spectrogram

问题 I run spectrogram(data, 64, 60, 256, 2, 'yaxis'); I get I want to get range from 0 to 180 Hz, instead of normalised range from 0 to 1. I can change axis by axis([0 450 0 180]) but it does not change the values. I run unsuccessfully spectrogram(180 .* data, 64, 60, 256, 2, 'yaxis'); How can you scale the range from normalised to real range? 回答1: The x-axis should be frequency. You need to know the sampling rate fs (is it 2 ?) of data . Then the frequency range will be (0:63)/64*fs Actually you

问题 I am working on speech recognition using neural network. To do so I need to get the spectrograms of those training audio files (.wav) . How to get those spectrograms in python ? 回答1: There are numerous ways to do so. The easiest is to check out the methods proposed in Kernels on Kaggle competition TensorFlow Speech Recognition Challenge (just sort by most voted). This one is particularly clear and simple and contains the following function. The input is a numeric vector of samples extracted

问题 I'm trying to figure out how MATLAB does the short time Fourier transforms for its spectrogram function (and related functions like specgram, or stft in Octave). What is curious to me is that you can apparently specify the length of the window and the FFT length (number of output frequencies) independently, whereas I would have expected that these two should be equal (since the length of an FFT'd signal is the same as the length of the original signal). To illustrate what I mean, here is the

问题 I'm analyzing some sound clips using the spectrogram() function in MATLAB . I would like to save the spectrogram as an image (jpg, png, etc). But regardless of what image format I save the figure in, the resulting image always looks different ("spotty") from what I see in the figure. Here's an example of the spectrograms: Matlab Figure vs. Saved Image All I want is to save exactly what I see in the figure as an image. I've already tried saving the figure in all the image formats possible but

问题 I'd like to obtain a spectrogram out of a wav file and then save it to a png, but I need just the content of the image (not axes or anything else). I came across these questions Matplotlib plots: removing axis, legends and white spaces scipy: savefig without frames, axes, only content I've also read the Matplotlib documentation but it seems useless and so either answers to questions above are outdated or I'm doing something wrong because simple plt.savefig('out.png', bbox_inches='tight', pad

问题 I have a signal with sampling rate 16e3, its frequency range is from 125 to 1000 Hz. So if i plot a specgram i get a pretty small colorrange because of all the unused frequencys. ive tried to fix it with setting ax limits but that does not work. is there any way to cut off unused frequencys or replace them with NaNs? Resampling the Data to 2e3 won't work because there are still some not used frequencys below 125 Hz. Thanks for your help. 回答1: specgram() is doing all the work for you. If you

问题 I have a Spectrogram: I want to clean the spectrogram up, so I only capture the frequencies within a specific range (i.e. in this example, between 2627 - 3939) and remove all of the blocks that are below this frequency. My overall aim is to only be left with the 4 segments that are within this frequency range, and, can be identified. Here is my code so far: import wave, struct, numpy as np, matplotlib.mlab as mlab, pylab as pl def wavToArr(wavefile): w = wave.open(wavefile,"rb") p = w

问题 I generated spectrogram of a "seven" utterance using the "egs/tidigits" code from Kaldi, using 23 bins, 20kHz sampling rate, 25ms window, and 10ms shift. Spectrogram appears as below visualized via MATLAB imagesc function: I am experimenting with using Librosa as an alternative to Kaldi. I set up my code as below using the same number of bins, sampling rate, and window length / shift as above. time_series, sample_rate = librosa.core.load("7a.wav",sr=20000) spectrogram = librosa.feature

问题 After using STFT(Short-time Fourier transform) the output is a matrix that represents a 3d plot as though (A[X, Y] = M) A is the output matrix, X is the time , Y is the frequency, and the third dimension M is the amplitude illustrated by the intensity of the pixel color as in the following pictures: Spectrogram 2 How do I draw the output matrix A with a gradient of colors like in the pictures in C#? Is there a library that contains a spectrogram control for C#? Update: After some

问题 Within my figure I have 2 axes, the first is the time series of the signal and the second is the ifft of the signal. I'd like to add a 3rd axes that contains the spectrogram of the signal. How can I do this? % Create the raw signal fs = 40; t = 0:( 1/fs ):4; y1 = [ sin( 2*pi*5*t( t<=2 ) ), sin( 2*pi*10*t( t>2 ) ) ]; % Compute the ifft of the signal Fy1 = abs(ifft(y1)); N = numel(t); idx = 1:numel(Fy1) / 2; f = fs*(0:(N-1)) / N; % Plot the raw signal as a time series subplot(311); plot(t,y1,'k