Adaptive Motion Compensated Temporal Filter for Video Noise Reduction
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Solution Overview
Problem
Existing motion compensated temporal filters (MCTFs) do not effectively remove all noise from video signals, leading to wastage of bandwidth resources.
Innovation Solution
A method and apparatus for filtering noise in video encoding that employs an adaptation scheme based on differences between frames, determining a discrimination value to modify the current frame and suppress random noise while allowing signal content to pass through.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If motion compensated temporal filtering is applied to reduce noise in video signals, then noise suppression is improved, but existing filters fail to remove all noise thereby wasting bandwidth resources
Solution Approach 1:
The patent applies dynamics by making the filter strength adaptive rather than fixed. The filter strength is dynamically adjusted based on the motion vector magnitude and temporal correlation characteristics of the video signal. When motion is detected, the filter strength is reduced to preserve signal content, while when motion is minimal, the filter strength is increased to maximize noise suppression. This dynamic adaptation allows the system to remove more noise effectively without wasting bandwidth on already-clean signals.
Solution Approach 2:
The patent changes the parameter of filter strength based on detected motion characteristics. By monitoring motion vectors and temporal correlation, the system adjusts the filtering parameters in real-time. The filter transitions between different strength levels (e.g., weak filtering when motion is present, strong filtering when motion is minimal), enabling optimal noise removal while preserving signal integrity and avoiding unnecessary bandwidth consumption on clean frames.
2Object-affected harmful factors
If temporal filtering is applied to exploit temporal correlation, then noise reduction is improved, but signal content may be disrupted
Solution Approach 1:
The patent applies local quality by differentiating between different regions of the video signal based on motion characteristics. Areas with high motion vectors receive weaker filtering to preserve signal content, while areas with low motion vectors receive stronger filtering to remove noise. This spatially and temporally adaptive approach ensures that noise suppression is applied locally where appropriate without disrupting signal content in motion-prone regions.
Solution Approach 2:
The system dynamically adjusts filter strength based on real-time motion detection. When motion is detected in a particular region or frame, the filter strength is automatically reduced to preserve signal content. When motion is minimal, the filter strength increases to maximize noise suppression. This dynamic adaptation resolves the contradiction by making the filtering behavior context-dependent rather than static.
Data Source
AI summary
A method (50) and apparatus (40) for reducing noise in a video signal calculates (53) a discrimination value of a filter based on a magnitude difference between a current frame and a prior frame of a sequence of frames and modifies (54) the current frame using the modified discrimination value. The output of the filter is calculated as follows:g(i, j, k)=f(i, j, k)±βwherein:f (i, j, k) is the current frame input to the filter;g(i, j, k) is the current frame output from the filter; andβ is the discrimination value of the filter, which is calculated as follows:β={κδ′+χ,δ′=max{δ,δ0},δ<δ10,δ≥δ1in which:κ and χ are constants less than one;δ is a magnitude difference between the current frame and the prior frame; andδ0 and δ1 are constants that satisfy δ0≦δ1.


