For a display position, the user specifies {TAIL ~ at least one subregion} of {HEAD ~ the subdivided original image} 
For a display position , the user specifies { TAIL ~ at least one subregion } of { HEAD ~ the subdivided original image }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD