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