基于模板匹配的视频对象分割

视频对象分割是MPEG-4标准关键技术.本文结合模板匹配和基于运动估值和补偿的对象跟踪方法,提出了一种可以从复杂场景中分割出MPEG-4视频对象的新方法.在使用运动估值和补偿得到分割掩膜后,以初始帧对象颜色为模板,在当前帧的轮廓边界区域通过模板匹配检测对象,使轮廓精确化.本文方法在一定范围内有效解决了遮挡问题,并能够以初始帧跟踪任意长序列中的对象.     

基于可变形模板的视频对象分割

提出一种基于原型的可变形模板进行图像分割的算法，从而可以将感兴趣的视频对象从静止的复杂背景中提取出来，首先定义一个原型模板来特征化感光趣的视频对象，得到一个先验概率密度函数的一个将运动信息与边缘方向结合起来的似然函数，然后应用贝叶斯准则将两者结合起来，得到后验概率密度函数。求它的最大值，从而确定对象的位置。     

基于多帧边缘差异的视频运动对象的分割与跟踪算法

从视频场景中分割和跟踪感兴趣的视频对象对于MPEG-4等基于对象的视频编码来说是关键性的技术之一。针对目前大部分视频对象分割和追踪算法相当复杂但仍不能有效地去除背景噪声的问题,该文提出用于分割和跟踪视频运动对象的一种基于多帧边缘差异的算法。该算法利用一组帧的边缘差异来提取运动对象区域,通过聚类方法去除背景像素点,利用形态学算子得到对象分割模板,同时通过建立前帧感兴趣对象与当前帧运动对象的帧间向量跟踪当前帧的感兴趣视频对象。不同标准视频测试序列的测试结果表明,该算法能够实现对感兴趣的视频运动对象更为精确、快速和有效地分割和跟踪。     

一种基于内容的快速视频运动对象分割算法

自从MPEG-4和MPEG-7标准公布以来。基于内容的视频编码与基于对象形状的检索成为视频领域新的发展趋势，而准确地从背景中分割出视频对象是实现上述功能的前提条件。对视频运动对象分割算法进行了研究，该算法结合对称差分和自适应阚值选取，获得变化检测模板，并最终分割出视频运动对象。实验结果表明该算法对运动对象敏感，能实时准确地分割出视频运动对象。但对象的关节运动以及背景的全局运动都将导致分割精度的降低，这也是今后研究的重点。     

一种基于内容的视频对象分割算法

提出了一种基于内容的视频对象分割算法。该算法先对分块的图像进行运动估计，利用运动矢量初步分割运动前景和背景，对于产生的背景噪声使用改进的中值滤波算法滤除，并用形态学的方法恢复出运动物体。实验结果表明：该算法能够较好地从视频序列中分割运动前景和背景，比较适合于在基于内容的视频编码标准MPEG-4中使用。     

一种视频对象分割新方法

提出一种半自动的视频对象分割新方法,通过对象跟踪分割视频序列的后继帧。这种方法首先采用基于块匹配和最大边缘强度的运动估值和补偿方法进行了对象轮廓定位,接着采用模板匹配以特定对象知识检测对象像素。为使轮廓定位更可靠,在块匹配的运动估值中使用了彩色信息。而模板匹配则使分割结果精确化,避免误差传递,并且在出现遮挡时只要对象颜色在整个序列中的一直保持相似性,就能够正确检测出对象。实验结果证明这种方法能够分割复杂场景中的任意对象。     

基于模糊聚类的运动对象分割算法研究

为了从视频序列中分割出完整的、一致的运动视频对象,该文使用基于模糊聚类的分割算法获得组成对象边界的像素,从而提取对象。该算法首先使用了当前帧以及之前一些帧的图像信息计算其在小波域中不同子带的运动特征,并根据这些运动特征构造了低分辨率图像的运动特征矢量集;然后,使用模糊C-均值聚类算法分离出图像中发生显著变化的像素,以此代替帧间差图像,并利用传统的变化检测方法获得对象变化检测模型,从而提取对象;同时,使用相继两帧之间的平均绝对差值大小确定计算当前帧运动特征所需帧的数量,保证提取视频对象的精确性。实验结果证明该方法对于分割各种图像序列中的视频对象是有效的。     

视频对象分割与两种面向对象的视频编码器

在基于对象的视频编码中,视频对象的分割是重要的任务.本文研究一种利用位移帧差(DFD)的高阶统计特性和数学形态学算子的视频对象自动分割方法.这种方法首先根据一组转移帧差的高阶矩来得到一个大体覆盖运动对象的区域(模板),接着用形态学的腐蚀算子从模板的边沿向内腐蚀,直到对象的边沿.提出一种简单而高效的基于查找人头肩像轮廓最大转折点的头肩分离算法.在分割的基础上,用软件实现了一种基于MPEG-4的视频编码系统.提出一种面向对象分配带宽(OOBA——object-oriented bandwidth allocation)的极低比特率视频编码器.该编码器与传统基于帧的视频编码器相比,在低比特率环境下,PSNR略为下降,但图像的主观视觉质量得到提高.     

一种新的基于时空信息的视频分割

提出了一种新的基于时空信息的视频分割算法．即先将原始图像标记成不同的区域,然后以帧间差分得到的对象运动信息作为评判准则,将这些区域分别归类于前景对象和背景．达到对象分割的目的。特别是在区域标记的过程中,采用了一种新的基于分水岭的区域标识技术。通过对标准图像序列的实验结果可以看到,利用该算法能够较精确地分割出视频对象。     

CBR中基于区域的视频分割技术

基于内容检索方法的提出,对视频对象的处理提出了新的要求.随着M PEG-4基于内容功能的提出以及M PEG-7标准的不断推广应用,视频对象分割技术已成为视频处理领域中的研究热点.视频对象分割就是从视频序列中分割出在语义上有意义的对象.文章从构成视频对象的区域出发,介绍了阈值分割、区域生长算法等视频分割技术,并对视频分割技术中需要深入研究的问题进行了探讨.     

An automatic segmentation method for moving objects based on the spatial-temporal information of video

The new MPEG-4 video coding standard enables content-based functions. In order to support the new standard, frames should be decomposed into Video Object Planes （VOP）, each VOP representing a moving object. This paper proposes an image segmentation method to separate moving objects from image sequences. The proposed method utilizes the spatial-temporal information. Spatial segmentation is applied to divide each image into connected areas and to find pre~：ise object boundaries of moving objects. To locate moving objects in image sequences, two consecutive image frames in the temporal direction are examined and a hypothesis testing is performed with Neyman-Pearson criterion. Spatial segmentation produces a spatial segmentation mask, and temporal segmentation yields a change detection mask that indicates moving objects and the background. Then spatial-temporal merging can be used to get the final results. This method has been tested on several images. Experimental results show that this segmentation method is efficient.     

Automatic moving object and background separation

In this paper, we propose a segmentation method of reduced computational complexity aimed at separating the moving objects from the background in a generic video sequence. This task may be accomplished at the coder site to support the functionalities foreseen by new multimedia scenarios, and in particular the content-based functionalities focused by the MPEG-4 activity, allowing the user to access and decode single objects of a video sequence. The proposed algorithm discriminates between background and foreground by means of a higher-order statistics (HOS) significance test performed on a group of inter-frame differences, followed by a motion detection phase, producing a binary segmentation map. The HOS threshold is adaptively changed, based on the estimated background activity and on the potential presence of slowly moving objects. The map is refined by a final regularization stage implemented by means of a cascade of morphological filters. The algorithm performance were tested through the wide experimental activity carried out during the ISO MPEG-4 N2 Core Experiment on Automatic Segmentation Techniques, in which the authors are currently involved. Typical results obtained on MPEG4 sequences are here shown, in order to illustrate the segmentation algorithm performance.     

运动检测算法的研究和仿真实现

帧间差法和背景差法都是重要的运动检测方法,其核心问题在于如何得到准确的运动对象.针对该问题,本文提出一种结合帧间差和背景差的自动分割算法.该算法通过累积的帧差信息构建出可靠的背景,再将背景与当前帧比较,进而提取出视频运动对象.本文运用了最大类间方差法OTSU(又名"大津法")来获得自适应阈值,能更准确地对背景差图像进行阈值化分割,克服了传统固定阈值容易失效的问题.还采用了形态滤波的方法,对二值图像进行去噪,填充空洞.     

复杂背景下的运动目标分割与阴影消除

针对目前运动对象分割不完整,以及存在阴影和鬼影对运动目标分割的影响,提出了一种基于复杂背景下的运动目标分割与阴影消除方法.首先利用高斯混合模型进行初始背景建模并提取初始前景对象,将当前视频帧和背景模型进行差分运算,且通过多尺度小波变换时空域特征,将多尺度分析和图像分割相结合,压制阴影并消除鬼影对运动目标分割的影响而得到...     

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.     

基于多个非刚体目标跟踪的视频对象平面生成算法

提出了一种提取运动对象的新的视频序列分割算法。算法的核心是一个对象跟踪器,它利用一种基于对象行为的跟踪算法对多个非刚体目标有效地进行对象跟踪,并与后续帧进行匹配,然后采用一种基于运动相连成分的模型刷新方法对模型的每一帧进行刷新,初始的模型自动产生,再利用滤波技术滤除静止背景,最后,利用边界图像模型从序列中提取出视频对象平面（VOP）。     

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     

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.