split blobs to get best result in osc

Hi, i try do a app with blobtracking and send the data via osc, all is fine but the problem begin when i try track a blob from a person because the size of each person get a big blob in his box but i only need the hand, i try fix this problem with threshold and blur amounts but i have bad results . So now i want split the blob in fixes parts or use convex hull algoritm. I am sure if this problem be solve, maybe be helpful for more people than just me.

sketch the objective:

Any help is welcome thanks.


you could start by walking through the blob contour and simply discarding points that aren’t in the region where you expect the hand to be.