Distances between frequency features for 3D visual pattern partitioning

In this paper we propose a technique for the decomposition of a 3D image into a set of low level patterns associated to phase congruency, which we call visual patterns. Those patterns have frequency components in a wide range of bands that are aligned in phase. The method involves clustering of the band-pass filtered versions of the image according to a measure of congruence in phase or, what is equivalent, alignment in the filter’s responses energy maxima. This is achieved by defining a distance between the responses of pairs of filters and applying a hierarchical clustering analysis to the resulting distance matrix. To measure the degree of maxima alignment we propose a set of alternative distances and study their suitability. From this study we conclude that a measure of linear dependence between the local energy of filters’ responses is more appropriate than a more general measure of dependence.