The two-image depth-from-focus problem is reconsidered in terms of entropy loss in a linear filter. It is shown that this formulation leads to a relatively simple solution whose variance is equal to or less than that from a regression approach. The formulation is appropriate even when the point-spread function of the optical system is not well suited to a low-order regression fit or when both images used contain some degree of defocusing with distance.
© 1993 Optical Society of America
Original Manuscript: March 9, 1992
Revised Manuscript: October 23, 1992
Manuscript Accepted: November 3, 1992
Published: April 1, 1993
V. Michael Bove, "Entropy-based depth from focus," J. Opt. Soc. Am. A 10, 561-566 (1993)