Rain streak removal by multi-frame-based anisotropic filtering

Dynamic weather conditions, such as rain and snow, often produce strong intensity discontinuity among frames, thus seriously degrade their visual or compression performance. How to remove these artifacts is a challenging task and has been intensively studies recently. The state-of-the-art algorithms detect these scratches before removing them from the scene. Visual effect of rain or snow is complex and difficult to be distinguished from the background; hence the precision of its detection and segmentation by hard decision is usually unsatisfactory. As an anisotropic filter performs well in structural noise removal, such as linear, planar as well as isotropic noise, it is utilized in this paper to analyze image content and suppress scratch noise simultaneously. Compared with the state-of-the-art algorithms, the proposed algorithm is better and more robust in dynamic scenes.