[Insight-users] region growing from local maxima

Ara.T.Howard Ara.T.Howard at noaa.gov
Tue Oct 4 21:34:05 EDT 2005


i'm working with night-time lights satelite imagery

   http://fortytwo.merseine.nu/india_shrunk/india_1995_stable_lights.small.png

although it's hard to tell from that stretch - all of the features have
considerable 'over-glow' caused by light scattering in the atmousphere.  i've
been working with several approaches to 'shrinking' the features that boils
down to finding local maxima and growing them 'downwards' from there.  ala

   http://fortytwo.merseine.nu/india_shrunk/india_1995_stable_lights.small.em.15.png

this is working o.k. but the toolkit i've been using has a flaw/bug/feature
that has become a glass ceiling for me.  i'm looking at moving to itk.
skimming the docs it would seem there is not builtin support for finding
extrema - but maybe i've missed it, the docs are large! ;-)

has anyone out there used itk to

   - local extrema, maxes in particular

   - grow regions from these seeds up to some tolerance (in my case i'm using
     percent difference within the total region as a limiter)

i'm also looking at the watershed segmentation method and it's depth feature.

and hints or pointers to docs appreciated.

kind regards.

-a
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