The region is encoded to generate a temporary encoded region and {HEAD ~ the temporary encoded region} is then decoded to generate {TAIL ~ a decoded region} 
is decoded to generate
The region is encoded to generate a temporary encoded region and { HEAD ~ the temporary encoded region } is then decoded to generate { TAIL ~ a decoded region }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL