Video Decoding Motion Vector Group Prediction
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Solution Overview
Problem
Existing video codecs face inefficiencies in encoding due to the limitations of block-based motion compensation methods, which struggle with irregular motions such as affine motion, leading to increased bit requirements and reduced encoding efficiency.
Innovation Solution
A method for determining a motion vector group and optimizing motion model parameters for a current encoding block, involving the calculation of prediction values and quantization precision to reduce the number of bits required for encoding and decoding, specifically by using an affine motion model with six parameters and quantizing certain parameters to minimize data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a six-parameter affine motion model is used for encoding, then motion prediction accuracy is improved, but the number of bits required for encoding increases
Solution Approach 1:
The patent extracts and transmits only the essential motion parameters (four parameters: two for translation and two for rotation) from the complete six-parameter affine model, separating the critical motion information from the less important deformation parameters, thereby reducing bit requirements while preserving prediction accuracy
Solution Approach 2:
The patent changes the parameter representation by using a simplified four-parameter model instead of the traditional six-parameter affine model, altering the mathematical formulation to reduce parameter count while maintaining adequate motion description capability for typical video sequences
2Device complexity
If block-based motion compensation is used, then encoding complexity is reduced, but motion prediction accuracy deteriorates due to inability to handle irregular motions
Solution Approach 1:
The patent introduces dynamic motion parameters that can adapt to different motion types within blocks, allowing the encoding system to transition from static block-based compensation to dynamic parameter-based compensation that handles irregular motions while controlling complexity through selective parameter updates
3Measurement precision
If affine motion model parameters are transmitted for each block, then motion description accuracy is improved, but data transmission volume increases
Solution Approach 1:
The patent segments the motion parameters into different categories (essential four parameters vs. optional deformation parameters), allowing selective transmission based on motion complexity and block characteristics, thereby reducing average data transmission volume while maintaining accuracy where needed
Solution Approach 2:
The patent transmits only the necessary four parameters for most blocks, using partial action rather than complete six-parameter transmission, and only adds the additional two parameters when motion complexity requires them, optimizing the balance between accuracy and data volume
Data Source
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AI summary
Embodiments of the present invention relate to a video image encoding method, a video image decoding method, an encoding device, and a decoding device. The method includes: determining a motion vector group of a current encoding block; determining prediction values of a first component set of a motion model initialization vector of the current encoding block according to the motion vector group; determining to-be-transmitted values of the first component set according to the prediction values of the first component set; and encoding the to-be-transmitted values of the first component set, and transmitting encoded to-be-transmitted values of the first component set to a decoder side. According to the video image encoding method, the video image decoding method, the encoding device, and the decoding device in the embodiments of the present invention, a motion model initialization vector of a current encoding block is determined according to a motion vector group; to-be-transmitted values of a motion model are determined according to the motion model initialization vector; the to-be-transmitted values of the motion model are encoded for transmission, so that a decoder side performs decoding according to the to-be-transmitted values of the motion model. In this way, a volume of data and a quantity of occupied bits in encoding and decoding transmission can be reduced.