All Questions

7 views

Speaker Recognition

How can you filter out a person's voice from a group of people talking? We have a sample of each person's voice from the group, and the sample of the entire group talking at once. Both samples are ...
33 views

Extracting features from a signal: a 21st century approach?

I have a discrete signal of random length (let's say between 500 and 800 in time). This signal has an important information which I want to collect and to put it together in a feature vector to train ...
6 views

How can i calculate the gaussian range and space parameters in bilateral filter?

Let's suppose i have the following [4x10] image . 1 3 4 5 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 5 3 5 6 8 9 0 0 2 3 4 6 7 8 9 0 8 9 How can i calculate its space and range parameters (standard ...
38 views

Difference between Convolution and multiplication

I read that multiplication is convolution in frequency domain. I also understand that convolution is just polynomial multiplication. Can somebody explain what are the advantages of doing convolution ...
13 views

Determining the uncertainty of an autocorrelation

My problem should probably be built up from the beginning, so lets start there. I performed a certain experiment 25 times. Every time, the experiment consists of 5000 measurements, and each ...
22 views

separate signal values from noise

let us consider following graph of singular values i want to make some kind of clustering of these data,namely to seperate main components from non main components,let say signal components ...
16 views

autocorrelation matrix for Linear predictive coefficients

I have wrote a matlab code for autocorrelation matrix ...
16 views

Signal to noise ratio software [on hold]

Also, please introduce me a software for mixing signal and noise with variable SNR values. Thanks again
25 views

Wavetables and Partials

I am reading Direct Synthesis versus Wavetable Synthesis. The quote below explains code I have read but I don't get why it's a division by the integer multiple, when multiples increase in frequency. ...
22 views

Lowpassfilter using TI's dsplib

I'd like to implement a lowpass filter on a C6747 using TI's dsplib but the documentation doesn't help very much and the examples are more a "proof of concept" in my eyes. Has anyone some pointer to ...
33 views

will always periodogram produce correct frequencies?

let say we have some data,some signal written in this form $x(t)=s(t)+\epsilon(t)$ where $s(t)$ is pure signal and $\epsilon(t)$ is white noise with mean zero and some variance ,question is ...
19 views

How to use pseudo frequencies with wavelet transforms

I'm slowly getting my head around the use of wavelet transforms (CWT & DWT) with my data, but I'm interested in how the wavelet transforms correspond to certain bands of frequencies. I'm using ...
51 views

Eigen value and Eigen Vectors in Image Processing

I have been reading about eigen values and eigen vectors but i haven't be able to find any decent explanation relating their application in image processing/computer Vision for example say face ...
12 views

I am currently working on a control mechanism which looks as in the following figure: In general, I'd like the input1 (the one where only gain and integrator are present), if and only when input2 ...
40 views

How to interpret results of Fourier transform by using Python

Connected with this topic , I would like to have some clarifications about the Fourier Transform and the Python tools that make it. Having my data set whose plot is showed in the above link, my array ...
22 views

Reason for bimodal behavior while low second fourier coefficient

If I have a time series (for eg. for 23 timestamps) and if I plot it and see that it is bimodal, that means it might be having high value of second fourier coefficient (with frequency = 2). But when I ...
23 views

How to check if Fourier components are in phase of out of phase?

I have a time series (of 23 timestamps) of which I take the Fourier transform. Now the fourier transform has 23 imaginary values and each has an amplitude and a phase. When I get the phase angle, it ...
39 views

Measuring similarity of music, using lossy compression

I have two sound clips $C_1,C_2$ which are pretty similar. I'd like to measure how perceptually similar they are, i.e., how similar a human would perceive the two to be. Is there a way to use a ...
59 views

IFFT and OFDM upconversion

I am trying to understand some basic concepts with IFFT as represented here OFDM Modem page 50-53, and 108-114. Some basics that are represented - The base sampling rate is 8khz. The symbol period ...
54 views

Why would you use DCT as oppose to DFT for detecting oscillation in a signal?

For my project, I needed to detect the primary oscillation frequency in a signal data. As I googled around, it turns out that DCT is the best tool to find this ...
38 views

reconstruction of time series in SSA

i am trying to reconstruct time series from SSA ,because according to this link http://en.wikipedia.org/wiki/Singular_spectrum_analysis there is procedure ...
37 views

Extra energy when altering frequency amplitudes

How can I convert a time signal (audio) into the frequency domain, multiply frequency amplitudes by a vector of scalars, and convert it back into the time domain, without messing up timing information ...
37 views

How to get Envelope of Audio Signal

I am having a problem understanding how the author gets the onset envelope of an audio song in this paper. The entire section in question has been quoted below: First the input sound is resampled ...
23 views

Intuition behind Wavelet Transform?

I was thinking sometime back about how to explain Wavelet Transform ELI5. So this is what I came across. The co-relation of two exact signals is 1. So if I have an input signal f(x) made up of an ...
31 views

How to find the inflection point in a noisy curve?

I have the the noisy curve defined by numpy 2D array: As you can see, it has the first flat segment, then rise, peak and decay phases. I need to find the starting point of the rise phase, marked ...
17 views

Autocorrelation function of a discrete signal

For a certain experiment of which I have data, I want to calculate the autocorrelation of the measurements. For this I used the expression from http://en.wikipedia.org/wiki/Autocorrelation#Estimation, ...
30 views

Convert .mp3/.wav to formula [on hold]

I have an .mp3/.wav file. This file was created with unknown to me tool. This tool used harmonic signals for left and right ears. How can I find formulas for harmonic signal from audio file?
10 views

New capture card YUV 4:2:2 leads to different images

I have just bought a new video capture card whose output format is YUV 4:2:2 (as my old one) and surprisingly when I capture images with both cards I get different results. Differences are very small ...
29 views

Matlab : Reconstructing signal from cosinusoïdes : DC offset question [code + picture]

i'm trying to reconstruct a signal from amplitude and phase of cosinusoides to understand totally how DCT works. So far i've managed to get the signal very close, only by a DC offset that i don't get. ...
52 views

Differential Equation of a Band Pass Filter

I'm struggling with a signal analysis electrical engineering college assignment. We need to a derive differential equation for a low-pass filter, high-pass filter and a band pass filter (made by ...
72 views

What is the maximum dynamic range of an N bit signal?

In this presentation on slide 15 there is a corollary: Rule of thumb: the dark noise must be larger than 0.5 Corollary: With a N bit digital signal you can deliver no more*) than N+1 bit ...
39 views

EEG signal processing

I have an EEG data set downloaded from physionet. I want to play that data into a brain monitoring device like for example BIS monitor or Narcotrend or any other similar brain monitoring device.I use ...
38 views

Savitzky-Golay filter parameters

I am trying to smooth a series of data in order to obtain a continuous function that could represent that given data set. It came out that the Savitzky-Golay method could be a good way. Now, I don't ...
28 views

How to display the time frequency distribution

I have the basis atoms after decomposing the signal via matching pursuit algorithm. How do I now make a color plot of the time frequency distribution?
16 views

How to calculate the freedom of projection matrix?

I learned projection matrix from textbook. It says that the 9th is redundant, so it has 8 freedom. But I can not know the reason clearly. Following the equations. I can not understand why i does ...
27 views

MATLAB QPSK MMSE plot is not working [on hold]

Error in r=s+w;. How can this be fixed? ...
32 views

Order analysis or order tracking

I've been trying the last week to implement the Order analyse in MATLAB in vain, I've read a lot of docs about it like this one , but I still can'T figure it out . This will be my last shot. Say I ...
25 views

Expectation of product of hermitian matrix

Let $\textbf{h} \in \mathbb{C}^{N\times 1}$, $\textbf{a} \in \mathbb{C}^{N\times 1}$, $\textbf{b} \in \mathbb{C}^{N\times 1}$ and $\textbf{c} \in \mathbb{C}^{N\times 1}$. The variable $h_i$ is defined ...
32 views

Plot real-time FFT using matplotlib

I'm trying to plot fft in python. I use pyalsaaudio for capturing audio in PCM (S16_LE) format. I use the ion() and draw() functions in matplotlib to have the fft plotted in real time. This is the ...