Adaptive Gradation Correction for Haze-Compromised Image Recognition
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Solution Overview
Problem
Image quality, including contrast and colors, is impaired by haze or fog, leading to degraded recognition of distant objects in photographs, as existing methods fail to effectively address the varying degrees of degradation across different image areas.
Innovation Solution
An image processing apparatus that detects the degree of degradation in image areas and applies adaptive gradation correction using a gain coefficient, weighting the correction to emphasize contrast in low-degradation areas while maintaining original values in high-degradation areas, thereby improving image recognizability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If contrast correction is applied to enhance image quality, then image recognizability is improved, but natural appearance and color accuracy deteriorate
Solution Approach 1:
The patent applies different contrast correction strengths to different regions of the image based on their degradation程度. High-degradation regions (heavy mist/fog) receive stronger contrast enhancement, while low-degradation regions maintain natural appearance. This local differentiation resolves the contradiction by making the correction adaptive rather than uniform.
Solution Approach 2:
The correction coefficient is dynamically adjusted based on the detected degradation degree of each region. The system calculates appropriate correction coefficients that vary with the mist/fog density, allowing the contrast correction to be strong where needed and subtle where natural appearance is preserved.
2Measurement precision
If strong contrast correction is applied to severely degraded regions, then image recognizability is improved, but color accuracy and natural appearance deteriorate
Solution Approach 1:
The patent calculates different correction coefficients for different regions based on their specific degradation characteristics. Each region receives tailored correction that matches its actual mist/fog density, preventing over-correction in moderately degraded regions while providing sufficient enhancement in severely degraded regions.
Solution Approach 2:
The correction coefficient is changed as a variable parameter that depends on the degradation degree. By making the correction coefficient a function of the detected degradation level, the system automatically adjusts the strength of contrast correction to match the actual image conditions, balancing enhancement needs with color accuracy preservation.
Data Source
AI summary
An image processing apparatus includes a degree-of-degradation detector, a correction coefficient calculator and an adaptive gradation correction unit. The degree-of-degradation detector detects a degree of degradation of image quality for each of areas included in image data and having predetermined size. The correction coefficient calculator calculates a correction coefficient for gradation correction, for each of the areas of the image data. The adaptive gradation correction unit performs adaptive gradation correction appropriate to the degree of degradation of the image data, based on the degree of degradation detected by the degree-of-degradation detector and the correction coefficient calculated by the correction coefficient calculator.