IR&ArF: Toward Deep Interpretable Arbitrary Resolution Fusion of Unregistered Hyperspectral and Multispectral Images

The fusion of hyperspectral image (HSI) and multispectral image (MSI) is an effective mean to improve the inherent defect of low spatial resolution of HSI. However, existing fusion methods usually rigidly upgrade the spatial resolution of HSI to that of matching MSI under the ideal assumption that multi-source images are accurately registered. In real scenes where multi-source images are difficult to be perfectly registered and the spatial resolution requirements are dynamically different, these fusion algorithms is difficult to be effectively deployed. To this end, we construct the spatial-spectral consistent arbitrary scale observation model (S2cAsOM) to model the dependence between the unregistered HSI and MSI and the ideal arbitrary resolution HSI. Furthermore, an optimization algorithm is designed to solve S2cAsOM, and a deep interpretable arbitrary resolution fusion network (IR&ArF) is proposed to simulate the optimization process, which achieves the model-data dual-driven arbitrary resolution fusion of unregistered HSI and MSI. IR&ArF breaks the dependence of traditional fusion methods on the accuracy of image registration in a robust way, and can flexibly cope with the dynamic requirements of diverse applications for the spatial resolution of HSI, which improves the application ability of HSI fusion in real scenes. Extensive systematic experiments demonstrate the superiority and generalization of the proposed method. Source code of the proposed method is available on https://github.com/Jiahuiqu/IR-ArF.