Encoder Decoder Harmonizing Matrix-Based Intra Prediction and Secondary Transform

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Solution Overview

Problem

Existing video coding technologies face challenges in achieving high compression ratios without sacrificing picture quality, particularly in streaming video data across networks with limited bandwidth.

Innovation Solution

The method involves determining the intra prediction mode of a current block and selecting a secondary transform based on this mode, specifically disabling the secondary transform when the block is predicted using a Matrix-Based Intra Prediction (MIP) mode, and applying it otherwise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a secondary transform is applied to all intra predicted blocks, then transformation accuracy is improved, but processing complexity increases and compression efficiency deteriorates

Engineering Contradiction:

Improvetransformation accuracyVSAvoidprocessing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies different transformation strategies to different regions/blocks based on their prediction mode. Specifically, blocks predicted using MIP mode exclude secondary transform, while other intra predicted blocks apply secondary transform. This localized approach optimizes processing complexity and compression efficiency for each block type rather than uniformly applying secondary transform to all blocks.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If MIP mode is used for intra prediction, then prediction accuracy is improved, but compatibility with secondary transform becomes problematic

Engineering Contradiction:

Improveprediction accuracyVSAvoidcompatibility with secondary transform

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent extracts or removes the secondary transform operation specifically for blocks predicted using MIP mode. By identifying MIP predicted blocks and excluding them from secondary transform processing, the patent resolves the compatibility issue between MIP mode and secondary transform while maintaining the high prediction accuracy benefits of MIP mode.

Inventive Principle:

Principle #2Taking out (Extraction)

3Productivity

If compression ratio is increased to handle limited bandwidth, then network transmission efficiency is improved, but picture quality deteriorates

Engineering Contradiction:

Improvecompression ratioVSAvoidpicture quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements a dynamic transformation strategy that adapts the processing approach based on the prediction mode of each block. By conditionally applying or excluding secondary transform based on whether MIP mode is used, the system optimizes the balance between compression ratio and picture quality for different block types, achieving better overall compression efficiency without uniformly sacrificing picture quality.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20250088631A1Encoder, a Decoder and Corresponding Methods Harmonizing Matrix-Based Intra Prediction and Secondary Transform Core Selection

Publication Date: 2025.03.13 HUAWEI TECH CO LTD

AI summary

A method of coding implemented by a decoding device or an encoding device comprises determining an intra prediction mode of a current block; and determining selecting of a secondary transform of the current block based on the intra prediction mode determined for the current block.