Need positional data of the edge or contour of a Kinect Silhoutte ?

Hi,

I am working on a personal project where I want to grow grass and plants from the contour of the kinect silhouttee. I want a list of coordinattes only along the edge from where I can emit grass as particles.How can I do this?

I am running a Kinect 1 on Mac OS using SimpleOpenNI 1.96

Please help if you have any idea of how to achieve this result.

Thanks.