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Restoration of degraded audiosignals using sparse representations
Mokrý, Ondřej ; Veselý, Vítězslav (referee) ; Rajmic, Pavel (advisor)
This bachelor thesis is focused on the problem of inpainting a segment of missing samples in an audiosignal. The signal is represented as sparse vector using discrete Gabor transform. The problem of inpainting missing samples while preserving the sparsity of the representation is formulated as an optimisation task, which is then solved using Douglas-Rachford algorithm. In contrast with the state-of-the-art approaches, the algorithm is extended by proposing method for compensating the energy decrease which occurs in the restored signal.
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Restoration of missing audio signal samples using a psychoacoustic model
Švento, Michal ; Záviška, Pavel (referee) ; Mokrý, Ondřej (advisor)
This bachelor thesis deals with the reconstruction of short-time damaged audio signal. The signal is represented by sparse signal representation using discrete Gabor transform. Convex optimalization tools are used for the reconstruction. The optimalization problem is solved using the Douglas—Rachford and Chambolle—Pock algorithm. Psychoacoustic model is involved in algorithm to obtain better results in objective metrics. The comparison is realised by an objective method SDR, PEMO-Q and also subjectively.
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Application of the Hermite basis for spectral analysis
Mihálik, Ondrej ; Tůma, Martin (referee) ; Jura, Pavel (advisor)
The work is concerned with an application of the Hermite functions in signal approximation. The purpose of the work is to show their properties in time and frequency domains, namely their orthogonality, Fourier transform, zeros and asymptotic behaviour as their order becomes high. The next subject of this work is the question of scaling these functions to minimize the square error of signal approximation. Several methods proposed by different authors are discussed. Finally these algorithms are tested by approximating simple signals so that their results can be compared.
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Gabor transform for heart rate variability analysis
Omastová, Martina ; Klimek, Martin (referee) ; Janoušek, Oto (advisor)
This bachelor thesis focuses on the problem of measurement of heart rate variability. Heart rate variability (HRV) is an oscillation in the interval between consecutive heartbeats. It can be analysed by several methods, but in this work was used method analysis in time domain and Gabor transform. There were evaluated changes in HRV caused by global ischemia by both methods and reveal differences between the two methods. The methods were compared. In the conclusion was evaluated which method is more suitable for analysis of HRV.
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Restoration of missing audio signal samples using a psychoacoustic model
Švento, Michal ; Záviška, Pavel (referee) ; Mokrý, Ondřej (advisor)
This bachelor thesis deals with the reconstruction of short-time damaged audio signal. The signal is represented by sparse signal representation using discrete Gabor transform. Convex optimalization tools are used for the reconstruction. The optimalization problem is solved using the Douglas—Rachford and Chambolle—Pock algorithm. Psychoacoustic model is involved in algorithm to obtain better results in objective metrics. The comparison is realised by an objective method SDR, PEMO-Q and also subjectively.
|
|
|
Application of the Hermite basis for spectral analysis
Mihálik, Ondrej ; Tůma, Martin (referee) ; Jura, Pavel (advisor)
The work is concerned with an application of the Hermite functions in signal approximation. The purpose of the work is to show their properties in time and frequency domains, namely their orthogonality, Fourier transform, zeros and asymptotic behaviour as their order becomes high. The next subject of this work is the question of scaling these functions to minimize the square error of signal approximation. Several methods proposed by different authors are discussed. Finally these algorithms are tested by approximating simple signals so that their results can be compared.
|
|
|
Restoration of degraded audiosignals using sparse representations
Mokrý, Ondřej ; Veselý, Vítězslav (referee) ; Rajmic, Pavel (advisor)
This bachelor thesis is focused on the problem of inpainting a segment of missing samples in an audiosignal. The signal is represented as sparse vector using discrete Gabor transform. The problem of inpainting missing samples while preserving the sparsity of the representation is formulated as an optimisation task, which is then solved using Douglas-Rachford algorithm. In contrast with the state-of-the-art approaches, the algorithm is extended by proposing method for compensating the energy decrease which occurs in the restored signal.
|
|
|
Gabor transform for heart rate variability analysis
Omastová, Martina ; Klimek, Martin (referee) ; Janoušek, Oto (advisor)
This bachelor thesis focuses on the problem of measurement of heart rate variability. Heart rate variability (HRV) is an oscillation in the interval between consecutive heartbeats. It can be analysed by several methods, but in this work was used method analysis in time domain and Gabor transform. There were evaluated changes in HRV caused by global ischemia by both methods and reveal differences between the two methods. The methods were compared. In the conclusion was evaluated which method is more suitable for analysis of HRV.
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