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.

hi,

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.