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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14 views

What is the official definition of a feature in signal classification?

Nowadays read any paper or reference on signal classification scheme you would invariably come across the term "feature". What does feature mean exactly? What is considered a time domain feature, what ...
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3answers
115 views

Need critical help: How to detect and distinguish two very similar looking signals?

Hi guys I have a really tough signal processing question here. How do you detect and distinguish two very very similar looking waves? I need to distinguish between these two signals for an online ...
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1answer
31 views

Classification from a feature vector

I'm quite new to this; I'm try to classify textures as defective or non-defective. I've used a Gabor filter bank with Matlab which outputs a column vector of the Gabor features of an image. I have a ...
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1answer
45 views

What are characteristics of shadows in an image given an outdoor setting from an image processing point of view?

I'm wondering what basic characteristics of shadows are. I'm looking from a camera image/video processing point of view. I'm considering the case of an outside scene in direct sunlight. These are the ...
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0answers
18 views

Classification of shadow border points in an image

I'm working on a problem concerning the classification of features (Fast features in my case) on shadow borders in an image. I would like to discriminate features on shadow borders from all other ...
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0answers
20 views

Isolated word classification using LDA

I would like to do a project on speech processing. How can I classify isolated word using linear discriminant analysis for my speaker recognition project.
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20 views

Common Spatial Patterns importance

The Algorithm Common spatial pattern, is used very frequently in EEG signal processing , and it's based on the idea of maximize variance of one class , and minimize the variance the other class , ...
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1answer
27 views

Pyramid Match Kernel: How to fit grid around data points?

I am planning to use Pyramid Match Kernel method for object recognition from depth images: I am going to extract a set of feature vectors $x \in \mathbb{R}^d$ for each object instance and then I want ...
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16 views

Good color distance metric for classifying color pairs

I have some two tone origami paper. This particular paper comes in six types, each with a different pair of colors. Here's an image that shows all six: Given a picture of one of these sheets, I ...
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29 views

Outlier removal before or after Kalman filtering?

I am getting radar data points in form of (x,y) coordinate system relative to my position every ms.[around 10-15 data points]. Now, inorder to have better position estimate of the points, I would like ...
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1answer
53 views

Classifying animated GIFs as animation or film

Is there any known way of differentiating between frames of real footage and animated content? It seems like there's probably range of colors more likely to appear in a histogram for real footage, or ...
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23 views

Useful features for classifying color images

I have two sets of images. In one set, the background and foreground differs significantly in color (either background is dark and foreground is light or vice versa). What would be some useful ...
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1answer
28 views

Binary classification of grayscale image with little texture

I want to carry out a binary classification/segmentation on a grayscale image with very little texture. The only prior knowledge that's supposed to be available is that the object of interest is ...
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23 views

Fixed-length training data from variable-length signals for dictionary learning

My question relates to the topic of dictionary learning for 1-D signal classification. In a nutshell, I have a training dataset of N signals that belong to one of two classes, and I want to find a ...
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1answer
112 views

How to classify accelerometer data?

I am trying to detect if a car did accelerate or did brake by using the accelerometer of the iPhone. In the figure below I plotted the collected data. (To collect the data the phone was laying flat ...
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1answer
37 views

How to choose the number of codewords in bag of words model

In the bag of words model, generally is it better to have more codewords or less? For example, if I have 1000 x 20 raw features, then what would be good value for codebooks? I am thinking of smaller ...
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0answers
30 views

Comparing two signal outputs from two clients on a networked computer game to identify lag

Basically, I'm running a server and two clients of the Unreal Engine and trying to figure out if there is lag in player movement on one of the clients (the clients are different in way that's not ...
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1answer
717 views

Feature extraction for sound classification

I'm trying to extract features from a sound file and classify the sound as belonging to a particular category (eg : dog bark, vehicle engine e.t.c). I'd like some clarity on the following things : 1) ...
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1answer
61 views

Missing Data in Machine Learning Classification

I have a training set of 4000 for ML with 36 features, two-class classifier. -But consider that due to some discrepancy feature no. 25 is missing for half of the data. But during data ...
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0answers
53 views

OpenCV: Is NormalBayesClassifier::train function running ok?

I am have the code from here. I have changed the images with some of my own and I have seen that SVM is not working. That is not a problem because I have found on ...
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2answers
172 views

Using ICA on EEG signals for feature extraction

I am attempting to use ICA (FastICA via scikit-learn) on EEG signals from seven electrodes per subject for feature extraction and identity classification – that is to extract signal which is related ...
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0answers
44 views

Intelligent feature vector for an image classification problem

I am a person who loves to learn machine learning from an application point of view. My Objective : To learn machine learning by doing examples in MATLAB or Python like environments. The priority ...
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3answers
813 views

Best way to remove unwanted region from image

I am finding the techniques to remove unwanted regions (small dots) from image. I have an image that includes object and some unwanted region (small dots- see first image). I want to remove it. Hence, ...
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1answer
100 views

What Matlab Classifiers to use

I'm currently trying to decide what classifier to use for my snore detection algorithm. Which uses some features like Zero cross rating, frequency band energy, first formants... The classifiers which ...
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3answers
125 views

What does natural scene image data-set mean?

I came across a paper that is trying to classify and detect object(s) present in what they call a natural scene data-set. They have images containing objects like cars, bikes and people. Can anyone ...
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0answers
47 views

Frequency contour cross-correlation

I'm trying to segment (or extract) different calls from a spectrogram. My current method, calculates a threshold value (variance) and then using RMS can detect voiced/unvoiced signals: $$ Thres = (1 ...
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2answers
126 views

what is the output of BoW after an image has been trained with SIFT algorithm and k-means

SIFT algorithm provides a 128 dimensional feature vector that is used for image classification.When all the interest points(key points) are taken together and K-means clustering is applied,the image ...
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3answers
243 views

Detection of wobbling sound with rising notes

In an audio file I would like to find calls of a specific bird specie, one that makes wobbling sound with rising notes. Can you recommend what would be the best audio feature to calculate in time or ...
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1answer
42 views

What's a good classification algorithm for a large amount of classes?

My requirements are these: Fast classification of vectors of length 100 to one of 30000 classes Iterative learning (can improve the model after it was first learnt) Preferably available ...
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2answers
169 views

Guidance/Brainstorming for a mapping/classification problem

I'm quite new to machine learning/data mining and I'm struggling to find the correct path for my problem and would appreciate some guidance or criticism of my proposed solution i.e. is there a ...
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1answer
73 views

Music/Speech Classification: How are frame based features used in a feature vector?

I'm a little confused on how frame based high dimensional features such as mfcc's and bfcc's are applied in the classification of musical instruments. Are statistical measures of the features used ...
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3answers
161 views

What is the standard way to handle images of different sizes for classification?

I'd like to create an image classifier that takes a set of labeled images and creates a classifier to be used on some unknown images. Most of the examples I see assume all images are the same size (m ...
3
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2answers
964 views

Mahalanobis vs Normalization+Euclidean

I'm using a set of features extracted from a signal for classifying the data window with KNN algorithm. Since the features have different value ranges, their influence on distance calculation is ...
3
votes
3answers
213 views

Low recognition rates using GMM for image classification

I want to use GMM for image classification. So, I have extracted SIFT features from each image in the corpus. Then, I apply EM algorithm to learn GMM parameters (I have coded it in matlab). I get ...
6
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1answer
123 views

Vehicle segmentation and tracking

I've been working on a project for some time, to detect and track vehicles in video captured from UAV's, currently I am using an SVM trained on bag-of-feature representations of local features ...
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1answer
169 views

Object Classification using pyramid match kernel

I have been reading up on the pyramid match kernel as an alternative to using the bag-of-words model for object classification using a SVM. The bag-of-words model provides a model for transforming a ...
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0answers
134 views

Evaluation of Keypoint Detector and Feature Descriptor Combos for Vehicle Detection

I am currently doing a research project into the effectiveness of different keypoint detector and feature descriptor combinations for the task of vehicle detection. At the moment I am using a SVM for ...
2
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1answer
86 views

Classifying 2D shapes by the smoothness of their boundaries

I'm doing image analysis, and I want to classify smooth objects (has smooth boundaries) from non-smooth objects (has zigzag-like boundaries). Which feature should be fed into ML framework? What are ...
3
votes
1answer
141 views

Recognizing hand-written archaeological signs

I have 75 images of handwritten signs from which I extracted 7 Hu moments and solidity features. How can I find similarities among them to train a classifier and predict the value? I thought SVM was a ...
3
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0answers
112 views

Grouping clusters using Mahalanobis distances

I need to know the "number of clusters" in a dataaset. To find the number of clusters, I am using a Gaussian Mixture model fitting, bear with me, Because the underlying distributions (each cluster) ...
9
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1answer
5k views

Image classification using SIFT features and SVM

I am hoping someone can explain how to use the bag of words model to perform image classification using SIFT/SURF/ORB features and a support vector machine? At the moment I can compute the SIFT ...
8
votes
3answers
1k views

Why transforming the data to a high-dimensional feature space in which classes are linearly separable leads to overfitting?

I read in my book (statistical pattern classification by Webb and Wiley) in the section about SVMs and linearly non-separable data: In many real-world practical problems there will be no linear ...
4
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1answer
447 views

Support Vector Machine: A non-probabilistic binary linear classifier

I read that SVM is a supervised learning method, it is also a non-probabilistic binary linear classifier. I understand why it is binary because it classifies our training pattern to two classes $w_1$ ...
8
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4answers
4k views

Scale and Rotation invariant feature descriptors

Can you list some scale and rotational invariant feature descriptors for use in feature detection. The application is for the detection of cars and humans in video captured by a UAV, using a ...
3
votes
1answer
717 views

KNN method for different values of K on a handwritten digit data set

We're supposed to use KNN (K Nearest Neighbor) method for different values of K to classify a handwritten digit data set. The problem is, this is the first time I want to do a project like that in ...
2
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1answer
648 views

How to do people detection from bird eye view?

I'm trying to do people detection from bird eye view. Actually, it is not a normal bird eye view because I don't have RGB images but I have disparity map, depth map as well. In these kind of images, ...
8
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1answer
221 views

Recognizing data clustered into shapes

I am working on a project in Python to detect and classify some bird song, and I have found myself in a position where I need to convert a wave file into frequency vs. time data. This hasn't been too ...
7
votes
1answer
480 views

How can I automatically classify peaks of signals measured at different positions?

I have microphones measuring sound over time at many different positions in space. The sounds being recorded all originate from the same position in space but due to the different paths from the ...
10
votes
1answer
5k views

How do I retrieve texture using GLCM and classify using SVM Classifier?

I'm on a project of liver tumor segmentation and classification. I used Region Growing and FCM for liver and tumor segmentation respectively. Then, I used Gray Level Co-occurence matrix for texture ...
8
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2answers
407 views

Good metric for qualitatively comparing image patches

I am trying to "match" little square patches in an image. At first glance, it seems reasonable to simply do a Euclidean distance style comparison of two of these arrays to get a "similarity" measure. ...