Results 231 to 240 of about 1,598,929 (274)
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Extended depth of field through wave-front coding
Applied Optics, 1995We designed an optical-digital system that delivers near-diffraction-limited imaging performance with a large depth of field. This system is the standard incoherent optical system modified by a phase mask with digital processing of the resulting intermediate image. The phase mask alters or codes the received incoherent wave front in such a way that the
E R, Dowski, W T, Cathey
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Extended depth of field through an axicon
Journal of Modern Optics, 2009One of the main disadvantages of imaging systems is the limited depth of field. We present the ability of a refractive axicon for imaging with an extended depth of field. We design an imaging system with a two-step imaging approach that uses a CCD camera to capture intermediate images and uses a digital process to obtain the final images.
Zhongsheng Zhai +4 more
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The Light Field Camera: Extended Depth of Field, Aliasing, and Superresolution
IEEE Transactions on Pattern Analysis and Machine Intelligence, 2012Portable light field (LF) cameras have demonstrated capabilities beyond conventional cameras. In a single snapshot, they enable digital image refocusing and 3D reconstruction. We show that they obtain a larger depth of field but maintain the ability to reconstruct detail at high resolution.
Tom E, Bishop, Paolo, Favaro
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Extended depth-of-field microscopy
SPIE Proceedings, 2010In this paper, we present details of a scanning two-photon fluorescence microscope we have built with a nearisotropic scan rate. This means that the focal spot can be scanned at high speed along any direction in the specimen, without introducing systematic aberrations.
Christopher Smith +4 more
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Extended depth of field by colored apodization
Optics Letters, 2011We describe an approach to achieving extended depth of field for a camera system based on reducing the aperture of the blue channel of a three-color camera by apodizing the lens with a yellow-colored filter. The resulting improvement in depth of field for the blue channel allows red and green channels to be digitally postprocessed for improved ...
Andrew, Kay +2 more
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Image processing for extended depth of field
Applied Optics, 1983Improvement in the depth of field is demonstrated by properly processing a succession of image samples. Due to the limited depth of field each image sample has in-focus as well as out-of-focus segments. By setting criteria for selecting the in-focus segments, an improved composite image is formed. Three algorithms for implementing this construction are
R J, Pieper, A, Korpel
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Extended Depth of Field in Microscope
Optics in the Life Sciences, 2013A cubic phase mask is used in an infinity microscope objective to extend depth of field. The mask is placed between the objective and tube lens, so that neither objective nor tube lens needs redesigning.
Tingyu Zhao, Guoqiang Li
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Multiple-frame photography for extended depth of field
Applied Optics, 2013For extending the depth of field, we analyze the result of superimposing several snapshots, which are taken while changing the amount of focus error, at full pupil aperture. We unveil the use of a varifocal lens for controlling the amount of focus error, without modifying either the lateral magnification or light throughput.
Jorge, Ojeda-Castañeda +2 more
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Digitized optical microscopy with extended depth of field
Applied Optics, 1989Partial information about a 3-D object, such as a stereoscopic pair of projections, is sometimes more desirable than the whole 3-D information. We demonstrate how to (1) synthesize a clear projection of a small complex object from a succession of digitized images obtained by moving the object stepwise through the focal plane, (2) synthesize a clear ...
K, Itoh, A, Hayashi, Y, Ichioka
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Asymmetric phase masks for extended depth of field
Applied Optics, 2004We present a family of asymmetric phase masks that extends the depth of field of an optical system. To verify our proposal, we compute several modulation transfer functions with focus errors, and we report numerical simulations of the images that can be achieved by use of our proposed procedure.
Albertina, Castro +1 more
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