An Historical Intermezzo
Fernand Meyer · 2019
This chapter shows how the watershed concept and the algorithms for constructing it emerged progressively. Christian Lantuejoul, in order to model a polycrystalline alloy, defined and studied the skeleton by zones of influence (SKIZ) of a binary collection of grains in his thesis. There are thus three milestones in the formulation of a watershed as a SKIZ of the regional minima. The first one is due to Lantuejoul and Beucher and constructs a watershed partition sequentially as a series of geodesic SKIZ in increasing thresholds of the function. The second defines a watershed as the SKIZ for the topographic distance. The last one defines a watershed as the SKIZ for an 8-steep lexicographic distance. Last but not least, the hierarchical queue (HQ) algorithm remains one of the simplest and fastest algorithm for constructing a watershed partition.