Talk:Watershed (image processing)

An image is definitely needed to help clarify the procedure!daviddoria (talk) 18:41, 20 September 2008 (UTC)

Merge with Watershed segmentation algorithm
what about merging the article Watershed segmentation algorithm here? It does not say much, and it is also orphaned... (and I always land there searching watershed segmentation in google). Momet (talk) 13:21, 16 April 2010 (UTC) Good idea, I will try. coupriec (talk) 20 April 2010 —Preceding undated comment added 07:52, 20 April 2010 (UTC).

This article can definately use some work...it is not really useful right now. The explanations are unclear, and seem incomplete. 69.196.185.126 (talk) 03:12, 16 May 2010 (UTC)

Heart_MRI_image.png‎ is missing
In the example, the file is missing. Anyone who knows what was there before and could reupload it? — Preceding unsigned comment added by Aegonis (talk • contribs) 11:29, 5 July 2011 (UTC)

Suggestion to revert to a 2009-era revision
This article is in a really bad state, mostly because a cleanup done by user Coupriec in April of 2009. Here is a revision from before and a revision from after their cleanup. In the end, the article may have gained more information but it lost readability.

I suggest either a revert to an earlier version (the one I linked) or a complete re-write. --Blacklemon67 (talk) 03:01, 22 April 2015 (UTC)

Is "watershed" meant to suggest a catchment basin or a ridge?
Serge Beucher, one of the co-creators of the watershed algorithm, later published a paper about it called The Watershed Transformation Applied to Image Segmentation. This paper includes the following:
 * Consider again an image f as a topographic surface and define the catchment basins of f and the watershed lines by means of a flooding process. Imagine that we pierce each minimum M (f) of the topographic i surface S, and that we plunge this surface into a lake with a constant vertical speed. The water entering through the holes floods the surface S. During the flooding, two or more floods coming from different minima may merge. We want to avoid this event and we build a dam on the points of the surface S where the floods would merge. At the end of the process, only the dams emerge. These dams define the watershed of the function f

This shows that the name "watershed" is meant to refer metaphorically to a drainage divide. An example is the European Watershed, the ridge that separates the part of Europe drained by the Mediterranean from that which drains directly into the Atlantic.

Parts of this article seem to have been created by editors who use the word "watershed" in its quirky North American sense, to mean a catchment basin. It's clear from the paragraph above that people who created and named the watershed algorithm did not have that North American usage in mind. (Which is unsurprising, since they're French.) TypoBoy (talk) 21:17, 14 February 2017 (UTC)

Pix??
Surely an image-processing article deserves a rich collection of images. Can't we find more than the few that are now here? Jmacwiki (talk) 17:55, 23 April 2020 (UTC)