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

Jie Huang, Yajing Liu, Feng Zhao, Keyu Yan, Jinghao Zhang, Yukun Huang, Man Zhou, Zhiwei Xiong ;

"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 and a phase sub-networks 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 FECNet achieves superior results than other methods with fewer parameters and can be extended to other image enhancement tasks, validating its potential for wide-range applications."