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3
votes
4answers
247 views
+300

“cascaded” cross-correlation

so, first let's do this for the circular correlation case (it might be easier). let's say we have three real and periodic functions or signals $x(t)$, $y(t)$, $z(t)$ all with period $2 \pi$: $$ ...
0
votes
1answer
78 views

Solution to Cross-correlation problem of 2 audio signals

There are 2 audio signals, X & Y. X is of 15 second duration. The duration of Y is not given. Y is a part of signal X (ie a small part of audio X is extracted & made into audio Y) I have to ...
0
votes
1answer
28 views

Avoid saturated pixels in cross-correlation computation

I am doing template maching using Normalized Cross-Correlation for measuring similarity between template and image. However, some images from my dataset contain saturated pixels (overshoot) which ...
1
vote
0answers
27 views

GCC-PHAT cross correlation

I am trying to implement GCC-PHAT in python. The approach is similar to the following two links: link1 and link2 It seems the only difference between GCC-PHAT and normal cross-correlation using FFT ...
1
vote
1answer
27 views

How to decode speaker gender from spoken transcript

I have 20 audio recordings (raw format) of people reciting the same ~50 word transcript. I would like to use audio signal analysis to decode speaker gender from audio recording. Intuitively, it ...
0
votes
1answer
43 views

Cross-Correlation : Comparing two signals or finding the location of a target

I read across places that cross-correlation of two signal (a radar sending a signal and receiving it back) one can detect the location (distance) of a target from a point and that cross-correlation ...
-1
votes
1answer
63 views

Correlation : Cross correlation why we need to multiply the samples

I understand what books states about cross-correlation of signals and their mathematical representation: For continuous functions f and g, the cross-correlation is defined as: $(f \star g)(\tau)\ ...
-1
votes
1answer
45 views

phase amplitude transform as a solution to reverberation

I am trying to use generalized cross correlation with phase transform (GCC_PHAT) on some audio processing indoor, with the existence of low noise. I ve read here that by canceling the magnitude ...
1
vote
1answer
46 views

What Information does the phase of a cross power spectra give me?

I obtain the cross power spectra by the following steps: compute the FFT of signal A and B Multiply A with the conjugate of B store it in C (cross power spectra) Now looking at the Phase of this ...
1
vote
0answers
31 views

Time delay analysis in different binary sequences

I am extracting a property of a signal which I represent with either a 0 for absent or 1 for present. This property is extracted for each data point in a time series and in the end I am left with a ...
1
vote
2answers
90 views

fast 2D cross correlation algorithm

I want to match a small template to a larger image, that the distance between the template and the subimage with the same size of the template is minimized. It can be solved directly or by applying 2D ...
0
votes
0answers
45 views

Noisy Signal auto/cross-correlation

I am trying to understand the basics of the cross/auto-correlation if the noisy signal $y(t)$ which is received from the channel at the receiver. Here at receiver we want to estimate the noise in the ...
1
vote
0answers
207 views

Correlation using FFT/IFFT (fast convolution) in Java - not centered

I try to find about the delay between two audio files using Cross Correlation in Java. I've already done this algorithm so far that i get a idea about how many samples is the delay. FFT x1 -> Zero ...
2
votes
0answers
86 views

DOA estimation 2 sources time delay estimation uniform array

I am new to signal processing, so sorry if the question is superbanal. I have been spending more days than I would admit on this and can't find the error. I have two triangle waves that are emitted ...
1
vote
1answer
40 views

Fast cross correlation with limited range

I am measuring the phase shift between two pseudorandom signals using correlation ifft(A.conjugate()*B) and picking out the maximum). That works very well, but takes a lot of time. I roughly know ...
1
vote
0answers
30 views

ACF and PACF Confidence Levels for ARMA

I'm trying to figure out where exactly to draw the confidence levels for the autocorrleation function (ACF) and the partial autocorrelation function (PACF) for an ARMA model. For PACF I found that a ...
1
vote
2answers
120 views

Subtracting Original Audio Signal

here is my scenario: one speaker is sending a chirp, and a microphone is recording it as well as all following echoes. The function of the chirp is already know. My goal: subtract the original chirp ...
0
votes
0answers
42 views

Describing a time delay at a maximum for maxima and minima but tends to 0 elsewhere

I have two force-time signals obtained from a couple of force plates, corresponding to input/output signals for some system. Plotting the two together one of the first things I noticed was a time ...
2
votes
1answer
60 views

Ultrasound Signal Processing Methods

I am sending 6.6Vpp square wave across a narrow-band, 40 kHz Transmitter to a narrow-band, 40 kHz Receiver. I want to find a very accurate distance between the two (sub millimeter). My assumption so ...
0
votes
1answer
192 views

How to compute the cross correlation of two fuctions

I am trying to implement Matlab's cross correlation function but I can't seem to replicate the results obtained when using Matlab's built in function "xcorr". Documentation for xcorr can be found ...
2
votes
2answers
95 views

Time delay estimate and sampling frequency

This is an extention to my other question. My sampling frequency is only about 2x my tone frequency. I want to estimate time delay of arrival using this signal. I am generating the tone signal so I ...
1
vote
1answer
98 views

Upsampling signal for cross correlation

I am recording a 17khz signal at a sample freq of 44.1khz. I want to perform cross-correlation between the received and transmitted signals for calculating TDOA. But when I do xcorr, the results are ...
1
vote
1answer
137 views

Time delay estimation using ultrasound

I have a sound source that generates an ultrasonic pulse. I have two microphones seperated by a distance which are at a distance from the source. I want to find the time delay of arrival of the ...
0
votes
2answers
213 views

Matching two audio inputs (signals) [duplicate]

this is for an application in which passwords are stored in the form of audio inputs . In order to provide user access , the password(in audio form) will be matched with already stored password(audio ...
2
votes
1answer
121 views

Cross-correlation of time compressed 1D signal

If I ave 2 otherwise identical 1D signals that are phase shifted from each other then cross-correlation is a perfect way to identify the time lag between the 2 signals. Now supposing I double the ...
2
votes
1answer
223 views

Normalized-cross correlation operation

According to my question about separability of Gabor filters in this link, I want now to convolve my image with this separable filter by using the normalized cross correlation operation. Assume my ...
0
votes
0answers
30 views

What is the time array in Generalized Cross Correlation method?

I work currently on a blind location of arrays of microphones and speakers. In my work, I have to find the time difference of arrival between a speaker and a microphone, with a high precision. So the ...
1
vote
1answer
33 views

A special case of 2 jointly WSS stochastic processes

I know that 3 conditions must be met in order a pair of stochastic processes X(t) and Y(t) to be characterized as jointly WSS: 1. X(t) WSS 2. Y(t) WSS 3. Rxy(t1,t2) = Rxy(t1 - t2) = Rxy(t2 - t1) ...
4
votes
1answer
279 views

Ambiguous results of phase correlation in pattern recognition

We are using phase correlation to find pattern on image and what we get is 15% of results is spurious. Ours pattern has 32x32 pixels and image for research has 32x512 pixels. So we put Pattern to ...
1
vote
1answer
79 views

Detecting a frequency pattern in the frequency domain

I am looking to detect a combination of frequencies in the frequency domain. For example, here is my spectrum: And I'm trying to detect the pilot tone. I have the FFT of the pilot tone: which ...
1
vote
2answers
291 views

Applications of Correlation in Signal Processing

There have been discussions on the differences between convolution and correlation, autocorrelation, cross-correlation, et al. In spite of looking at the visualizations, and understanding the ...
0
votes
1answer
80 views

how to calculate cross correlation of transient signal?

there. Let me have a noisy speech signal $y(k)$ as below. $$ y(k) = x(k) + v(k) $$ where, $k$ is the discrete-time index, $x(k)$ is clean speech signal, $v(k)$ is a zero-mean random process, ...
1
vote
1answer
347 views

Signal compare - cross corelation in frequency domain matlab

I need compare two signals. Signals have simliar shapes but completely different values (as on picture): So I think cross corelation in frequency domain should gave me a number that shows me how ...
0
votes
2answers
118 views

Normalized cross-correlation in detail

I'm trying to implement a normalized cross-correlation algorithm but I don't get what in fact is this measure. What confuses is the wikipedia definition: $\frac{1}{n} \sum \frac{(f(x,y)- ...
1
vote
0answers
53 views

Train Pulse Recognition in Medium Voltage Networks

I just started a project in the Smart Grids area. It involves the recognition and quick extinction of earth faults in a medium voltage system. The system works automatically and pretty much gets rid ...
1
vote
1answer
700 views

How can I compute a time-frequency cross-spectrum in MATLAB?

MATLAB has a spectrogram function for the time-frequency analysis of a single signal. It also has a cpsd function for estimating the cross-frequency spectrum for two signals. However, cpsd averages ...
0
votes
1answer
164 views

Speech discrimination from animal sound

i am looking for discrimination of speech from animal sound if you take a 150ms frame of speech and bird as shown below, what feature can i extract from them so that i can effectively state the ...
0
votes
0answers
248 views

Similarity of signals

I have a question concerning methods to find different aspects of "similarity" of signals. So, first, I'd like to characterize the signals to be dealt with: We have a number of close to rectangular ...
2
votes
1answer
158 views

how could correlation-based image patches matching works?

In general, correlation-based image matching can be referred to as $$c(I_1,I_2) = \sum_{x \in patch} f(I_1(x), I_2(x))$$ , I do think normalized cross-correlation like $$ncc(I_1, I_2) = \sum_{x \in ...
1
vote
2answers
214 views

Given an experimental FFT plot, how to find the best match from a set of generated FFT plots?

What I'm trying to do is, given some experimental data and it's (magnitude normalized to 1) FFT, match the FFT with one of say 1000 other (magnitude normalized to 1) FFT plots. Please note that the ...
2
votes
1answer
178 views

How do you find signal similarity when one signal has zero values? Correlation alternative?

I'm using cross-correlation to look for a Barker code in a BPSK signal. It occurred to me that if I send out a zero DC valued signal proceeding the barker code, it won't affect the correlation ...
1
vote
0answers
53 views

Iterative Auto and Cross Correleation Estimates

I'm looking for literature or other information that covers iteratively estimating the auto- and cross-correlation vectors and the auto-correlation matrix. Initially, I can assume the signal is ...
1
vote
3answers
252 views

Is possible to compare to audio samples with cross-correlation [duplicate]

Is it possible to compare two audio samples(meaning find word from one in another) realtime with cross-correlation?
0
votes
2answers
795 views

Matching 2 audio files

I'm doing research on how we can do matching between 2 audio files using Android to see if they have the same content or not. After doing lots of research, I have concluded that I must do 2 main ...
2
votes
1answer
74 views

Embedded Correlation Function

I'm trying to write a correlation function on an embedded device. Because its embedded, I need to make sure that the memory/CPU usage is minimum. Here's the deal: - I have a saved waveform sampled ...
1
vote
2answers
608 views

Cross-correlation peak

How get cross-correlation peak and based on it calculate correlation score for similarity of two audio samples. SO far I've FFT two samples complex conjugate second multiply results IFFT ...
2
votes
2answers
231 views

Why is image blurring called convolution and not cross correlation?

I've always thought that image convolution is a weighted sum of the nearby pixels using the convolution kernel as weights. But from the description on Wikipedia, this is what cross correlation does. ...
1
vote
1answer
148 views

What is the significance of first zero upcrossing of a cross correlation?

What is the significance of the first zero up-crossing of a cross-correlation? The signals being correlated are cosines signals with some phase difference. EDIT 1 : Cross-correlation plot attached. ...
1
vote
2answers
993 views

How do I get the phase angle from Cross Correlation?

Im trying to cross correlate two signals in matlab and get the phase difference between the signals. For cross correlation (the idea is to do it without xcorr) I used: ...
1
vote
1answer
176 views

Calculating an impulse response in a stable environment

I would like to estimate the impulse response of a simple environment (room, two speakers, one microphone). I am aware of the issues/limitations of working with "near" LTI systems. That said, I have a ...