Method and device for calibrating color gamut of display screen, and electronic device

Patent metadata

Field	Value
Publication number	US-11574577-B2
Application number	US-202017099695-A
Country	US
Kind code	B2
Filing date	Nov 16, 2020
Priority date	May 29, 2020
Publication date	Feb 7, 2023
Grant date	Feb 7, 2023

Abstract

A method for calibrating a color gamut of a display screen includes: acquiring a brightness level of the display screen, and original red green blue (RGB) values of a color to be displayed by a pixel in the display screen; determining, according to the brightness level of the display screen and the original RGB values, corrected color coordinates; and determining a calibrated RGB values according to the corrected color coordinates, and driving, with the calibrated RGB values, light emission of the pixel in the display screen.

First claim

What is claimed is:

1. A method for calibrating a color gamut of a display screen, comprising:
acquiring a brightness level of the display screen, and original red green blue (RGB) values of a color to be displayed by a pixel in the display screen;
determining, according to the brightness level of the display screen and the original RGB values, corrected color coordinates; and
determining a calibrated RGB values according to the corrected color coordinates, and driving, with the calibrated RGB values, light emission of the pixel in the display screen,
wherein the determining, according to the brightness level of the display screen and the original RGB values, the corrected color coordinates comprises:
determining, according to the brightness level of the display screen and the original RGB values, a set of brightness compensation values;
acquiring, according to the original RGB values, reference color coordinates corresponding to the original RGB values; and determining,
according to the set of brightness compensation values and the reference color coordinates, the corrected color coordinates.

2. The method according to claim 1 , wherein the determining, according to the brightness level of the display screen and the original RGB values, the set of brightness compensation values comprises:
determining, based on a preset mapping relationship, a brightness compensation value corresponding to each dimension of a color coordinate system according to the brightness level of the display screen and the original RGB values.

3. The method according to claim 2 , wherein the color coordinate system includes an x axis, a y axis, and a z axis, and the determining, according to the set of brightness compensation values and the reference color coordinates, the corrected color coordinates comprises:
determining an x-axis coordinate of the corrected color coordinates, according to a brightness compensation value corresponding to the x axis and an x-axis coordinate of the reference color coordinates;
determining a y-axis coordinate of the corrected color coordinates, according to a brightness compensation value corresponding to the y axis and a y-axis coordinate of the reference color coordinates; and
determining a z-axis coordinate of the corrected color coordinates, according to a brightness compensation value corresponding to the z axis and a z-axis coordinate of the reference color coordinates.

4. The method according to claim 3 , further comprising:
acquiring, under each of different brightness levels of the display screen, respective actual color coordinates of a color of light emitted by the pixel driven with set RGB values;
selecting the reference color coordinates from all the actual color coordinates obtained under the different brightness levels of the display screen;
when light emission of the pixel is driven with the set RGB values, acquiring a color coordinate difference according to the reference color coordinates and actual color coordinates corresponding to each of the different brightness levels of the display screen; and
acquiring, according to the color coordinate difference and the corresponding brightness level of the display screen, a mapping relationship from a corresponding set of brightness compensation values to brightness levels of the display screen.

5. The method according to claim 1 , wherein the determining the calibrated RGB values according to the corrected color coordinates comprises:
determining the calibrated color coordinates according to the corrected color coordinates; and
determining the calibrated RGB values according to the calibrated color coordinates.

6. The method according to claim 5 , wherein the determining the calibrated color coordinates according to the corrected color coordinates comprises:
converting, according to a rule of conversion from a source color gamut of the display screen to a target color gamut of the display screen, the corrected color coordinates into the calibrated color coordinates.

7. An electronic device implementing the method of claim 1 , comprising an organic light-emitting diode (OLED) display screen, wherein the electronic device is configured to:
determine the calibrated RGB values based on the brightness level of the OLED display screen as a reference quantity;
determine the corrected color coordinates according to the brightness level of the OLED display screen;
further determine the calibrated RGB values according to the corrected color coordinates;
drive light emission of a pixel of the OLED display screen using the calibrated RGB values, thereby unifying colors of light emitted by the pixel under different display brightness levels, such that hues of colors of light emitted by the pixel always corresponds to the corrected color coordinates under the different display brightness levels of the OLED display screen, the brightness of the OLED display screen only affects the brightness of the colors of the light emitted by the pixel, and does not affect the hues of the colors of the light emitted by the pixel, realizing accurate calibration of the color gamut under different the brightness levels of the OLED display screen.

8. A device for calibrating a color gamut, comprising a processor; and memory for storing instructions executable by the processor; wherein the processor is configured to:
acquire a brightness level of a display screen, and original red green blue (RGB) values of a color to be displayed by a pixel in the display screen;
determine, according to the brightness level of the display screen and the original RGB values, corrected color coordinates; and
determine a calibrated RGB values according to the corrected color coordinates, and driving, with the calibrated RGB values, light emission of the pixel in the display screen,
wherein the processor is configured to:
determine, according to the brightness level of the display screen and the original RGB values, a set of brightness compensation values;
acquire, according to the original RGB values, reference color coordinates corresponding to the original RGB values; and
determine, according to the set of brightness compensation values and the reference color coordinates, the corrected color coordinates.

9. The device of claim 8 , wherein the processor is further configured to:
determine, based on a preset mapping relationship, a brightness compensation value corresponding to each dimension of a color coordinate system according to the brightness level of the display screen and the original RGB values.

10. The device of claim 9 , wherein the color coordinate system includes an x axis, a y axis, and a z axis, and the processor is further configured to:
determine an x-axis coordinate of the corrected color coordinates, according to a brightness compensation value corresponding to the x axis and an x-axis coordinate of the reference color coordinates;
determine a y-axis coordinate of the corrected color coordinates, according to a brightness compensation value corresponding to the y axis and a y-axis coordinate of the reference color coordinates; and
determine a z-axis coordinate of the corrected color coordinates, according to a brightness compensation value corresponding to the z axis and a z-axis coordinate of the reference color coordinates.

11. The device of claim 10 , wherein the processor is further configured to:
acquire, under each of different brightness levels of the display screen, respective actual color coordinates of a color of light emitted by the pixel driven with set RGB values;
select the reference color coordinates from all the actual color coordinates obtained under the different brightness levels of the display scre

Assignees

• Beijing Xiaomi Mobile Software Co Ltd

Inventors

• Zhai Dong

Classifications

• G09G3/2003 Primary

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

• G09G3/3208 Primary

  organic, e.g. using organic light-emitting diodes [OLED] · CPC title

• G09G2340/06

  Colour space transformation · CPC title

• G09G2320/0666

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

• G09G2320/0693

  Calibration of display systems · CPC title