Time Frequency Analysis with Low Numerical Complexity Using a t-f-Mapping of the DFT Magnitude

Höldrich Robert
15.05.1995

Wissenschaftliche Publikation

Time Frequency Analysis with Low Numerical Complexity Using a t-f-Mapping of the DFT Magnitude

Proceedings IEEE Signal Processing Soc. Workshop A, 15.5.1995

The Short-Time Fourier Transform (STFT) or spectrogram data is the base for signal analysis in many computer music applications as resynthesis and sound interpolation. There is a tradeoff between time and frequency resolution due to the length of the analysis window used. This paper presents the Modified Moving Window Method, invented by Kodera, which performs a time-frequency mapping of the DFT magnitude yielding a more concentrated energy distribution in the t-f-plane. A simplified method is proposed to overcome the computational complexity of the original version leading to the "improved spectrogram". The resulting analysis data are used to form a parameter set of a sinusoidal signal representation which serves as the input to a resynthesis algorithm.

Time Frequency Analysis with Low Numerical Complexity Using a t-f-Mapping of the DFT Magnitude

Time Frequency Analysis with Low Numerical Complexity Using a t-f-Mapping of the DFT Magnitude

Institute of Electronic Music and Acoustics