Questions tagged [gaussian]

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376 views

Use Scale Space Representation to Filter Single Image

Currently I hope to use scale space representation to filter one image. Features in one image can be filtered using an Gaussian smooth filter with one optimal sigma. It means different features in one ...
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11 views

How to get sigma of gaussian from accelerometer noise ug/sqrt(HZ)

I'm trying to model an accelerometer with gaussian noise in my application. The actual accelerometer has the following specs: ...
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38 views

Determine Gaussian distribution parameters from the signal-to-noise ratio

Is there a straightforward formula for determining the mean and standard deviation of the gaussian distribution followed by noise applied on an image, knowing the signal-to-noise ratio between the ...
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17 views

Is splitting single white gaussian noise samples-stream in multiple sample-streams still gaussian noises?

Suppose I have a random generator that generates gaussian distributed samples (mean = 0, variance = sigma) at a rate of 4*N samples per second. I want to generate 4 different streams from this ...
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50 views

AWGN for a specific dBc

I have a square-ware signal with 1V peak-to-peak (alternating between -500 and +500mV, so its absolute value is a constant 500mV) and I would like to add to this an AWGN expressed in dBc ("decibels ...
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22 views

How would I modify a squared-exponential covariance kernel to be periodic?

I want to create a Gaussian process that resembles one generated by an exponential kernel (smooth and with a lot of variance) with a single caveat: I need the final value to be the same as the initial ...
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1answer
607 views

Introduction to IP : Laplacian of Gaussian?

I am very new to the concept of computer vision (and image processing), and trying to understand the algorithm used for edge detection. One thing I'm currently struggling to figure out is the ...
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2answers
74 views

Applying a Power on a Sum of Gaussians to Enhance Resolution

There is so-called Power Transform technique in signal processing where the unresolved signal is sharpened by raising each data to a constant positive power. The example shown below is a sum of two ...
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2answers
675 views

Why is second-order Gaussian called Laplacian Gaussian?

We usually use Laplacian of Gaussian as the filter for edge detection or blob detection. But the filter itself is essentially a second order Gaussian. So why do we call it Laplacian of Gaussian? Is ...
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2answers
4k views

When should the sum of all elements of a gaussian kernel be zero?

I found an approximation of a 5x5 2D convolution kernel like this : Here, the sum of the elements is zero and this one was used for Laplacian of Gaussian! Another one here : This one has all ...
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1answer
19 views

How good is the Leech lattice for AWGN coding or MSE quantization of Gaussian sources?

Anyone know where to find graphs showing how well it works vs other schemes? thanks
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1answer
248 views

Band Limit in Gaussian Pyramid

In the paper The Laplacian Pyramid as a Compact Image Code, it says The pyramid algorithm reduces the filter band limit by an octave from level to level. How is the conclusion drawn? Is this related ...
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2answers
1k views

What is DC level in white gaussian noise?

Am studying unbiased estimators and keep seeing this term "DC Level". What is the expansion of DC and what is a DC Level? Even the Wikipedia page on WGN says nothing about it.
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2answers
167 views

Conditions for symmetric and unimodal windows in both time and frequency domains

After a lecture on harmonic analysis and time/frequency methods, I reconsidered the Gaussian kernel, defined in continuous time. It is unimodal and symmetric, and its continuous Fourier transform is ...
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98 views

Audio experiment with intermodulation by multiplying two analytic signals

1) First, I describe intended processing with a basic case: Let's say on left channel I have a sin wave with frequency F1, and constant amplitude A1. Then on right channel a sin wave with frequency ...
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1answer
62 views

Low-Pass FIR that keeps all values positive

Let's say, that I want to low-pass the norm (hence positive values) of an analytic signal (related to Hilbert transform). This allows me to perform experiments with the envelope of audio. For low-...
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0answers
29 views

Gaussian Energy Broadening implementation to meet detector response

Respected Coding experts, I am trying to perform Gaussian broadening on an energy spectrum. The final result should convert "specrum.png" to a similar form of "Exp.png". The method is explained in ...
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29 views

Acoustic features

I am working on an automatic sound recognition project. I found that the LDA performs better than the SVMs. Does this mean that the acoustic features are Gaussian distributed? Also, is this the ...
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1answer
49 views

Time derivative of signal - effect on noise distribution

I have an angular velocity measurement that has a certain amount of ripple that yields an histogram shaped like a gaussian curve. I quantify that ripple using a standard deviation. I am interested in ...
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9 views

How to normalize data by mapping data points from one mixture of multivariate normal distributions to another

Problem description I am trying to normalize multivariate time series data. The individual data sets (spectrograms from temporal EEG) comes from sources that differ widely in their noise ...
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55 views

additive white Gaussian noise -ask fsk psk

i want to simulate a system that uses ask,fsk ,psk in Matlab with additive Gaussian noise for each mode . figure shows the system propti and Eb/N0=6db my question is how to calculate the standard ...
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55 views

How do I narrow the frequency from a time domain Gaussian signal?

I'm trying to get a frequency domain Gaussian signal that starts from 180.045 THz and ends in 180.65 THz. This is the matlab code I used to get the FFT of time domain Gaussian signal: ...
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1answer
245 views

Relation between constellation SNR and baseband SNR

Let's say I have an I/Q modulation, ie. QPSK. I can simulate an the effects of an AWGN channel by adding to my QPSK symbols the realizations of a complex normal. $\mathcal{CN}(0,\frac{1}{\mathrm{SNR}...
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1answer
456 views

Simulating Range Bearing Sensor with MATLAB with Gaussian Noise (Generating Gaussian Colored Random Vector)

I would like to simulate a sensor that provides range and direction of a beacon. This is for EKF localization, so the noise must be Gaussian (i.e. $\mathcal{N}(0, \sigma^{2})$. Also, I would like to ...
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94 views

Use of gauspuls command in matlab, unable to broad signal at frequency spectrum

I have a doubt in the gauspuls command in matlab, i entered a fbr(fractional bandwidth of 1.5,ie. bandwidth= 0.75Mhz ) but as i plot the signal in the frequency spectrum using fft. i dont see the ...
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2answers
345 views

STFT calculation with Gaussian Window

$$ f(t)=\exp(jat^2) \,\,\, and \,\,\, g(t)\,\,is\,\, a\,\, Gaussian\,\, Window:$$ $$ g(t)= \left (πσ^2\right)^{\frac{-1}{4}}\exp\left (\frac{-t^2}{2σ^2} \right ) , \,\,\,\,\,\,\left \|g(t) \right \|...
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191 views

I want to plot a gaussian pulse in MATLAB in the frequency domain, with its centre at the highest value

I have tried one way but i am getting 2 peaks at the edges as shown in the picture. I have used 1 part of my code for the signal generation where i used the gauspuls command (reference: www.simsonic....
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1answer
8k views

Simple fft to Gaussian pulse with MATLAB

trying simply to create femtosecond pulse in MATLAB exactly like in the attached image, the carrier frequency is around 374THz, and my sampling frequency is 10 times the carrier. The results of the ...
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1answer
140 views

Are There Common Values of Standard Deviation for Gaussian Noise of an Image?

For example, it occurs to me that there might be a standard deviation value of Gaussian noise in which the human eye could no longer distinguish an object because the standard deviation is very high ...
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84 views

Should I increase the mean or the variance of Gaussian noise?

I am new in DSP. I am currently working with a project and I want to try which algorithm works better given different image noises. To test it out, I have been using the Gaussian noise in images. ...
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228 views

How to implement one dimensional low pass Gaussian filter with zero-phase shift?

I am trying to apply a low pass Gaussian filter on a signal and find the exact location of maximum/minimum in the resulting smoothed signal. I have to do it for a few values of sigma (Gaussian ...
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1answer
419 views

Why Does 2D FFT of Gaussian Looks More Sharper than Gaussian Itself?

I am trying to understand why 2D FFT is done on a Gaussian process in a particular code. From my understanding from these posts: https://www.researchgate.net/post/...
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0answers
42 views

How to add noise with given autocorrelation to signal in Matlab?

My question is a mix of signal processing and Matlab coding. I have an FIR filter with added noise $w_n$ $$x_n=\sum_{m=0}^{N_h-1}h_mg_{n-m}+w_n.$$ Now the noise $w_n$ has the autocorrelation $$E[...
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3answers
588 views

Is there any way to measure of Gaussian-ness?

I have some sampled data that has $1/f$ noise in it, with departures from the mean. These are long term departures. I could use something like a median filter but the window length would be longer ...
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1answer
166 views

Higher-order moment of output of LTI system

Assume a very simple LTI system. Assume $x$ is white Gaussian i.i.d. with variance $\sigma^2$. The output variance is straightforward to obtain. For example, for a continuous-time system: $$\mbox{...
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1answer
625 views

How to Obtain Mathematically High Frequency and Low Frequency Component Separately Using Bilateral Filter?

I have asked this question before in the sense that what does a high frequency and low frequency component signify in a image and i got satisfactory answers now i want to know that how i can get high ...
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2answers
5k views

Gaussian Filter Close to Image Border

When applying Gaussian filters close to the borders of an image, algorithms usually zero-pad or replicate/mirror/wrap the borders. This is not good enough for my case, so I wonder if there is ...
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66 views
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1answer
159 views

Fast Recursive 1D Signal Smoothing - IIR / Auto Regressive Implementation of Gaussian Smoothing

I have just begun to dive into the field of signal processing, but there is the need to program a digital filter, that has to smooth a realtime signal from a sensor device. As far as I know, in my ...
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2answers
13k views

generating white gaussian noise in matlab using two different functions

I want to know the difference between the two Gaussian noises generated below? Which one is white and how can i make the other one white? y=wgn(1,10000,0) and <...
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37 views

Voice classification

I'm working to prepare research article for my project. While preparing for it, I've gone through the topics like Gaussian mixture model and Fourier transform for voice classification problems. I've ...
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1answer
125 views

Signal Denoising Uniformly in Frequency Domain

I have a noisy sparse signal containing number of frequency components. Is there any method to uniformly denoise this signal. in other words, a method that estimated and eliminates the noise power ...
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2answers
2k views

How to approximate gaussian kernel for image blur

From wiki, a $3 \times3$ gaussian kernel is approximated as: $$\frac{1}{16}\begin{bmatrix}1&2&1\\2&4&2\\1&2&1 \end{bmatrix}.$$ Applying this kernel in an image equals to ...
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1answer
391 views

Is there a clever way to implement cascaded moving average filters?

I'd like to effeciently approximate a gaussian filter's step response using cascaded moving average filters. I know about recursive moving average, but is there some clever algorithm to cascade them ...
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2answers
2k views

How Is Laplacian of Gaussian (LoG) Implemented as Four 1D Convolutions?

I am trying to understand the four 1D convolution operations involved in implementation of Laplacian of Gaussian(LoG). I have read this answer and I am also reading ...
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2answers
935 views

PSD of complex white gaussian noise

It may be a really simple question, but I'm not sure about this one: Given a complex white Gaussian noise process with iid real and imaginary parts and a double sided power spectral density of $N_0/2$...
2
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1answer
78 views

ARMA Model - DSP

I'm taking a DSP course and we're being introduced to the whole probability/stats side of DSP and I'm just confused on things like the ARMA models. These things don't seem intuitive to me at all. ...
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5answers
5k views

Why is random noise assumed to be normally distributed? [duplicate]

From residual in the linear regression to noise in signal processing are assumed to be normally distributed? By considering them as normally distributed we are kind of telling the pattern in the noise ...
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1answer
1k views

Convolution of Two Kernels [OpenCV]

I've been completely stuck on a portion of my assignment for a few days now. After plenty of searching around, I have been unsuccessful in discovering information that leads me to the correct solution....
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0answers
181 views

Distribution of the output of AWGN channel

$$\mathbf{Y}=\mathbf{X}+\mathbf{W}$$ $\mathbf{X}$ is input, an $n$-dimension equiprobable vector in a finite subset of complex space $\mathcal{A}^n \subset \mathbb{C}^n$ with norm $\sqrt{\rho n}$ (...