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.
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Showing 1 to 20 of 32 for “"modulation transfer function"”.
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Modulation transfer function and the role of focal length of a photogrammetric camera in image generation.
… in image generation through the criterion of Modulation Transfer Function. A comparative study is made of the MTF obtained from two lens cones under various aperture settings, detail size and light conditions. This includes an analysis by graphical methods.
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Modulation transfer function measurements, image quality metrics, and subjective image quality for soft-copy color images
… in several prominent image quality metrics. The Modulation Transfer Function Area (M1F A), the Square Root Integral (SQRI), the Integrated Contrast Sensitivity (ICS), the Subjective Quality Factor (SQF), and several other acutance-derived image quality metrics were evaluated for their ability to …
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The direct measurement of system Modulation Transfer Function (MTF) for an AN/AVS-6 Aviator's Night Vision Imaging System (ANVIS)
… response of these systems has been ignored. Modulation Transfer Function (MTF) performance specifications have been extensively researched for the components of night vision imaging systems such as the lenses and the image intensifier tube. The current method for calculating the system MTF is …
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Design of a dynamic calibration phantom to be used to calculate the temporal resolution of a tomographic imaging device
… imaging device exists. Analogous to the spatial modulation transfer function used for characterizing spatial resolution, the concept of temporal Modulation Transfer Function (t-MTF) can be used to enable characterization of temporal resolution. A scanner's t-MTF represents the percent amplitude …
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An image quality analysis of ANVIS-6 night vision goggles
… tasks. The image quality metrics examined Modulation Transfer Function Area (MTFA), Integrated Contrast Sensitivity (leS), Square Root Integral (SQRI), Resolution, and Signal-to-Noise Ratio (SNR). The performance tasks were detection and recognition of targets under various levels of moon …
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Characterizing the perceived quality degradation of still-camera motion blur
… (blur size, Subjective Quality Factor, SQF; Modulation Transfer Function ,Area, MTFA; and Equivalent Passband, Ne), derived analytically from the motion data, were used as dependent measures for statistical analysis. All three modulation-transfer-function (MTF)-based analytic quality metrics …
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Accurate characterization of nanophotonic grating structures
… measuring the resolution of the device using a Modulation Transfer Function, MTF, technique. MTF is commonly measured using either the line pair method or the slant edge method. This thesis proposes a new method to measure MTF using single pixel illumination and point spread function. Results …
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The effects of raster structure suppression on visual thresholds, target acquisition performance, and image quality
… raster structure suppression on visual sine wave modulation thresholds and dynamic target acquisition performance using normal and noise degraded imagery. Results indicate raster structure suppression and improvements in Sine wave threshold sensitivity are correlated and that a suppressed raster …
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The development of a predictive autofocus algorithm using a general image formation model
… resolution analysis. The model is based on the modulation transfer function of the imaging system in the presence of aberrations, in particular defocus. The extension of the model to include astigmatism is also included. The signals used are related to the ratios of the Fourier transforms of …
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Design and optimization of imaging systems by engineering the pupil function
… a particular purpose is to engineer the pupil function of the imaging system. This includes designing a pupil surface and often involves the simultaneous design of a post-processing algorithm. Currently these design processes are performed mostly by using numerical optimization methods. …
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Application of a High‑Resolution Computed Radiography System in Detecting an Iodinated X‑ray Contrast Agent: Small Animal Phantom Study
… of CR image quality by measuring presampled Modulation Transfer Function (MTF), Noise Power Spectrum (NPS), Relative Standard Deviation of Noise (RSD), Noise Equivalent Quanta (NEQ), and Detective Quantum Efficiency (DQE).</p> <p>Next, dual‑energy and temporal subtraction techniques were …
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A study of CMOS technologies for image sensor applications
… achievable optical lens resolution. Using the modulation transfer function (MTF) as an index, optical simulations are performed to examine the relation between the lens resolution and the lens complexity.
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Quantification of the Depth-of-Field in a Self-Aligned Focusing Schlieren System
… using a Fourier optics framework based on the modulation transfer function (MTF) and point spread function (PSF). Depth-dependent MTF measurements from a slanted-edge target and PSF measurements from a 100 µm pinhole target show that the depth response of the SAFS system changes gradually with …
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Theoretical and Experimental Evaluation of Spatial Resolution in a Variable Resolution X-Ray Computed Tomography Scanner
… described by the detector presampling modulation transfer function (MTF), and the post-reconstruction spatial resolution, given by the scanner reconstruction MTF. The detector presampling MTF was modeled by the Monte Carlo simulation and measured by the moving-slit method. The modeled …
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Quantitative Automated Object Wave Restoration in High-Resolution Electron Microscopy
… relied on the unjustified assumption that the Modulation Transfer Function (MTF) also correctly describes the spatial frequency dependent attenuation of the electron shot noise. A new theory is therefore presented that distinguishes between signal and noise transfer. This facilitates the …
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Acoustic models of consonant recognition in cochlear implant users
… with acoustic measurements of the temporal modulation transfer function of the processor, which showed almost no change across stimulation rates.
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Prediction of modulation detectability thresholds for line-scan displays
Determination of some form of modulation detectability threshold for sinusoidal gratings is a prerequisite to use of most measures of image quality for line-scan imaging systems. To develop predictive models for these thresholds, an experiment was conducted to determine the modulation detectability …
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An experimental determination of the effects of image quality on eye movements and search for static and dynamic targets
… Of the metrics that have been developed, the Modulation Transfer Factor Area (MTFA) has proven to be a useful predictor of observer performance. The MTFA metric takes into account the system's Modulation Transfer Function and observer threshold curves. Two experiments were performed to assess …
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Effects of field of view, MTF shape, and noise upon the perception of image quality and motion
… provides some additional model parameters to the Modulation Transfer Function Area (MTFA). However, based upon the studies that were conducted in this dissertation, it appears that the Integrated Contrast Sensitivity (ICS) and Square Root Integral (SQRI) provide significantly better estimates of …
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