to maintain focus by relying on the in-focus position of any one location or
simply by finding the in-focus positions at two locations on a slide and scanning
along the line between them [2]. Even with careful microscope stage calibration,
variations in focus over a scan area will still exist, due to such factors as
mechanical instability of the microscope, irregularity of glass slide surfaces,
and presence of artifacts and debris.
Moving between adjacent fields of view normally requires only a slight
change of focus. This can be exploited in the design of an efficient autofocusing
algorithm for scanning microscopy. After finding the in-focus position for one
field of view, it can be taken as the starting position for the adjacent field of view
because