A body part index may be a discrete value or a probability distribution indicating the likelihood that {HEAD ~ a pixel} belongs to {TAIL ~ two or more different body parts} 
belongs to
A body part index may be a discrete value or a probability distribution indicating the likelihood that { HEAD ~ a pixel } belongs to { TAIL ~ two or more different body parts }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL