Adaptive Edge Enhancement for Video Signal Noise Control
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Solution Overview
Problem
Existing edge enhancement techniques in video processing systems often overshoot or undershoot, leading to visually unnatural or noisy adjusted edges, particularly in chroma components which are prone to noise due to high compression.
Innovation Solution
An adaptive edge enhancement system that includes a transient improvement module and an adaptive peaking module, utilizing high-pass filters and gain paths to generate adjusted pixel values based on a window of pixel values, while controlling chroma component adjustments with associated luma values to prevent noise artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional edge enhancement filters are used to improve edge sharpness, then edge transition of luma is improved, but visually unnatural or noisy adjusted edges are created due to overshoot or undershoot
Solution Approach 1:
The patent applies dynamics by making the enhancement strength adaptive rather than fixed. The system dynamically adjusts the enhancement amount based on local image characteristics (edge strength, chroma content, noise levels) detected in different regions, allowing the filter to be aggressive where safe and conservative where risky, thus improving edge sharpness without consistent overshoot/undershoot artifacts
Solution Approach 2:
The patent implements local quality by applying different enhancement strategies to different parts of the image. Specifically, it analyzes local chroma content, edge orientation, and noise characteristics to determine the appropriate enhancement level for each pixel neighborhood, rather than applying a uniform enhancement across the entire image
2Manufacturing precision
If chroma components are enhanced to improve color edge sharpness, then color definition is improved, but noise artifacts are amplified due to high compression in chroma channels
Solution Approach 1:
The patent changes parameters by using luma-based edge detection to control chroma enhancement. Instead of directly enhancing chroma edges (which amplifies noise), it detects edges in the less-noisy luma channel and uses that information to guide selective chroma enhancement, changing the parameter space from direct chroma processing to luma-guided chroma processing
Solution Approach 2:
The patent introduces luma edge information as an intermediary between the enhancement goal and chroma processing. The luma channel serves as a mediator that provides reliable edge location information without the noise problems of chroma, which then guides the selective application of enhancement to chroma components
Data Source
AI summary
In at least one embodiment of the invention, an apparatus for adaptive edge enhancement of a video signal includes a transient improvement module. The transient improvement module is configured to generate a first adjusted pixel value based on a window of pixel values for pixels surrounding a pixel-of-interest initially having an input pixel value. The apparatus includes an adaptive peaking module configured to generate a second adjusted pixel value based on the first adjusted pixel value and the input pixel value. In at least one embodiment of the apparatus, the adaptive peaking module comprises a high-pass filter configured to generate a pixel adjustment based on the first adjusted pixel value. In at least one embodiment of the apparatus, the adaptive peaking module further comprises a gain path configured to apply at least one adaptive gain value to the pixel adjustment to generate an adaptive adjustment value.