基于随机森林和支持向量机的快速行人检测算法

提出了一种两步走的策略提高静态图像中的行人检测速率和性能。目前,利用梯度直方图（ HOG）+支持向量机（ SVM）依然是一种精度较高的方法,但一方面它难以训练足够多的样本,另一方面它的检测消耗太大。因此先采取随机森林的分类算法,快速地消除图像中的背景,并得到一定的感兴趣区域,再通过SVM进行检测。通过在INRIA库上的实验证明,该算法能够实现预期的双重效果。     

Pedestrian detection with unsupervised multispectral feature learning using deep neural networks

Multispectral pedestrian detection is an important functionality in various computer vision applications such as robot sensing, security surveillance, and autonomous driving. In this paper, our motivation is to automatically adapt a generic pedestrian detector trained in a visible source domain to a new multispectral target domain without any manual annotation efforts. For this purpose, we present an auto-annotation framework to iteratively label pedestrian instances in visible and thermal channels by leveraging the complementary information of multispectral data. A distinct target is temporally tracked through image sequences to generate more confident labels. The predicted pedestrians in two individual channels are merged through a label fusion scheme to generate multispectral pedestrian annotations. The obtained annotations are then fed to a two-stream region proposal network (TS-RPN) to learn the multispectral features on both visible and thermal images for robust pedestrian detection. Experimental results on KAIST multispectral dataset show that our proposed unsupervised approach using auto-annotated training data can achieve performance comparable to state-of-the-art deep neural networks (DNNs) based pedestrian detectors trained using manual labels.     

A feature reduced intrusion detection system using ANN classifier

Rapid increase in internet and network technologies has led to considerable increase in number of attacks and intrusions. Detection and prevention of these attacks has become an important part of security. Intrusion detection system is one of the important ways to achieve high security in computer networks and used to thwart different attacks. Intrusion detection systems have curse of dimensionality which tends to increase time complexity and decrease resource utilization. As a result, it is desirable that important features of data must be analyzed by intrusion detection system to reduce dimensionality. This work proposes an intelligent system which first performs feature ranking on the basis of information gain and correlation. Feature reduction is then done by combining ranks obtained from both information gain and correlation using a novel approach to identify useful and useless features. These reduced features are then fed to a feed forward neural network for training and testing on KDD99 dataset. Pre-processing of KDD-99 dataset has been done to normalize number of instances of each class before training. The system then behaves intelligently to classify test data into attack and non-attack classes. The aim of the feature reduced system is to achieve same degree of performance as a normal system. The system is tested on five different test datasets and both individual and average results of all datasets are reported. Comparison of proposed method with and without feature reduction is done in terms of various performance metrics. Comparisons with recent and relevant approaches are also tabled. Results obtained for proposed method are really encouraging.     

基于多特征与改进霍夫森林的行人检测方法

针对自然背景下的行人检测问题,提出一种多特征与霍夫森林结合的行人检测算法。在特征提取阶段,分别采用梯度方向直方图、局部二值模式和LAB颜色空间来提取行人的梯度、纹理和颜色频率特征,构成丰富的特征集来描述行人;采用霍夫森林算法来创建分类器,对其投票方式进行改进,提出一种基于高斯模板的区域加权投票方式,提高了检测精度。实验结果表明,该算法在误检率FPPW为10-4时,检测率为90.12％, ROC曲线性能上优于 HOG＋SVM 与原霍夫森林算法。     

利用小波变换和纹理特征实现运动对象检测

运动对象检测是计算机视觉应用中的一个重要问题。提出了一种新的检测运动对象的算法。首先通过计算图像块的小波变换域不同频率的纹理特征从而得到图像的特征，然后利用前景图像和背景图像的特征差异得到运动对象。同时，采用一种改进的背景维护方法以提高算法对环境光线变化的抗干扰能力。实验结果表明该算法具有快速、可靠的特点，可满足实时运动检测的需要。     

视觉注意原理局部特征的行人检测

在复杂背景下检测行人,具有重要的理论和应用价值。为了适应此类场景中光照的变化和行人姿态的多样性,依据人眼视觉注意原理,提出基于视觉注意的局部特征。该特征具有光照和旋转不变性,并能用于多尺度分析。采用基于特征块的行人表示模型,行人被表示为特征块的集合。每一个特征块用基于视觉注意局部特征的统计直方图和位置关系表示。用聚类的方法得到基于特征块的行人模型。依据每一个特征块在检测窗口中的最大响应训练AdBoost检测分类器,并用困难负样本和可信样本提高检测分类器的性能。用滑动窗口方法在图像和尺度空间中找到检测分类器的局部最大响应,以确定行人位置。实验结果表明,与现有方法相比,本文方法对竖直边缘不敏感,可以处理一定程度的遮挡以及姿态变化。     

AI-based smart prediction of clinical disease using random forest classifier and Naive Bayes

The Journal of Supercomputing - Healthcare practices include collecting all kinds of patient data which would help the doctor correctly diagnose the health condition of the patient. These data...     

随机傅里叶特征相异度的故障检测算法

针对大规模非线性动态过程故障检测问题, 提出随机傅里叶特征相异度(RFF–DISSIM)的故障检测方法.首先, 利用RFF对原始数据进行映射, 获得特征空间中的数据集; 然后, 在特征空间中应用滑动窗口技术并结合相异度指标对特征空间中的数据集进行过程状态监控. 本文方法通过RFF快速捕获数据的非线性结构并结合相异度指标消除样本间自相关性的影响, 有效地提高了过程监控性能. 通过一个数值例子和连续搅拌釜反应器(CSTR)的仿真实验并与传统的核主元分析、动态主元分析等方法对比分析, 仿真结果进一步证明了本文所提方法的有效性.     

基于多重特征选择和多分类器融合的文本层次分类研究*

针对大量电子文档需要准确地进行多层次自动分类管理的现实需求,提出基于多重特征选择和多分类器融合技术的层次分类方法。通过引入可信度函数对单分类器效果进行评价,适时采用辅助分类器对较难分类的文档进行分类投票判决。实验结果表明,相对于单分类器,该方法无论在平面分类和层次分类语料上都获得了更好的分类精度,且具有较好的时间复杂性,有很好的实际应用前景。     

Attribute bagging: improving accuracy of classifier ensembles by using random feature subsets

We present attribute bagging (AB), a technique for improving the accuracy and stability of classifier ensembles induced using random subsets of features. AB is a wrapper method that can be used with any learning algorithm. It establishes an appropriate attribute subset size and then randomly selects subsets of features, creating projections of the training set on which the ensemble classifiers are built. The induced classifiers are then used for voting. This article compares the performance of our AB method with bagging and other algorithms on a hand-pose recognition dataset. It is shown that AB gives consistently better results than bagging, both in accuracy and stability. The performance of ensemble voting in bagging and the AB method as a function of the attribute subset size and the number of voters for both weighted and unweighted voting is tested and discussed. We also demonstrate that ranking the attribute subsets by their classification accuracy and voting using only the best subsets further improves the resulting performance of the ensemble.     

颅骨灰度特征的小波分析与身份识别*

通过对活体颅骨X线图像直方图进行小波变换并进行多分辨率分析,多尺度地分解和表示了颅骨X线衰减特征和空间结构尺寸特征,通过设计多尺度识别准则,实现了快速实时的颅骨同一性身份认定。实验表明,该方法也支持对非活体的颅骨进行身份识别。     

Adaptive latent fingerprint segmentation using feature selection and random decision forest classification

Latent fingerprints are important evidences used by law enforcement agencies. However, current state-of-the-art for automatic latent fingerprint recognition is not as reliable as live-scan fingerprints and advancements are required in every step of the recognition pipeline. This research focuses on automatically segmenting latent fingerprints to distinguish between ridge and non-ridge patterns. There are three major contributions of this research: (i) a machine learning algorithm for combining five different categories of features for automatic latent fingerprint segmentation, (ii) a feature selection technique using modified RELIEF formulation for analyzing the influence of multiple category features on latent fingerprint segmentation, and (iii) a novel SIVV based metric to measure the effect of the segmentation algorithm without the requirement to perform the entire matching process. The image is tessellated into local patches and saliency based features along with image, gradient, ridge, and quality based features are extracted. Feature selection is performed to study the contribution of the various category features towards foreground ridge pattern representation. Using these selected features, a trained Random Decision Forest based algorithm classifies the local patches as background or foreground. The results on three publicly available databases demonstrate the efficacy of the proposed algorithm.     

改进特征与GPU加速的行人检测

目的 目前行人检测存在特征维度高、检测耗时的问题,行人图像易受到光照、背景、遮挡等影响,给实际行人检测造成了一定困难。为了提高检测准确性,减少检测耗时,针对以上问题,提出一种改进特征与GPU （graphic processing unit）加速的行人检测算法。方法 首先,采用多尺度无缩放思想,通过canny算子对所有样本进行预处理,减少背景干扰与统一归格化的形变影响。然后,针对实际视频中的遮挡问题,把图像分成头部、左臂、上身、右臂、左腿、右腿6个区域。接着选取比LBP （local binary patterns）特征鲁棒性更好的SILTP （scale invariant local ternary pattern）特征作为纹理特征,在GPU空间中并行提取;同时,分别提取6个区域的HOG （histogram of oriented gradient）特征值,结合行人轮廓在6个区域上的梯度方向分布特性,对其进行加权。最后,将提取的全部特征输出到CPU （central processing unit）,利用支持向量机（SVM）分类器实现行人检测。结果 在INRIA、NICTA数据集上进行实验,INRIA数据集上检测率达到99.80%,NICTA数据集上检测率达到99.91%,并且INRIA数据集上检测时间加速比达到12.19,NICTA数据集上达到13.49,相对传统HOG、LBP算法,检测率、时间比实现提高。结论 提出的改进HOG-SILTP特征与GPU加速的行人检测算法,能够有效表达行人信息,改善传统特征提取方式带来的耗时与形变影响,对环境变化、遮挡具有较强的鲁棒性。该算法在检测率、检测时间方面均有提高,能够实现有效、快速的行人检测,具有实际意义。     

基于Gabor变换和Adaboost算法的人体目标检测分类器

针对在图像中检测人体目标,提出一种基于Gabor变换和Adaboost算法的检测方法.首先利用二维Gabor小波变换进行特征提取,然后利用Adaboost算法对Gabor特征进行选取并训练强分类器.为了提高检测精度,提出采用单一正样本集合与多个负样本集合分别进行训练,形成多个强分类器级联的层级检测分类器.实验结果表明了该方法的有效性,同时显示该方法须与其它辅助手段相结合,才能提高检测的实时性.     

结合轮廓与形状特征的仿射形状匹配

目的 针对仿射变换下形状匹配中存在的描述子对形状的描述能力不足,以及描述子计算耗时大的问题,改进基于所有图像点投影的方法,提出一种利用轮廓计算投影面积的仿射形状匹配算法。方法 该算法分为粗匹配和精匹配两个阶段。粗匹配阶段以CSS角点作为备选特征点,首先统计轮廓投影面积分布作为特征点描述子;然后利用动态规划蚁群算法匹配两幅图片公共特征点序列,并将匹配好的特征点序列记为对应的新特征点;最后采用该新特征点划分目标曲线,得到对应的轮廓曲线;这一阶段的目的是对形状的筛选以及寻找一致的轮廓特征点,同时完成轮廓曲线的划分。精匹配阶段,采用小波仿射不变描述子,对粗匹配阶段匹配代价最小的5%的目标进行对应曲线匹配,得到精匹配阶段的匹配代价,从而实现对仿射目标的识别;精匹配弥补了描述子对轮廓细节描述不足的问题。结果 算法的平均检索速度比传统基于形状投影分布描述子提高44.3%,在MPEG-7图像库上的检索效果为98.65%,在MPEG-7仿射图像库上的查准率与查全率综合评价指标比传统的基于形状投影分布描述子高3.1%,比形状上下文高25%。结论 本文算法匹配效果好,效率高,抗噪性强,解决了仿射描述子计算速度慢、描述能力不足的问题,能有效地应用于仿射形状匹配与检索领域。     

带标志位的均匀性特征检测SIFT配准算法研究

针对尺度不变特征SIFT配准算法中检测到的特征点不具有均匀分布的特性,实现了均匀性特征检测方法,同时对像素点设置标志位对检测步长进行动态调整。均匀性特征检测方法能够检测到更有效、更具有代表性的特征点,从而得到更加精确的图像变换关系;设置标志位对动态步长进行调整,可以进一步减少检测的次数。将带标志位的均匀性特征检测SIFT算法应用于图像的配准,实验表明改进算法的性能得到了有效提高。     

Fast multi-feature pedestrian detection algorithm based on histogram of oriented gradient using discrete wavelet transform

A convergence between a natural user interface (NUI) and advanced driver assistance system is considered as a next generation technology. This kind of interfacing system technology becomes more popular in driver assistance system of automobile. Especially, pedestrian detection is an important cue for intelligent vehicles and interactive driver assistance system. In this paper, we propose a pedestrian detection feature and technique by combining histogram of the oriented gradient (HOG) and discrete wavelet transform (DWT). In the method, the magnitude of motion is used to set region of interest (ROI) for improving detection speed. Then, we employ multi-feature for a pedestrian detection based on the HOG and DWT. In last stage, to classify whether a candidate window contains a pedestrian or not, the designed multi-feature is learned by using the training data with the support vector machine (SVM) mechanism. Experimental results show that the proposed algorithm increases the speed-up factor of 27.21 % by comparing to the existing method using the original HOG feature.     

Facial expression recognition based on dual-feature fusion and improved random forest classifier

Facial expression recognition (FER) is an important means for machines to understand the changes in the facial expression of human beings. Expression recognition using single-modal facial images, such as gray scale, may suffer from illumination changes and the lack of detailed expression-related information. In this study, multi-modal facial images, such as facial gray scale, depth, and local binary pattern (LBP), are used to recognize six basic facial expressions, namely, happiness, sadness, anger, disgust, fear, and surprise. Facial depth images are used for robust face detection initially. The deep geometric feature is represented by point displacement and angle variation in facial landmark points with the help of depth information. The local appearance feature, which is obtained by concatenating LBP histograms of expression-prominent patches, is utilized to recognize those expression changes that are difficult to capture by only the geometric changes. Thereafter, an improved random forest classifier based on feature selection is used to recognize different facial expressions. Results of comparative evaluations in benchmarking datasets show that the proposed method outperforms several state-of-the-art FER approaches that are based on hand-crafted features. The capability of the proposed method is comparable to that of the popular convolutional neural-network-based FER approach but with fewer demands for training data and a high-performance hardware platform.     

于混合高斯莫型与联合特征的行人检测方法

针对视频环境下行人检测多数采用窗口滑动方法识别慢、不能快速找到行人窗口的缺点,提出了一种基于组合算法的行人目标识别方法,利用高斯混合模型方法提取视频中的运动前景,划定一个泛目标窗口,再使用HOG-l bp联合特征训练的分类器对泛目标窗口进行分类,得到分类结果,对行人目标进行标记.经实验验证:该方法相对于当前行人检测方法,检测速度和正确率都取得了很好的效果.