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