Adaptive Video Contrast Enhancement via Dynamic Range Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing video contrast enhancement methods for video signals often result in unrealistic artifacts due to the failure to preserve temporal and spatial visual effects, particularly in real-time processing and dynamic range adjustments.
Innovation Solution
A video processing system and method that adaptively enhances contrast by calculating effective input and output dynamic ranges and applying a transform to map these ranges while maintaining the original visual effects, using a statistics gathering module, knee-points calculation module, and enhancement module to ensure proportional and uniform enhancement across frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If still picture contrast enhancement methods are directly applied to video signals, then contrast visibility is improved, but temporal and spatial visual effects are distorted creating unrealistic artifacts
Solution Approach 1:
The patent applies dynamics by making the contrast enhancement parameters adaptive and time-varying. Instead of using fixed enhancement parameters, the system calculates frame-specific statistics (mean, standard deviation) and adjusts enhancement strength based on local contrast measurements and temporal continuity constraints. This allows the enhancement to adapt to different scenes and temporal contexts, preserving visual effects while improving contrast visibility.
Solution Approach 2:
The patent implements feedback through temporal continuity constraints that use previous frame information to guide current frame enhancement. The system measures local contrast and compares temporal variations, using this feedback to adjust enhancement parameters and prevent unrealistic artifacts. The feedback mechanism ensures that enhancement decisions are consistent with temporal visual effects observed in preceding frames.
2Productivity
If contrast enhancement is applied uniformly across all frames, then processing speed is improved, but frame-specific contrast variations and visual effects are lost
Solution Approach 1:
The patent applies local quality by computing frame-specific statistics (mean and standard deviation) for each video frame and using local contrast measurements to determine enhancement parameters for each frame individually. This allows different frames to receive customized enhancement treatment based on their specific luminance distributions and contrast characteristics, rather than applying a uniform enhancement across all frames.
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting enhancement parameters based on frame-specific statistics. The system calculates the mean and standard deviation for each frame, uses local contrast measurements to determine optimal enhancement strength, and modifies these parameters in real-time to adapt to varying frame characteristics while maintaining processing efficiency.
3Measurement precision
If aggressive contrast enhancement is applied, then visibility of details in low-contrast areas is improved, but intensity ordering between neighboring pixels may be inverted creating artifacts
Solution Approach 1:
The patent applies partial action by using moderate enhancement factors that are calculated based on local contrast measurements rather than applying maximum enhancement. The system determines the optimal enhancement strength for each frame and region, applying only the necessary amount of enhancement to improve visibility while staying below the threshold where intensity ordering inversion occurs. This prevents artifacts while still achieving detail visibility improvement.
Data Source
AI summary
A method for contrast enhancement of a video signal comprises receiving a video signal frame, gathering statistics about the video signal frame, calculating the effective input dynamic range of the video signal frame, calculating the effective output dynamic range of the video signal frame, and constructing a transform to enhance the picture in the video signal frame by mapping the effective input dynamic range to the effective output dynamic range via the transform.