基于雾气浓度估计的图像去雾算法

Image Haze Removal Algorithm Based on Haze Thickness Estimation

根据雾气浓度的视觉特征,提出一种雾气浓度估计模型.在此基础上,结合大气散射模型,提出一种新的图像去雾算法.首先,基于雾气浓度估计模型计算出雾气浓度量化图,利用模糊聚类算法在量化图中识别出雾气最浓区域并估计出全球光;然后,对量化图中的"非雾气最浓"区域再次进行聚类处理,根据文中所提最优透射率评价指标估计出每个聚类单元的透射率,将全球光与透射图以及有雾图像导入散射模型,便可达到去雾的目的;最后,针对去雾后图像较实际场景偏暗,提出一种基于小波域的多尺度锐化算法进行增强处理,以改善其主观视觉质量.实验结果表明,本文算法与现有主流算法相比,具有更好的去雾效果,并且其计算速度也相对较快.

This paper proposes a haze thickness estimation model based on visual characteristics of haze thickness, and combines this model with atmosphere scattering model to present an innovative image dehazing algorithm. First, a haze thickness quantitative map is calculated via the haze thickness estimation model, from which the thickest area is identified by the fuzzy clustering algorithm and global atmospheric light is estimated. After that, the algorithm carries on clustering processing towards the non-thickest area in the quantitative map, and estimates the transmission of each cluster unit according to the optimized transmission evaluation index mentioned in this paper. The haze-free image can be restored from scattering model with global light, refined transmission map and original hazy image. At last, we propose a multi- scale sharpening algorithm based on wavelet domain to make up for the defect that the haze-free image is dark-look so as to improve the visual effect. Several numerical experiments demonstrate that the proposed method outperforms the mainstream dehazing algorithms in daze removal effect at a much lower implementation cost.