KR20150012693A - Apparatus and method for converting color - Google Patents

Apparatus and method for converting color Download PDF

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KR20150012693A
KR20150012693A KR1020130088519A KR20130088519A KR20150012693A KR 20150012693 A KR20150012693 A KR 20150012693A KR 1020130088519 A KR1020130088519 A KR 1020130088519A KR 20130088519 A KR20130088519 A KR 20130088519A KR 20150012693 A KR20150012693 A KR 20150012693A
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South Korea
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compensation value
rgbw
data
white
max
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KR1020130088519A
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Korean (ko)
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박명진
문성학
김정환
백승찬
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엘지전자 주식회사
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/64—Circuits for processing colour signals
    • H04N9/643—Hue control means, e.g. flesh tone control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/64—Circuits for processing colour signals
    • H04N9/646—Circuits for processing colour signals for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters

Abstract

The present invention relates to a color conversion apparatus and method for preventing image retention in a multi-primary color display of an RGBW system, and more particularly, to a color conversion apparatus and method for preventing image retention in a multi- An RGBW compensation value generation unit for calculating each data compensation value for RGBW data based on the generated RGBW compensation value; and a compensation unit for compensating the RGBW data input from the RGBW conversion unit with the calculated data compensation value, (Red) color component, a G (green) color component, and a B (blue) color component from the RGBW data by decreasing the W Components can be increased by the data compensation value, respectively.

Description

[0001] APPARATUS AND METHOD FOR CONVERTING COLOR [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color conversion apparatus, and more particularly, to a color conversion apparatus and method for preventing afterimage of a multi-primary color display of the RGBW system.

In general, most displays currently in use can represent colors in three primary colors (RGB) as the primary color.

However, such a display has a problem in that it can not express all the colors that human can perceive.

Therefore, the color gamut limit of the display can be solved by expanding the gamut by using three narrow bands or by adding other main colors other than the three colors.

One such display device is a multi-primary color display (MPD). In a four-primary color display, a color other than three colors is added to further enhance color Can be expressed.

FIG. 1 is a view showing a pixel layout of a multi-primary color display, showing a pixel structure of an RGBW stripe type. FIG.

As shown in FIG. 1, the four primary color display can display colors by adding colors other than the three colors such as red (R), green (G), and blue (B) as well as white.

Therefore, the four primary color display has an extended gamut, and it is possible to minimize observer metamerism such as an observer, and it is attracting attention because of its simple implementation.

And, in the four primary color display, a color conversion device for converting an RGB image into an RGBW image is required.

In the general color conversion method, the smallest component value among the RGB component values may be used as a white W component value, and the remaining component values may be converted to a value obtained by subtracting the white W component value from each component value.

2, the RGB image has the largest green G component value and the smallest blue component value among RGB components, as shown in FIG. 2 .

Therefore, when the RGB image is converted into the RGBW image, the value of the blue B component having the smallest component value among the RGB components of the RGB image is used as the white W component value of the RGBW image as a reference, By converting the component values into values obtained by subtracting the white W component values from the respective component values, the RGBW component values of the RGBW image can be generated.

However, in this color conversion scheme, white W subpixels can be used more than RGB subpixels because common component values among RGB components are displayed in white subpixels.

Thus, for this reason, the white W subpixel may be more likely to degrade than the RGB subpixel.

Further, since the white W subpixel is used more than the RGB subpixel, there is also a problem of reducing the display lifetime due to the afterimage.

Therefore, there is a demand for a color conversion device capable of preventing deterioration of white W subpixel in the future to extend the life of the display.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color conversion apparatus and method capable of preventing degradation of a specific subpixel by generating an RGBW data compensation value for preventing pixel deterioration and compensating RGBW data do.

The color conversion apparatus according to an embodiment of the present invention includes an RGBW conversion unit for converting input RGB data into RGBW data, an RGBW compensation value generation unit for generating an RGBW compensation value from RGBW data, and based on the generated RGBW compensation value, And an RGBW compensation unit for compensating the RGBW data input from the RGBW conversion unit with the calculated data compensation value and outputting the final RGBW data, wherein the RGBW compensation unit comprises: From the data, the W (white) color component can be reduced by the data compensation value and the R (red) color component, G (green) color component and B (blue) color component can be increased by the data compensation value, respectively.

Here, the RGBW conversion unit may include a color component extraction unit for extracting a color component having the smallest color component value from the input RGB data, and a color component extraction unit for generating a W color component according to the color component value of the extracted color component, Value, the G color component value, and the B color component value by the extracted color component value, and converts the RGB color component.

The RGBW compensation value generating unit may include a compensation value generating unit for generating an RGBW compensation value from RGBW data and a data compensation value calculating unit for calculating each data compensation value for RGBW data based on the generated RGBW compensation value have.

Here, the compensation value generating unit may generate a value having the smallest difference from the maximum value of the gray level among the RGB subpixel data excluding the W subpixel data in each pixel, as the RGBW compensation value.

In addition, the compensation value generating unit may generate a compensation value for each of the RGBW subpixels in the pixel group having the first, second, third, and fourth pixels, Values from the first, second, third, and fourth pixels, respectively, and compares four first compensation values extracted from the first, second, third, and fourth pixels, 2 compensation value can be extracted and generated as the RGBW compensation value.

Next, a color conversion method according to an embodiment of the present invention includes: receiving RGB data; converting input RGB data to RGBW data; generating an RGBW compensation value from RGBW data; Calculating each data compensation value for RGBW data based on the RGBW compensation value and compensating the RGBW data input from the RGBW conversion unit with the calculated data compensation value and outputting the final RGBW data, Compensation of the RGBW data is performed by reducing the W (white) color component from the RGBW data by the data compensation value and by reducing the R (red) color component, G (green) .

Here, the step of generating the RGBW compensation value may include the step of generating, as the RGBW compensation value, a value having the smallest difference from the maximum value of the gray level among the RGB subpixel data excluding the data of the W subpixel in each pixel And calculating each data compensation value for the RGBW data based on the generated RGBW compensation value, wherein the compensation value of the W data is calculated to have the same value as the compensation value of the RGBW, It can be calculated by multiplying each color component conversion ratio by the RGBW compensation value.

In addition, the step of generating the RGBW compensation value may include a step of, in a group of pixels having the first, second, third, and fourth pixels, the difference between the maximum value of the gray level among the data of the RGBW subpixels of each pixel Extracting a first first compensation value from the first, second, third and fourth pixels, respectively, and outputting four first compensation values respectively extracted from the first, second, third and fourth pixels Extracting the smallest second compensation value to generate an RGBW compensation value; and calculating each data compensation value for RGBW data in one pixel group based on the generated RGBW compensation value, The compensation value of the W data in one pixel group is calculated by dividing the RGBW compensation value by 4. The compensation value of the R data in one pixel group is obtained by multiplying the R color component conversion ratio by the RGBW compensation value, And then multiplied by 4 to calculate Gday, The compensation value of the B color component conversion ratio is calculated by multiplying the GW component compensation ratio by the RGBW compensation value and by multiplying the result by 4, The compensation value is multiplied, and the resultant value is multiplied by 2 again.

In addition, the step of generating the RGBW compensation value may include a step of, in a group of pixels having the first, second, third, and fourth pixels, the difference between the maximum value of the gray level among the data of the RGBW subpixels of each pixel Extracting a first first compensation value from the first, second, third and fourth pixels, respectively, and outputting four first compensation values respectively extracted from the first, second, third and fourth pixels Extracting the smallest second compensation value to generate an RGBW compensation value; and calculating each data compensation value for RGBW data in one pixel group based on the generated RGBW compensation value, The compensation value of the W data in one pixel group is calculated to have the same value as the RGBW compensation value and the compensation value of the RGB data in one pixel group can be calculated by multiplying each of the color component conversion ratios by the RGBW compensation value.

According to an embodiment of the present invention, an RGBW data compensation value for preventing deterioration of a pixel is generated to compensate RGBW data, thereby preventing deterioration of a specific subpixel to reduce a residual image, There is an effect that can be made.

In addition, when the present invention is applied to a large area OLED display using the RGBW color filter method, it is possible to minimize afterimage while minimizing deterioration of image quality.

1 is a diagram showing a pixel layout of a multi-primary display;
2 is a diagram showing an example for explaining a general color conversion method;
3 is a block diagram showing a color conversion apparatus according to the present invention.
4A and 4B are diagrams for explaining the color conversion method according to the first embodiment of the present invention
5 is a view for explaining a method of generating an RGBW compensation value according to the first embodiment of the present invention;
6A and 6B are diagrams showing the compensated RGBW data according to the first embodiment of the present invention
7A to 7E are diagrams for explaining a method of generating an RGBW compensation value according to the second embodiment of the present invention
8 is a diagram for explaining a method of generating the RGBW compensation value for preventing deterioration according to the second embodiment of the present invention
9 is a diagram for explaining a method of calculating RGBW data compensated by the RGBW compensation value for preventing deterioration according to the second embodiment of the present invention
10A to 10E are diagrams for explaining the RGBW compensation value generation method according to the third embodiment of the present invention
11 is a diagram for explaining a method of generating an RGBW compensation value for preventing deterioration according to the third embodiment of the present invention
12 is a diagram for explaining a method of calculating RGBW data compensated with the RGBW compensation value for prevention of deterioration according to the third embodiment of the present invention
13 is a flowchart for explaining the color conversion method according to the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The suffix "module" and " part "for components used in the following description are given merely for ease of description, and the" module "and" part "

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

As used herein, terms used in the present invention are selected from general terms that are widely used in the present invention while taking into account the functions of the present invention, but these may vary depending on the intention or custom of a person skilled in the art or the emergence of new technologies. In addition, in certain cases, there may be a term arbitrarily selected by the applicant, in which case the meaning thereof will be described in the description of the corresponding invention. Therefore, it is intended that the terminology used herein should be interpreted based on the meaning of the term rather than on the name of the term, and on the entire contents of the specification.

3 is a block diagram showing a color conversion apparatus according to the present invention.

3, the color conversion apparatus of the present invention may include an RGBW conversion unit 10, an RGBW compensation value generation unit 20, and an RGBW compensation unit 30.

Here, the RGBW conversion section 10 can convert input RGB data into RGBW data.

Then, the RGBW compensation value generator 20 generates the RGBW compensation value from the RGBW data, and can calculate each data compensation value for the RGBW data based on the generated RGBW compensation value.

Next, the RGBW compensating section 30 can compensate the RGBW data input from the RGBW converting section 10 with the calculated data compensation value, and output the final RGBW data.

Here, the RGBW compensating unit 30 reduces the W (white) color component by the data compensation value from the RGBW data, and supplies the R (red) color component, G (green) Can be increased by the compensation value.

The RGBW converting section 10 may include a color component extracting section and a color component converting section.

Here, the color component extracting unit can extract a color component having the smallest color component value from the input RGB data.

The color component conversion unit generates the W color component according to the color component value of the extracted color component, and reduces the R color component value, the G color component value, and the B color component value by the extracted color component value, The color component can be converted.

Next, the RGBW compensation value generator 20 may include a compensation value generator and a data compensation value calculator.

Here, the compensation value generation unit may generate the RGBW compensation value from the RGBW data.

Then, the data compensation value calculation unit can calculate each data compensation value for RGBW data based on the generated RGBW compensation value.

At this time, the RGBW compensation value can be determined according to the ratio at which the W color component is converted into the RGB color component, as shown in Equation 1 below.

Equation 1

G white = W red G white + W green G white + W blue G white

Here, G white is the gray level of the W color component, W red is the conversion ratio of the R color component, W green is the conversion ratio of the G color component, and W blue is the conversion ratio of the B color component.

The compensation value generator of the RGBW compensation value generator 20 calculates a compensation value of the RGBW compensation value for each pixel from the RGB subpixel data excluding the data of the W subpixel, Can be generated.

Here, the RGBW compensation value of one pixel can be determined by the following equation (2).

Equation 2

RGBW compensation value ≤ Min {(G Max - G a) / W a, (G Max - G b) / W b, (G Max - G c) / W c, G d / W d}, (a, b , c, d) ∈ S

Here, G Max represents the maximum gray level (gray level), possible S is the sub-pixels other than the sub-pixels to prevent deterioration, Min {(G Max - G a) / W a, (G Max - G b) / W b, (G Max - G c ) / W c, G d / W d} are (G Max - G a) / W a, (G Max - G b) / W b, (G Max - G c) / W c , and G d / W d .

Then, the data compensation value calculating unit of the RGBW compensation value generating unit 20 can calculate each data compensation value for the RGBW data using the following equation (3) based on the generated RGBW compensation value.

Equation 3

W data compensation value C white ≤ Min {(G Max - G red) / W red, (G Max - G green) / W green, (G Max - G blue) / W blue, G white / W white}

Here, G Max represents the maximum gray level (gray level) as possible, Min {(G Max - G red) / W red, (G Max - G green) / W green, (G Max - G blue) / W blue, G white / W white } is the minimum value among (G Max - G red ) / W red , (G Max - G green ) / W green , (G Max - G blue ) / W blue and G white / W white .

R Data compensation value C red = W red × C white

G Data compensation value C green = W green × C white

B Data compensation value C blue = W blue C white

In some cases, the compensation value generator of the RGBW compensation value generator 20 may be configured such that, in one pixel group having the first, second, third, and fourth pixels, among the RGBW subpixel data of each pixel, The first compensation value having the smallest difference from the maximum value is extracted from the first, second, third, and fourth pixels, respectively, and the four compensation values extracted from the first, second, third, The first compensation values may be compared with each other to extract the smallest second compensation value to generate the RGBW compensation value.

Here, the first compensation value can be determined by the following equation (4).

Equation 4

First compensation value ≤ Min {(G Max - G red, i) / W red, i, (G Max - G green, i) / W green, i, (G Max - G blue, i) / W blue, G white / W white }

Here, i is any one of pixels within a pixel group of pixels, G Max represents the maximum gray level (gray level) as possible, Min {(G Max - G red, i) / W red, i, (G Max - G green, i) / W green, i, (G Max - G blue, i) / W blue, G white / W white} is, (G Max - G red, i) / W red, i, (G Max - G green , i ) / W green, i , (G max - G blue , i ) / W blue , and G white / W white .

Then, the second compensation value may be determined by the following equation (5).

Equation 5

The second compensation value? Min (the first compensation value of the first pixel, the first compensation value of the second pixel, the first compensation value of the third pixel, the first compensation value of the fourth pixel)

Next, the data compensation value calculating unit of the RGBW compensation value generating unit 20 can calculate each data compensation value for the RGBW data by the following Expression (6) based on the generated RGBW compensation value.

Equation 6

W data compensation value in a pixel group C white ≤ Min [(C white , i, C white, i + 1, C white, i + 2, C white, i + 3)] ÷ 4

Here, i is any one of the pixels in one pixel group.

R data compensation value C red in one pixel group = W red C white 4

G data compensation value in one pixel group C green = W green × C white × 4

B data compensation value in one pixel group C blue = W blue C white 2

In some cases, the data compensation value calculator of the RGBW compensation value generator 20 may calculate each data compensation value for the RGBW data on the basis of the generated RGBW compensation value using the following equation (7).

Equation 7

W data compensation value in a pixel group C white ≤ Min [(C white , i, C white, i + 1, C white, i + 2, C white, i + 3)]

Here, i is any one of the pixels in one pixel group.

R data compensation value C red in a pixel group = W red C white

G data compensation value in one pixel group C green = W green × C white

B data compensation value in one pixel group C blue = W blue C white

In this manner, the color conversion apparatus according to the present invention can prevent deterioration of characteristic pixels by compensating RGBW data by three methods.

That is, in order to display an RGBW data image, the present invention first converts RGB image data to RGBW color components, and then generates RGBW compensation data for anti-degradation compensation to prevent deterioration of a specific pixel, The RGBW compensation data for anti-degradation compensation can be compensated for the RGBW color component.

Therefore, the present invention is a method for compensating RGBW color components using RGBW compensation data for anti-deterioration compensation. The first method is a method of equally distributing data of W subpixels of one pixel to RGB subpixels .

The second method is to group four pixels into one group, to reduce the data of all the W subpixels in one group to the same value, and to reduce the data to W And distributing the data of the subpixels.

Next, the third method is a method of grouping four pixels into one group, and distributing data of W subpixels of one pixel in one group to subpixels of adjacent pixels.

Here, in the third method, an error diffusion method can be used to distribute data to adjacent pixels.

For the error diffusion, a method of reducing the data of W subpixels of one pixel in one group and compensating the error of each pixel with RGB color component compensation data calculated based on the reduced data in the adjacent remaining pixels . ≪ / RTI >

In the second method and the third method, a pixel for preventing deterioration is changed for every frame, and a deterioration preventing method can be applied to all the pixels.

The three types of deterioration prevention methods will be described in more detail as follows.

4A and 4B are views for explaining the color conversion method according to the first embodiment of the present invention.

4A and 4B, when the input RGB data is converted into RGBW data, each pixel 40 includes an R subpixel 41, a G subpixel 45, a B subpixel 47, a W Subpixel 43 may be included.

If the data of the W subpixel 43 in FIG. 4A is 100% in order to prevent deterioration of a specific pixel such as a W subpixel, which is frequently used, an RGBW compensation value is generated, The data of the RGB subpixels 41, 45 and 47 is decreased by 50% and the remaining 50% is distributed to the RGB subpixels 41, 45 and 47 by the reduced data .

Therefore, it is possible to prevent a deterioration phenomenon in which a load is concentrated only on a specific pixel such as a W subpixel.

As such, the compensation value to be distributed to the RGB subpixels 41, 45, 47 is the difference between the maximum value of the representable gray level (for example, 255 for 8 bit gray level) and the gray level value of the subpixel .

5 is a diagram for explaining a method of generating an RGBW compensation value according to the first embodiment of the present invention.

5, when the input RGB data is converted into RGBW data, each pixel 40 is divided into R sub-pixel 41, G sub-pixel 45, B sub-pixel 47, W sub- 43).

For example, if the data of the R subpixel 41 is 50, the data of the G subpixel 45 is 100, the data of the B subpixel 47 is 180, and the data of the W subpixel 43 is 255, RGBW The compensation value generating unit may calculate a compensation value for each pixel by subtracting the data of the RGB subpixel 41, 45, 47 excluding the data of the W subpixel 43 from the maximum value of the gray level Can be generated as an RGBW compensation value.

Here, the RGBW compensation value can be determined by the following equation (2).

Equation 2

RGBW compensation value ≤ Min {(G Max - G a) / W a, (G Max - G b) / W b, (G Max - G c) / W c, G d / W d}, (a, b , c, d) ∈ S

Here, G Max represents the maximum gray level (gray level), possible S is the sub-pixels other than the sub-pixels to prevent deterioration, Min {(G Max - G a) / W a, (G Max - G b) / W b, (G Max - G c ) / W c, G d / W d} are (G Max - G a) / W a, (G Max - G b) / W b, (G Max - G c) / W c , and G d / W d .

Thus, if the data values of each subpixel are applied to Equation 2, where W red = 1, W green = 0.9, and W blue = 0.7,

Degradation preventing RGBW compensation value ≤ Min {(G Max - G red) / W red, (G Max - G green) / W green, (G Max - G blue) / W blue, G white / W white} = Min { (255 - 50) / 1, (255-100) /0.9, (255-180) /0.7, 255/1} = Min {205, 172.2, 107.1,

The final anti-degradation RGBW compensation value may be 107. [

Therefore, each data compensation value for the RGBW data can be calculated based on the RGBW compensation value 107 for preventing deterioration.

Here, the RGBW compensation value for preventing deterioration may be determined according to the ratio at which the W color component is converted into the RGB color component, as shown in the following equation (1).

Equation 1

G white = W red G white + W green G white + W blue G white

Here, G white is the gray level of the W color component, W red is the conversion ratio of the R color component, W green is the conversion ratio of the G color component, and W blue is the conversion ratio of the B color component.

Then, based on the generated RGBW compensation value, the RGBW compensation value generating unit can calculate each data compensation value for RGBW data by the following equation (3).

Equation 3

W data compensation value C white ≤ Min {(G Max - G red) / W red, (G Max - G green) / W green, (G Max - G blue) / W blue, G white / W white}

Here, G Max represents the maximum gray level (gray level) as possible, Min {(G Max - G red) / W red, (G Max - G green) / W green, (G Max - G blue) / W blue, G white / W white } is the minimum value among (G Max - G red ) / W red , (G Max - G green ) / W green , (G Max - G blue ) / W blue and G white / W white .

R Data compensation value C red = W red × C white

G Data compensation value C green = W green × C white

B Data compensation value C blue = W blue C white

In this manner, when each data compensation value for RGBW data is calculated, it can be displayed by displaying the final RGBW data that has been compensated by compensating for the first RGBW data.

6A and 6B are diagrams illustrating compensated RGBW data according to the first embodiment of the present invention, wherein FIG. 6A is RGBW data before compensation, and FIG. 6B is RGBW data after compensation.

As shown in FIGS. 6A and 6B, when each data compensation value for RGBW data is compensated for the first RGBW data, it can be calculated as follows.

W data value after anti-degradation compensation G ' white = G white - C white

R data value after anti-degradation compensation G ' red = G red + C white

G data value after anti-degradation compensation G ' green = G green + C white

B data value after anti-degradation compensation G ' blue = G blue + C white

Here, G white, red G, green G, blue G is RGBW data prior to prevent deterioration compensation, G 'white, G' red , G 'green, G' blue is RGBW data after prevent deterioration compensation.

7A to 7E are diagrams for explaining a method of generating an RGBW compensation value according to the second embodiment of the present invention.

7A to 7E, when the input RGB data is converted into RGBW data, each pixel may include an R subpixel, a G subpixel, a B subpixel, and a W subpixel.

Here, as shown in FIG. 7A, four pixels can be grouped into one group.

For example, the first pixel 50 includes a first R subpixel 51, a first G subpixel 55, a first B subpixel 57, a first W subpixel 53 , The second pixel 60 includes a second R subpixel 61, a second G subpixel 65, a second B subpixel 67 and a second W subpixel 63, The pixel 70 includes a third R subpixel 71, a third G subpixel 75, a third B subpixel 77 and a third W subpixel 73, and the fourth pixel 80 ) May include a fourth R subpixel 81, a fourth G subpixel 85, a fourth B subpixel 87, and a fourth W subpixel 83. [

As shown in FIGS. 7B to 7E, the four pixels are grouped into one group, and the data of all the W subpixels 53, 63, 73, and 83 in one group is reduced to the same value, The data of the W subpixels can be dispersed by each RGB subpixel of the four pixels in the group.

Here, when dispersing the data of the W subpixel into each RGB subpixel, only one of the RGB color components is dispersed for each pixel, and the RGB components dispersed for each frame are changed to prevent degradation of RGB subpixels can do.

The method of the second embodiment of the present invention is similar to the method of the first embodiment of the present invention, but differs from the method of generating and compensating the RGBW compensation value for preventing deterioration.

FIG. 8 is a view for explaining a method of generating the RGBW compensation value for preventing deterioration according to the second embodiment of the present invention. FIG. 9 is a view for explaining a method of calculating the RGBW compensation value by the RGBW compensation value for prevention of deterioration according to the second embodiment of the present invention Fig.

As shown in FIGS. 8 and 9, the RGBW compensation value generating unit is a unit that, in one pixel group having the first, second, third, and fourth pixels, among the RGBW subpixel data of each pixel, The first compensation value is extracted from the first, second, third, and fourth pixels, respectively, and the four compensation values extracted from the first, second, third, 1 compensation values are compared with each other to extract the second smallest compensation value and generate the RGBW compensation value for preventing deterioration.

Here, the first compensation value can be determined by the following equation (4).

Equation 4

First compensation value ≤ Min {(G Max - G red, i) / W red, i, (G Max - G green, i) / W green, i, (G Max - G blue, i) / W blue, G white / W white }

Here, i is any one of pixels within a pixel group of pixels, G Max represents the maximum gray level (gray level) as possible, Min {(G Max - G red, i) / W red, i, (G Max - G green, i) / W green, i, (G Max - G blue, i) / W blue, G white / W white} is, (G Max - G red, i) / W red, i, (G Max - G green , i ) / W green , i , (G max - G blue , i ) / W blue , and G white / W white .

Then, the second compensation value can be determined by the following equation (5).

Equation 5

The second compensation value? Min (the first compensation value of the first pixel, the first compensation value of the second pixel, the first compensation value of the third pixel, the first compensation value of the fourth pixel)

Then, based on the generated anti-deterioration RGBW compensation value, the RGBW compensation value generation unit can calculate each data compensation value for RGBW data by the following expression (6).

Equation 6

W data compensation value in a pixel group C white ≤ Min [(C white , i, C white, i + 1, C white, i + 2, C white, i + 3)] ÷ 4

Here, i is any one of the pixels in one pixel group.

R data compensation value C red in one pixel group = W red C white 4

G data compensation value in one pixel group C green = W green × C white × 4

B data compensation value in one pixel group C blue = W blue C white 2

Here, since the B subpixel is weaker than the other subpixels, RGB data can be distributed to four pixels in one pixel group so that the compensation data is divided into two subpixels.

10A to 10E are views for explaining a method of generating an RGBW compensation value according to the third embodiment of the present invention.

As shown in FIGS. 10A to 10E, when the input RGB data is converted into RGBW data, each pixel may include an R subpixel, a G subpixel, a B subpixel, and a W subpixel.

Here, as shown in FIG. 10A, four pixels can be grouped into one group.

For example, the first pixel 50 includes a first R subpixel 51, a first G subpixel 55, a first B subpixel 57, a first W subpixel 53 , The second pixel 60 includes a second R subpixel 61, a second G subpixel 65, a second B subpixel 67 and a second W subpixel 63, The pixel 70 includes a third R subpixel 71, a third G subpixel 75, a third B subpixel 77 and a third W subpixel 73, and the fourth pixel 80 ) May include a fourth R subpixel 81, a fourth G subpixel 85, a fourth B subpixel 87, and a fourth W subpixel 83. [

As shown in FIGS. 10B to 10E, the four pixels are grouped into one group to reduce the data of W subpixels of one pixel in one group, and in the adjacent remaining pixels, the RGB colors And compensate for the error of each pixel with the component compensation data.

For example, FIG. 10B shows displaying the data of the W subpixel 53 of the upper left pixel among the four pixels as the RGB subpixel of the adjacent pixel, and FIG. 10C shows that of the four pixels, The data of the W subpixel 63 of the pixel of the adjacent pixel is displayed as the RGB subpixel of the adjacent pixel.

10D shows that the data of the W subpixel 73 of the lower left pixel among the four pixels is displayed by the RGB subpixel of the adjacent pixel, and FIG. 10E shows the data of the lower right pixel among the four pixels, And displaying the data of the W subpixel 83 of the pixel as the RGB subpixel of the adjacent pixel.

In the method of the third embodiment of the present invention, a pixel for preventing deterioration is changed every frame, and a deterioration preventing method can be applied to all the pixels.

FIG. 11 is a view for explaining a method of generating the RGBW compensation value for preventing deterioration according to the third embodiment of the present invention. FIG. 12 is a diagram for explaining a method for calculating the RGBW compensation value by the RGBW compensation value for prevention of deterioration according to the third embodiment of the present invention Fig.

As shown in Figs. 11 and 12, the RGBW compensation value generating unit generates RGBW compensation value data for each of the RGBW subpixels of each pixel in one pixel group having the first, second, third, and fourth pixels, The first compensation value is extracted from the first, second, third, and fourth pixels, respectively, and the four compensation values extracted from the first, second, third, 1 compensation values are compared with each other to extract the second smallest compensation value and generate the RGBW compensation value for preventing deterioration.

Here, the first compensation value can be determined by the following equation (4).

Equation 4

First compensation value ≤ Min {(G Max - G red, i) / W red, i, (G Max - G green, i) / W green, i, (G Max - G blue, i) / W blue, G white / W white }

Here, i is any one of pixels within a pixel group of pixels, G Max represents the maximum gray level (gray level) as possible, Min {(G Max - G red, i) / W red, i, (G Max - G green, i) / W green, i, (G Max - G blue, i) / W blue, G white / W white} is, (G Max - G red, i) / W red, i, (G Max - G green , i ) / W green , i , (G max - G blue , i ) / W blue , and G white / W white .

Then, the second compensation value can be determined by the following equation (5).

Equation 5

The second compensation value? Min (the first compensation value of the first pixel, the first compensation value of the second pixel, the first compensation value of the third pixel, the first compensation value of the fourth pixel)

Next, based on the generated anti-deterioration RGBW compensation value, the RGBW compensation value generator can calculate each data compensation value for RGBW data by the following equation (7).

Equation 7

W data compensation value in a pixel group C white ≤ Min [(C white , i, C white, i + 1, C white, i + 2, C white, i + 3)]

Here, i is any one of the pixels in one pixel group.

R data compensation value C red in a pixel group = W red C white

G data compensation value in one pixel group C green = W green × C white

B data compensation value in one pixel group C blue = W blue C white

Through such a method, data of a specific subpixel can be reduced by dispersing data of subpixels in which deterioration may occur to surrounding pixels.

Therefore, the subpixels in which the data are dispersed can be prevented from deteriorating, thereby reducing the occurrence of the afterimage.

13 is a flowchart for explaining a color conversion method according to the present invention.

13, first, the RGBW conversion unit of the present invention receives RGB data (S10)

Then, the RGBW converting unit converts the input RGB data into RGBW data (S20)

Next, the RGBW compensation value generating unit generates the RGBW compensation value from the RGBW data.

Next, the RGBW compensation value generation unit calculates each data compensation value for RGBW data based on the generated RGBW compensation value (S30)

Here, the step of generating the RGBW compensation value may include the step of generating, as the RGBW compensation value, a value having the smallest difference from the maximum value of the gray level among the RGB subpixel data excluding the data of the W subpixel in each pixel And calculating each data compensation value for RGBW data based on the generated RGBW compensation value.

At this time, the compensation value of the W data can be calculated to be the same value as the RGBW compensation value, and the compensation value of the RGB data can be calculated by multiplying each of the color component conversion ratios by the RGBW compensation value.

In some cases, the step of generating the RGBW compensation value may further comprise the step of, in a group of pixels having the first, second, third and fourth pixels, calculating a difference between the maximum value of the gray level Extracting the smallest first compensation value from the first, second, third, and fourth pixels, respectively, and determining four first compensations, respectively, extracted from the first, second, third, Comparing the values of the RGBW compensation values with each other to generate the RGBW compensation value, and calculating each data compensation value for the RGBW data in one pixel group based on the generated RGBW compensation value can do.

At this time, the compensation value of the W data in one pixel group is calculated by dividing the RGBW compensation value by 4. The compensation value of the R data in one pixel group is obtained by multiplying the R color component conversion ratio by the RGBW compensation value, The compensation value of the G data in one pixel group is calculated by multiplying the G color component conversion ratio by the RGBW compensation value and multiplying the resulting value by 4 to obtain a value of one pixel The compensation value of the B data in the group can be calculated by multiplying the B color component conversion ratio by the RGBW compensation value and multiplying the resultant value by 2 again.

In another case, the step of generating the RGBW compensation value may comprise the step of, in a group of pixels having the first, second, third and fourth pixels, of the data of the RGBW subpixels of each pixel, Extracting a first compensation value having the smallest difference value from the first, second, third, and fourth pixels, respectively, and extracting a first compensation value from the first, second, third, A step of extracting the smallest second compensation value by comparing the compensation values with each other to generate an RGBW compensation value; and calculating each data compensation value for RGBW data in one pixel group based on the generated RGBW compensation value .

At this time, the compensation value of the W data in one pixel group is calculated to be the same value as the RGBW compensation value, and the compensation value of the RGB data in one pixel group can be calculated by multiplying the RGBW compensation value by each color component conversion ratio have.

Next, the RGBW compensation unit compensates the RGBW data input from the RGBW conversion unit with the calculated data compensation value (S40)

Here, the compensation of the RGBW data is performed by reducing the W (white) color component from the RGBW data by a data compensation value, and replacing the R (red) color component, G (green) Respectively.

Finally, the RGBW compensation unit outputs the compensated final RGBW data to the display (S50)

 Therefore, the color conversion apparatus and method according to the present invention can generate RGBW data compensation values for preventing deterioration of pixels and compensate for RGBW data, thereby preventing the deterioration of specific subpixels to reduce the afterimage, It is possible to improve the life of the battery.

In addition, when the present invention is applied to a large area OLED display using the RGBW color filter method, it is possible to minimize afterimage while minimizing deterioration of image quality.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

10: RGBW conversion unit 20: RGBW compensation value generation unit
30: RGBW compensation unit

Claims (16)

An RGBW converter for converting input RGB data into RGBW data;
An RGBW compensation value generation unit for generating an RGBW compensation value from the RGBW data and calculating each data compensation value for the RGBW data based on the generated RGBW compensation value; And,
And an RGBW compensation unit for compensating the RGBW data input from the RGBW conversion unit with the calculated data compensation value and outputting final RGBW data,
Wherein the RGBW compensation unit comprises:
(Red) color component, G (green) color component, and B (blue) color component are increased from the RGBW data by the data compensation value Characterized by a color conversion device. The image processing apparatus according to claim 1,
A color component extracting unit for extracting a color component having the smallest color component value from the input RGB data;
A W color component is generated according to the color component value of the extracted color component, and the R color component value, the G color component value, and the B color component value are decreased by the extracted color component value, And a color component converting unit. The apparatus according to claim 1, wherein the RGBW compensation value generator comprises:
A compensation value generator for generating an RGBW compensation value from the RGBW data,
And a data compensation value calculating unit for calculating each data compensation value for the RGBW data based on the generated RGBW compensation value. 4. The method as claimed in claim 3,
Is determined according to a ratio at which a W color component is converted into an RGB color component as expressed by the following equation (1).
Equation 1
G white = W red G white + W green G white + W blue G white
(Where W white is the gray level of the W color component, W red is the conversion ratio of the R color component, W green is the conversion ratio of the G color component, and W blue is the conversion ratio of the B color component) 4. The apparatus of claim 3, wherein the compensation value generator comprises:
Wherein the RGBW compensation value is a value having a minimum difference from the maximum value of the gray level among data of the RGB subpixels excluding the data of the W subpixel in each pixel. 6. The method of claim 5, wherein the RGBW compensation value of the pixel
Is determined by the following equation (2).
Equation 2
RGBW compensation value ≤ Min {(G Max - G a) / W a, (G Max - G b) / W b, (G Max - G c) / W c, G d / W d}, (a, b , c, d) ∈ S
(G Max - G a ) / W a , (G Max - G b ) / (W max ) where G max is the maximum representable gray level, S is the subpixels excluding the sub- W b, (G Max - G c) / W c, G d / W d} are (G Max - G a) / W a, (G Max - G b) / W b, (G Max - G c) / W c , and G d / W d . The apparatus of claim 5, wherein the data compensation value calculator comprises:
And calculates each data compensation value for the RGBW data by using the following equation (3) based on the generated RGBW compensation value.
Equation 3
W data compensation value C white ≤ Min {(G Max - G red) / W red, (G Max - G green) / W green, (G Max - G blue) / W blue, G white / W white}
(Wherein, G Max represents the maximum gray level (gray level) as possible, Min {(G Max - G red) / W red, (G Max - G green) / W green, (G Max - G blue) / W blue , G white / W white} is (G Max - G red) / W red, (G Max - G green) / W green, (G Max - G blue) / W blue, G white / W white to a minimum value among )
R Data compensation value C red = W red × C white
G Data compensation value C green = W green × C white
B Data compensation value C blue = W blue C white 4. The apparatus of claim 3, wherein the compensation value generator comprises:
In a group of pixels having first, second, third, and fourth pixels,
Extracting from the first, second, third and fourth pixels a first compensation value having the smallest difference from the maximum value of the gray level among the RGBW subpixel data of each pixel,
Wherein the first compensation value is obtained by comparing the first compensation values extracted from the first, second, third and fourth pixels with each other to generate the RGBW compensation value. Conversion device. 9. The method of claim 8,
Is determined by the following equation (4).
Equation 4
First compensation value ≤ Min {(G Max - G red, i) / W red, i, (G Max - G green, i) / W green, i, (G Max - G blue, i) / W blue, G white / W white }
(Where, i is any one of pixels among the pixels in the pixel group, G Max represents the maximum gray level (gray level) as possible, Min {(G Max - G red, i) / W red, i, (G Max - G green, i) / W green , i, (G Max - G blue, i) / W blue, G white / W white} is, (G Max - G red, i) / W red, i, (G Max - G green , i ) / W green, i (G max - G blue , i ) / W blue and G white / W white . 9. The method of claim 8,
Is determined by the following equation (5).
Equation 5
The second compensation value? Min (the first compensation value of the first pixel, the first compensation value of the second pixel, the first compensation value of the third pixel, the first compensation value of the fourth pixel) The apparatus of claim 8, wherein the data compensation value calculator comprises:
And calculates each data compensation value for the RGBW data using the following equation (6) based on the generated RGBW compensation value.
Equation 6
W data compensation value in a pixel group C white ≤ Min [(C white , i, C white, i + 1, C white, i + 2, C white, i + 3)] ÷ 4
(Where i is any one of the pixels in one pixel group)
R data compensation value C red in one pixel group = W red C white 4
G data compensation value in one pixel group C green = W green × C white × 4
B data compensation value in one pixel group C blue = W blue C white 2 The apparatus of claim 8, wherein the data compensation value calculator comprises:
And calculates each data compensation value for the RGBW data based on the generated RGBW compensation value by the following equation (7).
Equation 7
W data compensation value in a pixel group C white ≤ Min [(C white , i, C white, i + 1, C white, i + 2, C white, i + 3)]
(Where i is any one of the pixels in one pixel group)
R data compensation value C red in a pixel group = W red C white
G data compensation value in one pixel group C green = W green × C white
B data compensation value in one pixel group C blue = W blue C white Receiving RGB data;
Converting the input RGB data into RGBW data;
Generating an RGBW compensation value from the RGBW data;
Calculating each data compensation value for the RGBW data based on the generated RGBW compensation value; And,
And outputting the final RGBW data by compensating the RGBW data input from the RGBW converter with the calculated data compensation value,
The compensation of the RGBW data may be performed,
(Red) color component, G (green) color component, and B (blue) color component are increased from the RGBW data by the data compensation value Color conversion method. 14. The method of claim 13, wherein generating the RGBW compensation value comprises:
Generating, as the RGBW compensation value, a value of the difference between the maximum value of the gray level among the data of the RGB subpixels excluding the data of the W subpixel in each pixel,
And calculating each data compensation value for the RGBW data based on the generated RGBW compensation value,
The compensation value of the W data is calculated to be the same value as the RGBW compensation value,
Wherein the compensation value of the RGB data is calculated by multiplying each color component conversion ratio by the RGBW compensation value. 14. The method of claim 13, wherein generating the RGBW compensation value comprises:
The first compensation value having the smallest difference from the maximum value of the gray level among the RGBW subpixel data of each pixel in one pixel group having the first, second, third, and fourth pixels, 2, third and fourth pixels, respectively,
Comparing the four first compensation values extracted from the first, second, third and fourth pixels with each other to extract a second smallest compensation value to generate the RGBW compensation value;
And calculating each data compensation value for RGBW data in the pixel group based on the generated RGBW compensation value,
The compensation value of the W data in the pixel group is calculated by dividing the RGBW compensation value by 4,
The compensation value of the R data in the pixel group is calculated by multiplying the R color component conversion ratio by the RGBW compensation value and multiplying the resultant value by 4 again,
The compensation value of the G data in the pixel group is calculated by multiplying the G color component conversion ratio by the RGBW compensation value and multiplying the resultant value by 4 again,
Wherein the compensation value of the B data in the pixel group is calculated by multiplying the B color component conversion ratio by the RGBW compensation value and multiplying the result by 2 again. 14. The method of claim 13, wherein generating the RGBW compensation value comprises:
The first compensation value having the smallest difference from the maximum value of the gray level among the RGBW subpixel data of each pixel in one pixel group having the first, second, third, and fourth pixels, 2, third and fourth pixels, respectively,
Comparing the four first compensation values extracted from the first, second, third and fourth pixels with each other to extract a second smallest compensation value to generate the RGBW compensation value;
And calculating each data compensation value for RGBW data in the pixel group based on the generated RGBW compensation value,
The compensation value of the W data in the pixel group is calculated to be the same value as the RGBW compensation value,
Wherein the compensation value of the RGB data in the pixel group is calculated by multiplying each of the color component conversion ratios by the RGBW compensation value.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108717839A (en) * 2018-04-17 2018-10-30 京东方科技集团股份有限公司 A kind of conversion method of RGB to RGBW, device and storage medium
US10170079B2 (en) 2015-08-28 2019-01-01 Samsung Electronics Co., Ltd. Display apparatus and display panel driving method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10170079B2 (en) 2015-08-28 2019-01-01 Samsung Electronics Co., Ltd. Display apparatus and display panel driving method thereof
CN108717839A (en) * 2018-04-17 2018-10-30 京东方科技集团股份有限公司 A kind of conversion method of RGB to RGBW, device and storage medium

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