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3
votes
2answers
166 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
votes
1answer
36 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 ...
1
vote
0answers
80 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
votes
0answers
12 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
133 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
vote
3answers
235 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
168 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
55 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
votes
0answers
89 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 ...
2
votes
1answer
196 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
votes
7answers
506 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
61 views

Normalise data which has peaks

Some methods #1 YData = YData / max(abs(YData)); #2 ...
2
votes
4answers
322 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
124 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 ...
4
votes
1answer
771 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
73 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
258 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
240 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
128 views

Amplitude calculation

I've got an array of different values representing the y-values in a plot: ...
9
votes
2answers
527 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
446 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
0answers
144 views

Tool for Harmonic Analysis & Synthesis

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
votes
2answers
263 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
votes
4answers
1k 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
847 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. ...
6
votes
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
votes
1answer
813 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
votes
2answers
722 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
votes
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. ...
7
votes
0answers
643 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 ...