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  • 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.
381

Wax distribution quantification using digital image analysis techniques

Saunders, Heath G. 10 November 2009 (has links)
A wax distribution quantification procedure using digital image analysis and fluorescence microscopy techniques was developed. The procedure was evaluated by investigating the effect that variable application rates have on wax distribution. The effect of emulsion type and application on |B strength, thickness swell, water absorption, and linear expansion of flakeboard panels were also investigated. Tests revealed that increasing the wax emulsion flow rate and application pressure had a significant affect on wax coverage. A lower amount of flake surface area was covered when the flow rate and air pressure was increased. It was also found that the presence of resin on the flakes affected wax coverage. Resin presence generally increased the wax coverage variability. The application flow rate and pressure also seemed to affect the interaction present between the resin and wax spots. The fractional coverage area of spot size classes was also significantly affected by the emulsion's application parameters. Increasing the flow rate and air pressure was shown to create more variable wax spot distributions. The presence of resin spots on the flakes was also shown to significantly affect the spot size distribution. Changes in the emulsion flow rate and application air pressure also appeared to have a significant affect on wax spot distribution. The type of wax emulsion used, as well as increased application flow rate and pressure, was shown to significantly affect both 2 hour and 24 hour water absorption (by weight). It was found that using a soap based emulsion improved the water absorption characteristics, and that increasing the emulsion's application flow rate and air pressure adversely affected the water absorption. Differences in IB strength and 24 hour thickness swell were also seen between the panels made using increased flow rate and pressure and the panels produced with standard parameters. However, due to possible influence of press malfunctions on the boards performance, conclusions about the effect of increased parameters can not be clearly drawn. No significant difference in linear expansion was seen for any of the samples tested. / Master of Science
382

Full-field deformation measurement in wood using digital image processing

Agrawal, Chandra Prakash 10 June 2012 (has links)
A digital image processing system was used to non-destructively measure the full-field deformation on aluminum and wood specimens loaded in compression and bending. The measurement technique consisted of creating a random speckle pattern on the specimen surface, recording images before deformation and after deformation, and computing the relative displacements of small image subsets. Two methods for producing speckle patterns on the specimens were studied: spray paint and adhesive-backed photographic film. Baseline tests were conducted to evaluate the influence of signal noise on the measurement system. Uniform translation tests were conducted to evaluate the capability of the system for measuring finite motion. the technique was used to monitor the full-field deformation response of aluminum and wood specimens tested in bending and static compression. Moderate duration compression creep tests were conducted, on the wood specimens to investigate the suitability of the system for monitoring the creep response of materials. The results obtained from the two speckle techniques were also. compared. The results showed that for the magnification and speckle patterns tested displacement measurements smaller than 3.29x10-4 inch may be unreliable due to signal noise. / Master of Science
383

Extending the depth of focus using digital image filtering

Hu, Guang-hua 14 November 2012 (has links)
Two types of image processing methods capable of forming a composite image from a set of image slices which have in-focus as well as out-of-focus segments are discussed. The first type is based on space domain operations and has been discussed in the literature. The second type, to be introduced, is based on the intuitive concept that the spectral energy distribution of a focused object is biased towards lower frequencies after blurring. This approach requires digital image filtering in the spatial frequency domain. A comparison among methods of both types is made using a quantitative uÌ delity criterion. / Master of Science
384

A robust variable order facet model for image data

Mainguy, Yves 22 October 2009 (has links)
The underlying piecewise continuous surface of a digital image can be estimated through robust statistical procedures. This thesis contains a systematic Monte Carlo study of M-estimation and LMS estimation for image surface approximation, an examination of the merits of postprocessing and tuning various parameters in the robust estimation procedures, and a new robust variable order facet model paradigm. Several new goodness of fit measures are introduced, and systematically compared. It is shown that the M-estimation tuning parameters are not crucial, postprocessing is cheap and well worth the cost, and the robust variable order facet model algorithm (using M-estimation, new statistical goodness of fit measures, and postprocessing) manages to retain most of the statistical efficiency of Mestimation yet displays good robustness properties, and preserves the main geometric features of an image surface: step edges, roof edges and corners. / Master of Science
385

Synthesis of 2-D Images From the Wigner Distribution with Applications to Mammography and Edge Extraction

Pettit, Elaine J. (Elaine Joyce) 12 1900 (has links)
A new method for the general application of quadratic spatial/spatial frequency domain filtering to imagery is presented in this dissertation. The major contribution of this research is the development of an original algorithm for approximating the inverse psuedo Wigner distribution through synthesis of an image in the spatial domain which approximates the result of filtering an original image in the DPWD domain.
386

Novel textural features and techniques for image segmentation and classification

Charalampidis, Dimitrios 01 July 2001 (has links)
No description available.
387

Improved data processing techniques for the High Efficiency HyperSpectral Imager (HEHSI)

Arabatti, Anand 01 January 2003 (has links)
No description available.
388

Multistage Filtering for Synthetic Enhancement of Digitized Images

Hartigan, Jean Carolyn 01 January 1990 (has links)
The potential is vast for the enhancement of graphic images that are used for human interpretation and/or image display. Sensor noise, blur due to camera misfocus, relative object-camera motion, and random atmospheric turbulence may contribute to photographic image deterioration. Image enhancement and restoration methods are useful for improving the quality and for augmenting specific characteristics of an image. Often, complex filtering of the image data is required. This paper presents a technique for enhancement of images using multistage filtering techniques which take advantage of a priori knowledge as to the images' content. Algorithms are designed and implemented which enhance edges as well as gray level contrast. In addition, the source images are passed through a sequence of controllable filter stages to provide varying degrees and types of enhancements. Image enhancement techniques do not increase the inherent information content in the data, but the techniques do accentuate distinct image features which result in an improved image display. The effects of the different filters and filter stages will be analyzed with regard to image enhancement and picture quality. Numerical results and graphic image results are included in the analysis. Further applications of the techniques analyzed are discussed as well.
389

A framework for the design of event detectors

Haering, Niels 01 January 1999 (has links)
No description available.
390

A flexible and efficient image retrieval system

Vu, Khanh 01 April 2002 (has links)
No description available.

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