Object contour in a photo

I'm trying to draw the contour of an object in scanned photos.
I've tried with no success to find existing algorithms that would
do that. I just can't believe that apart from the Adobe staff
nobody has tackled this problem before. Is there really no
shareware, or low cost software that does this? The only one
I found wants to be paid a lot (and I mean a lot).
Now if necessary I will do it myself but I'd rather not reinvent
the wheel (and lose so much time doing it).
Thanks

theres the open source equivalent of photoshop which is the GIMP

If you're referring to the "intelligent scissors" tool in GIMP, it doesn't seem to be that good. Maybe you could be more specific...

Dynamomite, sometimes you have to pay for quality...not that you should necessarily stop looking. There are known algorithms to do this, so you could do it yourself, but unless you're a genius, what you come up with won't be as good as what the team of experts whose job it was to implement it did. I only briefly studied this, but IIRC, maxflow/mincut can be used. But to use that, you need a way to assign to each pixel a probability that it is part of the object, which I don't know how to do (a nerd might experiment here). There could be better ways.