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