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Presentation Information     2011-02-09 (15:15)   •  The seminar room at Vi2

Speaker Ulf Hammarqvist
Type Master thesis presentation
Title Audio editing it the time-frequancy domain using the Gabor Wavelet transform
Abstract Modifying the coefficients of a time-frequency representation of a signal is analogous to creating a time variable filter. The focus here is on the Gabor Wavelet Transform and the scalogram and problems that surround such an editing environment. Reconstruction properties were looked at - a flaw of the Gabor Wavelet is mentioned and the Loglet is proposed as a replacement. A down-sample procedure was developed for computing the coefficients faster. A method interpolating long gaps in audio signals was developed and listening tests suggest the method works well. The feasibility of doing pitch shift by phase vocoding was also tested, but the performance does not warrant the computational cost. Methods to 'sharpen' the scalogram was tested, based of the ideas of re-assignment a simple yet effective weighting function is proposed.