Classification-Based Post-Filter Scaling for Video Compression Efficiency

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Solution Overview

Problem

Existing video coding systems face challenges in efficiently adapting post-filter corrections to improve video quality, particularly in classification-based systems, leading to suboptimal compression and transmission efficiency.

Innovation Solution

Implementing classification-based post-filter re-scaling with adaptive scaling parameters, utilizing existing classifiers to determine corrections for reconstructed picture samples, and applying neural network-based filtering to enhance video coding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If classification-based post-filter correction is applied to improve video quality, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improvevideo qualityVSAvoidsystem complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by introducing scaling parameters (scale and offset) that modify the post-filter correction values based on classification. Different scaling parameters are applied to different picture regions or blocks, allowing adaptive adjustment of correction strength without fundamentally changing the filter structure. This resolves the contradiction by improving video quality through parameter adaptation while maintaining the existing filter architecture.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the picture into multiple regions or blocks, each potentially receiving different scaling parameters based on local characteristics. This segmentation allows the system to apply simplified correction strategies to specific regions rather than uniformly complex processing across the entire picture, thereby improving overall quality while managing computational complexity through localized processing.

Inventive Principle:
Principle #1Segmentation

2Productivity

If adaptive scaling parameters are introduced to optimize post-filter correction, then productivity is improved, but device complexity increases

Engineering Contradiction:
Improvecoding efficiencyVSAvoidfiltering system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements preliminary action by pre-calculating and storing scaling parameters in lookup tables before the actual video coding process. These parameters are determined based on pre-established criteria and classification schemes, allowing the filtering system to quickly retrieve and apply appropriate scaling factors during encoding/decoding without performing complex real-time calculations. This improves coding efficiency while limiting the increase in system complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex mechanical computation with simplified table-based retrieval and basic arithmetic operations. Instead of performing elaborate real-time optimization calculations, the system substitutes pre-computed scaling parameters from tables, reducing computational burden and improving productivity while maintaining acceptable filtering performance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of information

If classification-based re-scaling is applied to improve compression efficiency, then loss of information is reduced, but device complexity increases

Engineering Contradiction:
Improvevideo quality lossVSAvoidprocessing system complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent uses parameter changes by applying scaling factors to correction values based on classification results. This allows the system to preserve more information in regions where it matters most (e.g., high-frequency areas or important picture regions) while applying simpler correction in less critical areas, thereby reducing overall information loss without requiring uniformly complex processing across the entire video stream.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4633149A1Classification-based post-filter re-scaling
Publication Date: 2025.10.15 INTERDIGITAL CE PATENT HOLDINGS SAS
  • EP4633149A1 patent drawingFigure 1A
  • EP4633149A1 patent drawingFigure 1B
  • EP4633149A1 patent drawingFigure 1C

AI summary

A codec may perform classification-based post-filter re-scaling. Scaling parameters may be adapted to associated classifications. Scaling parameters support modification of the post-filter correction. A classifier may re-use existing classifiers used by the post-filter or another classifier. An adaptive classifier may support: classification-based scaling correction; neural network (NN)-based post-filtering with classification-based scaling correction; and/or signaling of the scaling parameters. A codec may determine a classification associated with a reconstructed picture sample. Scaling parameters associated with the classification may be determined. A scaled correction may be determined based on the scaling parameters. The scaled correction may be applied to the reconstructed picture sample. A codec may perform neural network processing to determine a classification associated with a reconstructed picture sample. Scaling parameters associated with the classification may be determined. A scaled correction may be determined based on the scaling parameters. The scaled correction may be applied to the reconstructed picture sample.