The apparatus 1, wherein said {HEAD ~ image division unit} divides {TAIL ~ the reference image} into a first frequency region and a second frequency region, the second frequency region being higher in frequency than the first region, to thereby form two frequency division images, 
divides
The apparatus 1 , wherein said { HEAD ~ image division unit } divides { TAIL ~ the reference image } into a first frequency region and a second frequency region , the second frequency region being higher in frequency than the first region , to thereby form two frequency division images ,
OTH OTH OTH OTH OTH OTH HEAD 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH