Adaptive Intra Prediction Mode Sets for Reduced Signaling Bits

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Solution Overview

Problem

The increase in intra-prediction modes for next-generation video content leads to increased bit representation, degrading encoding rate.

Innovation Solution

Adaptive determination of intra prediction mode sets with varying resolutions for each pixel in a block, using neighboring samples and transform coefficients, and employing multiple intra prediction mode sets to signal modes to decoders.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of intra-prediction modes is increased to improve prediction accuracy, then prediction accuracy is improved, but the number of bits required to represent the intra-prediction mode increases, degrading the encoding rate

Engineering Contradiction:
Improveprediction accuracyVSAvoidencoding rate
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent divides the intra-prediction mode selection into multiple resolution levels. Instead of selecting from all possible modes at full resolution, the system segments the mode selection process into coarse-resolution and fine-resolution stages, reducing the immediate bit cost while preserving the ability to achieve high prediction accuracy when needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different prediction mode resolutions locally based on the complexity of the current block. Simple blocks use lower-resolution mode sets requiring fewer bits, while complex blocks use higher-resolution mode sets for better prediction accuracy. This local adaptation resolves the contradiction by matching the bit investment to the actual need of each block.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If more intra-prediction modes are used to enhance prediction precision, then prediction precision is improved, but the complexity of the encoding system increases

Engineering Contradiction:
Improveprediction precisionVSAvoidencoding system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the intra-prediction mode set dynamic by adapting it to the characteristics of each current block. The mode set is not fixed but changes based on the block's complexity, allowing the system to maintain high prediction precision for complex blocks while reducing complexity for simple blocks through adaptive selection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of prediction mode resolution based on block characteristics. By varying the resolution parameter of the intra-prediction mode set according to the complexity of the current block, the system achieves high prediction precision when necessary while reducing encoding complexity when simple prediction suffices.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If high-resolution intra-prediction modes are applied to all blocks, then prediction accuracy is improved, but the encoding rate is degraded due to increased bit representation

Engineering Contradiction:
Improveprediction accuracyVSAvoidencoding rate
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies high-resolution intra-prediction modes only locally to complex blocks that benefit from them, rather than uniformly to all blocks. Simple blocks use lower-resolution modes, thereby maintaining high overall prediction accuracy while significantly reducing the total bit cost and improving encoding rate.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by applying high-resolution prediction modes only to the extent necessary - specifically to complex blocks where they provide benefit. This avoids the excessive application of high-resolution modes to all blocks, thereby maintaining prediction accuracy where needed while improving overall encoding rate.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3565248B1Intra prediction mode-based image processing method, and apparatus therefor
Publication Date: 2025.07.30 LG ELECTRONICS INC
  • EP3565248B1 patent drawingFigure 1
  • EP3565248B1 patent drawingFigure 2
  • EP3565248B1 patent drawingFigure 3(a)~3(b)

AI summary

Disclosed is a method for encoding/decoding a still image or moving image based on an intra-prediction mode and an apparatus supporting the same. Particularly, a method for processing an image based on an intra prediction mode may include determining an intra prediction mode set used for an intra prediction in a current prediction processing unit among multiple intra prediction mode sets having different resolutions with each other, wherein the resolution represents a degree of distribution of the intra prediction mode in the intra prediction mode set; deriving an intra prediction mode applied to the current prediction processing unit in the determined intra prediction mode set using index information received from an encoder; and generating a prediction sample of the current prediction processing unit based on the derived intra prediction mode, and each of the intra prediction mode sets includes one or more intra prediction modes.