If the error measure is less than a specified threshold, then the region is encoded as {HEAD ~ a skipped region}, otherwise {TAIL ~ the region} is encoded as the temporary encoded region 
If the error measure is less than a specified threshold , then the region is encoded as { HEAD ~ a skipped region } , otherwise { TAIL ~ the region } is encoded as the temporary encoded region
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH