Image Analysis and Recognition

We present a method for automatic segmentation of grey-scale images, based on a recently introduced deformable model, the charged-particle model (CPM). The model is inspired by classical electrodynamics and is based on a simulation of charged particles moving in an electrostatic field. The charges are attracted towards the contours of the objects of interest by an electrostatic field, whose sources are computed based on the gradient-magnitude image. Unlike the case of active contours, extensive user interaction in the initialization phase is not mandatory, and segmentation can be performed automatically. To demonstrate the reliability of the model, we conducted experiments on a large database of microscopic images of diatom shells. Since the shells are highly textured, a postprocessing step is necessary in order to extract only their outlines.