Color Correction Using One-Dimensional Lookup Tables
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Solution Overview
Problem
Conventional color correction methods for liquid crystal display apparatuses, such as using three-dimensional lookup tables, require significant resources and often fail to properly correct γ characteristics and colors, especially for white and other colors, due to the large amount of correction data needed and the limitations in reducing data without compromising accuracy.
Innovation Solution
The use of multiple one-dimensional lookup tables for each primary color and white, allowing for separate tone conversion and correction, with additional tertiary tone values calculated based on contributions from secondary tone values, enables effective γ characteristic correction and color correction with reduced resource requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a three-dimensional lookup table is used for color correction, then color correction accuracy is improved, but device complexity and resource requirements increase significantly
Solution Approach 1:
The patent divides the three-dimensional lookup table into three separate one-dimensional lookup tables, each corresponding to a primary color (red, green, blue). This segmentation reduces the data storage requirements from 50,331,648 bits to 3 × 65,536 bits while maintaining color correction functionality through weighted combination of the separate color corrections.
Solution Approach 2:
The patent introduces weighting coefficients (α_R, α_G, α_B) that dynamically adjust the contribution of each primary color correction based on the input color characteristics. This parameter change allows the system to adapt the correction strength for each color channel, enabling accurate color correction with reduced hardware resources.
2Quantity of substance
If the distance between lattice points in the three-dimensional lookup table is increased to reduce correction data, then resource requirements are reduced, but color correction accuracy deteriorates
Solution Approach 1:
By segmenting the three-dimensional lookup table into three one-dimensional tables, each table only needs to store correction data for a single color channel with 256 entries (8-bit resolution). This maintains fine-grained correction accuracy for each primary color while reducing total data storage from 50,331,648 bits to 65,536 bits.
Solution Approach 2:
The patent applies different correction characteristics to each primary color channel independently through separate lookup tables. Each table can be optimized for its specific color's γ characteristics and display device properties, maintaining local correction quality while reducing overall system complexity.
3Device complexity
If one lookup table common to all three primary colors is used, then device complexity is reduced, but color correction capability is lost
Solution Approach 1:
The patent segments the single common lookup table into three separate one-dimensional lookup tables, one for each primary color. This segmentation enables independent color correction while maintaining a relatively simple overall structure compared to a full three-dimensional table.
Solution Approach 2:
The patent creates a universal color correction system that can handle all three primary colors and their combinations by using separate lookup tables for each color channel. The weighted combination mechanism provides multi-functionality, enabling correction for white, gray, and all other colors through the same three lookup tables.
Data Source
AI summary
R, G, and B are corrected according to a one-dimensional lookup table R_LUT, a one-dimensional lookup table G_LUT, and a one-dimensional lookup table B_LUT, respectively. W is corrected according to one-dimensional lookup tables W_LUT (R), W_LUT (G), and W_LUT (B). The extent of a contribution to post-correction tone values Rout, Gout, and Bout of each of tone values obtained from the former correction and tone values obtained from the latter correction is modified according to a color expressed by a group of pre-correction tone values Rin, Gin, and Bin. As the above-mentioned color is closer to white, the contribution to the tone values obtained from the latter correction increases.