Video Coding IBC Search Restricted to Candidate Blocks

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional video coding standards face inefficiencies in encoding synthetic screen content due to unrestricted intra block copying (IBC) searches, which increase computational load and power consumption without significant quality improvement for natural images.

Innovation Solution

Implement a 'smart' IBC search method that restricts the search area to blocks previously decoded using IBC or palette prediction modes, and limits block sizes to 32x32 pixels, reducing computational load while maintaining image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If unrestricted IBC search is performed on all previously decoded blocks, then compression ratio is improved, but computational load and power consumption increase significantly

Engineering Contradiction:

Improvecompression ratioVSAvoidcomputational load

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The patent segments the previously decoded blocks into two categories: IBC candidate blocks (those decoded using IBC or palette mode) and non-candidate blocks. The search is restricted to only the IBC candidate blocks, which are a subset of all previously decoded blocks. This segmentation reduces the search space while maintaining compression effectiveness for screen content with large uniform regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different search strategies to different types of content. For screen content with large flat or uniform regions, unrestricted IBC search is beneficial. For natural images with complex textures, the restricted search to IBC candidate blocks is sufficient. This local quality approach optimizes the search strategy based on content characteristics.

Inventive Principle:

Principle #3Local quality

2Loss of substance

If unrestricted IBC search is performed on all previously decoded blocks, then compression ratio is improved, but power consumption increases significantly

Engineering Contradiction:

Improvecompression ratioVSAvoidpower consumption

Core Design Contradiction:

Loss of substanceVSUse of energy by moving object

Solution Approach 1:

The patent segments the search space to include only IBC candidate blocks (previously decoded using IBC or palette mode) rather than all previously decoded blocks. This segmentation significantly reduces the number of blocks that need to be compared, thereby reducing power consumption while maintaining compression effectiveness for screen content.

Inventive Principle:

Principle #1Segmentation

3Productivity

If IBC search area is restricted to reduce computational load, then encoder efficiency is improved, but image quality may deteriorate

Engineering Contradiction:

Improveencoder efficiencyVSAvoidimage quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary classification of blocks during the decoding process, marking those decoded using IBC or palette mode as IBC candidate blocks. This preliminary action prepares the search space in advance, allowing the encoder to efficiently restrict the IBC search to only the relevant candidate blocks without sacrificing image quality, as these are the blocks most likely to contain matching patterns.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12388975B2Method and system of video coding with efficient intra block copying

Publication Date: 2025.08.12 INTEL CORP

AI summary

Methods, articles, and systems of video coding use efficient intra block copying.