Automatic color indexing of hierarchically structured classified images

The hierarchical structuring of a classified image with N classes provides a set of solutions for a classification problem, with N, N-1, ..., 2 classes. The visual analysis of this set of images requires that a consistent color indexing is available for the whole structure. This paper addresses this issue, proposing a number of methods for the automatic assignment of lookup tables for the classified images at the various levels of a hierarchical structure. The various strategies are compared and some methods illustrated with a section of a Landsat TM image classified in 15 classes. Color indexing; unsupervised classification; hierarchical clustering; HSI color space