Adaptive Intra Prediction Mode List Construction for Video Coding
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Solution Overview
Problem
Current video coding standards face challenges in achieving high coding efficiency for intra prediction due to a significant signaling overhead resulting from the limited adaptability of the selected intra prediction mode list, which is not adaptive to the properties of the currently processed picture block.
Innovation Solution
Incorporating intra prediction modes from both immediate and second-tier neighbors into the selected modes list to leverage correlations and improve coding efficiency, by generating a more adaptive mode list based on a rate distortion criterion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed set of intra prediction modes is used for all picture blocks, then device complexity is reduced, but coding efficiency deteriorates due to inability to adapt to local picture properties
Solution Approach 1:
The patent applies local quality by constructing different most probable mode (MPM) lists for different picture block types (e.g., luma vs. chroma, different block sizes, different coding modes). Each block type receives a customized MPM list tailored to its specific characteristics, allowing the system to adapt to local picture properties rather than using a uniform approach for all blocks.
Solution Approach 2:
The patent implements dynamics by making the MPM list construction adaptive and variable based on picture block properties. The system dynamically selects which neighbor blocks to include in MPM list construction and determines the number of MPM candidates based on the specific characteristics of the current picture block, allowing the mode selection process to flexibly adapt to different coding scenarios.
2Manufacturing precision
If more intra prediction modes are signaled to improve prediction accuracy, then coding efficiency improves, but signaling overhead increases
Solution Approach 1:
The patent applies partial action by signaling only the most relevant intra prediction modes through the MPM list rather than all available modes. The system identifies and signals a subset of probable modes based on neighbor block analysis, reducing the number of bits required for mode signaling while maintaining prediction accuracy for the most likely modes.
Solution Approach 2:
The patent implements feedback by using information from already-coded neighbor blocks to construct the MPM list for the current block. The encoder analyzes the intra prediction modes used in spatially adjacent blocks and uses this feedback to predict which modes are most probable for the current block, thereby reducing the search space and signaling requirements.
3Productivity
If intra prediction modes from second-tier neighbors are included in the selected modes list, then coding efficiency improves through better adaptability, but device complexity increases due to expanded neighbor analysis
Solution Approach 1:
The patent applies segmentation by organizing neighbor blocks into hierarchical tiers (first-tier direct neighbors and second-tier neighbors of neighbors). This segmented approach allows the system to systematically include remote neighbor information in the MPM list construction while maintaining a structured and manageable process for analyzing and incorporating modes from multiple spatial levels.
Data Source
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AI summary
The invention relates to an apparatus (100) configured to determine an adopted intra prediction mode on the basis of a most probable modes list, a selected modes list and a non-selected modes list, wherein the adopted intra prediction mode is one of a plurality of intra prediction modes comprising a plurality of angular intra prediction modes for predicting sample values of a current picture block (103), wherein the apparatus (100) comprises a processing unit (101 ) configured to: generate at least a portion of the most probable modes list of intra prediction modes by including intra prediction modes adopted for neighboring picture blocks (107) of the current picture block (103) in the most probable modes list; and generate at least a portion of the selected modes list of intra prediction modes by including intra prediction modes adopted for neighboring picture blocks of the neighboring picture blocks (107) of the current picture block (103) in the selected modes list. Moreover, the invention relates to an encoding apparatus and a decoding apparatus comprising the apparatus (100).