If {HEAD ~ the largest distance} from {TAIL ~ a focus point} to the best fit surface is larger than the predetermined value, then the virtual slide image is designated as needing a manual inspection and possible re scan 
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If { HEAD ~ the largest distance } from { TAIL ~ a focus point } to the best fit surface is larger than the predetermined value , then the virtual slide image is designated as needing a manual inspection and possible re scan
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