The improved signal restoring 15 wherein said reference region is along {HEAD ~ a crosstrack edge} of {TAIL ~ the platen} 
The improved signal restoring 15 wherein said reference region is along { HEAD ~ a crosstrack edge } of { TAIL ~ the platen }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL