Asymmetric Filter Array for Plenoptic Camera Demosaicing
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Solution Overview
Problem
Conventional Bayer color filter arrays in plenoptic cameras fail to produce clear images of objects out of focus in refocused images and are not effective for all integer disparities, leading to mosaicked images.
Innovation Solution
A new filter array pattern is introduced, comprising four blocks arranged in a specific configuration, with the second block below the first, the third block to the right of the first, and the fourth block below the third and to the right of the second, allowing for the replication to cover the entire sensor and ensuring automatic demosaicing of refocused images for any integer disparity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional Bayer color filter array is used in a plenoptic camera, then the camera can capture light-field data, but the refocused images of objects out of focus are not clear and the images remain mosaicked for certain integer disparities
Solution Approach 1:
The color filter array is segmented into four distinct blocks (A, B, C, D) arranged in a 2x2 pattern, where each block contains a specific color filter configuration. This segmentation allows different regions of the sensor to capture different color information, enabling automatic demosaicing for all integer disparities while maintaining clear images of objects out of focus in refocused images.
2Ease of operation
If a Bayer color filter array is positioned on top of the pixels sensor, then demosaiced images can be delivered for certain refocusing parameters, but good images of objects not in focus cannot be produced in the refocus images
Solution Approach 1:
Different blocks of the color filter array have different color filter configurations optimized for specific functions. Block A and Block C are configured for one type of color sampling, while Block B and Block D are configured for another type. This local quality differentiation enables the system to simultaneously achieve demosaicing capability and clear imaging of out-of-focus objects across all integer disparities.
3Measurement precision
If a color filter array with shuffled colors is used, then re-focused images are perfectly de-mosaiced for specific disparities, but the design is complex and does not work for all integer disparities
Solution Approach 1:
The color filter array employs an asymmetric 2x2 block pattern where the color filter configurations in blocks A, B, C, and D are deliberately different from each other. This asymmetric arrangement creates complementary sampling patterns that, when combined through the light-field processing, achieve automatic demosaicing for all integer disparities without requiring complex shuffled color arrangements.
Data Source
AI summary
A device comprising filtering means having a pattern of at least four blocks wherein a second block is located vertical to a first block, a third block is located horizontal to said first block and a fourth block is located vertical to said third block and horizontal to said second block; and means to generate a new image from images captured using said filtered rays.