In this case, a density of information in {HEAD ~ a record} on {TAIL ~ the file medium} undergone the data compression is different from a density of information in the original image 
on
In this case , a density of information in { HEAD ~ a record } on { TAIL ~ the file medium } undergone the data compression is different from a density of information in the original image
OTH OTH OTH 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 OTH OTH OTH OTH OTH OTH OTH