Hidden Path Selection Network for Semantic Segmentation of Remote Sensing Images

Targeting at depicting land covers with pixelwise semantic categories, semantic segmentation in remote sensing images needs to portray diverse distributions over vast geographical locations, which is difficult to be achieved by the homogeneous pixelwise forward paths in the architectures of existing deep models. Although specific algorithms have been designed to select pixelwise adaptive forward paths for natural image analysis, it still lacks theoretical supports on how to obtain optimal selections. In this article, we provide mathematical analyses in terms of the parameter optimization, which guides us to design a method called hidden path selection network (HPS-Net). With the help of hidden variables deriving from an extra mini-branch, HPS-Net is able to tackle the inherent problem about inaccessible global optimums by adjusting the direct relationships between feature maps and pixelwise path selections in existing algorithms, which we call hidden path selection. For the better training and evaluation, we further refine and expand the 5-class Gaofen image dataset (GID-5) to a new one with 15 land-cover categories, i.e., GID-15. The experimental results on both GID-5 and GID-15 demonstrate that the proposed modules can stably improve the performance of different deep structures, which validates the proposed mathematical analyses.