Shape-Aware Merge Candidate Derivation for Video Decoding

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Solution Overview

Problem

The increasing demand for high-resolution and high-quality images, such as HD and UHD, leads to higher data volumes, increasing the costs of transmission and storage, necessitating more efficient video signal encoding/decoding methods, particularly for stereographic content.

Innovation Solution

A method and apparatus that adaptively determine the transform type for video signals by considering horizontal and vertical transforms separately, allowing for efficient encoding/decoding through the use of multiple transform type candidates based on block characteristics and prediction modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high-resolution and high-quality image data is transmitted or stored using conventional methods, then image quality is improved, but transmission and storage costs increase

Engineering Contradiction:
Improveimage qualityVSAvoiddata volume
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by transforming image data from spatial domain to frequency domain using transform techniques (DCT, DST, KLT). This transformation changes the representation parameters of the data, allowing energy compaction where most information is concentrated in fewer coefficients, thereby reducing the effective data volume needed for high-quality reconstruction

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements local quality through block-based processing where different transform types are selectively applied to different blocks based on their local characteristics (intra/inter prediction mode, block size, texture complexity). This allows optimization of compression for each local region while maintaining overall image quality

Inventive Principle:
Principle #3Local quality

2Productivity

If a single transform type is used for all blocks, then device complexity is reduced, but encoding/decoding efficiency decreases

Engineering Contradiction:
Improveencoding efficiencyVSAvoidtransform selection complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamics by making the transform type adaptive rather than fixed. The transform type is dynamically selected based on block characteristics including prediction mode (intra/inter), block size, and texture complexity. This dynamic adaptation optimizes encoding efficiency for different content types while the decoder follows the same adaptation logic to maintain synchronization

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system applies self-service through transform skip mechanisms where the encoder and decoder autonomously determine whether to apply transform based on predefined criteria (e.g., when prediction residue is already small). This self-determination reduces the need for complex signaling and maintains efficiency without requiring extensive device complexity

Inventive Principle:
Principle #25Self-service

3Measurement precision

If transform is applied to all blocks, then reconstruction accuracy is improved, but processing time increases

Engineering Contradiction:
Improvereconstruction accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action through transform skip mechanisms where transform is selectively applied only to blocks that benefit from it. Based on analysis of prediction residue characteristics, the system determines whether transform will improve reconstruction accuracy, applying it partially rather than universally, thereby reducing processing time while maintaining accuracy where needed

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4645854A1Method and apparatus for processing video signal
Publication Date: 2025.11.05 KT CORP
  • EP4645854A1 patent drawingFigure 1
  • EP4645854A1 patent drawingFigure 2
  • EP4645854A1 patent drawingFigure 3~4

AI summary

A method for decoding a video according to the present invention may comprise: deriving a spatial merge candidate for a current block, generating a merge candidate list for the current block based on the spatial merge candidate, obtaining motion information for the current block based on the merge candidate list, and performing motion compensation for the current block based on the motion information. Herein, if the current block does not have a pre-defined shape or a size equal to or greater than a pre-defined size, the spatial merge candidate of the current block may be derived based on a block which have the pre-defined shape or a size equal to or greater than the pre-defined size, the block including the current block.