# Questions tagged [denoising]

Denoising is a collection of techniques to remove unwanted noise from a signal. Typically this is done by filtering, but a variety of other techniques is available. Often combinations are used in sequence to optimize the denoising.

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### understand short time fourier transform

I am reading this paper for signal denoising. In the paper, the authors says The core concept in this paper is to compute a regression between a noisy signal frame and a clean signal frame in the ...
• 135
5 votes
2 answers
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### Can the deconvolution Wiener filter reduce noise without having a blurred image?

I am trying to denoise many several noises with several filters for a research i have, i found a deconvolution Wiener filter made by "mr.tranleanh" on Github, as you can see here . what I ...
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### FFT denoising vs low pass filter

Say I have a noisy signal in which I want to denoise. There's two methods I'm considering FFT denoising, where I take the FFT of the signal and then threshold somewhere, attenuate all the frequencies ...
5 votes
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### Denoising a Grayscale Image Using Random Matrix Theory (RMT)

I am applying RMT on grayscale images. Basically for any matrix, it consists of two parts: one is pure noise and other is information. Now, to distinguish noise from information, RMT comes handy. We ...
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### Why NMSE is the same as output SNR but with an opposite sign?

I am doing denoising on signal, and as performance measures Normalized Mean Squared Error (NMSE) and output-SNR between original/clean and denoised signals are used. However, for several cases the ...
6 votes
2 answers
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### The Effect of Spatial or Temporal Averaging on Noise Properties

I generate two noise images using MATLAB's function imnoise(). If I average the two noise images, the resultant image looks like the original noise image but only ...
• 343
2 votes
1 answer
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### Hankel Matrix SVD Denoising

I have performed Hankel Matrix Singular Value Decomposition de-noising to smooth out my univariate time series. It is the close price of EUR/USD exchange rate. Here is a picture: The problem I have is ...
0 votes
0 answers
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### Removing the Dot-Patterns Like Noise

I am dealing with an image restoration problem with noisy measurement. I use the classical total variation norm to remove the noise, specifically, the TV-$L_2$ problem. I used the famous Lena image ...
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5 votes
1 answer
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### Solving a Weighted Basis Pursuit Denoising Problem (BPDN) with MATLAB / CVX

Following up from an answer by @Royi on adding weights to BPDN problem , I would like to use CVX to test this approach. How can we formulate in CVX the regularized LS L1 norm with weights given by a ...
• 586
1 vote
1 answer
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### Does BM3D really need the noise power spectrum beforehand?

I'm at the moment trying to implement a neural network which uses BM3D as a preprocessing step. The problem is, when using the python implementation of BM3D from the paper Collaborative Filtering of ...
1 vote
1 answer
84 views

### How to remove heartbeat signal from blood pressure signal?

I am working on a medical engineering project that involves processing signals received from a human body. We use a sensor to record the blood pressure, $B(t)$. However, if you put your finger on many ...
1 vote
1 answer
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3 answers
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### Help with Audio Signal noise removing using FFT and IFFT in Matlab

I dont understand why my modified fft of a audio signal returns complex values after ifft. I modified my signal by zeroing out all the unnecessary freq. FFT: Fast fourier transfrom IFFT: Inverse ...