Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 43 for “"depth-of-field"”.
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Automatic 2D-to-3D conversion of single low depth-of-field images
… a novel approach to the automatic rendering of 3D stereoscopic disparity image pairs from single 2D low depth-of-field (LDOF) images. Initially a depth map is produced through the assignment of depth to every delineated object and region in the image. Subsequently the left and right disparity …
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Quantification of the Depth-of-Field in a Self-Aligned Focusing Schlieren System
… future volumetric and quantitative measurements of three-dimensional compressible flows. Conventional schlieren imaging provides valuable visualization of density gradients, but it records only a line-of-sight projection and therefore does not directly resolve the spatial distribution of …
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Software simulation of depth of field effects in video from small aperture cameras
… digital video to introduce a simulated depth of field effect. Because the technique is implemented in software, it affords the user greater control over the parameters of the effect (such as the amount of defocus, aperture shape, and defocus plane) and allows the effect to be used even …
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An optical/digital incoherent image processing system for an extended depth of field
… an annular aperture in an optical system, the depth of focus can be extended. Isolated zeros in the OTF can therefore be avoided by choosing an annular aperture with a proper radius ratio. However, in the process of increasing the depth of focus of the system, this method results in a loss of …
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Application of Defocusing Technique to Bubble Depth Measurement
… a defocusing technique to extract bubble depth information. Typically, when a bubble is out of focus in an image, the bubble is ignored by applying a filter or thresholding. However, it is known that a bubble image becomes blurred as the bubble moves away from the focal plane. Then, this …
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Four-Dimensional Coherence Sensing
… focal plane arrays have made new combinations of optical sensing and digital processing possible. Using the framework of optical spatial coherence theory, this thesis proposes and investigates new combinations of optics and algorithms with capabilities not possessed by standard lens-based …
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Hardware accelerated computer graphics algorithms
The advent of shaders in the latest generations of graphics hardware, which has made consumer level graphics hardware partially programmable, makes now an ideal time to investigate new graphical techniques and algorithms as well as attempting to improve upon existing ones. This work looks at areas …
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GHOST IMAGE ANALYSIS FOR OPTICAL SYSTEMS
Ghost images are caused by the inter-reflections of light from optical surfaces that have transmittances less than unity. Ghosts can reduce contrast, provide misleading information, and if severe can veil parts of the nominal image. This dissertation develops several methodologies to simulate ghost …
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Digital Hologram Image Processing
… examine the contributions we have made to the field of digital hologram image processing. In particular, we will deal with the processing of numerical reconstructions of real-world three-dimensional macroscopic objects recorded by in-line digital holography. Our selection of in-line digital …
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Extended Depth-of-focus in a Laser Scanning System Employing a Synthesized Difference-of-Gaussians Pupil
… used for microscopy, typically image objects of finite thickness. If the depth-of-focus of such systems is low, as is the case when a simple clear pupil is used, the object must be very thin or the image will be distorted. Several methods have been developed to deal with this problem. A …
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Three-Dimensional Single-Molecule Localisation Microscopy and Visualisation Techniques
… understand the morphology and stoichiometry of proteins below the diffraction limit. 3 Dimensional (3D) SR tools such as the 3D double helix-point spread function (DH-PSF) and 3D single-molecule light field microscopy (SMLFM) are techniques which have an increased depth of field (4 µm and 8 …
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Developing a flexible range sensing system for industrial inspection applications
This thesis describes the development of a range sensing system. The goal was to create a range sensor that is robust and flexible so that a number of applications within the forest products manufacturing environment can be addressed. Features of the system include: the capability of producing …
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Image enhancement methods and applications in computational photography
… optics, image sensors and image processing fields to go beyond the limitations of traditional photography. The innovations of computational photography allow the photographer not only merely to take an image, but also, more importantly, to perform computations on the captured image data. …
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Volumetric Imaging Across Spatiotemporal Scales in Biology with Fluorescence Microscopy
Quantitative three dimensional maps of cellular structure, activity and function provide the key to answering many prevalent questions in modern biological research. Fluorescence microscopy has emerged as an indispensable tool in generating such maps, but common techniques are limited by …
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Three-Dimensional Imaging using a Novel Rotating Point Spread Function Imager
… the imaging community. To be able to extend the depth-of-field while simultaneously encoding depth in the point spread function (PSF) itself allows an imaging solution which is less time consuming and less data intensive than the inefficient multiscan based conventional 3D imaging. Light-field …
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Multi-view image refocusing
… To achieve the focusing job, it requires shallow depth of field to create a focus-defocus scene, which depends on larger size of lens aperture. In our project, we simulate a larger camera lens aperture by using several photos taken from slightly different viewpoints. Based on these images, a layer …
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Development of High-Speed Camera Techniques for Droplet Measurement in Annular Flows
… precise two-phase flow data in the development of computer simulation models, with a specific focus on the annular flow regime's droplet behavior. The study aims to contribute to the evaluation of safety and efficiency in nuclear reactors that handle fluids transitioning between liquid and gas …
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Characterization of Amorphous Carbon Films for Mask Protection during Ion Beam Bombardment
The field of lithography is in simplest terms the use of a beam, incident on a mask, to transfer the mask pattern onto the substrate. This process is utilized by every semiconductor company to create the microchips, which make modern life possible. Though photons are the industry standard, atom/ion …
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Depth map recovery from videos
The depth map of a video is a very important piece of information. Recovering the depth map of a video expands a 2D video into its 3rd dimension, and creates new possibilities, such as, object insertion, conversion to 3D, shallow depth of field simulation. In this work, we introduce our approach of …
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