Beyond Spatial Domain: Cross-domain Promoted Fourier Convolution Helps Single Image Dehazing

Vanilla convolution and window-based self-attention have shown significant success in image dehazing. However, they are constrained by limited receptive fields and ignore frequency gaps between dehazed and clear images. The former hampers the modeling of global dependencies, while the latter impedes the learning of high-frequency features, leading to suboptimal performance. In this paper, we propose the Joint Spatial and Fourier Convolutional Network (JSFC-Net), which leverages Fourier transformation to simultaneously address the two aforementioned problems with low computational overhead. We introduce the Frequency-Spatial Promoted and Physical Learning Block, which extracts high-level features from the spatial domain and frequency domain in parallel. We design a simple yet effective solution that uses spatial features to promote and modulate frequency features in a multi-scale manner, achieving refinement of frequency features and addressing robustness issue caused by global sensitivity. Additionally, we present the Receptive Field Selection Module to facilitate improved fusion of spatial and frequency domain features. Finally, we introduce frequency loss to further narrow frequency gaps. Comprehensive experiments on multiple datasets demonstrate that JSFC-Net is significantly superior to SOTA dehazing methods.