Affine Motion Compensation With Boundary-Only OBMC

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Solution Overview

Problem

Existing video coding standards like VVC and AVS3 face challenges in achieving optimal coding efficiency and reducing computational complexity, particularly with the use of overlapped block motion compensation (OBMC), which is inefficient for variable block sizes and introduces significant complexity in encoder and decoder designs.

Innovation Solution

An adaptive OBMC scheme is proposed, adjusting the OBMC application area and weights based on block size and coding modes, and limiting OBMC to boundaries between CUs and their neighbors, while disabling it for certain coding modes to reduce complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If OBMC is applied to all blocks in existing video coding standards, then motion compensation accuracy is improved, but computational complexity and encoder/decoder design complexity increase significantly

Engineering Contradiction:

Improvemotion compensation accuracyVSAvoidencoder and decoder design complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies OBMC selectively only to boundary blocks that are adjacent to other CUs, rather than uniformly to all blocks. This local application approach maintains motion compensation accuracy at block boundaries where it is most needed, while avoiding unnecessary complexity in regions where OBMC provides minimal benefit.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the application of OBMC by identifying and separating boundary blocks from non-boundary blocks. Boundary blocks are subjected to OBMC processing, while non-boundary blocks use standard motion compensation, thereby dividing the complex global problem into manageable local cases.

Inventive Principle:

Principle #1Segmentation

2Productivity

If OBMC is applied uniformly to all block sizes, then coding efficiency is improved, but adaptability to variable block structures deteriorates

Engineering Contradiction:

Improvecoding efficiencyVSAvoidadaptability to variable block sizes

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic adaptation of OBMC to variable block sizes by determining whether each block is a boundary block based on its position and size. The OBMC process is adaptively applied only when appropriate for the specific block configuration, allowing the system to handle diverse block sizes and shapes efficiently.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the application parameters of OBMC based on block characteristics. Instead of fixed uniform application, the method adjusts OBMC application based on block size, position, and boundary conditions, optimizing coding efficiency for each specific case.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12470733B2Overlapped block motion compensation for inter prediction

Publication Date: 2025.11.11 BEIJING DAJIA INTERNET INFORMATION TECH CO LTD

AI summary

A method for video decoding is provided. The method includes obtaining a plurality of sub-blocks within an affine coding unit (CU) of a video frame, where the plurality of sub-blocks include a plurality of boundary sub-blocks and a plurality of non-boundary sub-blocks. Further, the method may include applying both overlapped block motion compensation (OBMC) and affine secondary prediction (ASP) to at least one sub-block to generate a sub-block-based prediction for the affine CU or enabling the ASP for the plurality of non-boundary sub-block and disabling the OBMC for the plurality of non-boundary sub-blocks.