Video Decoder Motion Vector Refinement via Pixel Downsampling

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Solution Overview

Problem

The high calculation complexity of the decoder-side motion vector refinement (DMVR) technology in video encoding and decoding frameworks hinders efficient picture coding and decoding processes.

Innovation Solution

A method and apparatus that reduce the calculation amount of difference comparison by determining motion information, performing motion search with first precision, and downsampling pixel arrays to identify a target prediction motion vector, thereby improving picture coding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If decoder-side motion vector refinement (DMVR) technology is used to remove redundant information, then picture coding efficiency is improved, but calculation complexity increases

Engineering Contradiction:
Improvepicture coding efficiencyVSAvoidcalculation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the picture block into multiple sub-blocks and performs motion search separately for each sub-block. This segmentation reduces the overall calculation complexity by dividing the large-scale motion search into smaller, more manageable units while maintaining coding efficiency through localized motion compensation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different motion search strategies to different regions of the picture block. By performing motion search only in necessary sub-blocks and using different search ranges based on local characteristics, the method reduces unnecessary calculations while maintaining high prediction accuracy in critical areas.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If motion search with high precision is performed to obtain accurate prediction blocks, then picture quality is improved, but calculation amount increases

Engineering Contradiction:
Improveprediction accuracyVSAvoidcalculation amount
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent divides the motion search process into multiple precision levels across different sub-blocks. High-precision motion search is performed only where necessary, while other areas use lower precision, thereby reducing the total calculation amount while maintaining overall prediction accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs motion search with full precision only in sub-blocks that require it, rather than uniformly applying high precision across the entire picture block. This partial application of high-precision action reduces unnecessary calculations while maintaining quality where needed.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS12155853B2Picture encoding and decoding method and apparatus for video sequence
Publication Date: 2024.11.26 HUAWEI TECH CO LTD
  • US12155853B2 patent drawing
  • US12155853B2 patent drawing
  • US12155853B2 patent drawing

AI summary

A picture decoding method includes determining motion information of a to-be-decoded block; obtaining a first decoding prediction block of the to-be-decoded block based on the motion information; performing motion search with first precision in the prediction reference picture block to obtain at least two second decoding prediction blocks; performing downsampling on the first decoding prediction block and the at least two second decoding prediction blocks to obtain a first sampling pixel array and at least two second sampling pixel arrays, respectively; calculating a difference between the first sampling pixel array and each of the second sampling pixel arrays, and using, as a target prediction motion vector, a motion vector corresponding to a second sampling pixel array with a minimum difference; and obtaining a target decoding prediction block of the to-be-decoded block based on the target prediction motion vector, and decoding the to-be-decoded block based on the target decoding prediction block.