Fast Hyperspectral Image Sharpening using Learned Affine Transforms

2021, Submitted to ACM MM

Abstract

Hyperspectral images (HSIs) contain rich spectral information and are an important data source for many visual applications. Compared with RGB images, the application of HSI is limited due to the tradeoff between the spatial and spectral resolution in hyperspectral imaging systems. In this paper, we present a fast HSI sharpening (FHSIS) model for the super-resolution of a low spatial resolution (LR) HSI with the help of an auxiliary high spatial resolution (HR) RGB image. Different from the existing HSI and RGB image fusion based super-resolution methods, which predict the HR HSI image in an end-to-end manner, we directly predict the inverse spectral response and map the RGB image back to the HSI space using affine transforms. Specifically, the proposed method tries to learn a coarse grid (with a set of spectral bases) from the input LR HSI and a HR weight map from the HR RGB image. Combining the spectral bases and the weight map in a grid upsampling module, we can generate a per-pixel affine transform for the target HR HSI and directly apply it to the HR RGB to obtain a super-resolved HR HSI. Extensive experiments have demonstrated that our purposed method is comparable to state-of-the-art methods with much faster running speed.

Grid Upsampling Module

Objective results

Subjective results