Extracting Stone from Image

Question

Any thoughts on an algorithm to extract the stone from images like this?

stone http://www.highdesertlapidary.com/media/5/a2079181363c96d4d9c754_s.JPG

The stones are all different colors. I need to separate them from both the background and any rulers that might be present.

Thank you.

Answer 1

you could try this, http://www.eecs.berkeley.edu/Research/Projects/CS/vision/grouping/resources.html

and then choose a threshold what you desire, it is very good for grouping and segmentation, code is also publicly available.

It may be better if you place the stone on some other surface which is of a different color, may be placing a white sheet below would help(if that is possible)