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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What are the advantages/disadvantages of image set classification over single image based classification?

I've seen a lot of people use image set classification recently. However, I haven't been able to find anywhere explaining the specifics of why image set classification is preferred. Are there only ...
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Peaks detection in delta lookback interval for real time algorithm

So I am developing a signal processing algorithm to classify in real time depending on how many peaks I have in my time series, in a delta. I implemented a circular buffer and accumulator to keep in ...
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Classification of a system

I am preparing for an examination and have a study guide that I feel has a couple of errors. The questions concern the classification of discrete time dynamical system. Here are the problems that I am ...
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Setting ERBSpace for Filtering Audio (Audio Classification)

I have been creating different representations of audio as inputs to neural networks. I set my ERBSpace lower and upperbound to (20hz,20000hz) for the cochleagrams. Works without a hitch, and the ...
Lyle's user avatar
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Resampling Soft Labels to handle Class Imbalance Issue

I am working on a classification project in which I am required to detect a component of a railway switch using time-series data collected from an inductive sensor. After some signal processing, I ...
Aisha Nasir's user avatar
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1 answer
100 views

Log of Filterbank Energies

In common literature, when generating spectrograms, mel-spectrograms, and cochleagrams, the log of the resulting filterbank energies is taken. Why is this done? I notice that my convolutional neural ...
Lyle's user avatar
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3 votes
1 answer
120 views

Using Soft Labels in Classification Models

(Updated) I am working on a classification project in which I am required to detect a component of a railway switch using time-series data collected from an inductive sensor. After some signal ...
Aisha Nasir's user avatar
1 vote
0 answers
67 views

STFT for Classification

I am working on this project in which I am using Short Time Fourier Transform (STFT) for feature extraction before applying classification model. I have a time series sensor data, applied signal ...
Aisha Nasir's user avatar
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3 answers
181 views

How is this system nonlinear

Suppose we have a system S and the relationship between $x(t)$ and $y(t)$ is $y(t) = x(t)+1$ However despite the fact the system is made of linear operators the system is not linear.How is this ...
Miss Mulan's user avatar
4 votes
1 answer
70 views

Classifying samples from complex Gaussian distributions

Assume we are trying to classify a sample $X$ as coming from one of two distributions: $$ \mathcal{CN}(\mu, \sigma^2) \\ \mathcal{CN}(\nu, \sigma^2), $$ where $\mathcal{CN}$ denotes a (circularly ...
Sami's user avatar
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1 answer
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Help on choosing compatibility test for classification algoritm

I have designed an algorithm for classification and I need to add a suitability or compatibility test for accepting a signal as an input. Basically, not all signals are suitable for processing by my ...
GGChe's user avatar
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2 votes
2 answers
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Distinguishing between intensity image plots

I have a series of intensity images generated by varying different scatterer geometries. An example of variation observed by varying the aspect ratio of these geometries is shown below in the three ...
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Decision level fusion

I have trained three deep learning models, and used majority voting for the final decision. Applying majority voting has led to improving the accuracy of the classifier with all test samples, except ...
Noha's user avatar
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2 answers
68 views

Why is automatic modulation classification hard?

There is a huge amount of research into automatic modulation classification (AMC) using machine learning.. Why is AMC a hard/difficult problem that we need to use machine learning or even deep ...
Pyfisch's user avatar
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1 answer
181 views

Classification of Signals using Features Extracted from Wavelet Scattering Coefficients

I have a set of RF signal samples of 2s length each recorded at 2MHz sampling rate, such as this IQ file: https://www.dropbox.com/s/dd6fr4va4alpazj/move_x_movedist_1_speed_25k_sample_6.wav?dl=0 I can ...
rshah's user avatar
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Classifying STFT from multiple signal samples

I have a collection of signals (IQ wav) split up into ~2s samples of sampling rate 2MHz, and can collect the STFT information from these samples through the following code: ...
rshah's user avatar
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3 answers
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Is it possible to classify signal samples using STFT without (image-based) spectrograms?

I am aiming to conduct a classification-based study using signals collected from various devices. I've researched other approaches which make use of STFT for producing a spectrogram for speech and EEG/...
rshah's user avatar
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373 views

Identifying Instruments within a music file

Say I have a file that contains a few musical instruments, how can Identify the name of each one (ultimate goal) or at least the category they belong to, like wind instruments? For example, if I load ...
adimath's user avatar
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Classifying 2 Classes of Ultrasound Signal Using Machine Learning by Frequency Domain

I have two samples which, when exposed to ultrasound, emit their unique frequency responses. As can be seen in the attached figure, where the exciting frequency is 2.25 MHz, sample 1 emits a strong ...
nasrin's user avatar
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1 answer
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Feature Extraction for Image Classification of Vegetables and Fruits Using Classic Computer Vision Techniques

I don't know if this is the right place to ask this but lets go. I am a beginner in computer vision and I have a project of fruit recognition based on Kaggle's Fruit 360 dataset. I know that CNNs are ...
Manveru's user avatar
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Classification performance metrics of two simultaneous classification systems

I am working on a classification algorithm to recognize a sound anomaly. I have two audio classification systems placed at different locations. I would like to interconnect these systems and base my ...
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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. ...
Noha's user avatar
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1 answer
329 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 ...
qalis's user avatar
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1 answer
56 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 ...
Debbie's user avatar
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1 answer
276 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 ...
Tobias Hermann's user avatar
-1 votes
1 answer
229 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 ...
havakok's user avatar
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0 answers
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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 ...
suyol854's user avatar
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1 answer
65 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 ...
handsitter's user avatar
0 votes
2 answers
140 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 ...
volperossa's user avatar
2 votes
1 answer
5k 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 ...
Vishal Rana's user avatar
1 vote
2 answers
99 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' ...
Aaditya Ura's user avatar
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61 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}⁡(...
AMEER's user avatar
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0 votes
1 answer
159 views

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 ...
Kanmani's user avatar
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1 vote
1 answer
289 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 ...
Bilal's user avatar
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1 vote
4 answers
241 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 ...
João Pedro's user avatar
3 votes
1 answer
49 views

Simple Binary Image Classification (Person / No Person) 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 ...
stackexchanger1's user avatar
0 votes
1 answer
104 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 ...
panah's user avatar
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1 vote
1 answer
50 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 ...
KababChi's user avatar
-1 votes
1 answer
74 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 ...
philophilosophia's user avatar
-1 votes
1 answer
117 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 ...
black's user avatar
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0 votes
1 answer
60 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 ...
Filthy Man's user avatar
-1 votes
2 answers
549 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 ...
nechi's user avatar
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0 votes
1 answer
32 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 ...
AHF's user avatar
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0 answers
18 views

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 ...
Atem's user avatar
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1 vote
0 answers
70 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, ...
Hugo Sartori's user avatar
0 votes
1 answer
1k 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 ...
Armen  Hayrapetyan's user avatar
3 votes
1 answer
129 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{...
uzmeed's user avatar
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0 answers
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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 ...
swarna's user avatar
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1 vote
1 answer
49 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.
morteza's user avatar
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1 vote
0 answers
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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 ...
user38481's user avatar