Dynamic Gamma Correction for LCD Viewing Angle Color Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid Crystal Displays (LCDs) in Vertical Alignment (VA) mode suffer from complexion color shift and washed-out images at large viewing angles due to deviations in gamma values from the standard 2.2 curve, leading to suboptimal grayscale representation.
Innovation Solution
A method and system that calculate the accounting ratio of a complexion region in an image, applying specific gamma values for red, green, and blue color data based on this ratio to correct color shift, using a first gamma value greater than 2.2 for high ratios and a second value less than 2.2 for low ratios, with the first value being at least 2.4 and the second value being 2.2, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a standard gamma value of 2.2 is used for gamma correction in VA mode LCD, then the grayscale representation is optimized for front viewing angles, but the complexion color shifts and images appear washed out at large viewing angles
Solution Approach 1:
The patent implements dynamic gamma correction by switching between different gamma values (first gamma value > 2.2 for large viewing angles, second gamma value < 2.2 for front viewing angles) based on detected viewing angle conditions. This dynamic adjustment resolves the contradiction by adapting the gamma correction parameter to the actual viewing scenario, ensuring optimal grayscale representation and color accuracy regardless of viewing angle.
Solution Approach 2:
The patent changes the gamma value parameter from a fixed 2.2 to a variable parameter that can take different values (first gamma value or second gamma value) depending on the viewing angle. This parameter change enables the system to optimize both front viewing angle performance and large viewing angle color accuracy, resolving the technical contradiction between the two viewing conditions.
2Measurement precision
If the gamma value is increased to correct complexion color shift at large viewing angles, then color accuracy improves, but the standard gamma curve deviation increases for front viewing angles
Solution Approach 1:
The system dynamically selects between first gamma value (≥2.4) and second gamma value (<2.2) based on viewing angle detection. When large viewing angle is detected, the first gamma value corrects complexion color shift. When front viewing angle is detected, the second gamma value maintains standard gamma curve compliance, thus resolving the contradiction between color accuracy and standard compliance.
Solution Approach 2:
The patent applies different gamma correction qualities to different viewing scenarios: first gamma value for large viewing angles where color accuracy is prioritized, and second gamma value for front viewing angles where standard compliance is prioritized. This local quality differentiation resolves the contradiction by optimizing each scenario with appropriate gamma values.
Data Source
AI summary
The present invention discloses a method of correcting complexion color shift of LCD including obtaining accounting ratio of a complexion region of an image which will be shown in the LCD; comparing the accounting ratio of a complexion region to a predetermined value; and applying a first gamma value to conduct gamma correction of the data of red color, green color, and blue color if the accounting ratio is larger than the predetermined value; wherein the first gamma value is larger than 2.2. The present invention also discloses a system of correcting complexion color shift of LCD. The gamma value of front viewing angle of the LCD is increased. Accordingly, the gamma value of the image of big viewing angle approaches the curve of gamma value 2.2 more in the LCD and wash out of the complexion of the image of big viewing angle is eliminated.