Next, a black reference strip is scanned and, an offset value is determined and {HEAD ~ an offset voltage} is added to {TAIL ~ the D.C. restoration level} 
is added to
Next , a black reference strip is scanned and , an offset value is determined and { HEAD ~ an offset voltage } is added to { TAIL ~ the D.C. restoration level }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL