Comparing distances for quality assessment of fused images

This communication deals with the fusion of panchromatic (PAN) images of high spatial resolution and multispectral (MS) images of lower resolution in order to synthesize MS images at high resolution. These fused images should be as identical as possible to images that would have been acquired by the corresponding space borne sensor if it were fit with this high resolution. A protocol for the assessment of the quality of the fused images was discussed by the EARSeL Special Interest Group ‘‘data fusion’’ in 2004. It evaluates how much fused images comply with two properties, on multispectral and monospectral viewpoints. The compliance is measured through a set of distances between the set of fused images and the multispectral reference images. This communication analyses the distances that are found in literature. First of all, it proposes a classification of these distances into seven categories. Then it shows some relations between several distances through an empirical study. Finally, a typical choice of distances is proposed in order to assess most aspects of fused images.