In this paper a parallel implementation of a watershed algorithm is proposed. The algorithm is designed for a ring-architecture with distributed memory and a piece of shared memory using a single program multiple data (SPMD) approach. The watershed transform is generally considered to be inherently sequential. This paper shows that it is possible to exploit parallelism by splitting the computation of the watersheds of an image into three stages that can be executed in parallel.
Arnold Meijster, Jos B. T. M. Roerdink