Sparse representation-based detail-injection method for pan-sharpening

Abstract

Pan-sharpening is an important image preprocessing technique for remote sensing that aims to enhance spatial resolution of multispectral (MS) images under the guidance of panchromatic (PAN) image while preserving spectral properties. The existing pan-sharpening methods usually adopt the globally consistent detail-injection models, neglecting the detail differences between spectral channels, which leads to imprecise spatial details and distorted spectral properties of pan-sharpening results. We propose a sparse representation-based detail-injection model for pan-sharpening that utilizes the structure similarity and detail differences between PAN and low-resolution multispectral (LRM) images at each channel, to improve the performance of pan-sharpening. Specifically, to better express the inherent detail properties of the MS image, the overcomplete dictionary of each channel is constructed from synthesized high-resolution multispectral (HRM) images. Moreover, the most proposed methods require that the spectral responses of the PAN image and the MS image cover the same wavelength range; nevertheless, most sensors cannot match this condition. To address this problem, we propose constructing coupled low-resolution and high-resolution dictionaries from LRM and synthesized HRM images so that the structure similarities can be used for detail injection. The qualitative and quantitative experimental results on various data sets demonstrate the superiority of our proposed method over the state-of-the-art methods.