A pyramid-based approach to multisensor image data fusion with preservation of spectral signatures

In this work, a multi-resolution procedure based on a generalized Laplacian pyramid (GLP) with rational scale factor is proposed to merge image data of any resolution and represent them at any scale. The GLP-based data fusion is shown to be superior to a similar scheme based on the discrete wavelet transform (WT), according to a set of parameters established in the literature. The pyramid-generating filters can be easily designed for data of any resolutions, differently from the WT, whose filter-bank design is non-trivial when the ratio between the scales of the images to be merged is not a power of two. Images from Landsat TM and from Panchromatic SPOT are fused together. The resulting bands capture multi-spectral features with enhanced contrast and texture, and an increased spatial resolution, thereby expediting automatic analyses for contextual interpretation of the environment.