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[Christian Knudsen]

Some time ago I stumbled upon a link to a page that described a very simple algorithm for following the outline of an arbitrary shape. I think it was called "edge walking". However, I can't for the life of me find that page nor the link to it again. I think it was in a post here in the technical forum (or it may have been on gamedev.net, but I'm not sure). Anybody know what I'm talking about?

EDIT: Typical. I search for it for a couple of hours, then give up and post a message here. Then find the webpage I was talking about two seconds later: http://www.sakri.net/blog/2009/05/28/detecting-edge-pixels-with-marching-squares-algorithm/

[Hajo]

It reminds me of a method where you (the user) tells the tool one point of the outline (points the mouse at e.g.) the tool then determines the image gradient there, and starts to do some pathfinding along the gradient - in theory this should give the contour of the shape.

Edit: Ah, that was close but not exactly what I had in mind

[nikki]

the right hand rule ?

[moi]

Oh hay guys,


Just dropping by to say hello...

[Christian Knudsen]

Edge Walking^TM