Deep Fourier-Based Exposure Correction Network with Spatial-Frequency Interaction

Images captured under incorrect exposures unavoidably suffer from mixed degradations of lightness and structures. Most existing deep learning-based exposure correction methods separately restore such degradations in the spatial domain. In this paper, we present a new perspective for exposure correction with spatial-frequency interaction. Specifically, we first revisit the frequency properties of different exposure images via Fourier transform where the amplitude component contains most lightness information and the phase component is relevant to structure information. To this end, we propose a deep Fourier-based Exposure Correction Network (FECNet) consisting of an amplitude sub-network and a phase sub-network to progressively reconstruct the representation of lightness and structure components. To facilitate learning these two representations, we introduce a Spatial-Frequency Interaction (SFI) block in two formats tailored to these two sub-networks, which interactively process the local spatial features and the global frequency information to encourage the complementary learning. Extensive experiments demonstrate that our method achieves superior results than other approaches with fewer parameters and can be extended to other image enhancement tasks, validating its potential in wide-range applications. Code will be available at https://github.com/KevinJ-Huang/FECNet.