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http://dspace.mediu.edu.my:8181/xmlui/handle/10261/5325| Title: | Shift invariant wavelet processing of ultrasonic traces |
| Keywords: | Ultrasonic imaging and detection Signal processing Noise reduction Wavelet processing Discrete Wavelet Transform (DWT) Undecimated Wavelet Transform (UWT) Grain noise Ultrasonic traces |
| Publisher: | Sociedad Española de Acústica |
| Description: | Ponencia presentada en el XIX Congreso Internacional de Acústica (ICA2007), Madrid, 2-7 Sep 2007.-- PACS: 43.60.Hj. Wavelet processing has become a popular and well-established technique that offers good results and great flexibility for noise reduction. The basic wavelet de-noising scheme consists of a thresholding of the Discrete Wavelet Transform (DWT) coefficients. Nevertheless, some improvements over this basic non-linear scheme can be obtained by the use of Undecimated Wavelet Transforms (UWT), also known as redundant, shift-invariant or stationary wavelet transforms, because they provide redundant and translation invariant representations. The introduction of redundancy produces less efficient signal representations but it can be useful in de-noising. Ultrasonic traces are frequently contaminated with structural or grain noise, which can not be removed by classical time averaging or band-pass filtering. An analysis of wavelet de-noising of some individual traces is presented. In addition, a significant number of synthetic ultrasonic signals are also processed for a statistical study and comparison of UWT and DWT de-noising in terms of the signal-to-noise ratio of the resulting traces. This work has been supported by the Spanish MEC, R&D Project CICYT Ref. DPI2005-00124 of the I+D National Plan and grant FPI BES-2004-5296. Peer reviewed |
| URI: | http://dspace.mediu.edu.my:8181/xmlui/handle/10261/5325 |
| Other Identifiers: | XIX Congreso Internacional de Acústica (ICA2007) http://hdl.handle.net/10261/5325 |
| Appears in Collections: | Digital Csic |
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