# Questions tagged [feature-extraction]

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### 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 (...
672 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 ...
848 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\...
102 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 ) ...
390 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 ...
79 views

### Is there a way to extract the difference between the 2 signals? Fitting?

I'm very new to signal processing and have been struggling this far. I have a device that measures the signal due to the magnetization of iron particles. In order to calculate the response of the ...
376 views

### Palm Pilot Graffiti

I have been completely unable to find details on the underlying model that is used for the Palm Pilot Graffiti handwriting recognition. Given the computing power available for handheld PDA technology, ...
971 views

### Why is LPCC and LPC used in speech recognition

I am currently trying to understand why LPCC and LPC is being used in speech recognition and why? LPC as I understand is model similar to source filter model, modelling speech production, and LPC ...
555 views

### Detecting trough widths and locations in 1d signal

I have the following function obtained from averaging 2d camera image over one axis, where detection of aligned objects is desired: I need to detect (roughly speaking) locations and widths of the ...
42 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 ...
97 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 ...
111 views

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 ...
38 views

### How does a telephone change your voice? [closed]

Is it due to vocal length normalization during MFCC? Please be kind enough to explain.
2k 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 ...
2k views

### How do I get texture feature images from GLCM texture analysis?

In this paper under section 2. "Proposed Methodology", the author creates a GLCM from an image and then extracts texture features resulting in a new image for each feature. I've seen other authors do ...
24 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....
234 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 ...
35 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 ...
24 views

### Recognize irregular repetition of unknown feature (stamps at random locations)

I have an image which is generated by convolution between (1) a simple small patch and (2) larger image composed of localized point-like features (e.g. slat-and-pepper noise, sum of shifted $\delta$-...
436 views

### What are the drawbacks of Harris corner detector? [closed]

What are drawbacks of Harris corner detection when trying to match features in a stereo pair? I notice that whenever I use Harris corner detector to match features, images with strong occluded areas ...
57 views

### Image feature extraction for discrimination

I am using linear/quadratic discrimination to guess who is the artist of a painting. All the images are RGB format and I use matlab. I have used both original image and images that are resize to be ...
234 views

### VLFEat: How to extract the SIFT descriptor without SIFT feature detection?

I am using the MATLAB interface to the VLFeat toolbox in order to calculate a SIFT descriptor for image patches extracted around key points. Due to the greater framework of what I'm doing, I cannot ...
143 views

### Music Recommendation [closed]

I have idea of creating Content based Music recommendation system based on Music signals, Now I am asking how I can extract signal features from Music and how to represent them. There after I may find ...
1k 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 ...
117 views

### feature selection for classification for rare classes

I have a spectrogram of a signal and want to classify it. I used different features such as MFFC, the density of power spectrum and other common features and classify using the random forest, but I ...
96 views

### What is the use of perception calculation in Speaker Identification?

I'm currently trying to find audio features to train a neural network that distinguishes people, and I came across MFCC which is used a lot for speech verification. As far as I understand the ...
829 views

### Feature Vector from an audio signal [closed]

I want to develop a feature vector from an audio input. Up to now, I have identified fundamental frequency, max phonation time, timbre to be among the key features to be identified. Can someone ...
59 views

### How to make series circle shift invariant

I have a series of numbers. They may be integer, floating, or ...
1k 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 ...
115 views

### How signal moments work?

We know that moments extract important features of a signal that has no redundancy. For example Zernike moment gives us rotation invariant data of a signal like image or Fourier gives us frequency of ...
27 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 ...
13 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 ...
21 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 ...
13 views

### How to perform a speaker normalization of features before model training?

I am building a model using a supervised machine learning based on features I extract from speech signals. The features include MFCC, auto correlation and energy derivatives. According to this paper,...
62 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 ...
114 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 ...
104 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 ...
175 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 ...
601 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...
208 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 ...
84 views

### how to describe the color of a small 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 ...
69 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 $x(t)$...
568 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 ...