Method of detecting focus position of {HEAD ~ object} from variable gray level image of {TAIL ~ object} 
Method of detecting focus position of { HEAD ~ object } from variable gray level image of { TAIL ~ object }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL