On Sep 24, 2006, at 16:15 UTC, John Kubie wrote: > I'm searching for a fast algorithm for finding 'blobs' of contiguous > pixels above (or below) a threshold.
Sounds like a simple Flood-Fill problem to me. > Question: Does anyone know a source to a simple explanation of the > competing algorithms? I got mine from Graphics Gems, IIRC. > (wish) Does anyone have any realbasic versions of algorithms? Yes; before RGBSurface.FloodFill was added to the runtime framework, I used an implementation written in RB. That was some years ago though; I'm not sure whether I still have it. However, depending on what you mean by "above or below a threshold," I wonder if you could solve this by simply doing an RGBSurface.Transform based on your threshold, to make all the thresholded pixels a single color; and then do an RGBSurface.FloodFill to select them. Hmm, but I suppose that still doesn't give you the actual coordinates of the chosen pixels, which may be what you want. If you need me to dig around for that old implementation, just let me know. Best, - Joe > > John Kubie > _______________________________________________ > Unsubscribe or switch delivery mode: > <http://www.realsoftware.com/support/listmanager/> > > Search the archives of this list here: > <http://support.realsoftware.com/listarchives/lists.html> > -- Joe Strout -- [EMAIL PROTECTED] Verified Express, LLC "Making the Internet a Better Place" http://www.verex.com/ _______________________________________________ Unsubscribe or switch delivery mode: <http://www.realsoftware.com/support/listmanager/> Search the archives of this list here: <http://support.realsoftware.com/listarchives/lists.html>
