controlling {HEAD ~ the reading} and writing of {TAIL ~ signals} to and from said memory, respectively, in said zoom operation processing circuit 
controlling { HEAD ~ the reading } and writing of { TAIL ~ signals } to and from said memory , respectively , in said zoom operation processing circuit
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH