Dear Josh, What about this two third party libraries?: http://www.exelisvis.com/docs/locmax.... or http://www.exelisvis.com/docs/extreme... Cheers, Fernando

Apologies for the very very late reply. Thanks, both of those functions work. Getting the compliment of the image allows the locmax procedure to then find local minima. Finding regions of local minima or holes in an image requires a little more work. Region growing was fine for a few points, but the watershed worked better, and also allowed the use of the histogram to filter out the bright segmented areas. Merging regions still needs some work though. Once again thanks for that. Cheers Josh