# 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&...
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### 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 ...
1 vote
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 ...
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 ...
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 ...
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1 vote
86 views

### STFT normalization

In Scipy's implementation of STFT, an argument allows to scale the result as a spectrum or as a psd : ...
• 51
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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 ...
• 131
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# ...
• 101
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 ...
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 ...
• 1
742 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. ...
• 213
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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 ...
• 25
1 vote
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 ...
• 71
1 vote
49 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 ...
• 11
1 vote
119 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 ...
• 111
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. <...
• 53
1 vote
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 $$g_{s,u,\omega,\theta}(n) = \frac{K_{s,u,\omega,\theta}}{\sqrt{s}} e^{-\pi(n-u)^2/s^2} \cos[2\pi\omega(n-u)+\theta]$$ ...
1 vote
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 ...
1 vote
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: ...
• 55
1 vote
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 ...
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1 vote
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 ...
587 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 ...
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1 vote
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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 ...
• 147
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. ...
• 682
1 vote
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 ...
348 views

### The normalized cross-correlation of two signals

I wanted to calculate the normalized cross-correlation function of two signals. I use the command ...
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); ...
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 ...
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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. ...
• 177
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, ...
121 views

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1 vote
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 ...
• 121
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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 ...
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 ...
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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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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. ...
• 467
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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" ...
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? ...
1 vote