Questions tagged [normalization]
The normalization tag has no usage guidance.
84
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Improving the Time Domain Normalization of Acoustic Sound Data
I have tried to evaluate the analog microphone (IMP23ABSU) built into the STEVAL-STWINKT1B with the FP-SNS-DATALOG1 (HS-Datalogger). The values were exported as "raw values" (this is an ...
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For PCM audio samples, can values like max RMS and frequency magnitude be estimated?
I am using OpenAL and a loopback driver to grab PCM samples of whatever audio is being played on the computer in realtime. The PCM data is 1024 samples of 16 bytes (C# ...
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1
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42
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Normalize the output signal that may be as similar as possible the input
I'm having a problem to normalize my output signal (extracted EEG signal) after applying Independent Component Analysis (ICA) that may be as similar as the original source (EEG signal). I need do this ...
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Reducing or removing autocorrelation in spatially correlated data
I am trying to figure out how one can reduce or preferably remove autocorrelation in spatially correlated data. Using the R code below, one generates spatially correlated data that is normally ...
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6
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1
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443
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Why is scaling of images / pixels into `[0, 1]` range performed before SIFT (Scale Invariant Feature Transform) algorithm?
The SIFT paper and the paper of Anatomy of the SIFT Method do not mention that the input images should be preprocessed (normalized, re-scaled) before feeding images into the standard SIFT algorithm. ...
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Normalized Power of a signal [duplicate]
I have the following power values in Watts of a signal:
6.5e-8, 4.6e-8, 7.1e-8, 1.01e-7, 9.98e-7, 2.5e-6, 3.96e-6, 2.84e-5, 2e-4, 4.05e-4, 1.7e-6, 8e-7, 8.23e-8, 8.32e-8.
How do I normalize this to ...
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213
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Bring two Fourier transforms to same range to add them
I have Fourier transforms of two images which I wish to add (Basically I have an input Fourier transform which I mask, reconstruct the underlying image using an algorithm, and then try to replace the ...
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1
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42
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Standardizing signals from the same experiment setup with different recording tools
I've been looking to merge two datasets I have, that capture instances of the same phenomenon using two different recording tools. Both are multichannel electrical signals, but the recording tools ...
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105
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Mann-Kendall Trend Test
I'm using the pyMannKendall package in Python to detect the presence of slope of any given waveform. More details of the package here:
https://github.com/mmhs013/pyMannKendall
I'm not exactly able to ...
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1
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170
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Normalize Bessel filter
I am applying a low pass filter to my signal and I should make sure the transfer function of my filter is one. How can I normalize my filter?
I am learning about filters and I appreciate any help.
<...
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45
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How do I solve for the normalization constant of a discrete time-frequency Gabor atom?
Given the mathematical expression for the discrete Gabor time-frequency atom
$$g_{s,u,\omega,\theta}(n) = \frac{K_{s,u,\omega,\theta}}{\sqrt{s}} e^{-\pi(n-u)^2/s^2} \cos[2\pi\omega(n-u)+\theta]$$
...
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428
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Spectrogram normalizaion to train a Fully Convolutional Model for Audio dereverberation
I'm trying to implement a deep learning based dereverberation algorithm. The network I am using is inspired by the U-net.
The idea is to supply the reverberated spectrogram as input and 'clean' it ...
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1
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36
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0/1 dB normalization using clamp function
I would like to perform dB normalization on audio data to make less loud sound louder and to make unusually loud sound less loud, before feeding them into neural networks.
I came across this function:
...
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1
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58
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How to normalise 3D time-frequency sound intensity vector
I've got a 3D time-frequency sound intensity vector that I've derived from Ambisonic b-format signals. W acts as the sound pressure ...
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1
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1
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790
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sensor data windowing and normalization
I am getting up to speed with working with sensor accelerometer data. I am looking to conduct a FFT on this signal. I found that the signal being non periodic is causing issues so I have tried to look ...
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395
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simple explanation of rank transform and its relation to normal distribution
I tried to understand the rank transform, but I couldn't.
The first step common to all histogram remapping techniques is the transformation of the pixel intensity values of the given image via the ...
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667
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how to normalize DCT (or FFT) coefficients to compare different signals
I have signals that have a broad range of values. I want to compare them in a meaningful way. Just as an example, two of those signals might be:
$$f(t)=100\cos(50t)+40\cos(60t) \quad g(t)=2\cos(50t)+0....
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2
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141
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What's a Normalized function?
I'm studing Representations of Random Processes and the book talks about Orthonormal functions, but doesn't make it clear what is it.
I was able to realize that a set of functions are orthonormal if ...
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1
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45
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How to validate that an audio algorithm result is independent of microphone device?
I have a machine learning algorithm that takes speech sample audio recordings collected from mechanical Turk. During processing it was shown that some audio from certain OS/microphone devices have ...
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48
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Phase-vocoder normalization for different speed factors
Question in short: How can I normalize audio from a block-based phase-vocoder system without knowing the global minimum and maximum during runtime?
Longer version:
Hey! I am very new to DSP and need ...
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2
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1k
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Normalization factor in the convolution theorem
Maybe it's a trivial question, but I couldn't find any explanation for this.
According to the convolution theorem, in the continues case we add normalization factor, i.e.
$$
\mathcal F\left\{h\star g\...
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92
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How do you normalize a sample-by-sample processed signal?
I am writing an audio effect based on a second-order filter that adds two samples. The resulting output is clipped. So I multiplied the signal by 0.5, which results in an output that is too low. Since ...
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89
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Audio RMS normalization prior to a DNN classification
I want to normalize my data prior to a deep neural network model (DNN). It was recommended to me to use real mean square (RMS) normalization for audio, though I am not sure this is the best for a DNN. ...
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100
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Is it possible to normalize an un-normalized cross-correlation vector after computation
I have a C++ code that computes cross-correlation for a given 2 vectors as input. It doesn't have an implicit normalization or normalized implementation of cross-correlation. But I would prefer a ...
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255
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The normalized cross-correlation of two signals
I wanted to calculate the normalized cross-correlation function of two signals.
I use the command ...
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0
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29
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How to Normalize the ideal Tx and Equalized Waveforms in LMS algorithm
Below mentioned steps has been done but I don't know if I am doing the right way of Normalizing the 2 signals.
Ref_1 = load('Tx_16QAM_25_New.txt'); % transmitted data
Tx(:,1)=Ref_1(:,1)+1i*Ref_1(:,2);
...
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1
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1k
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audio reprocessing for machine learning
I have a bunch of phone interviews where there is large sound volume difference between two voices in some of the interview audios, because they were recorded only on one side of the phone. May I ask ...
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2
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Am I supposed to normalize FFT in Python?
I'm sorry if this question is posed often, I can't seem to understand the answers already out there. I'm working with several forms of the Fourier transform, including the FFT, PSD, and spectrograms. ...
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357
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Autocorrelation - Understanding reduced correlation at periodic time shifts using np.correlate (versus statistical autocorrelation)?
I'm going through the Think DSP by Allen B. Downey, and I'm struggling to understand a specific aspect of np.correlate and how it differs from statistic autocorrelation. The question is at the bottom, ...
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2
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111
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Amplitude of a signal. [-1, 1] vs variants and MFCC implications
I've seen two sort of audio signals, one where the y-axis takes values between -1 and +1. I'd think this means 1 means loudest? Not really sure
And the second one I saw goes between $-10 000$ and $+...
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2
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2k
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MFCCs and mean normalization
I'm reading a blog about extracting MFCCs features for Machine Learning applications, but I didn't understand the following points about the mean normalization:
To balance the spectrum and improve ...
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985
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How do I normalize a predesigned IIR filter?
Obviously my question here is very similar to this previously asked question: How to normalize predesigned IIR filter coefficients to have unity gain?
Unfortunately, in the responses available to ...
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Removing DC Offset (via removing mean) of input and output signals affects their coherence
I have input $x$ and output $y$ signals (fs=10 Hz, length N=10800). I have removed DC offset via the following equation:
$x_{normalized} = 100 \frac{(x-\bar x)} {\bar x }$
where $\bar x$ is the mean ...
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Spectrogram power/magnitude normalization in analogy with image intensity normalization
In analogy with the 8-bit grayscale image color depth, in which the intensity of a sample pixel is normalized to a value between 0 and 255 by taking into account the minimum and maximum intensities ...
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How enhance amplitude of audio signal without distortion?
After FFT I've set to zero some frequencies and I'd like to enhance the amplitude in order to recover the leak.
I'd like to do a normalization in order to avoid distortion.
I've done in this way but ...
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0
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1k
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Basics of Normalizing Cross-Correlation with a View to Comparing Signals
I'm trying to understand how cross-correlation is used determine the similarity of two signals. This tutorial offers a very clear explanation of the basics, but I still don't understand how to use ...
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What is the relationship between angular frequency and normalized angular frequency
This is a slide from my lecture notes:
My professor used the following words " We denote digital frequencies with capital letters and analogue frequencies with lower case letters"
The problem I have ...
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521
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Why do we use normalized angular frequency?
Let's say we want to generate a signal in MATLAB, using sin, representing the A-major chord (440 Hz, 550 Hz, 660 Hz, each with amplitude 0.1).
I know we have to use the normalized angular frequency. ...
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Overlap/add time-domain audio frames: How does normalization/scaling work with overlap greater than 50%?
I am attempting to overlap-add time-domain audio frames in a real-time context (with a continuous stream of data coming-in). Each frames consist of 1024 samples and have been previously "Hann" ...
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1
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1k
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why multiply grayscale images by 256
I am a newbie in image processing. in an open source code for convolution neural networks, the author is multiplying a gray scale image from MNIST dataset by 256. Please can any one tell me why?
...
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385
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Correctly scaling Power Spectrum and Correlation Function of Galaxies from Mock Catalogues
I'm currently writing a code to compute the two-point correlation function of a set of galaxies. As I work with a loooot of galaxies, it was suggested to me not to do it in real space, but to compute ...
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The concept of normalized frequency
This question has already been asked and answered, but the motivation behind the use of normalized frequency units still evades me.
The Discrete Time Fourier Transform $$X(\tilde{ \omega }) = \sum_{n=...
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What information does the abs(normalized_image - normalized_quantised_image) carry?
Given a grayscale image X2
And its (under)quantised version with 3 bits depth X3
What information does the abs(X2_normalized - X3_normalized) carry?As an example ...
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647
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Pole zero plot, normalizing frequency response plot?
I'm asked to plot the frequency response (amplitude) given a specific pole-zero diagram.
$$ H(z) = H_0 \frac{\prod\limits_{m=1}^{M} (z - q_m)}{\prod\limits_{m=1}^{M} (z - p_m)}$$
$$ H(e^{i\omega}) =...
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2
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2k
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Normalization of a signal with respect to another signal
Imagine that I gave one signal (call it master signal) with respect to which I would like to normalize all the others. How should I treat it mathematically? Any ideas?
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Design a filter which passes all frequencies except $\omega=\pm\frac{\pi}{2}$ and plot its pole-zero diagram
Also draw its normalized frequency response.
What is the ROC?
This has to be done in z-plane so there must be two poles at $+i$ and $-i$ since they cannot be included in region of convergence. Is my ...
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Making audio clips comparable in terms of RMS
I have a challenging question on how to normalize several audio clips so that they are comparable (similar) in RMS but without the clips clipping (having values over -1 and 1). Is there a systematic ...
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391
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Methods of scaling FFT power
I wanted to know what are the well-known methods of scaling the FFT power of a signal? I am referring to EEG signal but this should apply to all signals I guess.
I need to plot the powerspectrum/PSD ...
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1k
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Normalizing audio waveforms code implementation (Peak, RMS)
I have some audio data (array of floats) which I use to plot a simple
waveform.
When plotted, the waveform doesn't max out at the edges.
No problem - the data just needs to be normalized. I iterate ...
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309
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Normalization of signal against reference
I am trying to figure out if there is any standard way of normalizing a sequence such as a time series against a reference sequence. I am not an expert on signal processing but I was hoping someone ...
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