Improving Spectral Snapshot Reconstruction with Spectral-Spatial Rectification
Authors: Jiancheng Zhang, Haijin Zeng, Yongyong Chen, Dengxiu Yu, Yin-Ping Zhao

How to effectively utilize the spectral and spatial characteristics of Hyperspectral Image (HSI) is always a key problem in spectral snapshot reconstruction. Recently the spectra-wise transformer has shown great potential in capturing inter-spectra similarities of HSI but the classic design of the transformer i.e. multi-head division in the spectral (channel) dimension hinders the modeling of global spectral information and results in mean effect. In addition previous methods adopt the normal spatial priors without taking imaging processes into account and fail to address the unique spatial degradation in snapshot spectral reconstruction. In this paper we analyze the influence of multi-head division and propose a novel Spectral-Spatial Rectification (SSR) method to enhance the utilization of spectral information and improve spatial degradation. Specifically SSR includes two core parts: Window-based Spectra-wise Self-Attention (WSSA) and spAtial Rectification Block (ARB). WSSA is proposed to capture global spectral information and account for local differences whereas ARB aims to mitigate the spatial degradation using a spatial alignment strategy. The experimental results on simulation and real scenes demonstrate the effectiveness of the proposed modules and we also provide models at multiple scales to demonstrate the superiority of our approach.