Author:Christopher Mei (christopher.mei at sophia.inria.fr) History:2003/12/15 : First version

Requires:ImageJ 1.31p or later, which adds the ability to package plugins in JAR files Source:Contained in Watershed_Algorithm.jar, which can be opened using a ZIP utility Installation:Download Watershed_Algorithm.jar to the plugins folder, or subfolder, restart ImageJ, and there will be a new Plugins/Filters/Watershed Algorithm...command.See Also:Watershed plugin by Daniel Sage

Process/Binary/WatershedcommandDescription:This algorithm is an implementation of the watershed immersion algorithm written by Vincent and Soille (1991). @Article{Vincent/Soille:1991, author = "Lee Vincent and Pierre Soille", year = "1991", keywords = "IMAGE-PROC SKELETON SEGMENTATION GIS", institution = "Harvard/Paris+Louvain", title = "Watersheds in digital spaces: An efficient algorithm based on immersion simulations", journal = "IEEE PAMI, 1991", volume = "13", number = "6", pages = "583--598", annote = "Watershed lines (e.g. the continental divide) mark the boundaries of catchment regions in a topographical map. The height of a point on this map can have a direct correlation to its pixel intensity. WIth this analogy, the morphological operations of closing (or opening) can be understood as smoothing the ridges (or filling in the valleys). Develops a new algorithm for obtaining the watershed lines in a graph, and then uses this in developing a new segmentation approach based on the {"}depth of immersion{"}.", }A review of Watershed algorithms can be found at : http://www.cs.rug.nl/~roe/publications/parwshed.pdf@Article{RoeMei00, author = "Roerdink and Meijster", title = "The Watershed Transform: Definitions, Algorithms and Parallelization Strategies", journal = "FUNDINF: Fundamenta Informatica", volume = "41", publisher = "IOS Press", year = "2000", }

The image on the left represents the type of result obtained from the thresholding of classical images where Watershed segmentation is efficient. This could be a picture of coffee beans, blood cells, sand ...

The segmentation on the right was obtained with the following operations : invert image (Edit/Invert), calculate the distance transform (Process/Binary/Distance Map), invert result, apply Watershed.