Color adjustment method and device

• US 10,269,129 B2
• Filed: 12/29/2015
• Issued: 04/23/2019
• Est. Priority Date: 12/31/2014
• Status: Active Grant

• Current Assignee: Xiaomi Inc. (Xiaomi Corp.)
• Original Assignee: Xiaomi Inc. (Xiaomi Corp.)
• Inventors: Liu, Anyu, Ji, Chuanshun, Li, Guosheng
• Primary Examiner(s): Tswei, Yu-Jang
• Application Number:
  US14/981,912
• Publication Number:
  US 20160189399A1
• Time in Patent Office: 1,211 Days
• Field of Search: None
• CPC Class Codes: G06T 1/60 Memory management
• CPC Class Codes: G06T 7/40 Analysis of texture depth or shape recovery from texture G06T7/529
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/02 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 Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables
• CPC Class Codes: H04N 1/6002 Corrections within particular colour systems

Abstract

A color adjustment method and device are provided. The color adjustment method comprises: obtaining frame data from a frame buffer; mapping the frame data from an original color space to a linear original color space via a de-gamma correction process, so as to obtain frame data in the linear original color space; mapping the frame data in the linear original color space to a linear target color space, so as to obtain frame data in the linear target color space; and performing a gamma correction process on the frame data in the linear target color space by using a target gamma coefficient, so as to obtain frame data in a target color space.

Claims

1. A color adjustment method, comprising:

obtaining frame data from a frame buffer;

mapping the frame data from an original color space to a linear original color space via a de-gamma correction process, so as to obtain frame data in the linear original color space;

mapping the frame data in the linear original color space to a linear target color space, so as to obtain frame data in the linear target color space;

obtaining a color correction matrix of a target device, the color correction matrix being a deviation matrix obtained in the target color space according to deviations between color data of the target device and standard color data;

correcting the frame data in the linear target color space by using the color correction matrix, so as to obtain corrected frame data in the linear target color space; and

performing a gamma correction process on the corrected frame data in the linear target color space by using a target gamma coefficient, so as to obtain frame data in a target color space.

2. The color adjustment method according to claim 1, wherein mapping the frame data from the original color space to the linear original color space via the de-gamma correction process comprises:

obtaining a gamma coefficient, wherein the gamma coefficient is to be used by a target device for performing a gamma correction process on the frame data in the linear original color space at an operation system layer or at an application layer; and

performing the de-gamma correction process on the frame data in the original color space by using the gamma coefficient, so as to obtain the frame data in the linear original color space.

3. The color adjustment method according to claim 1, further comprising:

dispersing a length of data in each color channel of the frame data in the linear original color space from a first bit length to a second bit length, wherein the second bit length is greater than the first bit length.

4. The color adjustment method according to claim 3, further comprising:

if displaying the length of the data in each color channel of the frame data in the target color space as the second bit length is unsupported by a target device, changing the length of the data in each color channel of the frame data in the target color space from the second bit length to the first bit length.

5. The color adjustment method according to claim 1, wherein the target color space is a sRGB color space, and obtaining the color correction matrix of the target device comprises:

obtaining coordinates of R, G, B and white points of the target device in the sRGB color space; and

calculating deviations between the coordinates of R, G, B and white point of the target device and coordinates of R′

, G′

, B′ and

white point of standard sRGB respectively, so as to obtain the deviation matrix.

6. A color adjustment device, comprising:

a processor; and

a memory, configured to store instructions executable by the processor,

wherein, the processor is configured to;

obtain frame data from a frame buffer;

map the frame data from an original color space to a linear original color space via a de-gamma correction process, so as to obtain frame data in the linear original color space; and

map the frame data in the linear original color space to a linear target color space, so as to obtain frame data in the linear target color space;

obtain a color correction matrix of a target device, the color correction matrix being a deviation matrix obtained in the target color space according to deviations between color data of the target device and standard color data;

correct the frame data in the linear target color space by using the color correction matrix, so as to obtain corrected frame data in the linear target color space; and

perform a gamma correction process on the corrected frame data in the linear target color space by using a target gamma coefficient, so as to obtain the frame data in a target color space.

7. The color adjustment device according to claim 6, wherein the processor is configured to:

obtain a gamma coefficient, wherein the gamma coefficient is to be used by a target device for performing a gamma correction process on the frame data in the linear original color space at an operation system layer or at an application layer; and

perform the de-gamma correction process on the frame data in the original color space by using the gamma coefficient, so as to obtain the frame data in the linear original color space.

8. The color adjustment device according to claim 6, wherein the processor is further configured to:

disperse the length of the data in each color channel of the frame data in the linear original color space from a first bit length to a second bit length, wherein the second bit length is greater than the first bit length.

9. The color adjustment device according to claim 8, wherein the processor is further configured to:

change the length of the data in each color channel of the frame data in the target color space from the second bit length to the first bit length, if displaying the length of the data in each color channel of the frame data in the target color space as the second bit length is unsupported by a target device.

10. A non-transitory computer-readable storage medium having stored therein instructions that, when executed by a processor of a device, causes the device to perform a color adjustment method, the method comprising:

obtaining frame data from a frame buffer;

mapping the frame data from an original color space to a linear original color space via a de-gamma correction process, so as to obtain frame data in the linear original color space;

mapping the frame data in the linear original color space to a linear target color space, so as to obtain frame data in the linear target color space;

obtaining a color correction matrix of a target device, the color correction matrix being a deviation matrix obtained in the target color space according to deviations between color data of the target device and standard color data;

correcting the frame data in the linear target color space by using the color correction matrix, so as to obtain corrected frame data in the linear target color space; and

performing a gamma correction process on the corrected frame data in the linear target color space by using a target gamma coefficient, so as to obtain frame data in a target color space.

11. The storage medium according to claim 10, wherein mapping the frame data from the original color space to the linear original color space via the de-gamma correction process comprises:

obtaining a gamma coefficient, wherein the gamma coefficient is to be used by a target device for performing a gamma correction process on the frame data in the linear original color space at an operation system layer or at an application layer; and

performing the de-gamma correction process on the frame data in the original color space by using the gamma coefficient, so as to obtain the frame data in the linear original color space.

12. The storage medium according to claim 10, wherein the method further comprises:

dispersing a length of the data in each color channel of the frame data in the linear original space from a first bit length to a second bit length, wherein the second bit length is greater than the first bit length.

13. The storage medium according to claim 12, wherein the method further comprises:

if displaying the length of the data in each color channel of the frame data in the target color space as the second bit length is unsupported by a target device, changing the length of the data in each color channel of the frame data in the target color space from the second bit length to the first bit length.