Color gamut conversion method, color gamut converter, display device, image signal conversion method, computer device and non-transitory storage medium

Patent metadata

Field	Value
Publication number	US-11081081-B2
Application number	US-201916633925-A
Country	US
Kind code	B2
Filing date	Jun 12, 2019
Priority date	Jun 15, 2018
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A color gamut conversion method, a color gamut converter, a display device, an image signal conversion method, a computer device and a non-transitory storage medium are disclosed. The method includes: acquiring RGB signals and a preset grayscale value of a white subpixel in each pixel of a converted image according to grayscale values of monochromatic subpixels in each pixel of an original image corresponding to the RGB signals, the converted image is obtained by converting the original image from an RGB gamut to an RGBW gamut; and acquiring a target grayscale value of the white subpixel at least according to a first maximum grayscale of the white subpixels and the preset grayscale. As for a first saturation color patch in the original image, a first maximum grayscale of a white subpixel corresponding to each pixel in the first saturation color patch is equal to a grayscale threshold.

First claim

What is claimed is:

1. A color gamut conversion method, comprising:
acquiring, by one or more processors, RGB signals;
acquiring, by the one or more processors, a preset grayscale value of a white subpixel in each pixel of a converted image according to grayscale values of monochromatic subpixels in each pixel of an original image corresponding to the RGB signals, wherein the converted image is obtained by converting the original image from an RGB gamut to an RGBW gamut; and
acquiring, by the one or more processors, a target grayscale value of the white subpixel at least according to a first maximum grayscale of the white subpixels and the preset grayscale value, and setting, by the one or more processors, the target grayscale value of the white subpixel to be a value that is less than or equal to a minimum value of the first maximum grayscale of the white subpixel and the preset grayscale value,
wherein, as for a first saturation color patch in the original image, a first maximum grayscale of a white subpixel corresponding to each pixel disposed in the first saturation color patch is equal to a grayscale threshold, and the grayscale threshold is less than a maximum grayscale value allowed by a display device.

2. The color gamut conversion method according to claim 1 , wherein a first maximum grayscale of a white subpixel corresponding to each pixel, which is disposed in the original image and at outside of the first saturation color patch, is equal to the maximum grayscale value allowed by the display device; and
the maximum grayscale value allowed by the display device is equal to 255, and the grayscale threshold is selected from 90-110.

3. The color gamut conversion method according to claim 1 , further comprising:
dividing the original image into at least one detection area; and
determining whether a detection area of the at least one detection area is the first saturation color patch according to brightness, saturations and hues of a plurality of pixels in the each detection area.

4. The color gamut conversion method according to claim 3 , wherein the dividing the original image into the at least one detection area and determining whether the detection area of the at least one detection area is the first saturation color patch according to the brightness, saturations and hues of the plurality of pixels in the detection area comprises:
setting a preset saturation threshold, a preset hue range, a preset brightness threshold and a first preset proportion parameter;
acquiring a proportion of pixels in the detection area, of which saturations are greater than the preset saturation threshold, hues are within the preset hue range, and brightness is greater than the preset brightness threshold, in all pixels of the original image; and
determining that the detection area is the first saturation color patch when the proportion of pixels in the detection area is greater than the first preset proportion parameter.

5. The color gamut conversion method according to claim 1 , further comprising:
setting a second preset proportion parameter;
acquiring a proportion K of pixels in the original image, of which saturations are greater than the preset saturation threshold, in all the pixels of the original image, wherein K is a positive integer; and
setting a second maximum grayscale of the white subpixel to be K×255 when the proportion K is greater than the second preset proportion parameter,
wherein the acquiring the target grayscale value of the white subpixel at least according to the first maximum grayscale of the white subpixel and the preset grayscale value and setting the target grayscale value of the white subpixel to be a value that is less than or equal to the minimum value of the first maximum grayscale of the white subpixel and the preset grayscale value comprises: setting the target grayscale value of the white subpixel to be a minimum value of the first maximum grayscale, the preset grayscale value and the second maximum grayscale.

6. The color gamut conversion method according to claim 5 , wherein before acquiring the proportion K of the pixels in the original image, of which the saturations are greater than the preset saturation threshold, in all the pixels of the original image, the method further comprises:
acquiring a saturation of each pixel of the original image and normalizing the saturation of the each pixel.

7. The color gamut conversion method according to claim 1 , further comprising:
acquiring a grayscale value of red subpixel R 1i , a grayscale value of green subpixel G 1i , and a grayscale value of blue subpixel B 1i of each pixel in the RGBW gamut according to a grayscale value of red subpixel R i , a grayscale value of green subpixel G i , and a grayscale value of blue subpixel B i of each pixel in the RGB gamut,
wherein R i , R 1i , G i , G 1i , B i and B 1i satisfy following formulas: R i =R 1i ; G i =G 1i ; B i =B 1i .

8. The color gamut conversion method according to claim 7 , wherein the acquiring the preset grayscale value of the white subpixel in the each pixel of the converted image according to the grayscale values of the monochromatic subpixels in the each pixel of the original image corresponding to the RGB signals comprises: acquiring the preset grayscale value W 1i of the white subpixel according to a following formula:

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Assignees

• Beijing Boe Optoelectronics Tech Co Ltd
• Boe Technology Group Co Ltd

Inventors

• Li Yue
• Shi Tiankuo
• Ji Zhihua
• Shuai Chuan
• Shi Lingyun
• Zhang Xiaomang
• Chu Yifang
• Zhou Chengqi
• Liu Chuanjun
• Sun Zhou
• Sun Yilang

Classifications

• G09G5/02 Primary

  characterised by the way in which colour is displayed {(details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607)} · CPC title

• G09G2320/0666

  for control of colour parameters, e.g. colour temperature · CPC title

• G09G3/2003

  Display of colours (specific for liquid crystal displays G09G3/3607) · CPC title

• G09G2360/145

  the light originating from the display screen · CPC title

• G09G2360/16

  Calculation or use of calculated indices related to luminance levels in display data · CPC title