Pansharpening by a nonlocal channel-decoupled variational method

Joan Duran, Antoni Buades, Bartomeu Coll, Catalina Sbert, Gwendoline Blanchet

Abstract: Common satellite imagery products consist of a panchromatic image at high spatial resolution and several misregistered spectral bands at lower resolution. Pansharpening is the fusion process by which a high-resolution multispectral image is inferred. We propose a variational model for which pan-sharpening is defined as an optimization problem minimizing a cost function with nonlocal regularization. We incorporate a new term preserving the radiometric ratio between the panchromatic and each spectral band. The resulting model is channel-decoupled, thus permitting the application to misregistered spectral data. The experimental results illustrate the superiority of the proposed method to preserve spatial details, reduce color artifacts, and avoid aliasing.