obtaining quantized two dimensional image data including an object to be in {TAIL ~ focus} with {HEAD ~ respect} to an optical system by imaging the object through the optical system 
obtaining quantized two dimensional image data including an object to be in { TAIL ~ focus } with { HEAD ~ respect } to an optical system by imaging the object through the optical system
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH