Region and Edge Growing

Abstract

The general idea of the region growing methods is to create a partition of the picture into homogeneous regions by any kind of process which starts with small regions and then grows them according to some homogeneity criterion. The general idea of edge growing methods is to create an initial set of (“fine scale”) edges (e.g., by one of the above-mentioned theories) and to connect the edges iteratively, according to some criterion based on proximity and orientation. Both methods are “dual” and can be made to interact in “hybrid growing methods”. In this chapter, we shall review and formalize the three above-mentioned kinds of growing methods and we shall, as in the last section, associate with them a variational formulation. This formulation is obtained by identifying for each method an energy for which the growing process appears as a steepest descent algorithm.