Bayesian fusion of multispectral and panchromatic images using a multi-mode and multiorder gradient tensor-based l_1/2 sparse model

In this letter, based on the tensor representation modelling, we propose a multi-mode and multi-order gradient tensor-based non-convex model (M(2)GTNM) for Bayesian fusion of multispectral (MS) and panchromatic (Pan) images, which aims at producing the high-resolution MS (HRMS) images. Specifically, by modelling the MS image as the order-3 tensor, we mainly develop the multi-mode and multi-order gradient tensor sparse priors of MS image for fusion. For the spectral preservation of low-resolution MS (LRMS) image, the spectral fidelity constraint between HRMS and LRMS images is imposed. For the spatial-mode prior modelling, the multi-order spatial gradient tensor-based non-convex l(1/2) sparse prior between HRMS and Pan images is particularly imposed. Moreover, for the spectral-mode prior modelling, the spectral gradient tensor-based non-convex l(1/2) sparse prior between HRMS and upsampled LRMS images is further imposed. Then, we apply the alternating direction method of multipliers to optimize the proposed model. Finally, the reduced-scale and full-scale fusion experiments both validate the effectiveness of M(2)GTNM method.