LSRNet: A Novel Interpretable Low-rank Sparse Representation Guided Fusion Network for Polarization and Intensity Images.

Polarization and intensity images fusion (PIF) has extracted extensive attentions as it can generate images with clear scene information and salient texture details of the object surface that are important for downstream applications. However, existing deep learning-based PIF methods usually lack interpretability and ignore the interactions among multi-modal features. To this end, we propose a novel interpretable low-rank sparse representation guided fusion network for polarization and intensity images (termed LSRNet). Specifically, a low-rank sparse representation deep unfolding module is designed to acquire the base and detail features of the source images, with the ability of improving the interpretability of the network. In addition, a cross-modal connection complementary feature extraction module is proposed, which aims to establish dependency among features of multi-modalities to fully extract complementary features of the source images. In order to demonstrate the validity of our LSRNet and take into account shortcomings of existing datasets for PIF, a multi-scene polarization and intensity image dataset, named MSPI dataset, is constructed, which includes 1034 high-resolution aligned image pairs. According to the best of our knowledge, this is the most comprehensive dataset for PIF that with a large number of image pairs, high resolution and multiple scene types. Extensive experiments on our MSPI dataset and two publicly available datasets (i.e., 12CFC and HCP) demonstrate the superior fusion performance, generalization ability, and desirable running efficiency of our LSRNet. Our codes and dataset will be publicly available at https://github.com/thebinyang/LSRNet.