A Disjoint Set Algorithm for the Watershed Transform

In this paper the implementation of a watershed transform based on Tarjan’s Union-Find algorithm is described. The algorithm computes the watershed as defined previously. The algorithm consists of two stages. In the first stage the image to be segmented is transformed into a lower complete image, using a FIFO-queue algorithm. In the second stage, the watershed of the lower complete image is computed. In this stage no FIFO-queues are used. This feature makes parallel implementation of the watershed transform much easier.