多特征融合的尺度自适应KCF人脸跟踪

针对传统核相关滤波(KCF)跟踪算法在人脸跟踪中无法处理尺度变化、严重遮挡等问题,提出一种多特征融合的尺度自适应KCF人脸跟踪算法。该算法先对肤色与HOG特征进行融合来表征人脸,通过多通道相关滤波器定位人脸位置;学习一个一维的尺度滤波器来估计人脸的最优尺度;采用线性插值的方式对滤波器系数和人脸外观模型进行更新。实验结果表明,改进后的算法能明显提高跟踪的性能。通过定量与定性分析该算法对尺度变化、严重遮挡等问题有很好的鲁棒性,跟踪速度在36.7 f/s时达到实时应用的要求,优于近几年一些优秀的跟踪算法。     

基于多示例学习和随机蕨丛检测的在线目标跟踪

基于检测的目标跟踪方法目前在计算机视觉领域受到了广泛的关注,这类方法通过训练判别分类器将目标对象从背景中分离出来;分类器的训练是根据当前的跟踪状态从当前帧中提取正负样本来进行,但训练样本的不准确将导致分类器退化产生漂移。该文提出一种能够有效克服目标漂移的跟踪算法,采用检测器和跟踪器相结合的框架,利用中值流算法作为跟踪器,提高跟踪点的可靠性;级联若干个随机蕨弱分类器构成强分类器作为检测器;用在线多示例学习方法更新检测器,提高检测精度;最后将检测器、跟踪器的结果相融合得到最终的目标位置。实验结果表明,与其它方法相比,该方法对目标漂移有更强的鲁棒性。     

一种多人脸跟踪算法的研究与实现

结合人脸的运动模型提出了一种多人脸的跟踪算法,通过使用跟踪稳定系数来解决多人脸跟踪过程中目标发生粘连重叠或者由于目标检测质量的原因造成跟踪目标丢失等各种问题;同时目标跟踪器提供一个预测搜索区域指导下一帧的定位,从而进一步提高定位的速度.实验结果表明此算法具有很好的准确性和实时性.     

一种快速多人脸跟踪算法

提出一个基于肤色的快速多人脸跟踪算法.利用多个CAMShift跟踪器实现多人脸跟踪,提出最优排序法和目标消除法解决多人脸跟踪过程中目标发生粘连重叠的问题;引入多辅助信息和表决制解决了相邻两帧中人脸的对应问题.为进一步提高整个算法的跟踪速度和鲁棒性,引入卡尔曼滤波器对目标进行预测.实验结果表明,该算法可实时稳健地实现多人脸跟踪.     

一种改进的长时间压缩感知跟踪算法

压缩感知跟踪(CT)算法具有简单、高效、实时的优点,但是却存在着跟踪窗口尺寸不能自适应变化,无法有效处理遮挡以及跟踪失败后的目标再发现等问题.为了解决上述问题,提出了一种改进的长时间压缩感知跟踪算法.所提出的算法采用多尺度的目标外观再匹配方法,使得跟踪窗口大小能够适应目标尺寸变化.此外,通过分析滑动窗口内跟踪窗口图像的整体特征变化来判定目标是否发生遮挡.为了解决跟踪器漂移问题,采用Haar特征在线生成检测器,实现目标的再发现.实验结果表明提出的算法相比原CT算法具有更好的鲁棒性和准确性.     

一种同步人脸运动跟踪与表情识别算法

针对单视频动态变化背景下的人脸表情识别问题,提出了一种同步人脸运动跟踪和表情识别算法,并在此基础上构建了一个实时系统.该系统达到了如下目标:首先在粒子滤波框架下结合在线外观模型和柱状几何模型进行人脸三维运动跟踪;接着基于生理知识来提取人脸表情的静态信息;然后基于流形学习来提取人脸表情的动态信息;最后在人脸运动跟踪过程中,结合人脸表情静态信息和动态信息来进行表情识别.实验结果表明,该系统在大姿态和丰富表情下具有较好的综合优势.     

一种改进的基于ASM模型的人脸跟踪算法

ASM主动形状模型是一种基于点分布的模型。在该模型中,外观相似的物体,可以通过一定数量的关键点坐标来表示出位置和相对应的顺序。在常规的基于ASM模型的人脸跟踪技术中,会发生拟合点漂移的现象,造成定位的不准确。文中提出一种结合了Adaboost人脸跟踪和传统的ASM模型的算法,能够有效地减少在传统ASM模型中出现的跟踪漂移现象。     

应用于人脸自动实时跟踪的改进Struck算法

传统的Struck算法在人脸跟踪系统中,需要手动实现初始化且易受环境影响。文中提出一种基于AdaBoost目标自动检测和改进的Struck人脸自动跟踪算法。从图像中提取人脸的Haar特征,采用AdaBoost算法实现人脸的检测,并自动初始化跟踪器,再依据检测得到的相邻帧目标的相似度判定跟踪目标的有效性,采用Struck算法实现人脸的连续跟踪。实验结果表明,改进的算法有效解决了部分遮挡、尺度变化、光照变化等人脸跟踪难题,且具有较高的鲁棒性与准确性。     

基于KL散度与通道选择的热红外目标跟踪算法

为了解决单一跟踪器无法有效应对复杂背景及目标外观的显著变化,对于热红外目标跟踪准确度不高的问题,基于全卷积孪生网络提出了一种多响应图集成的跟踪算法用于热红外跟踪。首先,使用预训练的卷积神经网络来提取热红外目标的多个卷积层的特征并进行通道选择,在此基础上分别构建3个对应的跟踪器,每个跟踪器独立执行跟踪并返回一个响应图。然后,利用Kullback–Leibler（KL）散度对多个响应图进行优化集成,得到一个更强的响应图。最后利用集成后的响应图来确定目标位置。为了评估所提算法的性能,在当前最全面的热红外跟踪基准LSOTB-TIR（Large-Scale Thermal Infrared Object Tracking Benchmark）上进行了实验。实验结果表明,所提算法能够适应复杂多样的红外跟踪场景,综合性能超过了现有的红外跟踪算法。     

Lasso约束下融和光流信息的DCF目标跟踪算法

视频目标跟踪是计算机视觉的基础问题之一。近来由于 discriminative correlation filter（DCF）跟踪器的高效性和鲁棒性,出现了许多基于DCF的目标跟踪算法。为了克服DCF跟踪器对运动模糊目标的不适应性,本文提出了一种利用Lasso约束并融入光流信息的目标跟踪算法。首先在跟踪器抽取特征通道块中融入光流特征。然后在通道块之后进行多特征融合。其次利用Lasso约束DCF跟踪器的目标函数。考虑到所约束的目标函数在定义域上不连续和目标跟踪的优化效率。最后,采用块坐标下降算法来优化所约束的目标函数。实验结果表明,与基于DCF视觉跟踪算法相比,所提出的算法可以有效的处理运动模糊目标,实现复杂环境下鲁棒的视觉目标跟踪。      

复杂场景下基于多特征融合的视频跟踪

为了解决常见视频跟踪方法在复杂场景中难以有效跟踪运动物体的难题,研究了在粒子滤波框架下基于多特征融合的判别式视频跟踪算法.首先分析了特征提取和跟踪算法的鲁棒性和准确性的关系,指出融合多种特征能有效地提升算法在复杂场景中的跟踪效果,然后选择提取HSV颜色特征和HOG特征描述目标表观,并在线训练逻辑斯特回归分类器构造判别式目标表观模型.在公开的复杂场景视频进行测试,比较了使用单一特征和多种特征的实验效果,并且将所提算法和经典跟踪算法进行了比较,实验结果表明融合多种特征的视频跟踪更具鲁棒性和准确性.     

基于自适应响应融合的相关滤波红外目标跟踪

红外目标跟踪在军事和民用视频监控领域有重要的研究意义,但受热成像原理限制,红外目标分辨率低、对比度低、纹理信息缺失。针对红外目标特征信息量少导致跟踪性能较低的问题,提出一种基于自适应响应融合的相关滤波跟踪算法。该算法基于连续卷积运算的相关滤波跟踪框架,通过构造视觉显著性特征来增强目标外观描述,并结合对冲决策理论对由不同特征计算得到的多个滤波响应进行自适应融合,最终根据融合响应预测目标中心位置。此外,通过尺度滤波器来实现目标的尺度预测,得到完整的跟踪结果。在公开的红外视频数据集VOT-TIR2016进行测试,实验结果表明:与同类算法相比,该算法表现出更高的跟踪精确度和鲁棒性。     

基于关键区域特征匹配的视觉跟踪算法

针对视觉跟踪中目标表观的复杂变化问题,提出了一种基于关键区域特征匹配的鲁棒跟踪算法.首先对目标模板进行初始化并通过滤波预测得到目标候选;然后采用自适应标记分水岭算法对目标模板和目标候选进行分割以提取关键区域,并利用像素的空间和频率分布特性对关键区域进行多重特征描述;最后通过关键区域的特征匹配得到目标模板与目标候选的匹配关系,由此确定最终跟踪结果并进行模板更新.对目标发生尺度、遮挡、旋转、光照、姿态、复杂背景以及运动模糊等变化的视频序列进行了仿真测试.实验结果表明,所提算法能够有效处理目标表观的复杂变化问题,尤其对目标的部分遮挡、光照变化以及复杂背景等具有较强的鲁棒性.     

An efficient real-time target tracking algorithm using adaptive feature fusion

Visual-based target tracking is easily influenced by multiple factors, such as background clutter, targets’ fast-moving, illumination variation, object shape change, occlusion, etc. These factors influence the tracking accuracy of a target tracking task. To address this issue, an efficient real-time target tracking method based on a low-dimension adaptive feature fusion is proposed to allow us the simultaneous implementation of the high-accuracy and real-time target tracking. First, the adaptive fusion of a histogram of oriented gradient (HOG) feature and color feature is utilized to improve the tracking accuracy. Second, a convolution dimension reduction method applies to the fusion between the HOG feature and color feature to reduce the over-fitting caused by their high-dimension fusions. Third, an average correlation energy estimation method is used to extract the relative confidence adaptive coefficients to ensure tracking accuracy. We experimentally confirm the proposed method on an OTB100 data set. Compared with nine popular target tracking algorithms, the proposed algorithm gains the highest tracking accuracy and success tracking rate. Compared with the traditional Sum of Template and Pixel-wise LEarners (STAPLE) algorithm, the proposed algorithm can obtain a higher success rate and accuracy, improving by 2.3% and 1.9%, respectively. The experimental results also demonstrate that the proposed algorithm can reach the real-time target tracking with 50+fps. The proposed method paves a more promising way for real-time target tracking tasks under a complex environment, such as appearance deformation, illumination change, motion blur, background, similarity, scale change, and occlusion.     

Robust face tracking via collaboration of generic and specific models.

Significant appearance changes of objects under different orientations could cause loss of tracking, "drifting." In this paper, we present a collaborative tracking framework to robustly track faces under large pose and expression changes and to learn their appearance models online. The collaborative tracking framework probabilistically combines measurements from an offline-trained generic face model with measurements from online-learned specific face appearance models in a dynamic Bayesian network. In this framework, generic face models provide the knowledge of the whole face class, while specific face models provide information on individual faces being tracked. Their combination, therefore, provides robust measurements for multiview face tracking. We introduce a mixture of probabilistic principal component analysis (MPPCA) model to represent the appearance of a specific face under multiple views, and we also present an online EM algorithm to incrementally update the MPPCA model using tracking results. Experimental results demonstrate that the collaborative tracking and online learning methods can handle large pose changes and are robust to distractions from the background.     

Real-time background subtraction-based video surveillance of people by integrating local texture patterns

This paper presents a real-time surveillance system for detecting and tracking people, which takes full advantage of local texture patterns, under a stationary monocular camera. A novel center-symmetric scale invariant local ternary pattern feature is put forward to combine with pattern kernel density estimation for building a pixel-level-based background model. The background model is then used to detect moving foreground objects on every newly captured frame. A variant of a fast human detector that utilizes local texture patterns is adopted to look for human objects from the foreground regions, and it is assisted by a head detector, which is proposed to find in advance the candidate locations of human, to reduce computational costs. Each human object is given a unique identity and is represented by a spatio-color-texture object model. The real-time performance of tracking is achieved by a fast mean-shift algorithm coupled with several efficient occlusion-handling techniques. Experiments on challenging video sequences show that the proposed surveillance system can run in real-time and is quite robust in segmenting and tracking people in complex environments that include appearance changes, abrupt motion, occlusions, illumination variations and clutter.     

基于深度学习的无人机载平台多目标检测和跟踪算法研究

无人机技术和计算机视觉技术相结合,在民用和军用领域都有着广泛的需求,然而当前算法不能很好的适应无人机视角旋转、障碍物遮挡、目标尺度变化等特殊情况.根据实际的难点和挑战,提出了基于深度学习的无人机载平台多目标检测和跟踪算法.主要工作有:在检测方面,通过公开数据集和实际采集的大量数据,训练了基于Darknet53的检测网络...     

基于分块的多特征融合变尺度目标跟踪算法

为了增强彩色视频中目标外观描述能力和解决跟踪过程中目标尺度变化的问题,提出一种基于分块的多特征融合变尺度目标跟踪算法.设计了一个能处理不同挑战因素下对目标的精确跟踪算法,首先提取HSV分块的颜色直方图特征和PCA-HOG特征并采用多通道线性核函数对两种特征进行融合构建训练样本,然后求解线性岭回归函数获得位置核相关滤波器模型,并以线性核函数来计算候选区域在7个尺度空间上与跟踪目标的响应值,最后利用尺度自适应模板更新模型参数.实验结果表明,提出的算法在彩色视频中不仅能较好地自适应目标尺度的变化,在复杂场景下也具有较强的鲁棒性.     

词汇树融合SIFT的热成像和视觉图像人脸识别

针对热成像和视觉图像人脸识别问题,提出了一种基于词汇树融合尺度不变特征变换方法。首先,对视觉和热成像图像分别单独进行提取,利用Viola-Jones层叠检测器从自然图像中检测出人脸;然后,利用SIFT描述符从尺度空间提取稳定特征;最后,使用词汇树进行分类,利用评分融合和决策融合算法提高系统的精确性和安全性。在拍摄的41个人的脸部图像上的实验表明了该方法的有效性,识别率可接近100%,相比其他几种较为新颖的人脸识别方法,该方法取得了更高的识别精度,并且在一定程度上降低了计算耗时。     

Correlation filter tracking based on superpixel and multifeature fusion

For the correlation filtering(CF) tracking algorithm is not robust enough and cannot adapt to scale changes, target occlusion(OCC) and other complex interferences. We introduce a CF tracking algorithm based on superpixel and multifeature fusion(CFSMF). First, superpixel segmentation and clustering are performed for the target and its surrounding environment in the initial frame. Then, a target appearance is reconstructed through block segmentation-based overlapping analysis to remove redundant information. On this basis, the histogram of gradient(HOG) and HSI color features of the target sub-block are extracted to interact with their respective position filters. Accordingly, the target position is determined by the weighted fusion of the response values. In the scale prediction stage, we independently train a scale filter with a multiscale pyramid constructed at the estimated target location. The object scale is estimated in terms of the filter response, thereby enabling the tracking algorithm to adapt to the object scale change. Lastly, we introduce an OCC criterion for determining whether to update the model or not. Compared with the classical tracking algorithm kernelized correlation filters(KCF), the proposed algorithm boosts the tracking success rate by 20% and tracking accuracy by 15.9%. Our algorithm in this paper could track the target stably even when the target is occluded and its scale changes.