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0answers
17 views

computing peak to peak ratio in matlab

i need to compute a signal's peak to peak ratio..... i have a doubt... do we calculate a signal's Peak to peak ratio in time or freq domain.... and ok say for a sine wave i can understand how to ...
-1
votes
1answer
29 views

how to detect signal noise

I have data from a power transformer that has a frequency of 60 hz. Sometimes there are faults in the system and causes a large spike in the reading of the transformer. What I want to do is run the ...
1
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2answers
95 views

Filtering data so that only rising edge is left

I have data that looks like this: Sometimes the data has a higher point in the middle of the shallow slope I want to find a way to filter the data such that it smooths it and leaves the first ...
2
votes
1answer
85 views

O(1) peak segmentation algorithm in matlab?

I have an intensity image, similar to the image below. I would like to very quickly, segment this image, into separate peaks. Where each peak is labelled, and segmented. A notional segmentation of ...
0
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0answers
70 views

In a signal there is a peak, I want to find the start of the peak and the end of the peak

I want to the start time and end time for the peak shown below. The start and end are shown by the marked circles in the fig As there are number of such plots and want to know start and end time for ...
0
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5answers
146 views

How to detect impulse like peaks - Matlab

I have a signal which is a matched filter output. whose values are given here: Amplitude values Input to this matched filter is radar return signals mixed with additive gaussian random noise. ...
1
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0answers
106 views

Extraction of fundamental signal information-Fourier full cycle algorithm

After filtering my noisy input signal using an anti-aliasing and FIR filter, I now wish to get the basic signal information (peak voltage and impedance; $R$ and $X$) from the pre-filtered as well as ...
0
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0answers
71 views

Reliable peak picking algorithm?

I've written an application that estimates pitch based on autocorrelation function. I did peak picking by comparing vector values to determine whether the central one is a peak or not, but this method ...
4
votes
1answer
152 views

What is obtained from the cross correlation plot?

Let’s assume that we have two audio signals, x(t) and y(t) affected by the noise as shown below. And we would like to cross-correlate these two signals and the cross-correlation plot is shown as ...
2
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1answer
111 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
2answers
283 views

How to find peaks and periods?

I am looking at data like this: Source data: http://pastebin.com/raw.php?i=L6cd8d5K The data is quasi-periodic, there is a distinct cycle but it is not an exact repeat, and the period changes ...
3
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2answers
222 views

Algorithms for finding fundamental frequency based on ACF result

I am developing a software for fundamental frequency tracking. For this purpose, I have designed a function which calculates autocorrelation over the signal and a second function which, based on ...
0
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1answer
65 views

Peak detection from saturated signals

Say we have a sampled signal for which the inputs can be out of range. For instance, say a sampled sensor has a range of 0 to 1, and is presented with a time-varying stimulus where a peak occurs with ...
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0answers
118 views

Yet Another Peak Detection Request

I looked over the other entries regarding peak detection and none seem to answer my question. I'm working with Fourier spectra of digitized audio that can't be measured again. There are no ...
0
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0answers
16 views

Doubt A weighting curve's phon value

Some sources say A weighting curve is inverted from 40 dBSPL, i.e 40 phon, while some sources say it's inverted from 30 dBSPL. Which is true? PS: For example, this says 40 and this says 30 Someone ...
2
votes
1answer
255 views

Detecting peaks in a noisy 2D correlation plot

I'm doing pattern matching by means of normalized grey-scale correlation. My input image is noisy and so the peaks in the correlation plot cannot be found just by thresholding. The original ...
1
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3answers
313 views

Real-Time peak detection (amplitude)

I capture signal (sound) in 44100hz and I need get response if there is peaks at amplitude, actually. Is this possible? How I can do this in real-time?
1
vote
2answers
298 views

HPS Algorithm for detecting the fundamental frequency of a guitar string

When you plucked on a string, the string is vibrate and except the fundamental frequency, there are an integer multiple of the fundamental frequency, which are the harmonics. I know that the HPS ...
0
votes
2answers
60 views

Delay Search of two signals

I need to find the timedelay between two signals. I guess MSE is the best approach. How to find that MSE? I am writing the code and I have access to the autocorrelation matrix of one signal and the ...
3
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0answers
99 views

Remove the extra peaks by lag

Suppose that we have some peaks of a signal and we know the time lag between dominant peaks. How is it possible to remove the extra peaks by applying time lag ? Lets say it in MATLAB ...
3
votes
1answer
380 views

Onset Detection Peak Picking

I have a guitar music signal and I want to detect the onset points via energy. This is the signal example: This is the energy plot: My question is what would be the best method defining the ...
6
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7answers
916 views

Obtain a signal's peak value if it's frequency lies between two bin centers

Please suppose the following: The frequency of a signal's fundamental has been estimated using FFT and some frequency estimation methods and is lying between two bin centers The sampling frequency ...
0
votes
1answer
73 views

Normalise data which has peaks

Some methods #1 YData = YData / max(abs(YData)); #2 ...
2
votes
4answers
709 views

Estimate frequency and peak value of a signal's fundamental

How can I find out frequency and peak value of a signal's fundamental? Please do consider the following: The peak value of some harmonics might be higher than that one of the fundamental The ...
1
vote
1answer
143 views

Algorithm to find spike

I've been doing FFT's (on sound) for a while and usually use the highest intensity or the ones above average to get the spikes in an FFT result. What would be a good method to get all the 'spikes' in ...
5
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1answer
2k views

How Hessian feature detector works?

I know about Harris corner detector, and I understand the basic idea of its second moment matrix, $$M = \left[ \begin{array}{cc} I_x^2 & I_xI_y \\ I_xI_y & I_y^2 \end{array} \right]$$, edges ...
0
votes
1answer
78 views

What technique could I use to smooth the right amount these signals?

I'm developing an application which one of its capabilities is peak detection. I expect to handle three types of the similar data (Acceleration vs Frequency) but measured in different laboratories ...
3
votes
3answers
324 views

Removing unwanted peaks from signal

I have a signal which looks something like: The 12 main round peaks is what I'd like to keep. However, the peak detection algorithm I apply is picking up the in-between noisy peaks. Any strategies ...
5
votes
2answers
260 views

What is the uHz-rotator algorithm?

According to this page, the Baudline software tool implements ...the uHz-rotator algorithm that operates in the complex domain to calculate an extremely accurate estimate of the frequency. ...
1
vote
1answer
174 views

Amplitude calculation

I've got an array of different values representing the y-values in a plot: ...
9
votes
2answers
768 views

Finding zebra-like pattern in image (Detection of structured-light fringe centerline from photo)

I'm working in a project where fringes are projected against a subject, and a photo is taken. The task is to find the centerlines of the fringes, which represent, mathematically, the 3D curve of ...
5
votes
2answers
554 views

Remove negative slopes from signal

I'm very new to signal processing, and have been struggling this far. To cut to the chase, I've a rather messy signal measuring respiration using some chest bands and would like to focus my analysis ...
8
votes
1answer
2k views

Real time slope and peak detection and calculation

I have a signal that I sample at 500khz. I am trying to detect a rise, fall and the peak in the incoming data. The base of the peak could be  for 250 usec or 2.5msec, amplitude could be 6db or 15db ...
1
vote
1answer
175 views

Tool for Harmonic Analysis & Synthesis [closed]

I've been using a program for identifying harmonics for a wave after doing a fourier analysis. http://www.phon.ucl.ac.uk/resource/sfs/esynth.htm I would like to be able to tweak some of the ...
4
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2answers
280 views

Peak location estimation for a triangle wave in AGWN?

Is there a more optimal peak location estimator specifically for triangle waves in AGWN, compared with peak estimation for generic waveforms? For a "smooth" waveform in noise, a common peak locator ...
9
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4answers
2k views

Is up-sampling prior to cross-correlation useless?

Consider a simple case where two signals from two different sensors are cross-correlated, and the time-delay-of-arrival computed from the absissa of the peak of their cross-correlation function. Now ...
3
votes
4answers
906 views

Auto correlation correspondence to original time domain window

I'm trying to figure out how exactly an auto correlation corresponds to a time domain signal. Now I'm trying to find pitch periods in an audio file and 99% of the time I'm getting it spot on. ...
7
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2answers
1k views

Real-Time Human Pitch Detection

I'm trying to implement a singing game that will analise raw mic input and tell the player how good is he singing. That needs to be done in real-time. I've come across a lot of threads asking the ...
7
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1answer
1k views

How do I use a Savitzky Golay filter to find local maxima (in between samples) in a discretely sampled 1D signal?

I have a seismic signal y(i): Here I have found one maximum: i=152.54, y=222.29 manually and plotted it in red. I want to find all maxima automatically. I read that the Savitzky Golay Filter (SGF) ...
6
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2answers
963 views

Finding local peaks in-between samples

I have n discrete samples of a seismic signal y[n]: I want to find local maxima in the signal. A naive test for if y[n] is a maximum would be: y[n]: maxima if y[n] > y[n-1] and y[n] > y[n+1]. ...
13
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4answers
4k views

Peak detection approach

What are the peak detection algorithms in existence? I have noisy data, and I would like to implement peak detection for this data. Data is in reverse, actually I am trying to determine the bottom. ...
8
votes
1answer
834 views

Derivative calculation

I have a series of data (single array). If I take this data and plot it, I can see that there are multiple peaks. However If I zoom in to a section of data, I see that there is substantial noise. I ...