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Journal ArticleDOI

LIBSVM: A library for support vector machines

TL;DR: Issues such as solving SVM optimization problems theoretical convergence multiclass classification probability estimates and parameter selection are discussed in detail.
Abstract: LIBSVM is a library for Support Vector Machines (SVMs). We have been actively developing this package since the year 2000. The goal is to help users to easily apply SVM to their applications. LIBSVM has gained wide popularity in machine learning and many other areas. In this article, we present all implementation details of LIBSVM. Issues such as solving SVM optimization problems theoretical convergence multiclass classification probability estimates and parameter selection are discussed in detail.

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Citations
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Proceedings ArticleDOI
27 Feb 2007
TL;DR: A novel statistical model based on Benford's law for the probability distributions of the first digits of the block-DCT and quantized JPEG coefficients is presented and a parametric logarithmic law, i.e., the generalized Benford't law, is formulated.
Abstract: In this paper, a novel statistical model based on Benford's law for the probability distributions of the first digits of the block-DCT and quantized JPEG coefficients is presented. A parametric logarithmic law, i.e., the generalized Benford's law, is formulated. Furthermore, some potential applications of this model in image forensics are discussed in this paper, which include the detection of JPEG compression for images in bitmap format, the estimation of JPEG compression Qfactor for JPEG compressed bitmap image, and the detection of double compressed JPEG image. The results of our extensive experiments demonstrate the effectiveness of the proposed statistical model.

287 citations

01 Jan 2017
TL;DR: This work proposes a variety of hate categories and designs and implements two classifiers for the Italian language, based on different learning algorithms: the first based on Support Vector Machines (SVM) and the second on a particular Recurrent Neural Network named Long Short Term Memory (LSTM).
Abstract: While favouring communications and easing information sharing, Social Network Sites are also used to launch harmful campaigns against specific groups and individuals. Cyberbullism, incitement to self-harm practices, sexual predation are just some of the severe effects of massive online offensives. Moreover, attacks can be carried out against groups of victims and can degenerate in physical violence. In this work, we aim at containing and preventing the alarming diffusion of such hate campaigns. Using Facebook as a benchmark, we consider the textual content of comments appeared on a set of public Italian pages. We first propose a variety of hate categories to distinguish the kind of hate. Crawled comments are then annotated by up to five distinct human annotators, according to the defined taxonomy. Leveraging morpho-syntactical features, sentiment polarity and word embedding lexicons, we design and implement two classifiers for the Italian language, based on different learning algorithms: the first based on Support Vector Machines (SVM) and the second on a particular Recurrent Neural Network named Long Short Term Memory (LSTM). We test these two learning algorithms in order to verify their classification performances on the task of hate speech recognition. The results show the effectiveness of the two classification approaches tested over the first manually annotated Italian Hate Speech Corpus of social media text.

286 citations


Cites methods from "LIBSVM: A library for support vecto..."

  • ...In this work, we use the Keras [8] deep learning framework and LIBSVM [5] to generate, respectively, the LSTM and the SVM statistical models....

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Proceedings Article
01 Jan 2010
TL;DR: This work presents a system that can automatically extract relevant features from audio for a given task by using a Deep Belief Network on Discrete Fourier Transforms of the audio to solve the task of genre recognition.
Abstract: Feature extraction is a crucial part of many MIR tasks. In this work, we present a system that can automatically extract relevant features from audio for a given task. The feature extraction system consists of a Deep Belief Network (DBN) on Discrete Fourier Transforms (DFTs) of the audio. We then use the activations of the trained network as inputs for a non-linear Support Vector Machine (SVM) classifier. In particular, we learned the features to solve the task of genre recognition. The learned features perform significantly better than MFCCs. Moreover, we obtain a classification accuracy of 84.3% on the Tzanetakis dataset, which compares favorably against state-of-the-art genre classifiers using frame-based features. We also applied these same features to the task of auto-tagging. The autotaggers trained with our features performed better than those that were trained with timbral and temporal features.

286 citations


Cites methods from "LIBSVM: A library for support vecto..."

  • ...For both experiments, we use a non-linear Support Vector Machine (SVM) with a radial basis function kernel [6] as the classifier....

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Journal ArticleDOI
TL;DR: This is the first time that deep learning in recurrent neural networks is exploited for change detection and under the framework of the proposed method, changes can be detected under both binary detection and multi-class change detection.
Abstract: When exploited in remote sensing analysis, a reliable change rule with transfer ability can detect changes accurately and be applied widely. However, in practice, the complexity of land cover changes makes it difficult to use only one change rule or change feature learned from a given multi-temporal dataset to detect any other new target images without applying other learning processes. In this study, we consider the design of an efficient change rule having transferability to detect both binary and multi-class changes. The proposed method relies on an improved Long Short-Term Memory (LSTM) model to acquire and record the change information of long-term sequence remote sensing data. In particular, a core memory cell is utilized to learn the change rule from the information concerning binary changes or multi-class changes. Three gates are utilized to control the input, output and update of the LSTM model for optimization. In addition, the learned rule can be applied to detect changes and transfer the change rule from one learned image to another new target multi-temporal image. In this study, binary experiments, transfer experiments and multi-class change experiments are exploited to demonstrate the superiority of our method. Three contributions of this work can be summarized as follows: (1) the proposed method can learn an effective change rule to provide reliable change information for multi-temporal images; (2) the learned change rule has good transferability for detecting changes in new target images without any extra learning process, and the new target images should have a multi-spectral distribution similar to that of the training images; and (3) to the authors’ best knowledge, this is the first time that deep learning in recurrent neural networks is exploited for change detection. In addition, under the framework of the proposed method, changes can be detected under both binary detection and multi-class change detection.

286 citations


Cites methods from "LIBSVM: A library for support vecto..."

  • ...For the SVM method, LibSVM [35] is selected to evaluate the final multi-class changes, where the kernel is the radial basis function, the cost parameter is 100 and gamma is 0.01....

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  • ...The SVM and decision tree-based change detection methods performed well in the multi-class change detection experiments in terms of the OA, kappa and F-score values....

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  • ...In particular, concerning the F-score, for soil (C) and farmland (C), REFEREE achieved a 40% higher F-score than did the SVM and decision tree methods....

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  • ...For the SVM method, LibSVM [35] is selected to evaluate the final multi-class changes, where the kernel is the radial basis function, the cost parameter is 100 and gamma is 0....

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  • ...In this paper, the results obtained using the REFEREE method are compared to those from several other methods: (1) unsupervised Change Vector Analysis (CVA) [8], which is an effective method for multi-spectral change detection tasks; (2) PCA [34], which is simple in computation and can be applied to real-time applications; (3) Iteratively-Reweighted Multivariate Alteration Detection (IRMAD) [15], which is a classical transformation change detection method for multi-spectral data; (4) Supervised Slow Feature Analysis (SSFA) [19], which is one of the latest feature learning methods for change detection; (5) Support Vector Machine (SVM) [35], which is effective for remote-sensing image classification; (6) decision tree [36], which is a tree structure consisting of internal and terminal nodes that process data to ultimately yield a classification; and (7) Convolutional Neural Network (CNN) [37], which is a hierarchical architecture trained on large-scale datasets and that has shown promising performance in classification and detection....

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Journal ArticleDOI
TL;DR: This work analyzes the key properties of eight popular incremental methods representing different algorithm classes and evaluates them with regards to their on-line classification error as well as to their behavior in the limit, facilitating the choice of the best method for a given application.

286 citations


Cites methods from "LIBSVM: A library for support vecto..."

  • ...Only publicly available datasets (see [66, 67]), predefining a fixed train-test-split, were used to enable reproducibility and comparability of our results....

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References
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Journal ArticleDOI
TL;DR: High generalization ability of support-vector networks utilizing polynomial input transformations is demonstrated and the performance of the support- vector network is compared to various classical learning algorithms that all took part in a benchmark study of Optical Character Recognition.
Abstract: The support-vector network is a new learning machine for two-group classification problems. The machine conceptually implements the following idea: input vectors are non-linearly mapped to a very high-dimension feature space. In this feature space a linear decision surface is constructed. Special properties of the decision surface ensures high generalization ability of the learning machine. The idea behind the support-vector network was previously implemented for the restricted case where the training data can be separated without errors. We here extend this result to non-separable training data. High generalization ability of support-vector networks utilizing polynomial input transformations is demonstrated. We also compare the performance of the support-vector network to various classical learning algorithms that all took part in a benchmark study of Optical Character Recognition.

37,861 citations


"LIBSVM: A library for support vecto..." refers background in this paper

  • ...{1,-1}, C-SVC [Boser et al. 1992; Cortes and Vapnik 1995] solves 4LIBSVM Tools: http://www.csie.ntu.edu.tw/~cjlin/libsvmtools. the following primal optimization problem: l t min 1 w T w +C .i (1) w,b,. 2 i=1 subject to yi(w T f(xi) +b) =1 -.i, .i =0,i =1,...,l, where f(xi)maps xi into a…...

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01 Jan 1998
TL;DR: Presenting a method for determining the necessary and sufficient conditions for consistency of learning process, the author covers function estimates from small data pools, applying these estimations to real-life problems, and much more.
Abstract: A comprehensive look at learning and generalization theory. The statistical theory of learning and generalization concerns the problem of choosing desired functions on the basis of empirical data. Highly applicable to a variety of computer science and robotics fields, this book offers lucid coverage of the theory as a whole. Presenting a method for determining the necessary and sufficient conditions for consistency of learning process, the author covers function estimates from small data pools, applying these estimations to real-life problems, and much more.

26,531 citations


"LIBSVM: A library for support vecto..." refers background in this paper

  • ...Under given parameters C > 0and E> 0, the standard form of support vector regression [Vapnik 1998] is ll tt 1 T min w w + C .i + C .i * w,b,.,. * 2 i=1 i=1 subject to w T f(xi) + b- zi = E + .i, zi - w T f(xi) - b = E + .i * , * .i,.i = 0,i = 1,...,l....

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  • ...It can be clearly seen that C-SVC and one-class SVM are already in the form of problem (11)....

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  • ..., l, in two classes, and a vector y ∈ Rl such that yi ∈ {1,−1}, C-SVC (Cortes and Vapnik, 1995; Vapnik, 1998) solves the following primal problem:...

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  • ...Then, according to the SVM formulation, svm train one calls a corresponding subroutine such as solve c svc for C-SVC and solve nu svc for ....

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  • ...Note that b of C-SVC and E-SVR plays the same role as -. in one-class SVM, so we de.ne ....

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Proceedings ArticleDOI
01 Jul 1992
TL;DR: A training algorithm that maximizes the margin between the training patterns and the decision boundary is presented, applicable to a wide variety of the classification functions, including Perceptrons, polynomials, and Radial Basis Functions.
Abstract: A training algorithm that maximizes the margin between the training patterns and the decision boundary is presented. The technique is applicable to a wide variety of the classification functions, including Perceptrons, polynomials, and Radial Basis Functions. The effective number of parameters is adjusted automatically to match the complexity of the problem. The solution is expressed as a linear combination of supporting patterns. These are the subset of training patterns that are closest to the decision boundary. Bounds on the generalization performance based on the leave-one-out method and the VC-dimension are given. Experimental results on optical character recognition problems demonstrate the good generalization obtained when compared with other learning algorithms.

11,211 citations


"LIBSVM: A library for support vecto..." refers background in this paper

  • ...It can be clearly seen that C-SVC and one-class SVM are already in the form of problem (11)....

    [...]

  • ...Then, according to the SVM formulation, svm train one calls a corresponding subroutine such as solve c svc for C-SVC and solve nu svc for ....

    [...]

  • ...Note that b of C-SVC and E-SVR plays the same role as -. in one-class SVM, so we de.ne ....

    [...]

  • ...In Section 2, we describe SVM formulations sup­ported in LIBSVM: C-Support Vector Classi.cation (C-SVC), ....

    [...]

  • ...{1,-1}, C-SVC [Boser et al. 1992; Cortes and Vapnik 1995] solves 4LIBSVM Tools: http://www.csie.ntu.edu.tw/~cjlin/libsvmtools. the following primal optimization problem: l t min 1 w T w +C .i (1) w,b,. 2 i=1 subject to yi(w T f(xi) +b) =1 -.i, .i =0,i =1,...,l, where f(xi)maps xi into a higher-dimensional space and C > 0 is the regularization parameter....

    [...]

01 Jan 2008
TL;DR: A simple procedure is proposed, which usually gives reasonable results and is suitable for beginners who are not familiar with SVM.
Abstract: Support vector machine (SVM) is a popular technique for classication. However, beginners who are not familiar with SVM often get unsatisfactory results since they miss some easy but signicant steps. In this guide, we propose a simple procedure, which usually gives reasonable results.

7,069 citations


"LIBSVM: A library for support vecto..." refers methods in this paper

  • ...A Simple Example of Running LIBSVM While detailed instructions of using LIBSVM are available in the README file of the package and the practical guide by Hsu et al. [2003], here we give a simple example....

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  • ...For instructions of using LIBSVM, see the README file included in the package, the LIBSVM FAQ,3 and the practical guide by Hsu et al. [2003]. LIBSVM supports the following learning tasks....

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Journal ArticleDOI
TL;DR: Decomposition implementations for two "all-together" multiclass SVM methods are given and it is shown that for large problems methods by considering all data at once in general need fewer support vectors.
Abstract: Support vector machines (SVMs) were originally designed for binary classification. How to effectively extend it for multiclass classification is still an ongoing research issue. Several methods have been proposed where typically we construct a multiclass classifier by combining several binary classifiers. Some authors also proposed methods that consider all classes at once. As it is computationally more expensive to solve multiclass problems, comparisons of these methods using large-scale problems have not been seriously conducted. Especially for methods solving multiclass SVM in one step, a much larger optimization problem is required so up to now experiments are limited to small data sets. In this paper we give decomposition implementations for two such "all-together" methods. We then compare their performance with three methods based on binary classifications: "one-against-all," "one-against-one," and directed acyclic graph SVM (DAGSVM). Our experiments indicate that the "one-against-one" and DAG methods are more suitable for practical use than the other methods. Results also show that for large problems methods by considering all data at once in general need fewer support vectors.

6,562 citations