Is it Raining Outside? Detection of Rainfall using General-Purpose Surveillance Cameras
This work addresses the need for reliable rain detection in surveillance systems to improve video quality, but it is incremental as it builds on existing methods with a new dataset and model.
The paper tackles the problem of detecting rainfall in surveillance camera footage to enable rain removal algorithms, and shows that a proposed 3D CNN method outperforms the previous state-of-the-art by a large margin on a new dataset of 215 hours of video.
In integrated surveillance systems based on visual cameras, the mitigation of adverse weather conditions is an active research topic. Within this field, rain removal algorithms have been developed that artificially remove rain streaks from images or video. In order to deploy such rain removal algorithms in a surveillance setting, one must detect if rain is present in the scene. In this paper, we design a system for the detection of rainfall by the use of surveillance cameras. We reimplement the former state-of-the-art method for rain detection and compare it against a modern CNN-based method by utilizing 3D convolutions. The two methods are evaluated on our new AAU Visual Rain Dataset (VIRADA) that consists of 215 hours of general-purpose surveillance video from two traffic crossings. The results show that the proposed 3D CNN outperforms the previous state-of-the-art method by a large margin on all metrics, for both of the traffic crossings. Finally, it is shown that the choice of region-of-interest has a large influence on performance when trying to generalize the investigated methods. The AAU VIRADA dataset and our implementation of the two rain detection algorithms are publicly available at https://bitbucket.org/aauvap/aau-virada.