Raindrop Detection and Removal from Long Range Trajectories

In rainy scenes, visibility can be degraded by raindrops which have adhered to the windscreen or camera lens. In order to resolve this degradation, we propose a method that automatically detects and removes adherent raindrops. The idea is to use long range trajectories to discover the motion and appearance features of raindrops locally along the trajectories. These motion and appearance features are obtained through our analysis of the trajectory behavior when encountering raindrops. These features are then transformed into a labeling problem, which the cost function can be optimized efficiently. Having detected raindrops, the removal is achieved by utilizing patches indicated, enabling the motion consistency to be preserved. Our trajectory based video completion method not only removes the raindrops but also complete the motion field, which benefits motion estimation algorithms to possibly work in rainy scenes. Experimental results on real videos show the effectiveness of the proposed method.