Generalised laplacian pyramid-based fusion of MS + P image data with spectral distortion minimisation

This work presents a general and formal solution to the problem of fusion of a multi-spectral (MS) image with a higher-resolution panchromatic (P) observation. The method relies on the generalised Laplacian pyramid, which is an over-sampled structure obtained by subtracting from an image its low-pass version. The goal is to selectively performs spatial-frequencies spectrum substitution from an image to another with the constraint of thoroughly retaining the spectral information of the coarser MS data. To this end, a vector injection model has been defined: at each pixel, the detail vector to be added is always parallel to the MS approximation. Furthermore, its components are scaled by factors measuring the ratio of local gains between the MS and P data. Quantitative results are presented and discussed on simulated SPOT 5 data of an urban area ( P, XS) obtained from the MIVIS airborne imaging spectrometer.