Rethinking the High Frequency Components in Deep Sub-Pixel Mapping Network

Deep sub-pixel mapping network (DSMNet) is a state-of-the-art approach in the field of sub-pixel mapping (SPM, also called super resolution mapping), combining deep learning theory, to solve the mixed pixel problem, which is ubiquitous in remote sensing images due to the spatial-resolving limitation. However, traditional DSMNet usually do not consider the multi-scale distribution characteristics of the real geographical distribution exposed in urban landscape. Furthermore, the heterogeneous distribution characteristics (high-frequency components) are the most important for SPM, but are difficult to learn and usually ignored in the tradition network models. In this paper, the high-frequency component aware (HFCA) module was proposed, based on the hierarchical supervised deep sub-pixel mapping network (HiDSMNet). HiDSMNet establishes a hierarchical supervised architecture for explicit multi-scale supervision to prompt the network to learn a multi-scale representation. Besides, HFCA module is integrated to prompt the network to intensify the learning of the high-frequency representation. The experimental results with three public datasets validated the superiority of the proposed HiDSMNet.