Cross-Component Linear Model Prediction Filter Adaptation

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Solution Overview

Problem

Existing video coding technologies face challenges in achieving high compression ratios with minimal sacrifice in picture quality, particularly in streaming and storage applications where bandwidth and memory resources are limited.

Innovation Solution

The method involves determining a filter for luma samples based on the chroma format of a picture, applying this filter to reconstructed luma samples to obtain filtered reconstructed luma samples, and using these samples as input for cross-component linear model derivation to perform chroma prediction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If video data is compressed to reduce data size for transmission and storage, then bandwidth and memory resources are saved, but picture quality deteriorates

Engineering Contradiction:
Improvevideo data sizeVSAvoidpicture quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies different filtering operations based on the chroma format parameter (4:4:4, 4:2:2, or 4:2:0). By changing the filtering parameter according to the chroma format, the system achieves better compression efficiency while maintaining picture quality for each specific format, thus resolving the contradiction between data size reduction and quality preservation.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If compression techniques are improved to increase compression ratio, then bandwidth consumption is reduced, but picture quality sacrifice increases

Engineering Contradiction:
Improvecompression ratioVSAvoidpicture quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies different filtering strategies to different luma sample locations based on their chroma format. Specifically, boundary luma samples use one filtering approach while internal luma samples use another. This local differentiation allows the system to achieve high compression ratios while preserving picture quality in critical areas, thus resolving the contradiction between compression ratio and quality preservation.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If adaptive filtering is applied to different luma samples based on position and chroma format, then chroma prediction accuracy is improved, but computational complexity increases

Engineering Contradiction:
Improvechroma prediction accuracyVSAvoidfiltering complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the luma samples into two categories: boundary luma samples and internal luma samples. Different filtering operations are applied to each segment based on the chroma format. This segmentation approach improves chroma prediction accuracy by treating different regions differently, while keeping the complexity manageable through clear categorization and systematic processing of each segment.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12309378B2Method and apparatus of filtering for cross-component linear model prediction
Publication Date: 2025.05.20 HUAWEI TECH CO LTD
  • US12309378B2 patent drawing
  • US12309378B2 patent drawing
  • US12309378B2 patent drawing

AI summary

The disclosure relates to methods and a coding apparatus for intra prediction using a linear model. The method includes: determining a filter for a luma component of a current block based on a chroma format of a picture that the current block belongs to, and applying the determined filter to an area of reconstructed luma samples of the luma component of the current block and/or luma samples in selected position neighboring to the current block, to obtain filtered reconstructed luma samples. The method further includes: obtaining, based on the filtered reconstructed luma samples, linear model coefficients. Cross-component prediction is performed based on linear model coefficients of the linear model derivation and the filtered reconstructed luma sample.