Wavelet transform for time-frequency representation and filtration of discrete signals

Time-Frequency Representation of Microseismic Signals using the Synchrosqueezing Transform

Resonance frequencies can provide useful information on the deformation occurring during fracturing experiments or CO2 management, complementary to the microseismic event distribution. An accurate time-frequency representation is of crucial importance prior to interpreting the cause of resonance frequencies during microseismic experiments. The popular methods of Short-Time Fourier Transform (ST...

Non Separable Two Dimensional Discrete Wavelet Transform for Image Signals

Discrete Wavelet Transform in Compression and Filtering of Biomedical Signals

Biomedical signals are a kind of signals that are measured from a specific part of the body, for example from the hearth (electrocardiography: ECG), muscles (electromyography: EMG) and brain (electroencephalography: EEG). This kind of signals have a no-stationary behavior, it means the behavior through the time is changing every time window. For this reason, the pre-processing, processing, and ...

Reassigned time-frequency representations of discrete time signals and application to the Constant-Q Transform

In this paper we provide a formal justification of the use of time-frequency reassignment techniques on time-frequency transforms of discrete time signals. State of the art techniques indeed rely on formulae established in the continuous case which are applied, in a somehow inaccurate manner, to discrete time signals. Here, we formally derive a general framework for discrete time reassignment. ...

Analytical Analysis of Image Representation by Their Discrete Wavelet Transform

In this paper, we present an analytical analysis of the representation of images as the magnitudes of their transform with the discrete wavelets. Such a representation plays as a model for complex cells in the early stage of visual processing and of high technical usefulness for image understanding, because it makes the representation insensitive to small local shifts. We found that if the sign...