A Pansharpening Approach Based on Multiple Linear Regression Estimation of Injection Coefficients

Pansharpening techniques allow a detailed reproduction of the Earth surface by fusing a multispectral (MS) and a panchromatic (PAN) image acquired over the same area. Classical pansharpening methods consist in the extraction of the details from the PAN image and their subsequent injection into the MS image through a linear function. In this letter, we propose to apply a nonlinear injection procedure that implements the detail injection through a polynomial function. Optimal polynomial coefficients in the least squares sense can be easily obtained in the closed form, and the consequent pansharpening algorithm is shown to obtain superior performance with respect to the existing linear approaches, especially for MS bands with a reduced wavelength overlap with the PAN channel.