Import vertical characteristic of rain streak for single image deraining

Recently, deep convolutional neural networks show good effect for single image deraining. These networks always adopt the conventional convolution method to extract features, which may neglect the characteristic of rain streak. A novelty vertical module is proposed to focus on the vertical characteristic of rain streak. Such module uses 1 ×X\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times X$$\end{document} convolution kernel to extract the vertical information of rain streaks and a X×X\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$X \times X$$\end{document} convolution kernel to keep relative location information. Use this module in the front of deraining network can better detach rain streaks from background. In addition, the contrastive learning is employed to improve the performance of the model. Extensive experimental results demonstrated the superiority of the deraining methods with the proposed methods in comparison with the base ones.