A variational model for P+XS image fusion

We propose an algorithm to increase the resolution of multispectral satellite images knowing the panchromatic image at high resolution and the spectral channels at lower resolution. Our algorithm is based on the assumption that, to a large extent,. the geometry of the spectral channels is contained in the topographic map of its panchromatic image. This assumption, to-ether with the relation of the panchromatic image to the spectral channels. and the expression of the low-resolution pixel in terms of the high-resolution pixels given by some convolution kernel followed by subsampling, constitute the elements for constructing an energy functional (with several variants) whose minima will give the reconstructed spectral images at higher resolution. We discuss the validity of the above approach and describe our numerical procedure. Finally. some experiments on a set of multispectral satellite images are displayed.