Topic
Contrast transfer function
About: Contrast transfer function is a research topic. Over the lifetime, 934 publications have been published within this topic receiving 26533 citations.
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TL;DR: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 - July 30, 2009 as discussed by the authors, is presented in this paper.
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009
2 citations
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TL;DR: In this article, the authors presented an extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7-August 11, 2011.
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.
2 citations
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01 Jan 2013TL;DR: In this paper, an improved algorithm based on BA is presented, which adds a Δϕ(x,y) to the phase map retrieved by BA to make the reconstructed phase map more precise.
Abstract: Phase contrast imaging technique has been improved promptly in recent years. Among these techniques in-line phase contrast imaging is widely used. Various algorithms for in-line phase retrieval have been proposed so far such as TIE (transport of intensity equation), CTF (contrast transfer function), first Born-approximations, GSF (Gerchberg-Saxton-Fienup) and etc. Bronnikov’s algorithm (BA) is a type of linear algorithm that is simple and efficient. But it can only be used for no absorption situations. In this paper an improved algorithm based on BA is presented. The approach adds a Δϕ(x,y) to the phase map ϕ b (x,y) retrieved by BA to make the reconstructed phase map more precise. Further, the approach is evaluated on simulated images and confirmed to be accurate at higher absorption rates.
2 citations
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2 citations
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TL;DR: In this article, an equation is derived for minimizing the aberration itself, instead of the function Ls, and on the basis of the equation the object image distances can be found for which a given lens will exhibit an absolute minimum spherical aberration.
Abstract: Traditional treatments of third‐order spherical aberration of a thin lens express the results in terms of a function Ls, involving a lens shape factor q and an object‐image position factor p. The function Ls is defined in terms of the difference of the reciprocal paraxial and zonal image distances instead of the difference in distances, which is actually the longitudinal spherical aberration. The treatments show that a lens will have minimum spherical aberration for a shape q determined by minimizing Ls relative to q for a given p. In the present work it is shown that the same lens will actually exhibit smaller spherical aberration for values of p<0 determined by minimizing Ls relative to p. An equation is derived for minimizing the aberration itself, instead of the function Ls, and on the basis of the equation the object‐image distances can be found for which a given lens will exhibit an absolute minimum spherical aberration. The results of the analyses are in good agreement with the results of mathemati...
2 citations