Survey feedback indicates that the tool documentation is not good;
Documentation is strange: "Remark: The tool is (due to its implementation) faster if youuse lower levels. So in doubt you should start with high levels (supposed toundersegment) and then lower the levels until you are happy." This makes no sense - whystart with the slow execution?
Improve documentation.
I guess the text should state something like
This tool provides a watershed based segmentation algorithm. For a detailed explanation of the parameters level and threshold, please be referred to https://itk.org/Doxygen/html/classitk_1_1WatershedImageFilter.html. Remark: The tool is faster if you use higher values. So in doubt you should start with higher values (undersegment the image) and then lower the values until you find the anticipated number of segments.
Since Watershed was removed for the upcoming release (cf7f3935c4b6) I close this task. If we want to reactivate Watershed, we can come up with a better description of how to use the tool.