[comp.graphics] Autotracing bitmaps into objects

nj@magnolia.Berkeley.EDU (Narciso Jaramillo) (03/12/91)

In my spare time, I'm working on a freely redistributable
object-oriented drawing program for Amiga computers.  People have
requested that I include a bitmap autotrace feature--i.e., one
that would attempt to approximate a given bitmap by some set of
objects.  Unfortunately, I don't know any good algorithms for doing
this.  It would be relatively easy (for black-and-white bitmaps, at
least) to set up a scan-line algorithm to keep track of object
boundaries and trace them into lines or polygons, but figuring out
when you're dealing with a curved boundary and tracing it into (say) a
B-spline seems trickier.  And, of course, trying to do all this with
the minimum number of extraneous boundary lines requires some smarts.

Does anyone know of any good algorithms for doing such autotracings?

Thanks much.


nj