Enhancement of weather degraded video sequences using wavelet fusion

Under bad weather conditions, the contrast and colors of videos are degraded and it is imperative to include mechanisms that overcome weather effects from video sequences in order to make vision systems more reliable. Unfortunately it turns out that effects of weather cannot be overcome by simple image processing techniques. There are only few works and some existing methods in literature for enhancement of weather degraded video sequences. A novel approach is proposed in this paper that is used to enhance degraded video sequences. It enhances visibility of the frames and also maintains the color fidelity. First a background image is estimated for the video sequence. The enhancement method is then separately applied on this background image and on the estimated motion pixels. The enhancement method consists of three phases. The first phase estimates a global correction parameter and the second phase computes an approximate degradation measure. In the final phase a novel wavelet fusion method is used to obtain the enhanced frame. Performance analysis is carried out with the help of a contrast improvement index and sharpness measure. The method has been tested using real time video sequences and is found to give good results.