Corridor scissors: a semiautomatic segmentation tool employing minimum-cost circular paths

We present a new semiautomatic segmentation tool, which is motivated by the intelligent scissors algorithm, but which uses a modified concept of user-interaction. This new interface provides better capabilities for modifying previous segmentation results. The advantage of the new approach is that it enables to gradually increase the quality of the segmentation. The segmentation tool is based on a shortest circular path search within a corridor that is drawn by the user along the object boundary. For this purpose, we present a new algorithm for computing the shortest circular paths. Our algorithm is so fast that it almost achieves the speed of a regular noncircular shortest path search, while still ensuring an optimal solution.