Depth of focus and the moment expansion.
We introduce the so-called moment expansion of a defocused image as a tool for analyzing and improving the depth of focus in optical imaging. It is shown that a number of previously noted defocus phenomena can be readily derived or explained in terms of moment expansion. Some potential applications of the moment expansion to phase-shifting mask and pupil filter design for optical lithography are also briefly noted.
Wang
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Pati
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Kailath
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