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