Generalized Filter for Video Compression Artifact Removal

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Solution Overview

Problem

Current video coding technologies face challenges in effectively correcting artifacts introduced during video compression, particularly in filtering operations at both video encoders and decoders.

Innovation Solution

A generalized filter function is applied to pixels in a video frame, allowing for various regions of support and using real-valued coefficients to modify target samples based on neighboring values, with options for linear and non-linear functions, enabling in-loop or post-filtering capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional filtering operations are used in video coding, then artifacts during video compression can be corrected, but the filtering capability is limited and not flexible enough to handle various artifact types effectively

Engineering Contradiction:
Improvefiltering capabilityVSAvoidartifact correction effectiveness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements a universal filter function that can perform multiple filtering operations (deblocking, de-ringing, smoothing) through a single unified framework. The filter function accepts different parameter configurations to adapt to various artifact types, making the system versatile while maintaining reliable artifact correction across different video compression scenarios

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The filter parameters (beta_offset, tau_offset, filtering strength) are dynamically adjusted based on the strength of compression artifacts detected in the video data. This dynamic adaptation allows the filter to effectively handle varying artifact severity levels, improving both versatility and reliability in correcting different types of compression artifacts

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If filtering strength is increased to better correct artifacts, then video quality improves, but processing complexity and computational load increase

Engineering Contradiction:
Improvevideo qualityVSAvoidfiltering operation complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the parameters of the filter function (beta_offset, tau_offset, clipping thresholds) to control filtering strength. By adjusting these parameters, the system can achieve high video quality with strong artifact correction while managing computational complexity through optimized parameter selection and conditional filtering application

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If strong filtering is applied to correct severe artifacts, then video quality improves, but natural details and edges may be lost

Engineering Contradiction:
Improvevideo qualityVSAvoidnatural video details
Core Design Contradiction:
Manufacturing precisionVSLoss of information

Solution Approach 1:

The filter function uses feedback mechanisms where the filtering operation is applied iteratively or adaptively based on the detected artifact characteristics. The filter strength and application regions are adjusted based on local video content analysis, preserving natural details and edges while correcting artifacts in appropriate regions

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies filtering with locally adapted parameters differentiating between regions with compression artifacts and regions with natural video details. By analyzing local characteristics and applying filtering only where needed with appropriate strength, the system improves video quality without losing natural video information in non-artifact regions

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS10986374B2Generalized filter for removing video compression artifacts
Publication Date: 2021.04.20 CISCO TECHNOLOGY INC
  • US10986374B2 patent drawing
  • US10986374B2 patent drawing
  • US10986374B2 patent drawing

AI summary

A target sample x(i,j) of a two-dimensional array of reconstructed samples is filtered based on values of samples in a neighboring region of the target sample to produce a two-dimensional array of modified reconstructed samples, according to the equation: y(i,j)=round(x(i,j)+g(Σm,n∈Ra(m,n)ƒ(x(i,j)−b(m,n)×(m,n)))), where y(i,j) is a modified target sample value, R is the neighboring region of the target sample, a(m,n) and b(m,n) are real-valued coefficients, round(x) is a function that maps the value x to an integer value in the range [0,2B−1], B is the number of bits representing each sample of the two-dimensional array of modified reconstructed samples, f(x) and g(x) are functions, wherein (a) f(x) is a non-linear function, or (b) g(x) is a non-linear function and both a width and a height of R is more than one sample.