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2answers
98 views

Poisson noise and curve fitting - denoise first?

If I have an image that is severely corrupted by Poisson noise, and I want to fit a function to the image, is it "better" to attempt to denoise the signal first before fitting, or should I move ...
0
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2answers
52 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 ...
0
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1answer
91 views

denosing given signal using wavelet

let us suppose that we have given following model $y(t)=A_1 \sin(\omega_1*t+\phi_1) + A_2 \sin(\omega_2*t+\phi_2) + A_3 \sin(\omega_3*t+\phi_3)+ \ldots +A_p \sin(\omega_p*t+\phi_p)+z(t)$ where ...
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2answers
167 views

Image Noise Detection Using MATLAB

I want to implement the following algorithm. Let $I$ denote noisy image and for each pixel of $I$ is represented by $I(x,y)$. A Sliding window of size $3\times3$ centered at $I(x, y)$ is ...
5
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2answers
484 views

What is the math behind median filter's noise reduction property?

I am interested in understanding the mathematical reason for why does applying a median filter on an image (or signal) result in reduction of noise.
1
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3answers
126 views

Which filters are the most commonly used and easier to implement for ECG noise removal?

ECG signal is affected by interferences such as the Powerline Interference, Baseline Wandering and Muscle Noise. There are many filters available which can reasonably cancel these types of noise. ...
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0answers
55 views

Algorithms for removing oscillations?

I am interested in removing oscillations from a signal to capture the lower-frequency variations, similar to the objective of this problem. The oscillations vary in frequency in the time domain, so ...
1
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1answer
60 views

Karhunen loeve transform question

I have read some about Karhunen-Loeve Transform (KLT) and its application to the field of seismic data processing. The method as I understand it based on decomposing the data (actually mostly used in ...
2
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2answers
153 views

Using Total Variation Denoising to clean accelerometer data

I know this is maybe a very basic question but I am doing this as a hobby and I can't find a solution to this problem. Basically I am trying to remove some noise from data I am reading from an ...
2
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1answer
78 views

Metrics for Noisy Images

I have a doubt. We calculate metrics such as PSNR, SNR, and MSE to prove that the proposed algorithm is better than its counterparts. To do this we need Original image (Noise free), Noisy image (we ...
1
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1answer
72 views

nonlocal means filtering technique

how is a non local means filter different from others such as: 1. Gaussian smoothing 2. total variation denoising
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0answers
33 views

Is it possible to reconstruct or improve this old audio recording?

I have an old lecture recording and I’m trying to remove a tinny noise that is present especially at loud spoken vowels. Some frequencies seem to be more affected than others. It sounds as if the ...
5
votes
1answer
181 views

Removing a sinusoidal artifact from a set of movie frames

I am doing some post-hoc analysis of a dataset consisting of a series of movie frames that are contaminated by a strongly periodic artifact. I would like to remove this artifact from my frames. For ...
1
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2answers
125 views

Bandpass filter on noisy sinusoid that predicts turning points

Is there an application where it is required to predict turning-points of a signal that is like a sinusoid with constant frequency, variable amplitude and some noise (Gaussian additive noise)? The ...
3
votes
2answers
656 views

Noise reduction from very noisy audio

I am trying to write an algorithm that would automatically segment a piece of audio with bird calls recordings. My input data are 1 minute-long wave files and on the output I would like to get ...
8
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1answer
136 views

Remove artifact from space probe image

This is a photo of our homeworld, taken by the Juno spacecraft recently, sling-shotting on its way to Jupiter. What it gained in speed, we lost in ours, however thankfully we will not be falling into ...
0
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0answers
159 views

Sine-weighted moving average on non-periodic, stationary signal

I am looking for -or trying to create- a filter with a piece-wise monotonic second derivative in such a way that when placed on a non-periodic input signal, changes in sign of the second derivative ...
0
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2answers
122 views

Image noise removal is part of image enhancement or image restoration? [closed]

I am working in digital image processing field, recently I am studying about Image Noise, I just want to know that whether this noise removal is part of image enhancement or image restoration. I ...
1
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2answers
227 views

what does musical noise sound like and is there a sample clip for it?

Musical residual noise is created when a noisy signal passes through a noise reduction algorithm. For instance, please see the paper: Esch, T; Vary, P: "Efficient Musical Noise Suppression for Speech ...
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0answers
150 views

Limitation of Wiener filter in image denoising

In image processing, up to which value of mean and variance can a Wiener filter be used to denoise the image? Wiener filtering can be used when variance of the noisy image is low, but I don't know ...
0
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0answers
103 views

Solve a PDE with anisotropic diffusion for images regularization

I have problems in reproducing the work: Algorithms for 3D Shape Scanning with a Depth Camera of Yan Cui (This for my master thesis). In that work, Yan improve the resolution and a depth map ...
1
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1answer
97 views

Which anisotropic diffusion method is best for denoising now?

The best standard may be varing from PSNR to human's visual feeling. Any one is OK. I have tested J.Weickert's tensor diffusion and P&M's, they all can't satisfy me. Is there any anisotropic ...
-1
votes
1answer
215 views

Removing surrounding noises from voice recording

I have a wave file whose frequency spectrum looks like this. It contains audio, which I want to keep while removing the rest. The problem is that the surround noise changes, just those distinct ...
5
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1answer
569 views

How one apply correctly FFT in image denoising

I'm writing program (Qt widgets/c++) for removing noise from images. As denoising method, i selected non local means method. This method has incredible quality of restored images (that's why it's the ...
4
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1answer
75 views

Spectral analysis of positive signals

Suppose that I have a sensor that can acquire samples $X[k]$ of the Fourier transform of an unknown signal $Y[t]$. An example is MRI, where the acquired data is in $k-$space. Now suppose that the ...
1
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1answer
219 views

How to denoise a conversation between two people?

I would like to know how to determine (using any programming language) whether a given audio file contains noise, such as of people talking in background, how to remove the noise, and how to ...
2
votes
1answer
866 views

wavelet denoising routine for environmental data series

I have a time series of water temperature, e.g. y = 1+(30-10).*rand(1,365); I have previously used the wavelet denoising routine in the wavelet toolbox by matlab ...
0
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2answers
494 views

eliminate signal A from signal B

i have 2 audio signals, both available in time and frequency domain: A: Noise B: Noise(A with minor variations) + Additive sounds (C) i want to eliminate Signal A from B to leave only C. C is for ...
6
votes
1answer
363 views

Gradient of total variation of magnitude of complex function for denoising

Say I have a complex function $f^*$ (e.g. a MRI image) that has a near piece-wise constant magnitude, but a non constant phase. If I have an optimization problem to find $f^*$ and set up an objective ...
7
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4answers
283 views

Solving optimization problem used for high quality denoising

The highest voted answer to this question suggests that to denoise a signal while preserving sharp transitions one should minimize the objective function: $$ |x-y|^2 + b|f(y)| $$ where ...
6
votes
1answer
164 views

What is Super-Resolution, in the context of windowing?

I have been trying to understand what super-resolution is, in the context of DSP/DIP. What criteria is being maximized/minimized, and why? Most of my online searches yield super-res techniques from ...