Wavelet-domain low-rank/group-sparse destriping for hyperspectral imagery

Abstract

Pushbroom acquisition of hyperspectral imagery is prone to striping artifacts in the along-track direction. A hyperspectral destriping algorithm is proposed such that the subbands of a 3-D wavelet transform most affected by pushbroom stripes - namely, those with spatially vertical orientation - are the exclusive focus of destriping. The proposed method features an iterative image decomposition composed of a low-rank model for the stripes coupled with a group-sparse prior on the wavelet coefficients of the subbands in question. While low-rank stripe models have been widely used in the past, they typically have been deployed in conjunction with a total-variation prior on the image that is prone to oversmoothing and residual stripe artifacts. On the other hand, the proposed group-sparse prior not only captures the well-known sparse nature of wavelet coefficients but also capitalizes on their vertical clustering in the subbands in question. In addition, while many prior destriping methods are wavelet-based, they employ 2-D transforms band by band. In contrast, the proposed 3-D wavelet transform provides a greater concentration of stripe information into fewer wavelet coefficients, leading to more effective destriping. Experimental results on both synthetically striped imagery as well as real striped imagery from an actual hyperspectral sensor demonstrate superior image quality for the proposed method as compared with other state-of-the-art methods.