Bi-Prediction Reference Block Weighting for Lower Bitrate Decoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image encoding and decoding technologies face challenges in improving prediction encoding and decoding performance, particularly in reducing the amount of data required for inter prediction and bitstream bitrate.
Innovation Solution
The method involves determining weight information for combining first and second reference blocks based on their respective reference templates to generate a prediction block, which is then used for bi-prediction of a current block, thereby enhancing prediction encoding and decoding efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single reference block is used for prediction, then the encoding process is simple, but the prediction accuracy is insufficient
Solution Approach 1:
The current block is divided into two sub-blocks, and two different reference blocks from different reference images are used to predict these sub-blocks respectively. This segmentation allows each sub-block to be predicted by the most appropriate reference block, improving overall prediction accuracy while maintaining manageable encoding complexity through systematic processing.
Solution Approach 2:
Two prediction blocks generated from different reference blocks are merged to form the final prediction block for the current block. The encoder selects the reference blocks and merging method that minimize the residual error, combining the advantages of multiple reference sources to achieve superior prediction accuracy.
2Measurement precision
If more reference blocks and bi-prediction are used, then prediction performance improves, but the amount of data to signal increases
Solution Approach 1:
The encoder performs preliminary analysis to determine the optimal reference blocks and merging method before encoding. By pre-determining the best configuration based on rate-distortion optimization, the system avoids signaling unnecessary information while maintaining high prediction performance.
Solution Approach 2:
The system uses feedback from the encoding process (rate-distortion optimization) to select the optimal reference blocks and merging method. The encoder evaluates different combinations and selects the one that provides the best balance between prediction accuracy and bitstream efficiency, avoiding unnecessary data signaling.
3Measurement precision
If complex reference block combining methods are used, then prediction accuracy improves, but encoding and decoding complexity increases
Solution Approach 1:
The system dynamically selects the reference blocks and merging method based on the specific characteristics of each current block and available reference images. This dynamic adaptation allows the system to achieve high prediction accuracy for diverse block types while maintaining efficient encoding and decoding by adjusting complexity only where needed.
Solution Approach 2:
The encoder changes parameters (reference block selection, merging weights, reference image selection) based on the specific characteristics of each current block. By adapting these parameters to match the local image characteristics, the system achieves high prediction accuracy without requiring uniformly complex processing across all blocks.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An image decoding method according to an embodiment may include: determining a first reference block in a first reference image and a second reference block in a second reference image for bi-prediction of a current block; determining weight information for combining the first reference block and the second reference block, based on a current reference template of the current block, a first reference template of the first reference block, and a second reference template of the second reference block; generating a prediction block of the current block by combining the first reference block and the second reference block by using the weight information; and reconstructing the current block by using the prediction block.