{TAIL ~ This filtering} results {HEAD ~ such an image} that the mean square error of the restored image f′ from the input image f is minimal 
{ TAIL ~ This filtering } results { HEAD ~ such an image } that the mean square error of the restored image f′ from the input image f is minimal
TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH