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Questions tagged [normalization]

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Is it possible to normalize FIR filter coefficients to "perserve gain on average"?

Let's say we are given a random discrete time FIR filter. I'm wondering if there is a standard way to normalize its filter coefficient in a way to make the filter "energy preserving on average&...
bluenote10's user avatar
0 votes
1 answer
23 views

Constraints in Dynamic Time Warping for Speech

The Dynamic time warping is applied for time normalization. As shown in the diagram, two different signals with $Tx$ and $Ty$ time instants, are time-normalized to have $T$ time instants. $\phi$ is ...
Anantha Krishnan's user avatar
1 vote
0 answers
63 views

Normalized audio cross corelation

I'm trying to cross corelate two audio files to see where they line up. In scipy im doing: correlation = correlate(audio1, audio2, mode='full') Given the graph ...
Ethan Itovitch's user avatar
5 votes
1 answer
82 views

What algorithms exist for dynamic audio normalization?

I'm manually editing the WAV files for an audiobook. There are often sections where I have to amplify a section, and then amplify sub-sections due to the variability of the quality of the original ...
Robert Rapplean's user avatar
0 votes
2 answers
2k views

How to normalize the FFT?

I want to normalize my FFT signal. From this page it says that we can normalize it by dividing the FFT result by the lenght of the signal in time domain. On the other hand, my supervisor told me that ...
Apinorr's user avatar
  • 125
1 vote
0 answers
86 views

STFT normalization

In Scipy's implementation of STFT, an argument allows to scale the result as a spectrum or as a psd : ...
hugopb82's user avatar
3 votes
0 answers
78 views

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 ...
Tom's user avatar
  • 131
0 votes
0 answers
102 views

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# ...
McGuireV10's user avatar
0 votes
1 answer
47 views

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 ...
Văn Sư Hồ's user avatar
0 votes
0 answers
55 views

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 ...
Show's user avatar
  • 1
6 votes
1 answer
745 views

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. ...
Lion Lai's user avatar
  • 213
0 votes
0 answers
23 views

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 ...
MRR's user avatar
  • 25
1 vote
0 answers
240 views

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 ...
psj's user avatar
  • 71
1 vote
1 answer
50 views

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 ...
marpuech's user avatar
1 vote
0 answers
120 views

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 ...
EnigmAI's user avatar
  • 111
0 votes
1 answer
209 views

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. <...
Amy 's user avatar
  • 53
1 vote
1 answer
62 views

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 $$g_{s,u,\omega,\theta}(n) = \frac{K_{s,u,\omega,\theta}}{\sqrt{s}} e^{-\pi(n-u)^2/s^2} \cos[2\pi\omega(n-u)+\theta]$$ ...
J. Herrera's user avatar
1 vote
0 answers
443 views

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 ...
Lorenzoncina's user avatar
1 vote
1 answer
41 views

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: ...
JXuan's user avatar
  • 55
1 vote
1 answer
59 views

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 ...
Molem7b5's user avatar
1 vote
1 answer
1k views

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 ...
Jazim Sohail's user avatar
0 votes
1 answer
591 views

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 ...
Noha's user avatar
  • 349
1 vote
1 answer
878 views

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....
Schach21's user avatar
  • 162
1 vote
2 answers
146 views

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 ...
Ivo Tebexreni's user avatar
1 vote
1 answer
45 views

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 ...
kkawabat's user avatar
  • 133
0 votes
0 answers
48 views

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 ...
Koen's user avatar
  • 1
1 vote
2 answers
2k views

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\...
Nave Tseva's user avatar
0 votes
1 answer
106 views

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 ...
neolith's user avatar
  • 147
0 votes
0 answers
102 views

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. ...
havakok's user avatar
  • 682
1 vote
0 answers
111 views

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 ...
skrowten_hermit's user avatar
0 votes
0 answers
349 views

The normalized cross-correlation of two signals

I wanted to calculate the normalized cross-correlation function of two signals. I use the command ...
Malum Wolfram's user avatar
0 votes
0 answers
30 views

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); ...
Umar Farooq's user avatar
0 votes
1 answer
1k views

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 ...
Blue482's user avatar
  • 103
6 votes
2 answers
18k views

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. ...
Petra's user avatar
  • 177
0 votes
1 answer
429 views

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, ...
minifigmaster125's user avatar
0 votes
2 answers
121 views

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 $+...
Wouter Vandenputte's user avatar
1 vote
2 answers
2k views

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 ...
Abdulkader's user avatar
0 votes
1 answer
1k views

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 ...
Denis Barkats's user avatar
0 votes
0 answers
546 views

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 ...
Jack's user avatar
  • 1
1 vote
1 answer
1k views

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 ...
strangeloop's user avatar
0 votes
0 answers
171 views

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 ...
Ausilia's user avatar
2 votes
0 answers
2k views

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 ...
John Strong's user avatar
3 votes
1 answer
3k views

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 ...
Scavenger23's user avatar
0 votes
1 answer
556 views

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. ...
Niousha's user avatar
  • 467
1 vote
1 answer
2k views

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" ...
Darius Petermann's user avatar
0 votes
1 answer
1k views

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? ...
O'noel's user avatar
  • 3
1 vote
0 answers
401 views

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 ...
mivkov's user avatar
  • 111
-1 votes
1 answer
1k views

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=...
Mussé Redi's user avatar
0 votes
1 answer
121 views

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 ...
iviO's user avatar
  • 3
-1 votes
1 answer
687 views

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}) =...
CuriousButDumb's user avatar