Motion Compensation Prediction for Spherical Panoramic Images
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Motion-compensated prediction in spherical panoramic images faces challenges due to geometric deformation when reference pixels are not on the same projection plane, leading to inaccurate pixel value prediction across polyhedral formats.
Innovation Solution
The method determines a target reference pixel by finding a spherical reference location corresponding to the initial reference pixel, which is then used to calculate a polyhedral reference location, allowing for accurate prediction of pixel values across different sub-images in a polyhedral format.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If motion-compensated prediction is performed using reference pixels from different sub-images in polyhedral format, then the coverage of reference pixels is improved, but the prediction accuracy deteriorates due to geometric deformation at face boundaries
Solution Approach 1:
The patent introduces a spherical coordinate system as an intermediary to map reference pixel locations. By converting polyhedral face coordinates to spherical coordinates and back, the system accurately determines corresponding reference pixels across face boundaries while accounting for geometric deformations, thus maintaining prediction accuracy while expanding reference pixel coverage
Solution Approach 2:
The patent changes the coordinate parameter system from simple polyhedral face coordinates to spherical coordinates. This parameter transformation allows accurate representation of reference pixel locations across different faces by considering the spherical geometry, thereby resolving the prediction accuracy issue when using reference pixels from multiple sub-images
2Adaptability or versatility
If reference pixels are selected from adjacent faces to expand search range, then motion estimation flexibility is improved, but prediction error increases due to boundary deformation
Solution Approach 1:
The spherical coordinate system acts as a mediator to accurately map reference pixel positions across face boundaries. By using spherical coordinates to represent directions and converting back to polyhedral coordinates, the system maintains reliable pixel correspondence even when reference pixels are selected from adjacent faces, thus preserving prediction reliability while improving motion estimation flexibility
3Device complexity
If simple planar projection is used for polyhedral images, then processing complexity is reduced, but coding efficiency deteriorates due to boundary inconsistency
Solution Approach 1:
The patent changes the coordinate parameter representation from simple planar coordinates to spherical coordinates. This parameter change enables accurate handling of boundary pixels across different faces, improving coding efficiency by reducing prediction errors at boundaries while maintaining manageable processing complexity through systematic coordinate transformation
Data Source
Figure 1~2(k)
Figure 3
Figure 4(a)~4(b)
AI summary
Embodiments of this application provide a motion-compensated prediction method and a motion-compensated prediction apparatus. The motion-compensated prediction method includes: determining a location that is of an initial reference pixel of a current pixel and that is in a reference image, where the current pixel is located in a first sub-image in the current image; when the initial reference pixel is located outside a second sub-image that is in the reference image and that is at a location corresponding to the first sub-image, determining, based on the location of the initial reference pixel, a location that is of a target reference pixel of the current pixel and that is in the reference image; and determining a prediction value of a pixel value of the current pixel based on a pixel value of the target reference pixel and/or a pixel value of a neighboring pixel of the target reference pixel. In the embodiments of this application, accuracy of motion-compensated prediction can be improved.