红外图像的光流计算

图像光流的计算不需要在图像序列中建立特征之间的对应关系，因此光流法在计算机视觉的众多领域，包括运动物体的参数估计和目标跟踪方面都有广泛的应用，由于红外图像的噪声相对较大，光流法很少用于红外图像中目标的运动参数估计和跟踪，这里，使用几种常用的光流计算方法对部分实际红外图像进行了光流场计算。结果表明，当选择合适的方法或计算方法进行一定的改进时，这些红外图像可以得到比较接近实际情况的目标光流场，进而应用于红外图像中的目标分割，运动状态分析与目标跟踪等领域。     

Segmentation and tracking of moving objects for content-based videocoding

To enable content-based functionalities in video coding, a decomposition of the scene into physical objects is required. Such objects are normally not characterised by homogeneous colour, intensity, or optical flow. Therefore, conventional techniques based on these low-level features cannot perform the desired segmentation. The authors address segmentation and tracking of moving objects and present a new video object plane (VOP) segmentation algorithm that extracts semantically meaningful objects. A morphological motion filter detects physical objects by identifying areas that are moving differently from the background. A new filter criterion is introduced that measures the deviation of the estimated local motion from the synthesised global motion. A two-dimensional binary model is derived for the object of interest and tracked throughout the sequence by a Hausdorff object tracker. To accommodate for rotations and changes in shape, the model is updated every frame by a two-stage method that accounts for rigid and non-rigid moving parts of the object. The binary model then guides the actual VOP extraction, whereby a novel boundary post-processor ensures high boundary accuracy. Experimental results demonstrate the performance of the proposed algorithm     

引入光流法的活动轮廓模型

本文在活动轮廓模型的基础上，引入了“图象统计势能”和光流法，提出了一种新的图象分割方法，该方法改进了活动轮廓模型的一些不足，能准确地检测出物体轮廓边界，且分割结果对初始位置不敏感，同时提高了对运动速度较快的物体轮廓检测的正确性，实验结果证实了该方法的有效性。     

目标基视频编码中的运动目标提取与跟踪新算法

自动、快速的视频目标提取与跟踪是目标基视频编码中的一项关键技术.本文提出一种运动目标提取与跟踪新算法.首先,根据多帧运动信息和高阶统计检测方法得到二值运动掩模图像,然后提出一种改进分水岭算法对运动区域及其周围部分进行分割.将二者所得结果进行投影运算,得到最终运动目标.最后提出一种运动目标跟踪新算法,能对目标进行有效的跟踪.实验结果说明了本文算法的有效性.     

基于光流场分割和Canny边缘提取 融合算法的运动目标检测

在摄像机运动的情况下,提出了一种基于光流场分割和Canny边缘算子融合技术的运动目标检测方法.这种方法可分为三步:第一步利用运动的内极线约束和C-均值聚类算法完成目标区域的分割,并获得分割图;第二步在分割图中利用Canny边缘算子获得细化的目标区域边缘图;第三步根据光流场中的流速值完成分割图和边缘图的融合,并检测出完整的运动目标.实验表明,这种方法可以有效地从复杂自然场景的图像序列中检测出完整的运动目标.     

实时目标检测与跟踪系统的设计与实现

针对固定监控场景设计并实现了一个实时的运动目标检测与跟踪系统.在复杂背景下,改进的三帧差分法能准确、快速检测出运动目标.金字塔图像的Lucas Kanade光流法跟踪目标容易丢失;传统的模板匹配跟踪方法由于对图像利用率高,其跟踪比较准确,但计算量大.文章将两者结合起来,可以避免上述问题.实验表明,该算法能较好地实现目标跟踪、获得目标运动轨迹,且具有良好的实时性和鲁棒性.     

A semi-automatic seeded region growing algorithm for video object localization and tracking

This paper describes a semi-automatic method for moving object segmentation and tracking. This method is suitable when a few objects have to be tracked, while the camera moves and fixates on them. The user delineates approximately the initial locations in a selected frame and specifies the depth ordering of the objects to be tracked. First, motion-based segmentation is obtained through an initial application of a region growing algorithm. The partition map is sequentially tracked from frame to frame using motion compensation and location prediction. The segmentation map is obtained by the region growing algorithm. Translational motion is assumed for the moving objects, and local intensity or color average may be used as additional features. A post-processing procedure regularizes the object boundaries over time.     

Segmentation of Tracking Sequences Using Dynamically Updated Adaptive Learning

The problem of segmentation of tracking sequences is of central importance in a multitude of applications. In the current paper, a different approach to the problem is discussed. Specifically, the proposed segmentation algorithm is implemented in conjunction with estimation of the dynamic parameters of moving objects represented by the tracking sequence. While the information on objects' motion allows one to transfer some valuable segmentation priors along the tracking sequence, the segmentation allows substantially reducing the complexity of motion estimation, thereby facilitating the computation. Thus, in the proposed methodology, the processes of segmentation and motion estimation work simultaneously, in a sort of “collaborative” manner. The Bayesian estimation framework is used here to perform the segmentation, while Kalman filtering is used to estimate the motion and to convey useful segmentation information along the image sequence. The proposed method is demonstrated on a number of both computed-simulated and real-life examples, and the obtained results indicate its advantages over some alternative approaches.      

光照变动条件下基于图切割算法的运动目标跟踪

为解决光照大范围变动条件下跟踪运动目标丢失问题,本文基于光照估计的算法建立光照模型,对跟踪视频中的光照进行估计,然后结合图切割算法计算出运动目标的光流向量,利用光流向量进行目标跟踪。实验表明,本文算法对光照的改变具有一定的适应性,可以准确地跟踪目标,提高了跟踪算法的鲁棒性。     

港口背景下红外运动目标的一种检测方法

为了解决港口背景下红外运动目标检测中受背景干扰带来的误分割和误跟踪问题,提出了一种基于港口背景抑制和光流检测的红外运动目标检测方法。首先,通过对小波分解图像进行OTSU分割,得到天水线区域。然后使用多级滤波确定序列图像中港口背景的抑制基准点,并根据这些背景抑制基准点实现序列图像的港口背景抑制。最后,运用光流预测实现红外运动目标检测。通过对实际港口背景红外图像进行背景抑制和红外运动目标检测的实验,验证了所提方法的可行性和有效性。     

Optical flow estimation and moving object segmentation based onmedian radial basis function network

Various approaches have been proposed for simultaneous optical flow estimation and segmentation in image sequences. In this study, the moving scene is decomposed into different regions with respect to their motion, by means of a pattern recognition scheme. The inputs of the proposed scheme are the feature vectors representing still image and motion information. Each class corresponds to a moving object. The classifier employed is the median radial basis function (MRBF) neural network. An error criterion function derived from the probability estimation theory and expressed as a function of the moving scene model is used as the cost function. Each basis function is activated by a certain image region. Marginal median and median of the absolute deviations from the median (MAD) estimators are employed for estimating the basis function parameters. The image regions associated with the basis functions are merged by the output units in order to identify moving objects.     

A novel fast moving object contour tracking algorithm

If a somewhat fast moving object exists in a complicated tracking environment, snake’s nodes may fall into the inaccurate local minima. We propose a mean shift snake algorithm to solve this problem. However, if the object goes beyond the limits of mean shift snake module operation in suc- cessive sequences, mean shift snake’s nodes may also fall into the local minima in their moving to the new object position. This paper presents a motion compensation strategy by using particle filter; therefore a new Parti...     

基于OpenCV的运动目标跟踪系统研究

本文分析比较了传统运动目标检测的3种主要方法：背景图像差分法、时态差分法和光流法,在此基础上给出了一种背景图像预测算法,大大减少了因为背景变化而产生的目标检测误差。本文基于OpenCV设计出改进的运动目标检测与跟踪算法,实现了运动目标的跟踪,并在VC＋＋编译环境下,利用USB摄像头作为视频采集器,通过观察实验结果可以看出,本文的运动目标检测算法能够正确地检测出视频图像中的运动目标,而且在检测性能上优于普通的自适应背景差分法。     

红外序列图像目标跟踪的自适应Kalman滤波方法

提出了一种用于动态序列图像目标跟踪的自适应Kalman滤波方法。该方法用函数估计的思想估计目标的当前运动模型，同时实时修改滤波器的统计模型，并将最小二乘支持向量机应用于对当前目标运动模型的估计。实验表明，此种改进的Kalman滤波器的算法在跟踪机动目标时具有良好的性能。     

基于Snake活动轮廓模型的视频跟踪分割方法

基于Snake活动轮廓模型,采用时空融合的方式,根据短时间内相邻帧的运动趋势差异相似的前提,首先将视频序列分成若干个小段,每段有k帧视频,选取段内的前两帧为关键帧,通过运动检测的方式自动得到这两帧中运动对象的大致区域;然后进行帧内Snake演变,搜索精确轮廓;最后以关键帧间运动对象形心的运动矢量预测勾勒后续帧的初始轮廓,进行帧内Snake精确轮廓定位,从而实现所有帧的视频对象分割。相比于传统方法,本文方法克服了手动绘制初始轮廓的缺点,在空域对Snake贪婪方法进行了改进而且精确度高,速度快。实验表明,本文方法成功地实现了前后帧图像之间运动对象的对应匹配关系,并通过改进后的Snake贪婪方法得到了精确的分割结果。     

基于自适应背景图像更新的运动目标检测方法

在运动目标的实时检测中常用的方法是背景图像差分法,但因其缺乏背景图像随监视场景光照变化而及时更新的合理方法,限制了本方法的适应性.对此,本文首先提出了一种基于光流场等技术的自适应背景逼近更新方法,并根据彩色差值模型得到差分图像;然后引入Gauss模型实现运动目标的自适应阈值分割.实验结果表明:本文提出的背景更新方法可随着光照条件的变化实时、准确地更新背景图像,在此基础上提出的基于Gauss模型的自适应阈值分割方法可以实现运动目标的完整分割,这为运动目标的后续识别与理解奠定了基础.     

空域视频场景监视中运动对象的实时检测与跟踪技术

本文分析了空域视频场景中运动对象实时检测、跟踪系统的模型。提出了一种在运动背景下实时检测与跟踪视频运动目标的技术。该方法首先进行背景的全局运动参数估计,并对背景进行补偿校正,将补偿校正后的相邻两帧进行差分检测。然后利用假设检验从差分图像中提取运动区域,利用遗传学方法在指定区域内确定最优分割门限,提取视频运动对象及其特征;最后利用线性预测器对目标进行匹配跟踪。在基于高速DSP的系统平台上的实验结果表明该方法取得了很好的效果。     

较大尺度运动下的人体特征点跟踪算法研究

利用光流法可以对视频中运动目标进行特征点跟踪,当目标存在较大尺度运动时,光流法图像一致性假设难以满足,导致特征点跟踪丢失。针对此问题,提出了一种基于Lucas-Kanade(L-K)金字塔光流算法的运动人体特征点跟踪方法。首先,利用帧间差分法得到帧差图像序列,获取行人的运动区域;然后用尺度不变特征变换（SIFT）算法检测选定初始帧中的特征点;最后运用L-K金字塔光流算法跟踪这些特征点在后续帧中的位置。实验结果表明,该算法对较大尺度运动的特征点跟踪有很好的效果,提高了跟踪的准确性。      

Figure-ground segmentation from occlusion.

Layered video representations are increasingly popular; see [2] for a recent review. Segmentation of moving objects is a key step for automating such representations. Current motion segmentation methods either fail to segment moving objects in low-textured regions or are computationally very expensive. This paper presents a computationally simple algorithm that segments moving objects, even in low-texture/low-contrast scenes. Our method infers the moving object templates directly from the image intensity values, rather than computing the motion field as an intermediate step. Our model takes into account the rigidity of the moving object and the occlusion of the background by the moving object. We formulate the segmentation problem as the minimization of a penalized likelihood cost function and present an algorithm to estimate all the unknown parameters: the motions, the template of the moving object, and the intensity levels of the object and of the background pixels. The cost function combines a maximum likelihood estimation term with a term that penalizes large templates. The minimization algorithm performs two alternate steps for which we derive closed-form solutions. Relaxation improves the convergence even when low texture makes it very challenging to segment the moving object from the background. Experiments demonstrate the good performance of our method.     

A novel approach to motion segmentation based on gamma distribution

We provide a new motion segmentation method in image sequences based on gamma distribution. Motion segmentation is very important because it can be employed for video surveillance, object tracking, and action recognition. The Gaussian mixture model (GMM) has been widely used as a distribution model for motion segmentation. However, we found that the gamma distribution model is more suitable than the GMM for the optical flow based motion segmentation. Experimental results show that the proposed method is very effective in producing accurate motion segmentation results in image sequences.