A region of an image having {HEAD ~ a plurality} of {TAIL ~ corresponding image values} is encoded to generate a temporary encoded region 
of
A region of an image having { HEAD ~ a plurality } of { TAIL ~ corresponding image values } is encoded to generate a temporary encoded region
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH