基于混合高斯模型的窄带目标跟踪方法

基于混合高斯模型的轨迹分布融合方法适用于窄带目标跟踪系统.这种算法针对宽带跟踪结果的不精确,目标模糊,窄带跟踪需要依赖人工实现的问题,提出了一种基于混合高斯模型的自动窄带目标跟踪技术.该方法首先将目标方位分布看做是混合高斯模型,利用期望最大化算法估计混合高斯模型中的参数,然后利用混合高斯模型对目标方位进行聚类,最后利用平均加权法对目标方位进行融合,得到清晰稳定的目标跟踪结果.     

Active curve axis Gaussian mixture models

Gaussian Mixture Models (GMM) have been broadly applied for the fitting of probability density function. However, due to the intrinsic linearity of GMM, usually many components are needed to appropriately fit the data distribution, when there are curve manifolds in the data cloud.

In order to solve this problem and represent data with curve manifolds better, in this paper we propose a new nonlinear probability model, called active curve axis Gaussian model. Intuitively, this model can be imagined as Gaussian model being bent at the first principal axis. For estimating parameters of mixtures of this model, the EM algorithm is employed.

Experiments on synthetic data and Chinese characters show that the proposed nonlinear mixture models can approximate distributions of data clouds with curve manifolds in a more concise and compact way than GMM does. The performance of the proposed nonlinear mixture models is promising.     

一种基于ICA空间高斯混合模型的新颖检测*

新颖检测中,可应用高斯混合模型建立已知数据模型,拟合数据分布,但当数据维数较高时,自由参数太多,训练需要巨大的数据采样,而ICA搜寻数据的最大统计独立表示,可以将数据从高维空间投影到低维空间。提出一种基于ICA空间高斯混合模型的新颖检测,可有效减少估测的自由参数,降低训练数据采样的苛刻要求,实验也验证了该方法的可行性。     

高斯混合模型、求解算法及视觉应用综述

高斯混合模型(GMMs)是统计学习理论的基本模型,在可视媒体领域应用广泛。近些年来,随着可视媒体信息的增长和分析技术的深入,GMMs在(纹理)图像分割、视频分析、图像配准、聚类等领域有了进一步的发展。从GMMs的基本模型出发,从理论和应用的角度讨论和分析了GMMs的求解算法,包括EM算法、变化形式等,论述了GMMs的模型选择问题:在线学习和模型约简。在视觉应用领域,介绍了GMMs在图像分段、视频分析、图像配准、图像降噪等领域的扩展模型与方法,详细地阐述了一些最新的典型模型的原理与过程,如用于图像分段的空间约束GMMs、图像配准中的关联点漂移算法。最后,讨论了一些潜在的发展方向与存在的困难问题。     

Type-2 fuzzy Gaussian mixture models

This paper presents a new extension of Gaussian mixture models (GMMs) based on type-2 fuzzy sets (T2 FSs) referred to as T2 FGMMs. The estimated parameters of the GMM may not accurately reflect the underlying distributions of the observations because of insufficient and noisy data in real-world problems. By three-dimensional membership functions of T2 FSs, T2 FGMMs use footprint of uncertainty (FOU) as well as interval secondary membership functions to handle GMMs uncertain mean vector or uncertain covariance matrix, and thus GMMs parameters vary anywhere in an interval with uniform possibilities. As a result, the likelihood of the T2 FGMM becomes an interval rather than a precise real number to account for GMMs uncertainty. These interval likelihoods are then processed by the generalized linear model (GLM) for classification decision-making. In this paper we focus on the role of the FOU in pattern classification. Multi-category classification on different data sets from UCI repository shows that T2 FGMMs are consistently as good as or better than GMMs in case of insufficient training data, and are also insensitive to different areas of the FOU. Based on T2 FGMMs, we extend hidden Markov models (HMMs) to type-2 fuzzy HMMs (T2 FHMMs). Phoneme classification in the babble noise shows that T2 FHMMs outperform classical HMMs in terms of the robustness and classification rate. We also find that the larger area of the FOU in T2 FHMMs with uncertain mean vectors performs better in classification when the signal-to-noise ratio is lower.     

二型Takagi-Sugeno-Kang模糊模型和不确定高斯混合模型的等价性

不确定的高斯混合模型和二型Takagi-Sugeno-Kang(TSK)模糊模型之间的对应关系被建立: 任何一个不确定的高斯混合模型都唯一对应着一个二型TSK模糊系统, 不确定的高斯混合模型的条件均值和二型TSK模糊 系统的输出是等价的. 基于此, 一种设计二型模糊系统的新方法被提出: 通过建立不确定的高斯混合模型确定二型TSK模糊系统, 即用概率统计的方法设计二型模糊系统. 仿真实验结果表明利用不确定高斯混合模型设计的二型模糊系统比其它模型具有更强的抗噪性和更快的速度.     

空间约束混合高斯运动目标检测

目的 针对传统混合高斯模型前景检测运算量过大问题,提出一种基于空间约束的混合高斯前景检测算法。方法 通过快速初始化缩短模型的初始建立过程;采用双重背景模型机制,以自适应背景减法的前景检测结果作为混合高斯前景检测的空间约束条件,降低模型在背景区域的冗余运算;运用多策略自适应模型更新,提高前景检测的准确性。结果 在各种测试场景下,与传统混合高斯法、CodeBook、GMG、偏差均值混合高斯模型(MODGMM)等算法相比,该算法具有更好的准确率以及4倍以上的处理速度。结论 在固定相机场景下的运动目标检测中,算法能有效提高传统混合高斯法的准确性且具有极高的实时性。     

动态场景的自适应高斯混合模型的研究

混合高斯模型能够拟合像素颜色值分布、跟踪复杂的场景变化,基于它的算法已经成为对视频序列实施背景减法时的一个标准背景建模方法。分析了GMM算法的理论框架,提出了算法改进的两个方面：模型参数更新和BG/FG分类决策。在综述各种已有的算法的基础上,从学习因子控制、模态个数调节、算法评价以及算法初始化等几个方面展开分析。这些分析结果将为后续研究提供思路和方向。     

Fusion of Gaussian mixture models for possible mismatches of sensor model

This paper addresses estimation fusion in the presence of possible mismatches of sensor model. The main concerns of the paper lie in two aspects. One is to improve the filter performance of the single sensor when there are possible mismatches about the sensor model. The other one is to adopt a good fusion scheme to combine local estimates. For these purposes, the measurement process of the local sensor is modeled by multiple models firstly, and the IMM (interacting multiple model) estimator is implemented to produce estimates for individual models. Next, we describe the local estimate by a Gaussian mixture rather than a single Gaussian density in the baseline IMM filter. Such a GMM (Gaussian mixture model) representation of the system state allows us to keep the detailed information about the local tracker, which contributes to the further fusion if treated properly. Finally, the fusion of two Gaussian mixtures is done in the probabilistic framework, and a close-form solution is derived without complex numerical operations. Simulation results demonstrate the effectiveness of the proposed approach.     

基于FPGA的混合高斯背景建模实现

为了解决PC机上高清视频运动目标检测的实时性瓶颈问题,设计了一种基于FPGA的运动目标检测系统.系统采用基于自适应混合高斯背景模型的背景差分法,对环境扰动具有很好的适应性.本设计应用于1 280×1 024高清视频的运动目标检测,针对硬件实现的特点,对OpenCV混合高斯背景模型算法进行改进和适当的参数定点化,设计了适...     

混合空间新型贝叶斯网络模型的图像分割应用研究

现有研究工作没有确定概率向量模型的混合部分比例,所以无法解决MCMC方法的迭代收敛性问题。在具有空间平滑约束的高斯混合模型GMM基础上提出新型贝叶斯网络模型并应用于图像分割领域。模型应用隐Dirichlet分布LDA的概率密度模型和Gauss-Markov随机域MRF的隐Dirichlet参数混合过程来实现参数平滑过程,具有如下优点:针对空间平滑约束规范概率向量模型比例;使用最大后验概率MAP和期望最大化算法EM完成闭合参数的更新操作过程。实验表明,本模型比其他应用GMM方法的图像分割效果好。该模型已成功应用到自然图像和有噪声干扰的自然艺术图像分割过程中。     

融合密度峰值的高斯混合模型聚类算法

针对高斯混合模型（GMM）聚类算法对初始值敏感且容易陷入局部极小值的问题,利用密度峰值（DP）算法全局搜索能力强的优势,对GMM算法的初始聚类中心进行优化,提出了一种融合DP的GMM聚类算法（DP-GMMC）。首先,基于DP算法寻找聚类中心,得到混合模型的初始参数;其次,采用最大期望（EM）算法迭代估计混合模型的参数;最后,根据贝叶斯后验概率准则实现数据点的聚类。在Iris数据集下,DP-GMMC聚类准确率可达到96.67%,与传统GMM算法相比提高了33.6个百分点,解决了对初始聚类中心依赖的问题。实验结果表明,DP-GMMC对低维数据集有较好的聚类效果。     

基于高斯混合聚类的切换系统的辨识

针对具有未知切换规则与未知子系统数量的切换系统的辨识问题,提出一种两阶段辨识方法,包括模式检测与参数辨识.在模式检测阶段,首先建立高斯混合模型表示采样数据的分布,并通过轮盘法选择合适的初始模型参数.其次,计算采样数据属于每个子系统的后验概率,通过极大似然估计算法迭代更新模型参数,使高斯混合模型最大化地拟合采样数据的分布.在此基础上,通过贝叶斯信息准则确定子系统的数量,并根据最大后验概率准则估计切换规则.在参数辨识阶段,通过递推增广最小二乘法估计每个子系统的参数向量.最后,通过仿真结果验证了所提方法的有效性.     

Gaussian mixture modeling of histograms for contrast enhancement

The current major theme in contrast enhancement is to partition the input histogram into multiple sub-histograms before final equalization of each sub-histogram is performed. This paper presents a novel contrast enhancement method based on Gaussian mixture modeling of image histograms, which provides a sound theoretical underpinning of the partitioning process. Our method comprises five major steps. First, the number of Gaussian functions to be used in the model is determined using a cost function of input histogram partitioning. Then the parameters of a Gaussian mixture model are estimated to find the best fit to the input histogram under a threshold. A binary search strategy is then applied to find the intersection points between the Gaussian functions. The intersection points thus found are used to partition the input histogram into a new set of sub-histograms, on which the classical histogram equalization (HE) is performed. Finally, a brightness preservation operation is performed to adjust the histogram produced in the previous step into a final one. Based on three representative test images, the experimental results demonstrate the contrast enhancement advantage of the proposed method when compared to twelve state-of-the-art methods in the literature.     

Fusion of possibly biased location estimates using Gaussian mixture models

A probabilistic framework for fusing location estimates, which may be biased and inconsistent, is presented. The proposed method, involving Gaussian mixture models (GMMs), utilizes prior information regarding the sensor bias, firstly, to reduce errors in the fused location estimate, and secondly, to produce a fused covariance matrix that better reflects the expected location error. Simulations are used to evaluate performance, relative to other techniques, such as the covariance union (CU) method. A passive geolocation application involving an airborne electronic support (ES) system is considered.     

Fitting multisite binding equilibria to statistical distribution models: Turbo Pascal program for Gaussian models

A computer program is described for implementing and fitting Gaussian statistical models of proton binding or metal binding (at constant pH) to complex mixtures of binding sites, such as humic substances. Both unimodal and bimodal continuous ligand distribution models are incorporated, providing fitting capability for data corresponding to either one or two classes of binding sites. Turbo Pascal source code is given along with an example of program usage.     

Automated selection of transcription factor binding sites

Double-stranded DNA binding sites that bound with high affinity to the nuclear factor kappa B (NFκB) p50 homodimer were selected using a Tecan Genesis workstation. The adaptation of the Tecan to automated selection required the integration of multiple devices and modifications to standard selection protocols, and resulted in a significant increase in throughput. The sequences obtained by automated selection strongly correlated with the well-known family of natural NFκB double-stranded DNA binding sites and with previous manual selection experiments. In addition, the selection experiments better defined the contributions of residues outside of the well-known, decameric core binding site for NFκB.     

复杂场景下自适应背景减除算法

目的 复杂场景下的背景减除是智能视频监控研究领域的研究重点和热点之一.针对混合高斯模型中高斯分布个数固定和参数初始化粗糙问题,提出一种应用于复杂场景中的基于混合高斯模型的自适应背景减除算法(AMGBS).方法 通过灰度值归类算法自适应调整模型的高斯分布个数,使得背景模型能够适应场景的变化,并且结合在线 K均值(online K-means)算法和在线期望最大化(online EM)算法初始化混合高斯模型参数.结果 针对灰度值统计结果调整高斯分布数,以及采用优化参数初始化过程,实验表明,本文方法的平均查准率和平均查全率比传统的混合高斯算法高出10%左右,比其他改进的混合高斯算法高出2%左右.结论 提出一种新的自适应背景减除算法,针对灰度值统计结果调整高斯分布数,以及采用优化参数初始化过程.实验结果表明,该方法对复杂场景有较强的适应能力,能够有效快速地完成背景减除,进而实现运动目标的提取.     

Myocardial infarction classification with multi-lead ECG using hidden Markov models and Gaussian mixture models

This study presented a new diagnosis system for myocardial infarction classification by converting multi-lead ECG data into a density model for increasing accuracy and flexibility of diseases detection. In contrast to the traditional approaches, a hybrid system with HMMs and GMMs was employed for data classification. A hybrid approach using multi-leads, i.e., lead-V1, V2, V3 and V4 for myocardial infarction were developed and HMMs were used not only to find the ECG segmentations but also to calculate the log-likelihood value which was treated as statistical feature data of each heartbeat's ECG complex. The 4-dimension feature vector extracted by HMMs was clustered by GMMs with different numbers of distribution (disease and normal data). SVMs classifier was also examined for comparison with our system in experimental result. There were total 1129 samples of heartbeats from clinical data, including 582 data with myocardial infarction and 547 normal data. The sensitivity of this diagnosis system achieved 85.71%, specificity achieved 79.82% and accuracy achieved 82.50% statistically.     

Simultaneous feature selection and Gaussian mixture model estimation for supervised classification problems

A new expectation maximization (EM) algorithm for time-critical supervised classification tasks in remote sensing is proposed. Compared to standard EM and other approaches, it has the following advantages: (1) No knowledge about the class distributions is needed. (2) The number of components is estimated. (3) It does not require careful initialization. (4) Singular estimates are avoided due to the ability of pruning components. (5) The best discriminating features are identified simultaneously. (6) The features are identified by incorporating Mahalanobis distances.