Picture Boundary Split Mode Selection in Multi-Tree Video Coding

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Solution Overview

Problem

Conventional video coding methods are rigid in handling picture boundaries, leading to low flexibility and inefficient bit budget for signaling.

Innovation Solution

A recursive multi-tree partitioning method is used to partition pictures into leaf blocks, reducing the set of split modes based on the position of blocks relative to picture boundaries, allowing for flexible handling and efficient signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If conventional implicit quad-split derivation is used at picture boundaries, then signaling efficiency is improved, but flexibility in handling picture boundaries deteriorates

Engineering Contradiction:
Improvesignaling efficiencyVSAvoidflexibility in picture boundary handling
Core Design Contradiction:
Loss of informationVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the split mode selection adaptive rather than fixed. The encoder dynamically selects between implicit quad-split and explicit split modes based on the actual picture boundary position relative to the block, allowing the system to adapt to different boundary scenarios while maintaining signaling efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of split mode selection based on the position of picture boundaries. When a block extends beyond the picture boundary, the system changes from using implicit quad-split to using explicit split modes (horizontal or vertical binary split), optimizing both signaling efficiency and boundary handling flexibility

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If explicit split mode signaling is used for blocks at picture boundaries, then flexibility in picture boundary handling is improved, but bit budget for signaling increases

Engineering Contradiction:
Improveflexibility in picture boundary handlingVSAvoidbit budget for signaling
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by applying different split mode strategies to different spatial locations. Blocks that extend beyond picture boundaries use explicit split mode signaling, while blocks fully within the picture use implicit quad-split derivation, optimizing the bit budget by applying explicit signaling only where necessary

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes the signaling parameter based on block position relative to picture boundaries. The split mode flag is only explicitly signaled when needed (when blocks extend beyond boundaries), otherwise implicit derivation is used, thus reducing the overall bit budget while maintaining flexibility where required

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4192010B1Apparatus and method for encoding and decoding a picture using picture boundary handling
Publication Date: 2026.04.29 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP4192010B1 patent drawingFigure 1
  • EP4192010B1 patent drawingFigure 2
  • EP4192010B1 patent drawingFigure 3

AI summary

The present invention concerns an apparatus (10) for encoding a picture (12), configured to partition the picture (12) into leaf blocks using recursive multi-tree partitioning, block-based encode the picture (12) into a data stream (14) using the partitioning of the picture (12) into the leaf blocks, wherein the apparatus (10) is configured to, in partitioning the picture (12) into the leaf blocks, for a predetermined block (801a, 801b, 801c, 801d, 802a, 802b, 802d, 803a, 803b, 803c) that corresponds to a predetermined tree level of the multi- tree partitioning and which extends beyond a boundary of the picture (12), reduce an available set of split modes for splitting the predetermined block (801a, 801b, 801c, 801d, 802a, 802b, 802d, 803a, 803b, 803c) depending on a position at which the boundary of the picture (12) crosses the predetermined block (801a, 801b, 801c, 801d, 802a, 802b, 802d, 803a, 803b, 803c) in order to obtain a reduced set of one or more split modes, wherein, if a cardinality of the reduced set is one, the apparatus (10) is configured to apply the split mode of the reduced set for splitting the predetermined block (801a, 801b, 801c, 801d, 802a, 802b, 802d, 803a, 803b, 803c), and if a cardinality of the reduced set is greater than one, the apparatus (10) is configured to select one of the split modes of the reduced set and to apply the selected one of the split modes for splitting the predetermined block (801a, 801b, 801c, 801d, 802a, 802b, 802d, 803a, 803b, 803c) and to signal the selection in the data stream (14). The present invention further concerns an apparatus (20) for decoding a picture (12), a method for encoding a picture (12) and a method for decoding a picture (12).