• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 85
  • 24
  • 10
  • 8
  • 8
  • 8
  • 8
  • 8
  • 8
  • 2
  • Tagged with
  • 133
  • 133
  • 133
  • 33
  • 27
  • 19
  • 18
  • 16
  • 15
  • 15
  • 13
  • 13
  • 12
  • 10
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

PHOTOGRAPHIC GRAIN NOISE SUPPRESSION BY DENSITY QUANTIZATION: ITS INFLUENCE ON IMAGE QUALITY

Hoffman, Robert Stocking, 1944- 12 1900 (has links)
QC 351 A7 no. 85 / A technique is described for suppressing unwanted grain noise in scanned and digitized photographic images. The technique employs the rms granularity statistics of the film to divide, or quantize, the density range of the digital image into distinguishable ranges of density. For Eastman Kodak type 3414 film, the rms granularity statistics determined indicate constant Selwyn granularity for the range of scanning spot diameters from approximately 16 to 4 micrometers, and this result agrees with Kodak data for a 48 micrometer diameter spot. For spots from 16 to 4 micrometers diameter, the rms granularity is also determined to be a function of the square root of diffuse density. The number of distinguishable density levels, required to sup- press the grain noise of the digitally processed image, is found to be directly related to the scanning spot diameter. Finally, evaluation of the resulting digitally processed images indicates that subjective image quality is directly related to the spatial resolution of the image. That is, with the grain noise suppressed, subjective quality is improved by scanning the original image with a smaller diameter spot.
32

Spectrogram generation with a minicomputer and a graphics terminal

Sauder, Ronald Dale January 2010 (has links)
Typescript, etc. / Digitized by Kansas Correctional Industries
33

A Fourier method for image reconstruction using projection data

Parikh, Dakshesh D January 2011 (has links)
Digitized by Kansas Correctional Industries
34

All-optical switching and variable delay using nonlinear optical signal processing techniques.

January 2008 (has links)
Cheng, Lap Kei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / ABSTRACT --- p.I / 摘要 --- p.II / ACKNOWLEDGEMENTS --- p.V / TABLE OF CONTENTS --- p.IV / INTRODUCTION --- p.0 / Chapter 1.1 --- Different ways to achieve all-optical tunable delay --- p.2 / Chapter 1.1.1 --- Optical buffer realized with optical switching --- p.2 / Chapter 1.1.2 --- Slow light technique --- p.3 / Chapter (i) --- Basics of slow light --- p.4 / Chapter (ii) --- Slow light via electromagnetically induced transparency (EIT) --- p.6 / Chapter (iii) --- Slow light via coherent population oscillation (CPO) --- p.7 / Chapter (iv) --- Slow light via optical parametric amplification (OPA) --- p.8 / Chapter (v) --- Slow light via stimulated Raman and Brillouin scattering --- p.8 / Chapter 1.1.3 --- Tunable delay using wavelength conversion together with chromatic dispersion --- p.10 / Chapter 1.1.4 --- Comparison of different schemes for constructing all-optical delay line --- p.11 / Chapter 1.2 --- Overview of the thesis --- p.12 / References --- p.14 / ALL-OPTICAL SWITCHING OF DPSK SIGNAL IN AN SOA USING NONLINEAR POLARIZATION ROTATION --- p.18 / Chapter 2.1 --- Introduction --- p.19 / Chapter 2.2 --- Birefringence and nonlinear polarization rotation --- p.20 / Chapter 2.3 --- Differential-phase-shift keying (DPSK) modulation format --- p.22 / Chapter 2.4 --- Experimental setup --- p.23 / Chapter 2.5 --- Experimental results --- p.25 / Chapter 2.6 --- Conclusion --- p.29 / References --- p.30 / WIDEBAND SLOW LIGHT VIA STIMULATED BRILLOUIN SCATTERING IN AN OPTICAL FIBER USING A PHASE-MODULATED PUMP --- p.32 / Chapter 3.1 --- Introduction --- p.33 / Chapter 3.2 --- Stimulated Brillouin scattering (SBS) --- p.34 / Chapter 3.3 --- Slow light via SBS --- p.35 / Chapter 3.4 --- Experimental setup --- p.37 / Chapter 3.5 --- Experimental result --- p.39 / Conclusion --- p.42 / References --- p.43 / SIGNAL WAVELENGTH TRANSPARENT SBS SLOW LIGHT USING XGM BASED WAVELENGTH CONVERTER AND BRILLOUIN FIBER LASER --- p.45 / Chapter 4.1 --- Introduction --- p.46 / Chapter 4.2 --- Brillouin fiber laser and XGM wavelength converter --- p.47 / Chapter 4.3 --- Operating principle --- p.50 / Chapter 4.4 --- Experimental setup and results --- p.51 / Conclusion --- p.56 / References --- p.57 / ALL-OPTICAL TUNABLE DELAY LINE FOR CHANNEL SELECTION IN A 40-GB/S OPTICAL TIME DIVISION MULTIPLEXING SYSTEM --- p.59 / Chapter 5.1 --- Introduction --- p.60 / Chapter 5.2 --- Principle of four-wave mixing --- p.61 / Chapter 5.3 --- Channel selection in an OTDM system --- p.63 / Chapter 5.4 --- Experimental setup --- p.64 / Chapter 5.5 --- Experimental results --- p.67 / Conclusion --- p.70 / References --- p.71 / TUNABLE OPTICAL DELAY WITH CSRZ-OOK TO RZ-OOK OPTICAL DATA FORMAT CONVERSION USING FOUR-WAVE MIXING WAVELENGTH CONVERSION AND GROUP VELOCITY DISPERSION --- p.73 / Chapter 6.1 --- Introduction --- p.74 / Chapter 6.2 --- Carrier-Suppressed Return-to-Zero --- p.76 / Chapter 6.3 --- Operating Principle --- p.77 / Chapter 6.4 --- Experimental setup --- p.79 / Chapter 6.5 --- Experimental result --- p.81 / Conclusion --- p.86 / References --- p.87 / CONCLUSION --- p.90 / Chapter 7.1 --- Summary of work --- p.90 / Chapter 7.2 --- Prospects of future work --- p.92 / APPENDIX: LIST OF PUBLICATIONS A
35

Depth-based object segmentation and tracking from multi-view video. / 基于深度的多视角视频物体分割与追踪 / CUHK electronic theses & dissertations collection / Ji yu shen du de duo shi jiao shi pin wu ti fen ge yu zhui zong

January 2011 (has links)
Zhang, Qian. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 97-111). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
36

Optimizing inspection of high aspect ratio microstructure using a programmable optical microscope

Ceremuga, Joseph Thomas, II 01 December 2003 (has links)
No description available.
37

Firefly web-based interactive tool for the visualization and validation of image processing algorithms /

Beard, Daniel, Palaniappan, K. January 2009 (has links)
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on December 21, 2009. Thesis advisor: Dr. Kannappan Palaniappan. Includes bibliographical references.
38

Optimizing inspection of high aspect ratio microstructure using a programmable optical microscope

Ceremuga, Joseph Thomas, January 2003 (has links) (PDF)
Thesis (M.S. in M.E.)--School of Mechanical Engineering, Georgia Institute of Technology, 2004. Directed by Thomas R. Kurfess. / Includes bibliographical references (leaves 110-112).
39

Multidimensional data encryption with virtual optics /

Yu, Lingfeng. January 2003 (has links)
Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.
40

Discovery and representation of human strategies for visual search

Tavassoli, Abtine, 1978- 29 August 2008 (has links)
Visual search can simply be defined as the task of looking for an object of interest in a visual environment. Due to its foveated nature, the human visual system succeeds at such task by making many discrete fixations linked by rapid eye movements called saccades. However, very little is known about how saccadic targets (fixation loci) are selected by the brain in such naturalistic tasks. Discoveries to be made are not only invaluable to the field of vision science but are very important in designing automated vision systems, which to this day lag in performance vis-à-vis human observers. What I have sought to accomplish in this dissertation has been to reveal previously unknown saccadic targeting and target selection strategies used by human observers in naturalistic visual search tasks. My driving goal has been to understand how the brain selects fixation loci and target candidates upon fixation, with the objective of using these findings for automated fixation selection algorithms employed for visual search. I have proposed a novel and efficient technique akin to psychophysical reverse correlation to study human observer strategies in locating low-contrast targets under a variety of experimental conditions. My technique has successfully been used to study saccadic programming and target selection in various experimental conditions, including visual searches for targets with known characteristics, targets whose orientation attributes are not known a priori, and targets containing multiple orientations. I have found visual guidance in saccadic targeting and target selection under all experimental conditions, revealed by observers' selectivity for spatial frequencies and/or orientations of stimuli close to that of the target. I have shown that under uncertainty, observers rely on known target characteristics to direct their saccades and to select target candidates upon foveal scrutiny. Moreover, I have demonstrated that multiple orientation characteristics of targets are represented in observer search strategies, modulated by their sensitivity / selectivity for each orientation. Some of my findings have been applied towards applications for automated visual search algorithms.

Page generated in 0.1498 seconds