Adaptive Affine Motion Compensation Subblocks for Video Coding
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Solution Overview
Problem
Conventional motion compensation prediction technologies for high-definition video coding face high complexity due to fixed sizes of picture subblocks, leading to either excessive complexity or reduced efficiency, especially in sequences with rotational or scaling motion.
Innovation Solution
Determine a motion vector difference and precision for an affine picture block, and adjust the size of affine motion compensation picture subblocks based on these parameters and the distance between control points to optimize coding/decoding processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed-size picture subblocks are used in motion compensation prediction, then device complexity is reduced, but coding efficiency deteriorates for sequences with rotational or scaling motion
Solution Approach 1:
The patent applies dynamics by making the picture subblock size adaptive rather than fixed. The subblock size is dynamically adjusted based on motion characteristics (rotational or scaling motion detection) and affine transformation parameters. When rotational or scaling motion is detected, the system selects smaller subblock sizes to improve prediction accuracy, while using larger subblock sizes for other motion types to maintain low complexity.
2Productivity
If picture subblocks are divided into smaller sizes, then coding efficiency improves, but device complexity increases due to more operations per pixel
Solution Approach 1:
The patent changes the parameter of subblock size dynamically based on motion characteristics. Instead of using a fixed small subblock size that increases complexity, the system adjusts the subblock size parameter according to the detected motion type (rotational/scaling vs. other motions) and affine transformation parameters, achieving coding efficiency improvement only when necessary.
Solution Approach 2:
The patent applies local quality by using different subblock sizes for different regions or different picture blocks based on their motion characteristics. Picture blocks with rotational or scaling motion use smaller subblocks for better prediction, while other blocks use larger subblocks to reduce complexity, optimizing the overall system performance.
3Device complexity
If picture subblocks are divided into larger sizes, then device complexity is reduced, but coding efficiency deteriorates
Solution Approach 1:
The system dynamically adjusts subblock size based on motion characteristics. When rotational or scaling motion is detected, it switches to smaller subblocks to improve coding efficiency. When such motion is not present, it uses larger subblocks to reduce complexity, thus adapting to different scenarios optimally.
Data Source
AI summary
The present disclosure provides a video picture coding method, a video picture decoding method, a coding device, and a decoding device. The method includes: determining a distance between control points for an affine picture block; determining a motion vector difference for the affine picture block, motion vectors of the control points being used to determine the motion vector difference; and performing coding processing on the affine picture block over a size that includes a horizontal length and a vertical length, wherein the horizontal length and the vertical length vary based on the distance between the control points, the motion vector difference, and a motion vector precision.