Intra Prediction Mode Encoding Using Candidate Lists
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increase in intra-frame prediction modes in video encoding technologies leads to a reduction in encoding efficiency due to reduced statistical correlation between prediction modes and increased bit count for encoding prediction mode information.
Innovation Solution
An image predictive encoding method that generates a candidate prediction mode list for neighboring blocks, encodes a flag to indicate the presence of the optimum prediction mode, and uses an index or reassigns numbers to encode the prediction mode efficiently, even when the mode is not in the list.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of intra-frame prediction modes is increased to improve prediction accuracy, then the prediction accuracy is improved, but the encoding efficiency of prediction mode information deteriorates due to reduced statistical correlation and increased bit count
Solution Approach 1:
The patent applies preliminary action by pre-defining a limited set of candidate prediction modes (typically 3 modes: vertical, horizontal, and diagonal) that are most likely to be optimal for a given block type. This preliminary selection is performed before the actual encoding process, allowing the encoder to efficiently choose from a small, pre-optimized set of modes rather than searching through all possible modes, thereby maintaining high prediction accuracy while minimizing the bit count required for mode signaling.
Solution Approach 2:
The patent changes the parameter of candidate prediction mode selection by adapting the candidate modes based on block characteristics such as block size and block type (e.g., luma vs. chroma). Different block types are assigned different candidate mode sets, allowing the system to optimize prediction accuracy for each specific case while keeping the total number of candidates limited. This parameter-based adaptation enables the system to maintain encoding efficiency while improving prediction accuracy for diverse block types.
2Measurement precision
If more intra-frame prediction modes are provided to improve prediction accuracy, then the prediction accuracy is improved, but the bit count for encoding prediction mode information increases
Solution Approach 1:
The patent applies preliminary action by pre-defining a limited set of candidate prediction modes (typically 3 modes: vertical, horizontal, and diagonal) that are most likely to be optimal for a given block type. This preliminary selection is performed before the actual encoding process, allowing the encoder to efficiently choose from a small, pre-optimized set of modes rather than searching through all possible modes, thereby maintaining high prediction accuracy while minimizing the bit count required for mode signaling.
Solution Approach 2:
The patent changes the parameter of candidate prediction mode selection by adapting the candidate modes based on block characteristics such as block size and block type (e.g., luma vs. chroma). Different block types are assigned different candidate mode sets, allowing the system to optimize prediction accuracy for each specific case while keeping the total number of candidates limited. This parameter-based adaptation enables the system to maintain encoding efficiency while improving prediction accuracy for diverse block types.
3Measurement precision
If the number of intra-frame prediction modes is increased, then the prediction accuracy is improved, but the statistical correlation between prediction modes is reduced
Solution Approach 1:
The patent applies preliminary action by pre-defining a limited set of candidate prediction modes (typically 3 modes: vertical, horizontal, and diagonal) that are most likely to be optimal for a given block type. This preliminary selection is performed before the actual encoding process, allowing the encoder to efficiently choose from a small, pre-optimized set of modes rather than searching through all possible modes, thereby maintaining high prediction accuracy while minimizing the bit count required for mode signaling.
Solution Approach 2:
The patent changes the parameter of candidate prediction mode selection by adapting the candidate modes based on block characteristics such as block size and block type (e.g., luma vs. chroma). Different block types are assigned different candidate mode sets, allowing the system to optimize prediction accuracy for each specific case while keeping the total number of candidates limited. This parameter-based adaptation enables the system to maintain encoding efficiency while improving prediction accuracy for diverse block types.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
When a larger number of prediction modes are provided in generation of intra-frame predicted signals, mode information to identify an intra-frame prediction method of a target block is efficiently encoded. An image predictive encoding method includes: determination of an optimum prediction mode from a plurality of prediction methods for a pixel signal of a target block; a predicted signal is generated according to the mode; a residual signal is determined between the pixel signal of the target block and the predicted signal; the residual signal and the optimum prediction mode are encoded to generate a compressed signal; the compressed signal is restored; the restored signal is stored as a reproduced pixel signal. In the prediction mode encoding, a candidate prediction mode list is generated as one containing elements of optimum prediction modes of a plurality of previously-reproduced blocks neighboring the target block; a flag to indicate whether the list contains an element corresponding to the optimum prediction mode is encoded; an index to the corresponding element is encoded if the corresponding element is present in the list; the optimum prediction mode is encoded based on numbering the elements in the list, unless there is no corresponding element in the list.