Video Decoder Deblocking With Asymmetric Boundary Filters

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Solution Overview

Problem

Symmetrical deblocking filters in existing video coding standards like H.265/HEVC are inefficient in reducing pixel value errors when there are discontinuous error distributions across block boundaries, leading to increased errors in pixel values.

Innovation Solution

Implementing asymmetrical deblocking filters across block boundaries by adjusting filter characteristics based on block sizes, pixel values, prediction directions, and quantization parameters to selectively enhance or reduce filtering effects on pixels with larger or smaller errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If symmetrical deblocking filters are used in existing video coding standards, then the filtering process is simple and consistent, but the error reduction efficiency is poor when error distribution is discontinuous across block boundaries

Engineering Contradiction:

Improvefiltering process simplicityVSAvoidpixel value error reduction efficiency

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies asymmetry by using different filter coefficients for pixels on different sides of a block boundary. Specifically, the filter coefficient for a pixel is determined based on whether the pixel is located in a block with larger or smaller quantization parameter, creating asymmetric filtering that adapts to discontinuous error distributions and improves pixel value error reduction efficiency

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent implements local quality by making the filter characteristic pixel-dependent based on local block properties. Each pixel receives a filter coefficient tailored to its specific block's quantization parameter, allowing the filtering process to adapt to local error characteristics rather than applying a uniform symmetric filter across the entire boundary

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If filter coefficients are adjusted based on block size and pixel position, then pixel value errors are reduced more effectively, but the device complexity increases

Engineering Contradiction:

Improvepixel value error reduction efficiencyVSAvoidfilter coefficient selection complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by dynamically selecting filter coefficients based on block size and pixel position parameters. The filter coefficient is determined by comparing block sizes and pixel positions, changing the filtering parameters adaptively to match local characteristics, which improves error reduction while maintaining manageable complexity through systematic parameter-based selection

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12513293B2Encoder, decoder, and related non-transitory computer readable medium

Publication Date: 2025.12.30 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA

AI summary

Various embodiments provide a decoder configured to select a filter based on a block size of a first block and a block size of a second block in an image, and change values of pixels in the first block and the second block. The filter includes a first set of multipliers and a first set of offsets for the first block, and a second set of multipliers and a second set of offsets for the second block. The values of the pixels in the first block and the second block are changed by performing multiplication with each multiplier in the first set of multipliers, by performing multiplication with each multiplier in the second set of multipliers, and by using the first set of offsets and the second set of offsets.