity coordinates are D2 points in the RGB triangle. Finally, according to the principle that the brightness is closest to the brightness of the original RGB signal, the final output RGBY signal is determined.

Through the above color signal conversion method, all colors can be made more vivid and balanced when the input color is not yellow.

In a possible implementation manner, in the above step S2020, the point D2 corresponding to the third RGBY signal in the RGB triangle can be obtained according to the following formula 3,

OD2＝OD*S1 Formula 3

Among them, OD2 is the length of line segment OD2, OD is the length of line segment OD, and S1 is the relative saturation after promotion.

FIG. 4 shows a specific example of a color signal conversion method when the input color is not yellow in an embodiment of the present invention. As shown in FIG. 4 , the color signal conversion method may mainly include the following steps.

(1) Use the color analyzer CA310 or other instruments to measure the XYZ of the RGB signal of the LCD, and according to the linear superposition principle of light, the chromaticity (x, y) and brightness Y of any RGB signal input can be calculated (as shown in Figure 4 Steps S300, S310 in). Specifically, according to the principle of linear superposition of light, XYZ of any RGB signal can be obtained by formulas: X=Xr+Xg+Xb, Y=Yr+Yg+Yb, Z=Zr+Zg+Zb. Then, according to the chromaticity formula x=X/(X+Y+Z), y=Y/(X+Y+Z), the corresponding chromaticity value, that is, the chromaticity coordinate can be calculated. In this way, the chromaticity (x, y) and brightness Y corresponding to all colors displayed by the LCD can be calculated. Here, the gray scale values of the R signal, the G signal, and the B signal in the RGB signals can all range from 0 to 255, that is, the minimum gray scale value is 0, and the maximum gray scale value is 255. In other words, for an 8bit LCD, there are a total of 255 ³ RGB combinations and colors.

(2) According to the above chroma data, the relative saturation S of any input RGB signal can be calculated (step S320 shown in FIG. 4 ).

Specifically, according to the RGB measured in step (1) from the minimum gray scale value to the maximum gray scale value, that is, the chromaticity values of 0 to 255 levels, the color gamut range of the LCD can be obtained as shown in Figure 3 triangle (hereinafter referred to as RGB triangle).

According to step (1), the chromaticity value of any RGB combination can be calculated, and the point corresponding to the chromaticity value in the RGB triangle can be determined according to the calculated chromaticity value of the RGB combination. Taking the RGB signal to be converted as an example, its chromaticity value can be calculated first, and then the point corresponding to the chromaticity value can be determined, as shown in FIG. 3 as D1. Wherein, as shown in FIG. 3 , in the RGB triangle, the chromaticity point corresponding to RGB=(255, 255, 255) is O. Connect OD1 and extend the line segment OD1 along the direction of OD1 to get the ray OD1. In addition, a point where the ray OD1 intersects with the side of the above-mentioned RGB triangle can be referred to as D.

Thus, the relative saturation of the RGB signal can be calculated as S=OD1/OD, where OD1 and OD represent the lengths of the line segments OD1 and OD respectively.

(3) Convert the saturation S using the sine function S1=sin(S*pi/2) (step S330 shown in FIG. 4 ).

Specifically, for the relative saturation S obtained in step (2), in a possible implementation, the sine function S1=sin(S*pi/2) can be used for proper stretching to enhance the RGB The relative saturation of the signal. Since S is within the range of (0, 1), and the sin function is nonlinearly increasing within (0, pi/2), therefore, S1 increases with the increase of S. In this way, a new relative saturation S1 of the RGB signal can be obtained, and a smooth transition of the RGB signal can be ensured without oversaturation. The graph of the sinusoidal function stretched to saturation can be roughly as shown in FIG. 5 .

Using the above sine function, the relative saturation of the RGB signal can be appropriately increased. When the saturation of the RGB signal itself is higher, the degree to which it can be improved will become smaller and smaller. In this way, oversaturation and the appearance of color bands or color blocks can be avoided.

The above uses the sine function as an example to illustrate the improvement of the relative saturation of the RGB signal. In a possible implementation, other functions can also be used to increase the relative saturation of the RGB signal, as long as the function can meet the requirements of increasing the relative saturation of the RGB signal, and the function is in the range of (0, 1) It can be changed linearly. For example, it is also possible to multiply the relative saturation S of the RGB signal by a number greater than 1.

(4) Keep the hue H unchanged, and calculate the chromaticity coordinate D2 of the new chromaticity point according to the new relative saturation S1 (step S340 shown in FIG. 4 ).

Specifically, according to the saturation S1 obtained in step (3) and the length of the line segment OD in the RGB triangle in step (2), the new chromaticity point D2 after the relative saturation is increased is determined. For example, using the above formula 3, the length of the line segment OD2 can be used to determine the new chromaticity point D2 after the relative saturation is increased. As shown in Figure 3, the hue H of the new chromaticity point D2 is the same as that of the original chromaticity point D1, but the saturation is changed, that is, the relative saturation of the new chromaticity point D2 compared with the original chromaticity point D1 has been improved .

(5) According to the coordinates of D2 and the original measurement data, find some RGB combinations so that their chromaticity coordinates are at D2, and then determine the final output RGB signal Y according to the principle that the brightness is closest to the original RGB brightness (wherein, The gray scale value of Y is the minimum gray scale value) signal (step S350 shown in FIG. 4 ).

It should be noted that, in the above color signal conversion method, the chromaticity point D1 is used for illustration. Those skilled in the art can know that by using the above color signal conversion method, the chromaticity point corresponding to any RGB signal can be converted to obtain an RGB signal with increased relative saturation but unchanged hue H.

Through the above-mentioned color signal conversion method, when the input color is not yellow, the color of the RGB signal can be enhanced, so that the color of the output RGB signal is more vivid.

It should be noted that, in the above embodiments, the present invention is described with the grayscale value range of the RGB signal being 0-255, and those skilled in the art will know that the grayscale value range of the RGB signal may be in other ranges. In addition, in the above embodiments, the present invention is described with the predetermined gamma value of the brightness curve being 2.2, and those skilled in the art can know that the predetermined gamma value of the brightness curve may be other values.

Example 4

FIG. 6 shows a structural block diagram of a color signal conversion device for a liquid crystal display according to an embodiment of the present invention. As shown in FIG. 6 , the color signal conversion device 60 may mainly include a comparison unit 61 and a conversion output unit 62 . Wherein, the comparing unit 61 is mainly used for comparing the size of the gray scale value of the R signal, the G signal and the B signal in the RGB signal of the input; When the comparison result is that the grayscale value of the B signal in the RGB signals is the smallest and the grayscale value of the R signal is greater than the grayscale value of the G signal, the RGB signal is converted into a first RGBY signal and the first RGBY signal is output. An RGBY signal, wherein the grayscale value of the Y signal in the first RGBY signal is the grayscale value of the G signal in the RGB signal, and the grayscale value of the G signal in the first RGBY signal is the smallest grayscale value, the grayscale value of the B signal in the first RGBY signal is the grayscale value of the B signal in the RGB signal, and the grayscale value of the R signal in the first RGBY signal is based on the RGB The grayscale value of the R signal in the first RGBY signal, the grayscale value of the Y signal in the first RGBY signal, the maximum grayscale value, and the predetermined brightness curve gamma value are determined.

In a possible implementation manner, the conversion output unit 62 is further configured to determine that the grayscale value of the B signal in the RGB signals is the smallest and the grayscale value of the R signal is less than or If it is equal to the grayscale value of the G signal, convert the RGB signal into a second RGBY signal and output the second RGBY signal, wherein the grayscale value of the Y signal in the second RGBY signal is the The grayscale value of the R signal in the RGB signal, the grayscale value of the R signal in the second RGBY signal is the minimum grayscale value, and the grayscale value of the B signal in the second RGBY signal is the RGB signal The grayscale value of the B signal in the second RGBY signal, the grayscale value of the G signal in the second RGBY signal is based on the grayscale value of the G signal in the RGB signal, the grayscale value of the Y signal in the second RGBY signal value, the maximum grayscale value, and the predetermined gamma value of the brightness curve.

The above-mentioned color signal conversion apparatus of this embodiment can be used to implement the color signal conversion method of the above-mentioned Embodiment 1. For the specific process of the color signal conversion method, refer to the specific description of the above-mentioned Embodiment 1.

In a possible implementation manner, when the grayscale value of the R signal in the RGB signal is greater than the grayscale value of the G signal, the conversion output unit 62 calculates the first RGBY according to the following formula 1 The grayscale value of the R signal in the signal,

Formula 1

Wherein, R2 is the gray scale value of the R signal in the first RGBY signal, N is the maximum gray scale value, R1 is the gray scale value _of the R signal in the RGB signal, and _Y2 is the first _RGBY signal. The grayscale value of the Y signal in the RGBY signal, and γ is a predetermined gamma value of the brightness curve.

In a possible implementation manner, when the grayscale value of the R signal in the RGB signal is less than or equal to the grayscale value of the G signal, the conversion output unit 62 calculates the first The grayscale value of the G signal in the two RGBY signals,

Formula 2

Wherein, G2 is the grayscale value of the G signal in the _second RGBY signal, N is the maximum grayscale value, _G1 is the grayscale value of the G signal in the RGB signal, and _Y2 is the second The grayscale value of the Y signal in the RGBY signal, and γ is a predetermined gamma value of the brightness curve.

The above-mentioned color signal conversion device of this embodiment can be used to implement the color signal conversion method of the above-mentioned embodiment 2. For the specific process of the color signal conversion method, refer to the specific description of the above-mentioned embodiment 2.

In a possible implementation manner, the conversion output unit 62 is further configured to convert the RGB Converting the signal into a third RGBY signal and outputting the third RGBY signal, wherein converting the RGB signal into a third RGBY signal and outputting the third RGBY signal includes: performing a relative saturation of the RGB signal Boosting: according to the boosted relative saturation of the RGB signal and the length of the line segment OD in the RGB triangle, the corresponding point D2 in the RGB triangle is obtained, and the RGB triangle is used to represent the color of the liquid crystal display domain range; and output the third RGBY signal according to the chromaticity coordinates of D2, wherein the grayscale value of the Y signal in the third RGBY signal is the minimum grayscale value, wherein, in the RGB triangle, O The point is determined by the coordinates of the reference white point, the point D1 is the point corresponding to the RGB signal in the RGB triangle, and the point D is the intersection point of the ray OD1 and the RGB triangle.

In a possible implementation manner, the conversion output unit 62 obtains the point D2 corresponding to the third RGBY signal in the RGB triangle according to the following formula 3,

OD2＝OD*S1 Formula 3

Among them, OD2 is the length of line segment OD2, OD is the length of line segment OD, and S1 is the relative saturation after promotion.

The above-mentioned color signal conversion apparatus of this embodiment can be used to implement the color signal conversion method of the above-mentioned embodiment 3. For the specific process of the color signal conversion method, refer to the specific description of the above-mentioned embodiment 3.

The color signal conversion device for a liquid crystal display according to an embodiment of the present invention can convert an original RGB signal into an RGBY signal. When the input color is yellow, RGBY signals that make yellow more vivid can be output, and when the input color is not yellow, RGB signals that make other colors more vivid can be output. In this way, the color signal conversion device according to the embodiment of the present invention can make the color of the converted color signal more vivid.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (12)

1. A kind of 1. chrominance signal conversion method of LCDs, it is characterised in that including：

   Compare the size of the grey decision-making of R signal in the rgb signal of input, G-signal and B signal；

   In the case of the grey decision-making minimum of B signal in the rgb signal, the R signal in the rgb signal is believed with G Number grey decision-making size；

   In the case that the grey decision-making of R signal in the rgb signal is more than the grey decision-making of G-signal, the rgb signal is changed Into the first RGBY signals and the first RGBY signals are exported,

   Wherein, the grey decision-making of the Y-signal in the first RGBY signals is the grey decision-making of the G-signal in the rgb signal,

   The grey decision-making of G-signal in the first RGBY signals is minimum gray value,

   The grey decision-making of B signal in the first RGBY signals is the grey decision-making of the B signal in the rgb signal,

   The grey decision-making of R signal of the grey decision-making of R signal in the first RGBY signals in the rgb signal, described Grey decision-making, maximum gray value and the predetermined brightness curve gamma value of Y-signal in one RGBY signals determines so that first The color of R signal in RGBY signals is enhanced.
2. 2. according to the method for claim 1, it is characterised in that also include：

   In the case that the grey decision-making of R signal in the rgb signal is less than or equal to the grey decision-making of G-signal, the RGB is believed Number it is converted into the 2nd RGBY signals and exports the 2nd RGBY signals,

   Wherein, the grey decision-making of the Y-signal in the 2nd RGBY signals is the grey decision-making of the R signal in the rgb signal,

   The grey decision-making of R signal in the 2nd RGBY signals is minimum gray value,

   The grey decision-making of B signal in the 2nd RGBY signals is the grey decision-making of the B signal in the rgb signal,

   The grey decision-making of G-signal of the grey decision-making of G-signal in the 2nd RGBY signals in the rgb signal, described Grey decision-making, maximum gray value and the predetermined brightness curve gamma value of Y-signal in two RGBY signals determines.
3. 3. according to the method for claim 1, it is characterised in that the grey decision-making of the R signal in the rgb signal is more than G In the case of the grey decision-making of signal, the grey decision-making of the R signal in the first RGBY signals is calculated according to equation below 1,

   Wherein, R₂For the grey decision-making of the R signal in the first RGBY signals, N is maximum gray value, R₁For in the rgb signal R signal grey decision-making, Y₂For the grey decision-making of the Y-signal in the first RGBY signals, γ is the predetermined brightness curve Gamma value.
4. 4. according to the method for claim 2, it is characterised in that the grey decision-making of the R signal in the rgb signal be less than or In the case of grey decision-making equal to G-signal, the GTG of the G-signal in the 2nd RGBY signals is calculated according to equation below 2 Value,

   Wherein, G₂For the grey decision-making of the G-signal in the 2nd RGBY signals, N is maximum gray value, G₁For in the rgb signal G-signal grey decision-making, Y₂For the grey decision-making of the Y-signal in the 2nd RGBY signals, γ is the predetermined brightness curve Gamma value.
5. 5. according to the method any one of claim 1-4, it is characterised in that methods described also includes：

   In the case that the grey decision-making of B signal in the rgb signal is not minimum, the rgb signal is converted into the 3rd RGBY signals simultaneously export the 3rd RGBY signals,

   Wherein, the rgb signal is converted into the 3rd RGBY signals and exports the 3rd RGBY signals, including：

   Relative saturation degree to the rgb signal is lifted；

   The length of line segment OD in the relative saturation degree and RGB triangles after the lifting of the rgb signal, to obtain Corresponding point D2 in RGB triangles is stated, the RGB triangles are used for the gamut range for representing the LCDs；And

   The 3rd RGBY signals are exported according to D2 chromaticity coordinate, wherein the ash of the Y-signal in the 3rd RGBY signals Rank value is minimum gray value,

   Wherein, in the RGB triangles, for O points by being determined with reference to white point coordinates, D1 points are the rgb signal in the RGB tri- Corresponding point in angular, D points are ray OD1 and the RGB triangles intersection point.
6. 6. according to the method for claim 5, it is characterised in that the 3rd RGBY signals are obtained according to equation below 3 The corresponding point D2 in the RGB triangles,

   OD2=OD*S1 formulas 3

   Wherein, OD2 is line segment OD2 length, and OD is line segment OD length, and S1 is the relative saturation degree after lifting.
7. A kind of 7. chrominance signal conversion equipment of LCDs, it is characterised in that including：

   Comparing unit, the size of the grey decision-making of the R signal in rgb signal, G-signal and B signal for comparing input；And

   Output unit is changed, is connected with the comparing unit, for being the rgb signal in the comparative result of the comparing unit In B signal grey decision-making it is minimum and in the case that the grey decision-making of R signal is more than the grey decision-making of G-signal, by the rgb signal It is converted into the first RGBY signals and exports the first RGBY signals,

   Wherein, the grey decision-making of the Y-signal in the first RGBY signals is the grey decision-making of the G-signal in the rgb signal,

   The grey decision-making of G-signal in the first RGBY signals is minimum gray value,

   The grey decision-making of B signal in the first RGBY signals is the grey decision-making of the B signal in the rgb signal,

   The grey decision-making of R signal of the grey decision-making of R signal in the first RGBY signals in the rgb signal, described Grey decision-making, maximum gray value and the predetermined brightness curve gamma value of Y-signal in one RGBY signals determines so that first The color of R signal in RGBY signals is enhanced.
8. 8. device according to claim 7, it is characterised in that the conversion output unit is additionally operable in the comparing unit Comparative result be B signal in the rgb signal grey decision-making it is minimum and the grey decision-making of R signal is less than or equal to G-signal Grey decision-making in the case of, the rgb signal is converted into the 2nd RGBY signals and exports the 2nd RGBY signals,

   Wherein, the grey decision-making of the Y-signal in the 2nd RGBY signals is the grey decision-making of the R signal in the rgb signal,

   The grey decision-making of R signal in the 2nd RGBY signals is minimum gray value,

   The grey decision-making of B signal in the 2nd RGBY signals is the grey decision-making of the B signal in the rgb signal,

   The grey decision-making of G-signal of the grey decision-making of G-signal in the 2nd RGBY signals in the rgb signal, described Grey decision-making, maximum gray value and the predetermined brightness curve gamma value of Y-signal in two RGBY signals determines.
9. 9. device according to claim 7, it is characterised in that the grey decision-making of the R signal in the rgb signal is more than G In the case of the grey decision-making of signal, the conversion output unit calculates the R in the first RGBY signals according to equation below 1 The grey decision-making of signal,

   Wherein, R₂For the grey decision-making of the R signal in the first RGBY signals, N is maximum gray value, R₁For in the rgb signal R signal grey decision-making, Y₂For the grey decision-making of the Y-signal in the first RGBY signals, γ is predetermined brightness curve gamma Value.
10. 10. device according to claim 8, it is characterised in that the grey decision-making of the R signal in the rgb signal is less than Or in the case of the grey decision-making equal to G-signal, the conversion output unit calculates the 2nd RGBY letters according to equation below 2 The grey decision-making of G-signal in number,

    Wherein, G₂For the grey decision-making of the G-signal in the 2nd RGBY signals, N is maximum gray value, G₁For in the rgb signal G-signal grey decision-making, Y₂For the grey decision-making of the Y-signal in the 2nd RGBY signals, γ is predetermined brightness curve gamma Value.
11. 11. according to the device any one of claim 7-10, it is characterised in that the conversion output unit is additionally operable to The comparative result of the comparing unit is in the case that the grey decision-making of the B signal in the rgb signal is not minimum, by described in Rgb signal is converted into the 3rd RGBY signals and exports the 3rd RGBY signals,

    Wherein, the rgb signal is converted into the 3rd RGBY signals and exports the 3rd RGBY signals, including：

    Relative saturation degree to the rgb signal is lifted；

    The length of line segment OD in the relative saturation degree and RGB triangles after the lifting of the rgb signal, to obtain Corresponding point D2 in RGB triangles is stated, the RGB triangles are used for the gamut range for representing the LCDs；And

    The 3rd RGBY signals are exported according to D2 chromaticity coordinate, wherein the ash of the Y-signal in the 3rd RGBY signals Rank value is minimum gray value,

    Wherein, in the RGB triangles, for O points by being determined with reference to white point coordinates, D1 points are the rgb signal in the RGB tri- Corresponding point in angular, D points are ray OD1 and the RGB triangles intersection point.
12. 12. device according to claim 11, it is characterised in that the conversion output unit obtains according to equation below 3 The 3rd RGBY signals corresponding point D2 in the RGB triangles is taken,

    OD2=OD*S1 formulas 3

    Wherein, OD2 is line segment OD2 length, and OD is line segment OD length, and S1 is the relative saturation degree after lifting.