Re: Splitting concave figures.

On Oct 24, 6:57 am, A n g l e r <p|k|o|n|i|u|...@xxxxxxxxxxxxxxxxxxx>
wrote:
Dear all.

Imagine yourself a binary snap of a boomerang or a propeller or any
other figure which is partially concave. I wonder how I could split it
onto convex objects.  OK, they don't have to be convex, though the
original image should be split at the most concave coordinates that
affect the overall shape the most. There definitely will be some noise
as well, therefore a small concave bit shouldn't give a rise to
splitting, only big salient bits. Any ideas? Any publications or
well-studied algorithms you're aware of? Speed is kind-of crucial.

Cheers in advance,
Peter.

Knowing nothing about the topic, but eager to take a guess, how about:
1. Calculate the convex hull of the object
2. from the convex hull outline, measure the perpendicular distance to
the object outline (perpendicular wrt the convex hull)
3. Where the distance is greatest, that's probably a good point to cut
the object. (i.e. cut along to any other identified maxima, or to the
opposite side of the object.
4. Repeat for any of the generated sub objects until they are all
convex.

Chris
.