Questions tagged [feature-extraction]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1
vote
1answer
39 views

What is the purpose of dividing an audio signal into segments and analysis each segment?

I read bunch of materials for extracting feature from audio signal and they all tell me to break signal into segments, why don't we analyze all the audio signal? I don't know what are the advantages ...
1
vote
2answers
99 views

Why do we need multiple layers in each octave and multiple octaves in SIFT?

I skimmed through the SIFT paper. I understand that there are multiple octaves, which are composed of multiple layers. The layer $k$ of an octave (btw, where does this name come from?) corresponds to ...
0
votes
2answers
186 views

Down sampling an EEG signal

I have a set of 10 minute EEG signals that were sampled at 400 Hz and have 16 channels which corresponds to a 16x240000 matrix. These EEG signals belong to two different classes. I am trying to ...
0
votes
0answers
10 views

Mutual information smaller on data subsets compared to entire data set

I am estimating the mutual information for a continuous data set using the kNN-based mutual information estimator proposed by Kraskov et al [1]. Lets consider two features $X$ and $Y$, and the ...
0
votes
0answers
13 views

how to implement Bark filter bank on the power spectrum for PLP feature extraction?

So the implementations for PLP feature extraction I have seen in python and Matlab, are as follows: suppose the FFT features of an audio signal are of the size 257 (512 point FFT). if we have one ...
0
votes
0answers
24 views

How can I stitch bottom of some image to topside of another image by erasing as much overlapped image as possible?

I have 2 images of size 1920*1080 and I want to try image-stitching on them. These are images (images are from wind turbine blade.) This is the first image And the second image. I already have ...
0
votes
0answers
15 views

How does Lowe's ratio test work when you compute more than 2 nearest neighbours?

Lowe's ratio test can be used to discard matches that are possibly irrelevant or noisy. However, it isn't clear to me how the ratio test should be performed when you retrieve more than 2 nearest ...
0
votes
1answer
26 views

KLT for an ECG Signal

I am currently searching for methods of feature extraction from an ECG signal and I've stumbled upon the Karhunen–Loeve Transform. I've read some papers and I think I get the basics but my question ...
0
votes
1answer
187 views

how to extract a radio signal features with python?

I have a dataset of radio signals that i want to classify. So, I decided to extract features. After some googling, I have noticed that I have to calculate moments, cumulants, Kutosis and skewness to ...
0
votes
0answers
23 views

How to save MFCC features and frame energy of several wav files to one .npz file for machine learning training?

I am creating a English-Italian corpus of around 100 hours of English audio from LibriVox aligned with their Italian textual translation. The alignment is at a sentence level and the corpus consist of ...
0
votes
0answers
19 views

Rule of thumb / Best practice for Audio (voice) data normalization for use in Classification

TRIVIAL QUESTION: I am currently working with some audio data of speech utterances. I am attempting to perform classification on the data based on the phonemes. This means that I manually label the ...
1
vote
1answer
39 views

Understanding the Threshold Process in Harris Corner and Edge Detector

I have read the paper Chris Harris , Mike Stephens - A Combined Corner and Edge Detector about the Harris Corner and Edge Detector, but I didn't understand the point that after low and high threshold ...
0
votes
1answer
252 views

extracting MPEG-7 low-level audio descriptors using essentia

According to https://www.ntnu.edu/documents/1001201110/1266017954/DAFx-15_submission_43_v2.pdf, the audio processing toolbox Essentia includes the 100% of MPEG-7 low-level audio descriptors. However I ...
0
votes
2answers
82 views

log base in log-power spectral features

Is the log in log-power spectral features natural logarithm, or common log of base 10? does it even matter? I found sources for how to calculate it, but they all call it 'log'. no one mentions the ...
0
votes
1answer
773 views

Comparing band-pass filters and convolutional kernels?

I am currently working on extracting features for speech recognition purposes. I wanted to try an approach similar to MFCC features in which the center frequency of each band pass filters are placed ...
2
votes
1answer
393 views

Common Spatial Pattern for EEG Signals

I am having difficulty in understanding the use of CSP for EEG signal feature extraction and subsequently. Since I am using two classes, this query will be restricted to it. In essence CSP requires 2 ...
0
votes
0answers
14 views

Calculating Marginal Hilbert Spectrum across IMFs using mhs() in MATLAB

I'm working on an EEG dataset from which I need to extract the power of five different frequency bands. I'm doing this by performing Hilbert Transform on the ICA activations from performing channel-...
0
votes
1answer
72 views

Extract same in phase signal from 3 different sources with shared delayed noise?

If I have 3 signals coming from 3 microphones with noise $n$ delayed like this: $S_1(t) = x(t) + n(t+\phi_1)$ $S_2(t) = x(t) + n(t+\phi_2)$ $S_3(t) = x(t) + n(t+\phi_3)$ Their shared feature $x(t)$...
0
votes
0answers
33 views

Wind turbine vibration analysis approach

This is going to be a bit of a long post. My questions are: Do the 5 signal processing steps look "correct"? Next steps could be to perform order analysis, and extract features from time, frequency, ...
0
votes
0answers
29 views

How to approach Feature Extraction and Feature Selection part in machone learning in python?

I am a bit new to machine learning and I have the following questions: Question 1: When dealing with feature extraction with signals from sensors, what is the typical approach to extract features ...
0
votes
0answers
53 views

Feature extraction for exponentially damped signals

I am looking into exponentially damped signals where it is a stationary signal (after implementing the Adfuller statistical test) and I would like to look into how can I extract meaningful features ...
1
vote
1answer
123 views

How to Describe the Color of an Image Patch?

I want to describe the color of an image patch (say, of size 5x5) centered around a pixel of an RGB image. The most straightforward way to do that is to calculate the average color over that patch and ...
1
vote
1answer
45 views

What is the HOMING operator?

I was reading "Optical Recognition Systems" book and in chapter 3.3.2.3 where methods for full genetic programming are described, a paper is describing an ADF (automatically defined functions) like ...
0
votes
1answer
39 views

which features fundamental frequency is correlated?

I'm unable to compute $f_0$ (fundamental frequency) in librosa feature extraction. By ready much in github issues check the second comment. I see that $f_0$ is ...
0
votes
0answers
49 views

How to normalize features after windowing for future test data?

I have an eeg data about 10 minutes. I want to extract some features (e.g. statistical features, power spectrum features, interchannel features, . . .) from this data to apply them to the machine ...
3
votes
2answers
4k views

ORB Algorithm: What Is Intensity Centroid?

So, I am reading a paper about ORB: An Efficient Alternative to SIFT or SURF and it happens to calculate the direction of corner from it center . According to Rosin the author of the paper;moments of ...
0
votes
0answers
15 views

What features can be extracted from accelerometer sensor used for Structural Health Monitoring (SHM)?

I am using dataset found online for SHM which uses accelerometer sensor to detect changes in the structure. I know that I can transform the time-domain data into a frequency-domain and into a time-...
1
vote
2answers
346 views

Scratch Detection On Noisy Textured Surface

I wish to extract long thin scratches from the noisy background image.I have tried several ways such as stacking smoothed image with input image to remove some of the noisy background patch before ...
1
vote
0answers
35 views

Calculate the tension of a triad of notes

I'm trying to implement and calculate the tonal tension of a triad (and its harmonics) following the definition given here: https://pdfs.semanticscholar.org/f05e/56c9548fa18c64efeed248742e3a6afb0c02....
0
votes
0answers
15 views

What features can I extract from optical fibre signal?

I have sensors placed in pipelines and I have amplitudes coming from it. I want to detect the type of activity taking place at the sensors(like digging,tunneling,clamping etc). So I have a signal ...
7
votes
1answer
5k views

What's the correct graphical interpretation of a series of MFCC vectors?

I'm studying speech-recognition, in particular the use of MFCC for feature extraction. All examples I've found online tend to graph a series of MFCC extracted from a particular utterance as follows (...
1
vote
1answer
116 views

Fast Vocal Tract Length Normalization(VTLN) implementation?

My team is building a speech recognition model. As far as I know, Vocal Tract Length Normalization (VTLN) is an effective warping method that may help improve the model performance by diminishing ...
0
votes
1answer
24 views

What are the ranges of values for each audio feature/descriptor?

I need to normalize some audio feature measurements I've done with the software Wolfram Mathematica. Coming from a non signal processing background, I have some difficulties understanding what ...
2
votes
2answers
467 views

How to extract features of individual spikes in non-negative signal?

I have data of non-negative (in the sense there's no signal below baseline) spiking waveforms, which are in the form of a 1D array of numbers: Spikes that cross some threshold are considered real ...
1
vote
1answer
508 views

what is the output of MFCCs?

I had calculated 13 MFCCs coefficients of a speech signal and i got output in the form numerical vectors please see below figure. My confusion whether it is in time domain or frequency domain. suppose ...
1
vote
2answers
242 views

Understanding of Histogram-of-Oriented-Gradients

I am learning about HOG and I understand it from here. A well-explained page with an example. I am not understanding this concept that how it works A 16×16 block has 4 histograms which can be ...
4
votes
2answers
816 views

Using Convolution as Feature Extraction

I am now studying image processing in my spare time. My understanding of convolution is about 'response to a specific filter': When we have a raw image, or raw signal; and a filter, aka kernel; we ...
0
votes
1answer
371 views

How can I extract information about timbre from a .wav file. In which form can I study those features?

To study the frequencies of a piece of audio, we can generate a spectrogram from that audio file. I'm wondering how the features of timbre are saved in such tiny wave files, and how we can extract ...
0
votes
1answer
134 views

Extracting feature from audio track using DWT

Our teacher gave us an assignment: Write a program to transform an audio track to time - frequency domain, and create a vector include at least 4 features extracted from transformed output signal. I ...
2
votes
0answers
126 views

How do I extrapolate a 1D chirped signal?

Following a past question, I'd like to extrapolate a signal like the one below: (red is signal, blue is the the extrapolated ) ...
2
votes
1answer
1k views

MFCC delta: How to compute delta, in real time, with no future frames?

I am trying to compute Delta coefficients for real-time audio analysis. As far as I know, a valid formula is: $$d_t= \frac{\displaystyle\sum_{n=1}^{N}n\left(c_{t+n}-c_{t-n}\right)}{2\displaystyle\...
1
vote
1answer
43 views

How does a telephone change your voice? [closed]

Is it due to vocal length normalization during MFCC? Please be kind enough to explain.
-1
votes
1answer
35 views

Is it possible to classify biosignal data based on feature extraction through multiple linear regression model? [closed]

i have 16 channel 2 class motor imaginary right hand ,right leg data.IS it possible to classify this through multiple linear regression model based on feature extraction?can i classify 3 class data ...
1
vote
2answers
2k views

Is there a program to extract features from an audio signal?

I am looking for a way to take a .wav file and extract features from it that could be used for further classification (the features could be MFCC statistics, an autoencoder representation, etc.). I ...
1
vote
1answer
3k views

Feature Extraction of FFT for One Class SVM

I'm looking for a good way of extracting features from the frequency domain of vibration data for a one-class support vector machine. The image below shows an example from the dataset found in this ...
0
votes
1answer
62 views
0
votes
1answer
849 views

MPEG-7 low-level audio descriptors

I'm working on an application which need to use the full set of 17 MPEG-7 low-level descriptors. Is there any library I can use for it? Preferably with a Python wrapper/API...
1
vote
0answers
41 views

zernik moments and Local binary pattern

Both of zernik moments and Local binary pattern (LBP) are feature detectors and can achieve rotation invarient. How can they achieve rotation invarient over an image? What are the advantages of ...
1
vote
1answer
2k views

How to extract prosodic cues from a wav file using Python

How do I extract the following features as from wav files in Python - Voicing rate (Voice rate) - frequency of phonemes while speaking, and represents the pace of a conversation Number of ...
-1
votes
3answers
366 views

Features Used for Instrument Recognition?

I'm building a neural network for instrument recognition based on the IRMAS data set. However, I'm a bit at a loss for what features to use. MFCC seems to be quite popular but extracting this per ...