基于雾气遮罩理论的图像去雾算法

针对场景中雾气分布可能不均匀的问题,本文提出了一种基于雾气遮罩减除的图像去雾算法。首先对降质图像平滑滤波以估计其亮度分量,对亮度分量求均值得到均匀分布的雾气遮罩,并结合退化图像获取与场景深度信息相关的雾气遮罩。在对数域中从降质图像中减除获得的雾气遮罩,即可得到场景的反射图像。对反射图像进行自适应的对比度拉伸,可以得到最终的去雾结果。所提算法能较容易地扩展至视频去雾应用,真实场景的图片与视频实验验证了所提算法的有效性。

An Image Defogging Algorithm Based on the Fog Veil Theory

A new image defog algorithm based on fog veil subtraction is proposed to deal with the situation where the fog might not be uniformly distributed.The proposed algorithm first estimates the illumination component of the image by applying smoothing to the degraded image,and then obtains the uniform distributed fog veil through a mean calculation of the illumination component.Next,we multiply the uniform veil by the original image to obtain a depth-like map and extract its intensity component to produce a fog veil whose distribution is in accord with the real fog density of the scene.Once the fog veil is calculated,the reflectance map can be obtained by subtracting the veil from the degraded image.Finally,we apply an adaptive contrast stretching to the reflectance map to obtain an enhanced result.This algorithm can easily be extended to video domains and is verified by both real-scene photographs and videos.