Questions tagged [classification]

is a system of grouping objects of study or observation in accordance with their common features. The classification problem is a formalized task in which a set of objects (cases), separated in some way to classes.

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Signal Labelling in python

I would like to show the problem that I want to solve with python and I can't find the best solution. It turns out that I have a very long signal, about 30 minutes, sampled with a frequency of 2KHz, ...
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44 views

Performance assessment metrics for biometric identification

Suppose that we have a fingerprint database consisting of 1000 images from 100 persons (10 images per person), and it is required to design a system to identify the person from his fingerprint image. ...
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21 views

Z-score normalization

I have extracted the wavelet features from an image and then applied z score normalization on the extracted features. I noticed that the z score normalization step has a noticeable effect on ...
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1answer
36 views

Extracting "frequency domain features" from signal for classification

I have a real signal with only nonnegative values (actigraph measurements). Many papers say they use "frequency domain features" for classification, such as mean, variance etc. But I'm ...
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34 views

Classification of very noisy EMG signals

I'm an absolutely newbie to signal processing. I'm trying to classify EMG signals which are very noisy (decibel values are more than -70 dB in some cases). After applying EMD technique these values ...
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Predicting the class of an event or its probability in n days after

I have a dataset with time series and for some of them (test sample) dates are known (maybe from zero to several pieces per time series), which we will call target events, the occurrence of which I ...
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14 views

Can we do image classification using bag of features and classifier other than SVM

I developed code for image classification using SURF features , bag of features as instructed in https://www.mathworks.com/help/vision/ug/image-category-classification-using-bag-of-features.html but ...
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16 views

Measure of Separability for Classification Problems

Hello are there any methods, for a given set of features (possibly high dimensional) and labels (class 1 and class 0), to measure how "separable" the data is? E.g., if the problem was 2 ...
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1answer
73 views

How to detect rectangular images inserted into another image?

It's just for a simple binary classification, so it's not needed to find the location of the inserted image or the content. I'm only interested in checking whether something like that is present or ...
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51 views

Audio classification without deep learning

I am looking for code or papers, for methods to classify audio signals, without the use of deep neural networks (DNN). A current paper which reviews methods will also be most welcome. I have searched ...
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30 views

What is the best feature selection method when working with audio and a binary output?

I am working on a problem as I am trying to determine which is the best feature to use when working with audio. I have a piece of audio and I am trying to determine which is the best feature to use ...
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1answer
55 views

High FIR order in time critical classification task

I have a question regarding filtering (bandpass in my case) as a preprocessing step before a classification task. The frequency band I am interested in lies between 0.5 - 22 Hz which results in a ...
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2answers
105 views

why is the signal divided into epochs in EEG classification?

I'm new in EEG signal classification. Studying the literature on this topic, I wonder why the EEG signals are divided in epochs, so, instead of classifying the whole signal all at once, we usually ...
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652 views

Upsampling vs downsampling. Which to use when?

Downsampling reduces dimensionality of the features while losing some information. It saves computation. Upsampling brings back the resolution to the resolution of previous layer. My question is which ...
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59 views

How mic setting will affect audio classification model?

I have audio samples with three classes : 100 audio samples : class 'A' 100 audio samples : class 'B' 100 audio samples : class 'C' ...
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49 views

Estimation of Power Spectral Density

I'm learning some basic signal processing to use in my research. So I'm trying to solve this combined signal: $x(t)= \text{sin}⁡(60\pi t+\theta)+ 0.5 \text{sin}⁡(120\pi t+\theta)+ 0.3 \text{sin}⁡(...
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Using the log power spectrum as features for a Classifier

I have a set of time series signals for which I have to develop a anomaly detection algorithm. I am considering using classifiers like SVM to do this. However I am confused about how to properly ...
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1answer
134 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 ...
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3answers
116 views

System classification: unit-time delay

I'm reading a book on linear systems and I can't understand why the unit-time delay is a distributed system. This is the example given in the book: I understand that the initial state of the system ...
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Image classification in c

i have to do a project for university which is basically to program a tool to classify small greyscale images like those below into person or non-person, in C. The project is scheduled for around ...
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1answer
59 views

How to classify audio files based on their ZCR, energy, and enthropy of energy features?

Let's say I wanna classify the audio files of race car exhaust and normal car exhaust. I attain few features such as ZCR, energy and enthropy of energy from the training set and I wanna build the ...
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1answer
47 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 ...
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1answer
65 views

audio classification based only on first few seconds

I record audio notes on my recorder, and each belongs to a certain category ("work", "parenting", "miscellaneous", etc.). At the beginning of each recording, I say the name of the category, then stay ...
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1answer
76 views

Audio Activity Detection and Classification

I am starting a new project. Actually, my real intention is to learn speech recognition but for warming up I want to improve in audio signal processing. In my project, I aim to record sounds except ...
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1answer
50 views

Objective Noise Classification for speech enhancement

I'm working on my thesis and it is about an speech enhancement system to use proper noise reduction method/algorithm for different types of noise. I want to test and compare some filters/algorithms ...
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2answers
319 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 ...
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1answer
29 views

Gender classification using Periocular Region [closed]

I have a dataset of the periocular region, I have images of the male and female periocular region but they are only labeled as left and right periocular region, Folder is a mixture of male and female ...
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Tracking a signal

I have two signals representing steering wheel angles, one representing the driver’s inputs (red), while the other one represents the system’s reference signal (blue). I want to estimate in real time ...
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59 views

MFCC parameters for gunshot recognition

I'm writing a gunshot detector software. I'm using this article as reference:https://arxiv.org/ftp/arxiv/papers/1706/1706.08759.pdf. For now, my software is able to recognize an impulsive sound. Now, ...
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1answer
775 views

MFCC classification model

I have audio samples which MFCCs i want to train, but there is a problem. I can't find a classification model, because the samples have different length and consequently the MFCC matrices will also ...
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1answer
90 views

Covariance block of MUSIC Algorithm

I am implementing MUSIC algorithm in Verilog, and I need to implement the blocks in following order $$\text{Input signal}{\longrightarrow}\text{Co-variance/Correlation matrix}{\longrightarrow}\text{...
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9 views

impact of lombard effect on language identification

I have collected samples for 2 different languages. Now i need to extract MFCC features and identify which language using wave files. I need to do classification using R studio and perform an ...
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1answer
29 views

Feature normalization (scaling) for Hyperspectral images

have been straggling with the concept of feature normalization for the hyperspectral images. Respect to my problem I have attached a picture of my problem which clearly stands the issue which I have.
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71 views

Can I have some feedback on this research paper on vibration diagnostics?

I have submitted this paper "Detecting a Valve Spring Failure of a Piston Compressor with the Help of the Vibration Monitoring" to figshare.com. I would like to get some feedback on the methodology ...
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41 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 ...
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1answer
34 views

What kind of noise is city noise?

White, pink, brown...? In general, to what category does it subscribe the spectrum of city noises, like traffic noise, ambulance/police siren, alarms, etc, put together? If the question is too broad, ...
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1answer
64 views

Is there a public repository of labeled sound files coming from an industrial area?

I know about the UCI Machine Learning Repository for ML datasets; Where could one find sound files e.g. in wav format, which are partially or completely labelled?
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1answer
5k views

Python: Least Squares Support Vector Machine (LS-SVM)

I'm looking for a Python package for a LS-SVM or a way to tune a normal SVM from scikit-learn to a Least-Squares Support Vector Machine for a classification problem. The goal of a SVM is to maximize ...
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1answer
115 views

Video processing to detect a logo in frames

I am trying to detect a TV channel logo inside a video file, so simply given an input .mp4 video, detect if it has that logo present in all (or most) of frames or not (or maybe what percentage of ...
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66 views

Classify type of motion using decision trees and features

Consider a decision tree for separating between the following activities: Sitting, Driving, Running, Walking. Assume that you are given the following features: Dominant frequency (F1), meanX, meanY, ...
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47 views

Accelerometer to track Potholes

So I am trying to make an application to track potholes in a road. I am using accelerometer readings for that. Assuming that the phone is mounted in a car and our orientation doesn't change. After ...
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5answers
1k views

How to deal with audio with different length in Audio Classification

Currently, I am trying to work with the Dataset UrbanSound8K to try some Audio classification. And I got stuck in the preprocessing step already. Since the audios are of different lengths, like 4 ...
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1answer
123 views

How to obtain the probability of a detection?

I will use a specific example from image processing to illustrate my question, but I'm actually interested in the higher level / abstract procedure. I must lack the specific vocabulary and my hunch is ...
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2answers
497 views

Calculate lines of the Inverse of Autocorrelation Matrix

I need to calculate the inverse of a autocorrelation matrix $$\mathbf R_{xx} = E\left\{\mathbf x \mathbf x^T\right\}$$ Where the samples $\mathbf x$ are $266000\times 1$ vectors, which means I'll ...
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42 views

How to do training of the Ant Colony used for classification?

I'm using the Ant colony for my database of EEG signal for the detection of epileptic seizure. I read this article and I'm confused. Is this algorithm for training set to genertae rules or just for ...
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71 views

If a K-NN ($ k $ Nearest Neighbors) Algorithm Performs Very Well for Low $ k $, Can Something Be Inferred About the Data Set?

I am running kNN on a very small data set for binary classification. Each class has 100 samples. I am getting the best performances for $k=1$ and $k=3$. Can I deduce information about my data set ...
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Classification test by embedding true positives in high frequency recordings

I'm evaluating a cyclostationary approach to signal classification. My first step in doing so was generating signals and embedding them into a few specified parameter sets of the Watterson channel ...
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1answer
126 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 ...
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1answer
2k views

From MFCC to Machine learning. What are the steps?

I was able to get a dataset with MFCC coefficients. However, depending on the length of my sound file I get a different sized matrix. As in, 13 (13 MFCC coefficients) by XXX, where XXX will vary ...
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547 views

What would the target matrix to train Neural Network?

I'm new at Artificial Neural Network and I'm using MATLAB developing Facial expression recognition and There are six expressions ; I'm not able to understand about How to create a target matrix? My ...