WATERSHED - imprecise contour and loss of small objects

Hi, I am using marker-controlled watershed segmentation (flooding from marker mask to a bwdist-ed, object mask) in MATLAB. I am doing ok-ish but I have objects of a relatively wide spectrum of sizes, and the smaller ones tend to be lost - I think during the watershed step. There is a general problem of imprecision at reaching the original mask boundaries, which I think it is typical of the watershed transform, I suspect it is related to the loss of objects.

Does anyone know about a simple way round it? I am trying a slight dilation of the object mask before the watershed but it does not help.

Thanks, Joaquin

[Mike Alonzo]

Hi Joaquin --

Did you ever happen to figure this out. I think I'm in the same boat. I have my original perimeter (http://www.uweb.ucsb.edu/~malonzo/Crown_perims.jpg) and then my marker-controlled watershed result (http://www.uweb.ucsb.edu/~malonzo/Crown_segments_mediocre.jpg)

I was hoping that the original perimeters could be maintained...

Thanks for any insight.

Mike