Method of self-adaptive conversion for images

Patent metadata

Field	Value
Publication number	US-9818333-B2
Application number	US-201514901033-A
Country	US
Kind code	B2
Filing date	Sep 22, 2015
Priority date	Sep 14, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

A method of self-adaptive conversion for images includes: calculating the degree of color saturation of each pixel of an RGB image and original grey value of each primary color component, and calculating a global gain value; calculating a total gain value of each pixel based on the global gain value and the partial gain value of each pixel; enhancing luminance of the white color component of each primary color component of each pixel based on the total gain value of each pixel, so to output an RGBW image. The present invention improves deviated color saturation to ensure display quality while elevating the display luminance when a conversion from an RGB image into an RGBW image.

First claim

What is claimed is:

1. A method of self-adaptive conversion for images, comprising:
extracting an original grey value of each primary color component of a plurality of pixels of an inputted image, wherein the plurality of pixels is all the pixels of the inputted image or all the pixels of an area of the inputted image;
linearizing normalized original grey values through inverse gamma correction, so to acquire a first middle grey value of each primary color component of each pixel;
calculating a degree of color saturation of each pixel based on the first middle grey value of each primary color component;
calculating a first middle grey value of a white color component and a second middle grey value of each primary color component of each pixel based on the first middle grey value of each primary color component;
calculating a global gain value based on the first middle grey value of the white color component and the second middle grey value of each primary color component of the plurality of pixels;
calculating a maximum partial gain value based on a pre-defined maximum total gain value and the global gain value;
calculating a maximum partial gain value based on a pre-defined maximum total gain value and the global gain value;
calculating a total gain value of each pixel based on the global gain value and the partial gain value of each pixel;
enhancing luminance of the first middle grey value of the white color component and the second middle grey value of each primary color component of each pixel based on the total gain value of each pixel, so to acquire a second middle grey value of the white color component and a third middle grey value of each primary color component of each pixel;
performing gamma correction to the second middle grey value of the white color component and the third middle grey value of each primary color component of each pixel, so to acquire final grey values of the white color component and primary color components of corresponding pixels of an outputted image; and
mapping the final grey values of the white color component and primary color components of the corresponding pixels of the outputted image to corresponding display areas of a display device to display the outputted image.

2. The method of claim 1 , wherein linearizing normalized original grey values through inverse gamma correction comprises:
calculating the first middle grey value of each primary color component of each pixel by the following formula,

RGB
i

=

(

RGB

H
⁢
1

)



where RGB is the original grey value of each primary color component of each pixel, RGB i is the first middle grey value of each primary color component of each pixel, H 1 is a maximum grey value allowed by the inputted image, and γ is a gamma correction factor.

3. The method of claim 1 , wherein calculating the degree of color saturation of each pixel based on the first middle grey value of each primary color component comprises:
calculating the degree of color saturation of each pixel by the following formula,

Chroma
=

1
-

M
i

M
a

where Chroma is the degree of color saturation of each pixel, M i is a minimum first middle grey value of each primary color component of each pixel, M a is a maximum first middle grey value of each primary color component of each pixel.

4. The method of claim 1 , wherein calculating the first middle grey value of the white color component and the second middle grey value of each primary color component of each pixel based on the first middle grey value of each primary color component comprises:
calculating the first middle grey value of the white color component and the second middle grey value of each primary color component of each pixel by the following formula,

W

i
⁢
1

⁢

{

M
a
2

2

,

M
i
2

≥

M
a
2

2

M
i
2

,

M
i
2

<

M
a
2

2

RGB

i
⁢
1

=

RGB
i

-

W

i
⁢
1

Assignees

• Shenzhen China Star Optoelect
• Shenzhen China Star Optoelect

Inventors

• Li Hao
• Jou Ming-Jong
• Syu Shen-Sian
• Jin Yufeng
• Li Lin
• Wang Ronggang

Classifications

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G3/2074

  using sub-pixels · CPC title

• G09G2320/0673

  for control of gamma adjustment, e.g. selecting another gamma curve · CPC title

• G09G3/2003 Primary

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

• G09G2300/0452

  Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components · CPC title