Internal and external transmission encoder–decoder network for single-image deraining

The visual quality of images captured in rainy weather is degraded by rain streaks, which may significantly reduce the accuracy of computer vision systems. In this paper, an internal and external transmission encoder–decoder network is proposed for eliminating rain streaks in a single image. Since rain streaks and background structures tend to be spatially long, we apply an internal connected aggregation unit to leverage global information and aggregate features at different scales to help remove rain streaks while restoring scene details. To fully exploit effective features of the encoder network and remove redundant information, we utilize an external connected enhancement unit to obtain effective feature maps for predicting clear outputs. By utilizing the efficient information inside and outside the unit, the proposed method can remove the rain streaks of different sizes and directions in the image and restore clear background structure details. Extensive experimental results on synthetic datasets and natural samples show that our method can achieve better rain removal performance than other advanced methods.