MSP-Former: Multi-Scale Projection Transformer for Single Image Desnowing

Image restoration of snow scenes in severe weather is a difficult task. Snow images have complex degradations and are cluttered over clean images, changing the distribution of clean images. The previous methods based on CNNs are challenging to remove perfectly in restoring snow scenes due to their local inductive biases' lack of a specific global modeling ability. In this paper, we apply the vision transformer to the task of snow removal from a single image. Specifically, we propose a parallel network architecture split along the channel, performing local feature refinement and global information modeling separately. We utilize a channel shuffle operation to combine their respective strengths to enhance network performance. Second, we propose the MSP module, which utilizes multi-scale avgpool to aggregate information of different sizes and simultaneously performs multi-scale projection self-attention on multi-head self-attention to improve the representation ability of the model under different scale degradations. Finally, we design a lightweight and simple local capture module, which can refine the local capture capability of the model. In the experimental part, we conduct extensive experiments to demonstrate the superiority of our method. We compared the previous snow removal methods on three snow scene datasets. The experimental results show that our method surpasses the state-of-the-art methods with fewer parameters and computation. We achieve substantial growth by 1.99dB and SSIM 0.03 on the CSD test dataset. On the SRRS and Snow100K datasets, we also increased PSNR by 2.47dB and 1.62dB compared with the Transweather approach and improved by 0.03 in SSIM. In the visual comparison section, our MSP-Former also achieves better visual effects than existing methods, proving the usability of our method.