Color Filter Array Cyclic Pattern for False Color Reduction
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Solution Overview
Problem
Conventional color imaging devices face challenges in reducing false color occurrence, achieving high resolution, and simplifying processing, particularly with random filter arrays which are ineffective in high-frequency areas and complicate subsequent synchronization processing.
Innovation Solution
A single-panel color imaging device with a basic array pattern of NxN, where the first filter (contributing most to brightness) and second filters are arranged in a cyclic pattern in both horizontal and vertical directions, improving high-frequency reproducibility and simplifying processing by maintaining a specific pixel ratio and symmetry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a random filter array is used, then false color occurrence is reduced, but high-frequency reproducibility deteriorates and processing complexity increases
Solution Approach 1:
The color filter array is segmented into multiple distinct patterns (first pattern with green filters at corners/center, second pattern with red/blue filters) that are repeatedly arranged in a cyclic manner. This segmentation allows different regions to handle different frequency components effectively, resolving the contradiction between false color reduction and high-frequency reproducibility.
Solution Approach 2:
Different local regions of the color filter array have different filter arrangements optimized for their specific function: the first pattern with green filters at corners and center is optimized for luminance and high-frequency content, while the second pattern with red/blue filters handles color information. This local optimization resolves the contradiction by allowing each region to excel at its specific task.
2Reliability
If a random filter array is used, then false color occurrence is reduced, but subsequent processing becomes complicated
Solution Approach 1:
The color filter array uses periodic repetition of the first and second patterns in both horizontal and vertical directions. This periodic structure enables efficient demosaic processing through regular, predictable patterns that can be handled by standardized algorithms, significantly reducing processing complexity compared to truly random arrangements while maintaining false color reduction benefits.
Solution Approach 2:
The invention changes the arrangement parameters of color filters from random to a specific cyclic pattern with defined ratios (2:1 ratio of first to second patterns). This parameter optimization allows for efficient processing algorithms that exploit the regularity and predictability of the pattern, reducing computational complexity while maintaining effectiveness in false color reduction.
3Device complexity
If green pixels are arranged in checkered pattern with red and blue line-sequentially, then device complexity is reduced, but high-frequency reproduction accuracy deteriorates
Solution Approach 1:
The invention transitions from the traditional Bayer arrangement (green in checkered pattern, red/blue in lines) to a two-dimensional cyclic repetition of multiple patterns. This dimensional reorganization places green, red, and blue filters in a more balanced two-dimensional distribution, improving high-frequency reproduction in all directions while maintaining reasonable device complexity through the regular cyclic structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces false color occurrence, enhances high-resolution imaging, and simplifies subsequent processing by optimizing pixel ratios and symmetry in the color filter array.
Implementation Method 1
a photoelectric conversion device that photoelectrically converts light
Data Source
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AI summary
It is possible to reduce occurrence of a false color, achieve high resolution, and simplify subsequent processing as compared with a conventional random array. A color filter array includes a basic array pattern P1 (pattern that is indicated by a thick frame) that is constituted by a square array pattern that corresponds to 3×3 pixels, and in the color filter array, the basic array pattern P1 is arranged in a horizontal direction and a vertical direction repeatedly. In the basic array pattern P1, G filters that are brightness system pixels are arranged at the four corners and the center, that is, arranged on the both diagonal lines. As a result, the G filters are in each line of horizontal, vertical, and diagonal directions of the color filter array, and the color filter array includes a square array that corresponds to 2x2 pixels that are constituted by the G filters. In addition, a ratio of the number of G pixels that help most to obtain a brightness signal of the basic array pattern P1 is greater than each ratio of the number of R pixels and the number of B pixels that correspond to the color other than G, thereby executing synchronization processing effectively.