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You searched for +publisher:"McMaster University" +contributor:("Shahram, Shirani"). Showing records 1 – 2 of 2 total matches.

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McMaster University

1. Kinsner, Michael. Close-range Machine Vision for Gridded Surface Measurement.

Degree: PhD, 2011, McMaster University

Accurate measurement of surface grids through imaging enables a variety of applications. One important example can be found in automotive manufacturing, where deformed sheet metal surface strains must be validated in safety critical regions, and rapidly measured to correct process variations. This thesis advances machine vision techniques in the context of close-range surface imaging and measurement. Sheet metal surface strain analysis provides a motivating application, but the contributions may be directly transferred to a variety of other machine vision applications where reliable, accurate measurements are required in adverse imaging conditions. Close-range imaging in practical environments presents a number of challenges, primarily relating to depth of field blur and the regional field of view. This thesis contributes to three major components required for close-range optically-based surface measurement. First, an approach for grid line intersection measurement in the presence of significant and varying depth-of-field blur is considered, with a solution based on scale-space ridge extraction. An architecture for acceleration of the computationally intensive algorithm is then developed, and implemented using state of the art graphics (GPU) hardware. Acceleration to camera video frame rates is achieved. The second contribution is a novel approach for interframe motion tracking of uniform gridded surfaces. The algorithm exploits topological structure of the imaged grid pattern, thereby reducing dimensionality of the interframe tracking problem. Intrinsic fiducial measurement is proposed to avoid the need for explicit feature detectors that locate fiducials in the presence of varying size and blur. Close-range interframe tracking is demonstrated, and statistics are presented on the registration objective function. Finally, an approach is considered for camera and hand-eye calibration of a monocular camera mounted to the tool point of a coordinate measuring machine (CMM). Pre-processing algorithms are contributed to prepare close-range gridded image data for the calibration process. Ideal model coordinate points are coherently assigned to detected grid features across video sequences, and grid approximation is performed for highly blurred image frames where reliable features have not been extracted. The contributions of this thesis make significant progress toward enabling video frame rate, close-range, computer vision-based sheet metal surface strain analysis, and other applications where challenging image conditions impede measurement.

Doctor of Philosophy (PhD)

Advisors/Committee Members: Capson, David, Spence, Allan, Nicola Nicolici, Shahram Shirani, Electrical and Computer Engineering.

Subjects/Keywords: Computer vision; machine vision; grid measurement; grid tracking; Other Computer Engineering; Other Computer Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kinsner, M. (2011). Close-range Machine Vision for Gridded Surface Measurement. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/11075

Chicago Manual of Style (16th Edition):

Kinsner, Michael. “Close-range Machine Vision for Gridded Surface Measurement.” 2011. Doctoral Dissertation, McMaster University. Accessed February 27, 2020. http://hdl.handle.net/11375/11075.

MLA Handbook (7th Edition):

Kinsner, Michael. “Close-range Machine Vision for Gridded Surface Measurement.” 2011. Web. 27 Feb 2020.

Vancouver:

Kinsner M. Close-range Machine Vision for Gridded Surface Measurement. [Internet] [Doctoral dissertation]. McMaster University; 2011. [cited 2020 Feb 27]. Available from: http://hdl.handle.net/11375/11075.

Council of Science Editors:

Kinsner M. Close-range Machine Vision for Gridded Surface Measurement. [Doctoral Dissertation]. McMaster University; 2011. Available from: http://hdl.handle.net/11375/11075


McMaster University

2. Faramarzpour, Naser. CMOS Photodetectors for Low-Light-Level Imaging Applications.

Degree: PhD, 2008, McMaster University

Weak optical signals have to be measured in different fields of sciences including chemistry and biology. For example, very low levels of fluorescence emission should be detected from the spots on a DNA microarray that correspond to weakly expressed genes. High sensitivity charge-coupled devices (CCDs) are used in these applications. CCDs require special fabrication and are difficult to integrate with other circuits. CMOS is the technology used for fabrication of CPUs and other widely used digital components. CMOS is not optimized for light detection. CMOS circuits are however cheap, low power and can integrate several components. Active pixel sensor (APS) is the most common pixel structure for CMOS photodetector arrays. In this work we provide an accurate analysis of the APS signal using new models for the capacitance of the photodiode. We also provide a complete noise analysis of the pixel to calculate the SNR of the pixel and provide optimum operation points. We propose a new mode of operation for APS that can achieve at least l 0 dB higher SNR, than conventional APS, at light levels of less than 1 μW/cm2. We fabricated several APS pixels in CMOS 0.18 μm technology and measured them to confirm the proposed analyzes. There are applications like fluorescence lifetime imaging that require both sensitivity and fast response. Photomultiplier tubes (PMTs) are commonly used in these applications to detect single photons in pico- to nano-seconds regime. PMTs are bulky and require high voltage levels. Avalanche photodiodes (APDs) are the semiconductor equivalent of PMTs. We have fabricated different APDs along with different peripheral circuitries in CMOS 0.18 μm technology. Our APDs have a 5.5 percent peak probability of detection of a photon at an excess bias of 2 V, and a 30 ns dead time, which is less than the previously reported results. The low price of CMOS makes modem diagnosis devices more available. The low power of CMOS leads to battery-driven hand-held imaging solutions, and its high integration leads to miniaturized imaging and diagnosis systems. A low-light-level CMOS imager paves the way for the future generation of biomedical diagnosis solutions.

Thesis

Doctor of Philosophy (PhD)

Advisors/Committee Members: Deen, M. Jamal, Shahram, Shirani, Electrical and Computer Engineering.

Subjects/Keywords: weak optical signals; light detection; CMOS; Active pixel sensor; biomedical diagnosis devices

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Faramarzpour, N. (2008). CMOS Photodetectors for Low-Light-Level Imaging Applications. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/16726

Chicago Manual of Style (16th Edition):

Faramarzpour, Naser. “CMOS Photodetectors for Low-Light-Level Imaging Applications.” 2008. Doctoral Dissertation, McMaster University. Accessed February 27, 2020. http://hdl.handle.net/11375/16726.

MLA Handbook (7th Edition):

Faramarzpour, Naser. “CMOS Photodetectors for Low-Light-Level Imaging Applications.” 2008. Web. 27 Feb 2020.

Vancouver:

Faramarzpour N. CMOS Photodetectors for Low-Light-Level Imaging Applications. [Internet] [Doctoral dissertation]. McMaster University; 2008. [cited 2020 Feb 27]. Available from: http://hdl.handle.net/11375/16726.

Council of Science Editors:

Faramarzpour N. CMOS Photodetectors for Low-Light-Level Imaging Applications. [Doctoral Dissertation]. McMaster University; 2008. Available from: http://hdl.handle.net/11375/16726

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