Wavelet-based blind deconvolution and denoising of ultrasound scans for non-destructive test applications
| dc.contributor.author | Taylor, Jason Richard Benjamin | |
| dc.contributor.examiningcommittee | Hossain, Ekram (Electrical and Computer Engineering) McCurdy, Boyd (Physics & Astronomy) | en_US |
| dc.contributor.supervisor | Thomas, Gabriel (Electrical and Computer Engineering) | en_US |
| dc.date.accessioned | 2012-12-20T15:52:56Z | |
| dc.date.available | 2012-12-20T15:52:56Z | |
| dc.date.issued | 2012-12-20 | |
| dc.degree.discipline | Electrical and Computer Engineering | en_US |
| dc.degree.level | Master of Science (M.Sc.) | en_US |
| dc.description.abstract | A novel technique for blind deconvolution of ultrasound is introduced. Existing deconvolution techniques for ultrasound such as cepstrum-based methods and the work of Adam and Michailovich – based on Discrete Wavelet Transform (DWT) shrinkage of the log-spectrum – exploit the smoothness of the pulse log-spectrum relative to the reflectivity function to estimate the pulse. To reduce the effects of non-stationarity in the ultrasound signal on both the pulse estimation and deconvolution, the log-spectrum is time-localized and represented as the Continuous Wavelet Transform (CWT) log-scalogram in the proposed technique. The pulse CWT coefficients are estimated via DWT shrinkage of the log-scalogram and are then deconvolved by wavelet-domain Wiener filtering. Parameters of the technique are found by heuristic optimization on a training set with various quality metrics: entropy, autocorrelation 6-dB width and fractal dimension. The technique is further enhanced by using different CWT wavelets for estimation and deconvolution, similar to the WienerChop method. | en_US |
| dc.description.note | February 2013 | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/14161 | |
| dc.language.iso | eng | en_US |
| dc.rights | open access | en_US |
| dc.subject | wavelet | en_US |
| dc.subject | ultrasound | en_US |
| dc.subject | deconvolution | en_US |
| dc.subject | denoising | en_US |
| dc.title | Wavelet-based blind deconvolution and denoising of ultrasound scans for non-destructive test applications | en_US |
| dc.type | master thesis | en_US |