Asymmetric Cubemap Mapping for 3D Image Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image processing techniques, such as pyramid mapping, suffer from a significant deterioration in image quality when the field of view deviates from the primary field of view, leading to unacceptable image quality and high bit rates due to symmetric cubemap mapping limitations.
Innovation Solution
The method involves mapping an inputted 3D model into an asymmetric cubemap or sphere model, which is offset from the traditional mapping center, and then stretching this model into a 2D plane, maintaining high resolution in the region of interest while gradually reducing resolution in other areas, thereby reducing overall data requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If symmetric cubemap mapping is used, then the area of encoded image is reduced and bit rate is lowered, but the compression quality of region of interest cannot be improved
Solution Approach 1:
The patent applies asymmetry by introducing an offset between the cubemap center and the sphere model center. This asymmetric mapping allows the region of interest to be positioned at the cubemap center where highest resolution is maintained, while other regions have progressively lower resolution. The offset parameter enables flexible positioning of the ROI, resolving the contradiction by allowing high compression quality for specific regions while maintaining overall reduced bit rate compared to symmetric equirectangular mapping.
2Manufacturing precision
If pyramid mapping is used to improve compression quality of ROI, then the image quality of regions away from ROI quickly deteriorates
Solution Approach 1:
The patent implements local quality by applying different resolution levels to different regions of the panoramic image. The cubemap mapping with offset creates a gradient where the ROI region maintains high resolution while regions progressively farther from the ROI have lower resolution. This resolves the contradiction by ensuring acceptable quality for ROI while allowing controlled quality reduction in peripheral regions, avoiding the abrupt deterioration seen in pyramid mapping.
3Device complexity
If equirectangular mapping is used, then the mapping is simple, but the area of mapped image becomes overly large resulting in high bit rate
Solution Approach 1:
The patent uses asymmetric cubemap mapping which, while slightly more complex than symmetric mapping, still maintains relative simplicity compared to pyramid mapping. The offset-based asymmetric mapping reduces the total mapped area compared to equirectangular projection, thereby reducing bit rate while keeping the mapping process computationally feasible through straightforward coordinate transformation formulas.
Data Source
AI summary
The disclosed embodiments relate to image processing methods and apparatuses. In one embodiment, a method includes: mapping an inputted three-dimensional (3D) model map into an asymmetric cubemap, the asymmetric cubemap located at a different place than the mapping center of the inputted 3D model map; and stretching the asymmetric cubemap mapped for the inputted 3D model map into a two-dimensional (2D) stretched plane map. Since the asymmetric cubemap is located at a different place than the mapping center of the inputted 3D model map, after the inputted 3D model map is mapped into the asymmetric cubemap and stretched into a 2D plane, the image resolution can be maintained in one face of the asymmetric cubemap and the image resolution can be reduced in other faces, so that high image resolution in an ROI of a user can be maintained, and the resolution of regions away from the ROI can slowly decrease, thereby lowering the overall resolution of the 2D stretched plane map and reducing the amount of data for subsequent processing.