Chan-Vese Segmentation

While many segmentation methods rely heavily in some way on edge detection, the “Active Contours Without Edges” method by Chan and Vese [7, 9] ignores edges completely. Instead, the method optimally fits a two-phase piecewise constant model to the given image. The segmentation boundary is represented implicitly with a level set function, which allows the segmentation to handle topological changes more easily than explicit snake methods. This article describes the level set formulation of the Chan-Vese model and its numerical solution using a semi-implicit gradient descent. We also discuss the Chan–Sandberg–Vese method [8], a straightforward extension of Chan–Vese for vector-valued images. Source Code ANSI C source code to produce the same results as the demo is accessible on the article web page http://dx.doi.org/10.5201/ipol.2012.g-cv. Future software releases and updates will be posted at http://dev.ipol.im/~getreuer/code. Supplementary Material A video on the article web page http://dx.doi.org/10.5201/ipol.2012.g-cv shows animated segmentation evolutions for several of the examples in this work.