Region-driven distance regularized level set evolution for change detection in remote sensing images

Change detection is a fundamental task in the interpretation and understanding of remote sensing images. The aim is to partition the difference images acquired from multitemporal satellite images into changed and unchanged regions. Level set method is a promising way for remote sensing images change detection among the existed methods. Unfortunately, re-initialization, a necessary step in classical level set methods is known a complex and time-consuming process, which may limits their practical application in remote sensing images change detection. In this paper, we present an unsupervised change detection approach for remote sensing image based on an improved region-based active contour model without re-initialization. In order to eliminate the process for re-initialization and reduce the numerical errors caused by re-initialization, we describe an improving level set method for remote sensing images change detection. The proposed method introduced a distance regularization term into the energy function which could maintain a desired shape of the level set function and keep a signed distance profile near the zero level set. The experimental results on real multi-temporal remote sensing images demonstrate the advantages of our method in terms of human visual perception and segmentation accuracy.     

支持向量机和水平集的高分辨率遥感图像河流检测

河流是重要的地理结构特征,对河流进行检测识别研究,在军事上和民用上都具有十分重要的意义.提出了一种基于支持向量机(SVM)和水平集的高分辨率遥感图像河流检测算法.首先根据高分辨率遥感图像河流目标的特点,采用样本图像的纹理特征和基准点信息扩散特征构造特征向量,并基于样本训练支持向量机分类器实现河流目标的粗分割;然后以粗分割结果为基础,采用距离正则化水平集演化(DRLSE)模型提取河流的精确轮廓,获得完整的河流区域.以1 m分辨率的IKONOS图像进行实验验证,结果表明本文算法准确性高,灵活性强,可以在复杂背景下准确地检测河流目标区域,在实践中具有广泛适用性.     

Shape-based object extraction in high-resolution remote-sensing images using deep Boltzmann machine

In this article, we proposed a novel method based on deep learning shape priors for object extraction in high-resolution (HR) remote-sensing images. Specifically, the deep Boltzmann machines (DBMs) are applied to model the shape priors via the unsupervised training process, which qualify for the advantages of deep learning method, especially the powerful feature learning and modelling ability. The deep shape model is integrated into a new energy function to eliminate the influence of disturbing background. The energy function combines image appearance information and region information. A new region term in the function is proposed to eliminate the influence of object shadow. The process of object extraction is achieved by minimizing the energy function with an iterative optimization algorithm and the Split Bregman method is applied to derive a global solution during the minimization process. Quantitative and qualitative experiments are conducted on the aircraft data set acquired by QuickBird with 60 cm resolution and the results demonstrate the effectiveness of the proposed method.     

一种处理较大规模数据分类的支持向量机

对支持向量分类机中的一些基本方法作出详细地介绍,并进一步研究了方法的求解与改进。并通过对标准支持向量机的改造考虑了一种改进的方法,并进行相关的理论分析,通过数据实验验证了这种方法比传统的分类机在运算速度上有提高,特别是在处理较大规模的数据集时运算时间的效果更明显。     

Facial neuromuscular signal classification by means of least square support vector machine for MuCI

Facial neuromuscular signal has recently drawn the researchers’ attention to its outstanding potential as an efficient medium for Muscle Computer Interface (MuCI) applications. The proper analysis of such electromyogram (EMG) signals is essential in designing the interfaces. In this article, a multiclass least-square support vector machine (LS-SVM) is proposed for classification of different facial gestures EMG signals. EMG signals were captured through three bi-polar electrodes from ten participants while gesturing ten different facial states. EMGs were filtered and segmented into non-overlapped windows from which root mean square (RMS) features were extracted and then fed to the classifier. For the purpose of classification, different models of LS-SVM were constructed while tuning the kernel parameters automatically and manually. In the automatic mode, 48 models were formed while parameters of linear and radial basis function (RBF) kernels were tuned using different optimization techniques, cost functions and encoding schemes. In the manual mode, 8 models were shaped by means of the considered kernel functions and encoding schemes. In order to find the best model with a reliable performance, constructed models were evaluated and compared in terms of classification accuracy and computational cost. Results reported that the model including RBF kernel which was tuned manually and encoded by one-versus-all scheme provided the highest classification accuracy (93.10%) and consumed 0.98 s for training. It was indicated that automatic models were outperformed since they required too much time for tuning the parameters without any meaningful improvement in the final classification accuracy. The robustness of the selected LS-SVM model was evaluated through comparison with Support Vector Machine, fuzzy C-Means and fuzzy Gath-Geva clustering techniques.     

Multi-class support vector machine for classification of the ultrasonic images of supraspinatus

This article proposes an effort to apply the multi-class support vector machine classifiers to classify the supraspinatus image into different disease groups that are normal, tendon inflammation, calcific tendonitis and supraspinatus tear. The supraspinatus tendon is often involved in the above-mentioned disease groups. Four different texture analysis methods – texture feature coding method, gray-level co-occurrence matrix, fractal dimension evaluation and texture spectrum – are used to extract features of tissue characteristic in the ultrasonic supraspinatus images. The mutual information criterion is adopted to select the powerful features from ones generated from the above-mentioned four texture analysis methods in the training stage, meanwhile, the five implementations of multi-class support vector machine classifiers are also designed to discriminate each image into one of the four disease groups in the classification stage. In experiments, the most commonly used performance measures including sensitivity, specificity, classification accuracy and false-negative rate are applied to evaluate the classification of the five implantations of multi-class support vector machines. In addition, the receiver operating characteristics analysis is also used to analyze the classification capability. The present results demonstrate that the implementation of multi-class fuzzy support vector machine can achieve 90% classification accuracy, and performance measures of this implementation are significantly superior to the others.     

基于支持向量机和贝叶斯分类的异常检测模型

通过对网络攻击类型和入侵检测方法的研究,发现常用的入侵检测方法不能很好地检测U2R和R2L两类攻击。为解决异常检测中对于U2R和R2L两类攻击检测率低的问题,提出了一种基于支持向量机和贝叶斯分类的异常检测模型,该模型利用BIRCH聚类算法减少训练数据集中重复记录,并利用支持向量机分类算法和贝叶斯分类算法分别检测DoS、Probe攻击和U2R、R2L攻击。实验结果表明,该模型对于U2R和R2L的检测率分别提高到了68.6%和45.7%。     

A novel change detection approach based on visual saliency and random forest from multi-temporal high-resolution remote-sensing images

ABSTRACT

This article presents a novel change detection (CD) approach for high-resolution remote-sensing images, which incorporates visual saliency and random forest (RF). First, highly homogeneous and compact image super-pixels are generated using super-pixel segmentation, and the optimal segmentation result is obtained through image superimposition and principal component analysis. Second, saliency detection is used to guide the search of interest regions in the initial difference image obtained via the improved robust change vector analysis algorithm. The salient regions within the difference image that correspond to the binarized saliency map are extracted, and the regions are subject to the fuzzy c-means (FCM) clustering to obtain the pixel-level pre-classification result, which can be used as a prerequisite for super-pixel-based analysis. Third, on the basis of the optimal segmentation and pixel-level pre-classification results, different super-pixel change possibilities are calculated. Furthermore, the changed and unchanged super-pixels that serve as the training samples are automatically selected. The spectral features and Gabor features of each super-pixel are extracted. Finally, super-pixel-based CD is implemented by applying RF based on these samples. Experimental results on Quickbird, Ziyuan 3 (ZY3), and Gaofen 2 (GF2) multi-spectral images show that the proposed method outperforms the compared methods in the accuracy of CD, and also confirm the feasibility and effectiveness of the proposed approach.     

A set of new Chebyshev kernel functions for support vector machine pattern classification

In this study, we introduce a set of new kernel functions derived from the generalized Chebyshev polynomials. The proposed generalized Chebyshev polynomials allow us to derive different kernel functions. By using these polynomial functions, we generalize recently introduced Chebyshev kernel function for vector inputs and, as a result, we obtain a robust set of kernel functions for Support Vector Machine (SVM) classification. Thus in this study, besides clarifying how to apply the Chebyshev kernel functions on vector inputs, we also increase the generalization capability of the previously proposed Chebyshev kernels and show how to derive new kernel functions by using the generalized Chebyshev polynomials. The proposed set of kernel functions provides competitive performance when compared to all other common kernel functions on average for the simulation datasets. The results indicate that they can be used as a good alternative to other common kernel functions for SVM classification in order to obtain better accuracy. Moreover, test results show that the generalized Chebyshev kernel approaches to the minimum support vector number for classification in general.     

Segmentation and classification of brain images using firefly and hybrid kernel-based support vector machine

Abstract

Magnetic resonance imaging segmentation refers to a process of assigning labels to set of pixels or multiple regions. It plays a major role in the field of biomedical applications as it is widely used by the radiologists to segment the medical images input into meaningful regions. In recent years, various brain tumour detection techniques are presented in the literature. The entire segmentation process of our proposed work comprises three phases: threshold generation with dynamic modified region growing phase, texture feature generation phase and region merging phase. by dynamically changing two thresholds in the modified region growing approach, the first phase of the given input image can be performed as dynamic modified region growing process, in which the optimisation algorithm, firefly algorithm help to optimise the two thresholds in modified region growing. After obtaining the region growth segmented image using modified region growing, the edges can be detected with edge detection algorithm. In the second phase, the texture feature can be extracted using entropy-based operation from the input image. In region merging phase, the results obtained from the texture feature-generation phase are combined with the results of dynamic modified region growing phase and similar regions are merged using a distance comparison between regions. After identifying the abnormal tissues, the classification can be done by hybrid kernel-based SVM (Support Vector Machine). The performance analysis of the proposed method will be carried by K-cross fold validation method. The proposed method will be implemented in MATLAB with various images.     

One-class support vector machines—an application in machine fault detection and classification

Fast incipient machine fault diagnosis is becoming one of the key requirements for economical and optimal process operation management. Artificial neural networks have been used to detect machine faults for a number of years and shown to be highly successful in this application area. This paper presents a novel test technique for machine fault detection and classification in electro-mechanical machinery from vibration measurements using one-class support vector machines (SVMs). In order to evaluate one-class SVMs, this paper examines the performance of the proposed method by comparing it with that of multilayer perception, one of the artificial neural network techniques, based on real benchmarking data.     

Automatic computer-aided caries detection from dental x-ray images using intelligent level set

Multimedia Tools and Applications - Dental diseases have high risk of affection across the globe and mostly in adult population. The analysis of dental X-ray images has some difficulties in...     

基于快速支持向量机的图像型火灾探测算法*

图像型火灾探测的核心问题是火焰和疑似火焰物体的分类和识别。以火灾视频和疑似火灾视频为分析对象,提取了火灾图像的面积重叠率、圆形度以及火焰尖角数目三个特征量,选择快速支持向量机进行分类器训练,最终利用训练好的分类器实现了火焰及干扰物体的分类识别问题。实验结果表明,该算法提高了火灾图像的分类精度和火灾识别的准确率,同时具有较高的检测效率。     

基于偏好型支持向量机的遥感图像云检测技术

针对以往遥感图像云检测方法对雪地等特殊地貌识别效果不理想的问题,基于偏好型支持向量机(preference support vector machine,PSVM)提出一种云检测技术。利用图像的灰度特征和纹理特征,提取图像的能量、对比度、逆差矩、熵、自相关性以及平均灰度值6个分类指标,使用偏好训练的方式,提高对云和普通地貌的识别准确率,准确区分云和雪地等特殊地物。实验结果表明,PSVM方法综合识别准确率达到了97.66%,特殊地貌识别准确率达到了99.31%,相比于传统的云检测算法性能提升显著。     

基于对支持向量机的多类分类算法在入侵检测中的应用

针对基于传统支持向量机(SVM)的多类分类算法在处理大规模数据时训练速度上存在的弱势,提出了一种基于对支持向量机(TWSVM)的多类分类算法。该算法结合二叉树SVM多类分类思想,通过在二叉树节点处构造基于TWSVM的分类器来达到分类目的。为减少二叉树SVM的误差累积,算法分类前首先通过聚类算法得到各类的聚类中心,通过比较各聚类中心之间的距离来衡量样本的差异以决定二叉树节点处类别的分离顺序,最后将算法用于网络入侵检测。实验结果表明,该算法不仅保持了较高的检测精度,在训练速度上还表现了一定优势,尤其在处理稍大规模数据时,这种优势更为明显,是传统二叉树SVM多类分类算法训练速度的近两倍,为入侵检测领域大规模数据处理提供了有效参考价值。     

支持向量机在入侵检测中的应用

入侵检测是网络安全的重要领域.安全问题的日益严峻对于检测方法提出更高的要求.支持向量机是一种基于小样本学习的有效工具.继它在字体识别,人脸识别中得到成功应用后,它被成功地应用到入侵检测领域中.介绍了支持向量机的多种算法,例如二分类的支持向量机,一分类的支持向量机,多分类的支持向量机和针对大量训练样本的支持向量机在入侵检测中的应用.通过比较发现,用支持向量机进行检测入侵大大提高了入侵检测系统的性能.     

基于粗集理论的支持向量机分类方法研究

介绍了粗集理论的基本概念和支持向量机分类的基本原理,提出将粗集理论和支持向量机方法相结合.通过应用粗集理论对数据的预处理,消除决策表中大量的冗余信息和冲突对象,但不丢失任何有用信息.通过这样对数据维数的约简,大大简化了支持向量分类模型的结构,同时也有效地提高了支持向量机的分类效率.通过对一组实验数据的仿真验证了该方法的可行性.     

Semantic analysis of real-world images using support vector machine

Digital cameras and thus digital images are now ubiquitous. How to efficiently manage a large amount of images has become important. The semantic analysis of images is an important issue in multimedia processing. Region-based image retrieval systems attempt to reduce the gap between high-level semantics and low-level features by representing images at the object level. Recently, the support vector machine (SVM) has been proposed to solve the classification problem. It can generate a hyperplane to separate two sets of features and provides good generalization performance. In this paper, we propose a novel method which integrates principal component analysis (PCA) and SVM neural networks for analyzing the semantic content of natural images, in which principal component analysis (PCA) is applied to reduce the dimension of features. Experimental results show that the proposed method is capable of analyzing the components of photographs into semantic categories with high accuracy, resulting in photographic analysis that is similar to human perception. The performance of the proposed method is better than that of the traditional radial basis function (RBF) neural network.     

Agricultural crop-type classification of multi-polarization SAR images using a hybrid entropy decomposition and support vector machine technique

This article presents the application of a hybrid classification technique of entropy decomposition and support vector machine (EDSVM) for crop-type categorization. It takes the advantage of the desired parameters from the entropy decomposition (ED) method and the statistical learning method based on the support vector machine (SVM) method that determines the optimal separation between classes in a higher dimensional feature space to improve on the existing classification results. ED is capable of extracting valuable decomposed parameters of entropy H and alpha α for image interpretation with analysis of the underlying scattering mechanisms. H demonstrates the randomness of the underlying scattering mechanisms and α is used to define the type of scattering mechanisms. However, in the application of agricultural crops where the scattering mechanisms of the crops are quite similar to each other, the distribution of the H and α in the H–α feature space overlaps from one class to another. Moreover, the drawback of ED is the arbitrariness of the boundaries for each class. To overcome this issue, SVM classifier is deployed to determine the decision boundaries by projecting the training sets of the classes into higher dimensional feature space. Hence, the hybrid EDSVM is developed to provide an alternative solution to improve the classification accuracy. In this article, EDSVM classifier is applied on a multi-crop field Airborne Synthetic Aperture Radar (AIRSAR) image of Flevoland in the Netherlands and the robustness of the classifier is evaluated. The classification is done with the purpose of separating the different types of crops with the characteristics of the scattering mechanism. At the same time, a hybrid entropy decomposition and neural network (EDNN) classifier method is developed to validate the effectiveness of the EDSVM classifier. As a result, EDSVM is proved to be robust and to yield a superior result compared with neural network (NN), SVM and EDNN classifiers.     

支持向量机模型分类能力指标的统计分析

在支持向量机（support vector machines, SVM）中,如何衡量SVM的分类能力,最小化风险泛函是一个重要的指标。根据支持向量机小样本特点,给出了支持向量机分类能力的一个量化标准：最优超平面的可靠度β。详细讨论了β的下界和置信区间,并给出了在实际应用中,如何根据样本数据估计β的下界和置信区间。实验也证明了β的下界估计和置信区间的合理性、有效性。