Luma-Chroma Tree Coding Dependency Constraints

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Solution Overview

Problem

The existing video coding technologies, such as HEVC, face challenges in managing data dependency between luma and chroma components, leading to increased latency and buffer requirements due to separate tree structures, which complicates the processing and increases system resources.

Innovation Solution

The method involves constraining data dependency between luma and chroma tree structures by allowing it only when the tree structures are mutually inclusive, ensuring each chroma leaf block is completely included in or includes luma leaf blocks, thereby reducing latency and buffer requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate partition trees are used for luma and chroma blocks, then coding flexibility and adaptability to local characteristics are improved, but processing latency and buffer requirements increase

Engineering Contradiction:
Improvecoding flexibilityVSAvoidprocessing latency
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent segments the partitioning process by introducing separate partition trees for luma and chroma blocks. This allows independent optimization of each component's partitioning structure, improving coding flexibility while managing complexity through structured separation of concerns.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic constraints that adaptively control data dependency between luma and chroma trees based on partition alignment. When partitions are aligned, full dependency is allowed; when misaligned, dependency is constrained. This dynamic approach maintains coding flexibility while reducing buffer requirements and latency.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If separate partition trees are used for luma and chroma blocks, then coding adaptability is improved, but system resource requirements and complexity increase

Engineering Contradiction:
Improvecoding adaptabilityVSAvoidsystem resource requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

By segmenting the partitioning into separate luma and chroma trees, the patent enables targeted optimization for each component while maintaining overall system manageability. The segmentation allows independent control of partitioning parameters without affecting the entire coding system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dynamic constraint mechanism adapts the degree of data dependency between trees based on actual partition alignment, avoiding unnecessary complexity. The system automatically adjusts dependency levels rather than requiring complex static configurations, reducing overall system resource requirements.

Inventive Principle:
Principle #15Dynamics

3Productivity

If data dependency is allowed between misaligned luma and chroma leaf blocks, then coding efficiency is improved, but buffer usage and processing complexity increase

Engineering Contradiction:
Improvecoding efficiencyVSAvoidbuffer usage
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies dynamic constraints that adaptively control data dependency based on partition alignment. When luma and chroma partitions are misaligned, the constraint mechanism selectively allows or disallows data dependency on a block-by-block basis, optimizing buffer usage while maintaining coding efficiency where beneficial.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements local quality control by applying different dependency rules to different regions of the image based on partition alignment. Rather than uniformly allowing or disallowing dependency across all blocks, the system applies localized constraints that optimize buffer usage in each specific region.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3881534B1Method and apparatus of luma-chroma separated coding tree coding with constraints
Publication Date: 2025.11.05 HFI INNOVATION INC
  • EP3881534B1 patent drawingFigure 1~2
  • EP3881534B1 patent drawingFigure 3~4
  • EP3881534B1 patent drawingFigure 5~6

AI summary

A methods and apparatus for adaptive data dependency between corresponding blocks partitioned from separate partition trees according to an embodiment of the present invention are disclosed. The data dependency between different tree structures is allowed when the tree structures are mutually inclusive. When the splitting is not used in one tree or when splitting is used in one tree and the same splitting or no split is used in the other tree, the data dependency between different tree structures is allowed. When the splitting in different tree structures are different, then the data dependency between different tree structures is disallowed. For each leaf CU in chroma tree, it should include one or more complete luma leaf CUs or it is completely included in one luma leaf CU, when the data dependency between different tree structures is allowed. Otherwise, then the data dependency between different tree structures is disallowed.