Journal ArticleDOI
A method to increase the depth of focus by two step image processing
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TLDR
The method to obtain an increased depth of field consists of producing a modified incoherent image of the three dimensional object which, though degraded, has the same degradation for all object planes.About:
This article is published in Optics Communications.The article was published on 1972-09-01. It has received 207 citations till now. The article focuses on the topics: Image processing & Depth map.read more
Citations
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Journal ArticleDOI
Extended depth of field through wave-front coding
TL;DR: An optical-digital system that delivers near-diffraction-limited imaging performance with a large depth of field that is the standard incoherent optical system modified by a phase mask with digital processing of the resulting intermediate image.
Journal ArticleDOI
New paradigm for imaging systems
TL;DR: In this article, the authors describe a new paradigm for designing hybrid imaging systems, which is termed wave-front coding, which allows the manufacturing tolerance to be reduced, focus-related aberrations to be controlled, and imaging systems to be constructed with only one optical element plus some signal processing.
Patent
Extended depth of field optical systems
W. T. Cathey,Edward R. Dowski +1 more
TL;DR: In this paper, a special purpose optical mask was designed to cause the optical transfer function to remain essentially constant within some range from the in-focus position, resulting in an infocus image over an increased depth of field.
Journal ArticleDOI
Extended focused image in microscopy by digital Holography.
Pietro Ferraro,Simonetta Grilli,Domenico Alfieri,Sergio De Nicola,Andrea Finizio,Giovanni Pierattini,Bahram Javidi,Giuseppe Coppola,V. Striano +8 more
TL;DR: It is demonstrated that an extended focused image of an object can be obtained through digital holography without any mechanical scanning or special optical components.
Journal ArticleDOI
Production of high current particle beams by low pressure spark discharges
J. Christiansen,Ch. Schultheiss +1 more
TL;DR: In this paper, a new type of particle accelerator was developed based on low pressure spark discharges, which produces pulsed ion as well as electron beams of high intensities in a gas atmosphere at pressures of the order of 1 mbar.
References
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Journal ArticleDOI
The Frequency Response of a Defocused Optical System
TL;DR: In this paper, the response of a defocused aberration-free optical system to line-frequencies in the object is studied analytically, and curves are given showing the response as a function of line-frequency for a range of values of defect of focus.
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Properties of a Defocused Optical System
TL;DR: In this article, the exact diffraction optical transfer function (OTF) and point spread function (PSF) are compared to the geometrical OTF and PSF, respectively, for both small and large amounts of defocusing.
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Use of Annular Apertures to Increase Focal Depth
TL;DR: In this paper, a theoretical study of the possibilities of using an annular aperture to increase the focal depth of a photographic objective is made and it is shown that for a given gain in focal depth the loss in speed is the same for both annular apertures and conventional stopping down.
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Improvement in the OTF of a Defocused Optical System Through the Use of Shaded Apertures.
TL;DR: To improve the imaging properties of a defocused optical system, the use of shaded apertures is studied theoretically and experimentally and shows that near focus the OTF for T(A) has higher values in the low frequency region than has either T(B) or T(c).
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La Diffusion Résiduelle des Surfaces Polies et des Réseaux
TL;DR: In this article, the authors describe a set of developpements theoriques, les verifications experimentales devant etre publiees aussitot qu'elles seront completes, and the cases des defauts desordonnes de mise en place des traits des reseaux.