LCD Dithering Masks for Full 8-Bit Color on 6-Bit Drivers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dithering techniques in LCDs result in Gamma degeneracy, reducing the number of displayable color levels from 16,777,216 to 16,194,277, missing approximately 580,000 colors due to the inability to process 8-bit signals effectively with 6-bit driving ICs, leading to suboptimal color representation.
Innovation Solution
A dithering method utilizing multiple large and small dithering masks with adjustable thresholds, applied on a frame-by-frame basis, to convert M-bit video data into N-bit data, ensuring the LCD can display the full range of 8-bit color levels without Gamma degeneracy by using a dithering module with a first and second dithering unit and a controlling unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional dithering techniques are used to convert 8-bit video signals to 6-bit signals, then the hardware cost is reduced, but the color level precision deteriorates due to Gamma degeneracy
Solution Approach 1:
The patent segments the dithering process into multiple stages using different dithering masks with varying thresholds. Instead of applying a single dithering operation, the system divides the conversion from 8-bit to 6-bit into sequential steps, each with its own mask, thereby preserving more color information throughout the conversion process and avoiding Gamma degeneracy.
Solution Approach 2:
The patent employs dynamic dithering masks that are adjusted on a frame-by-frame basis. The dithering thresholds are not fixed but vary dynamically across different frames and even within different regions of the same frame, allowing the system to adaptively preserve color precision while maintaining cost-effectiveness with 6-bit hardware.
2Ease of manufacture
If 6-bit driving IC is used instead of 8-bit driving IC, then the unit price is reduced, but the number of displayable color levels decreases
Solution Approach 1:
The patent applies preliminary dithering operations before the final 6-bit conversion. By pre-processing the 8-bit video signal through multiple dithering stages with carefully designed masks, the system prepares the color data in advance to maximize the utilization of the limited 6-bit output capacity, thereby preserving more color levels than direct conversion would allow.
Solution Approach 2:
The patent changes the dithering parameters (thresholds, mask patterns) dynamically during the conversion process. By adjusting these parameters across different frames and regions, the system optimizes the mapping from 8-bit to 6-bit space, effectively expanding the number of displayable color levels beyond what a static 6-bit system could provide.
3Device complexity
If simple dithering masks are used for cost reduction, then the device complexity is reduced, but the color accuracy deteriorates
Solution Approach 1:
The patent segments the dithering mask into multiple sub-masks applied in sequence rather than using a single complex mask. This segmentation allows each individual mask to remain relatively simple in structure, but the combination of multiple masks achieves high color accuracy, thus maintaining low device complexity while improving measurement precision.
Solution Approach 2:
The patent employs periodic variation in dithering mask patterns across different frames. By systematically varying the mask patterns in a periodic manner, the system achieves better color accuracy through temporal dithering, while keeping each individual mask relatively simple. This periodic action allows the system to encode additional color information over time without requiring overly complex instantaneous mask structures.
Data Source
AI summary
A dithering method includes: utilizing a plurality of large dithering masks to perform dithering on a first set of Least Significant Bits (LSBs) of M-bit video data, utilizing a plurality of small dithering masks to perform dithering on a second set of LSBs of the M-bit video data, and adjusting the content of at least one of the plurality of large dithering masks and/or the content of at least one of the plurality of small dithering masks on a frame-by-frame basis. Each of the plurality of large dithering masks includes a plurality of sub-dithering masks. Each of the plurality of sub-dithering masks includes a plurality of dithering thresholds. Each of the plurality of small dithering masks includes a plurality of dithering thresholds.