Similarity is a geometer
Multimedia databases (in particular image databases) are different from traditional system since they cannot ignore the perceptual substratum on which the data come. There are several consequences of this fact. The most relevant for our purposes is that it is no longer possible to identify a well defined meaning of an image and, therefore, matching based on meaning is impossible. Matching should be replaced by similarity assessment and, in particular, by something close to human preattentive similarity. In this paper we propose a geometric model of similarity measurement that subsumes most of the models proposed for psychological similarity.
image databases similarity measures riemann geometry search by content query by visual example