动态背景下融合运动线索和颜色信息的视频目标分割算法

针对现有动态背景下目标分割算法存在的局限性,提出了一种融合运动线索和颜色信息的视频序列目标分割算法。首先,设计了一种新的运动轨迹分类方法,利用背景运动的低秩特性,结合累积确认的策略,可以获得准确的运动轨迹分类结果;然后,通过过分割算法获取视频序列的超像素集合,并计算超像素之间颜色信息的相似度;最后,以超像素为节点建立马尔可夫随机场模型,将运动轨迹分类信息以及超像素之间颜色信息统一建模在马尔可夫随机场的能量函数中,并通过能量函数最小化获得每个超像素的最优分类。在多组公开发布的视频序列中进行测试与对比,结果表明,本文方法可以准确分割出动态背景下的运动目标,并且较传统方法具有更高的分割准确率。     

基于多种上下文结构与线性融合的特定敏感视频识别

本文中特定敏感视频是指恐怖和暴力视频,现有的特定敏感视频识别算法或是忽略了视频的多种上下文结构信息;或是忽略了各种特征间潜在的依赖关系.因此,本文提出了一种基于多种上下文结构与线性融合的特定敏感视频识别方法,首先针对某种视频提取多种有效特征,并获取镜头间的上下文结构信息;然后,在每一个特征空间中利用上下文结构训练一个SVM分类器;最后,获取不同特征间的依赖关系,采用线性依赖模型融合多个分类器的结果,提高视频的识别率.在特定敏感视频库上的实验结果验证了该方法比现有的其它算法有更好的性能和稳定性.     

The local and the global: an exploration into the Finnish andEnglish Websites of a Finnish company

This paper compares the Finnish and English Web sites of a Finnish company to find out what culturally geared strategies emerge and what constitutes the genre of company information on the Internet. Drawing on genre theory and cultural studies, the paper further explores the relationship between linear texts and nonlinear hypertext genre. The paper shows how the Web sites aimed at the English-speaking readers are different from the sites targeted to the Finnish readers. It further illustrates the company strategies employed to establish the Web site in Finnish and English. These are endorsed by a company representative who was interviewed for the paper. The Finnish Web site meant for local Finnish readers contained detailed and itemized information and portrayed a retail-oriented strategy. The Internet presence targeted toward English-speaking readers portrayed an investor-oriented strategy. The characteristics of hypertext that distinguish it from linear texts are high rate of repetition and low macrolevel cohesion     

Web video classification with visual and contextual semantics

On the social Web, the amount of video content either originated from wireless devices or previously received from media servers has increased enormously in the recent years. The astounding growth of Web videos has stimulated researchers to propose new strategies to organize them into their respective categories. Because of complex ontology and large variation in content and quality of Web videos, it is difficult to get sufficient, precisely labeled training data, which causes hindrance in automatic video classification. In this paper, we propose a novel content‐ and context‐based Web video classification framework by rendering external support through category discriminative terms (CDTs) and semantic relatedness measure (SRM). Mainly, a three‐step framework is proposed. Firstly, content‐based video classification is proposed, where twofold use of high‐level concept detectors is leveraged to classify Web videos. Initially, category classifiers induced from VIREO‐374 detectors are trained to classify Web videos, and then concept detectors with high confidence for each video are mapped to CDT through SRM‐assisted semantic content fusion function to further boost the category classifiers, which intuitively provide a more robust measure for Web video classification. Secondly, a context‐based video classification is proposed, where twofold use of contextual information is also harnessed. Initially, cosine similarity and then semantic similarity are measured between text features of each video and CDT through vector space model (VSM)‐ and SRM‐assisted semantic context fusion function, respectively. Finally, classification results from content and context are fused to compensate for the shortcomings of each other, which enhance the video classification performance. Experiments on large‐scale video dataset validate the effectiveness of the proposed solution.     

Violence in Music Videos: Examining the Prevalence and Context of Physical Aggression

The purpose of this study was to examine violence in music video programming. Using a representative sample of television content, we assessed whether the amount and context of physical aggression varied across different music video channels (BET, MTV, VH-1) and genres (adult contemporary, heavy metal, rap rhythm and blues, and rock). The results reveal that 15% of music videos feature violence, and most of that aggression is sanitized, not chastised, and presented in realistic contexts. Significant differences emerged in the prevalence and nature of violence by channel and genre, however. The findings are discussed in terms of the risk that exposure to violence in each channel and genre may be posing to viewers' learning of aggression, fear, and emotional desensitization.     

Double compression detection based on local motion vector field analysis in static-background videos

Videos captured by stationary cameras are widely used in video surveillance and video conference. This kind of video often has static or gradually changed background. By analyzing the properties of static-background videos, this work presents a novel approach to detect double MPEG-4 compression based on local motion vector field analysis in static-background videos. For a given suspicious video, the local motion vector field is used to segment background regions in each frame. According to the segmentation of backgrounds and the motion strength of foregrounds, the modified prediction residual sequence is calculated, which retains robust fingerprints of double compression. After post-processing, the detection and GOP estimation results are obtained by applying the temporal periodic analysis method to the final feature sequence. Experimental results have demonstrated better robustness and efficiency of the proposed method in comparison to several state-of-the-art methods. Besides, the proposed method is more robust to various rate control modes.     

基于图像分割网络的深度假脸视频篡改检测

随着深度学习技术的快速发展,利用深度神经网络模型伪造出的深度假脸(deepfake)视频越来越逼真,假脸视频造成的威胁也越来越大。文献中已出现一些基于卷积神经网络的换脸视频检测算法,他们在库内获得较好的检测效果,但跨库检测性能急剧下降,存在泛化能力不足的问题。该文从假脸篡改的机制出发,将视频换脸视为特殊的拼接篡改问题,利用流行的神经分割网络首先预测篡改区域,得到预测掩膜概率图,去噪并二值化,然后根据换脸主要发生在人脸区域的前提,提出一种计算人脸交并比的新方法,并进一步根据换脸处理的先验知识改进人脸交并比的计算,将其作为篡改检测的分类准则。所提出方法分别在3个不同的基础分割网络上实现,并在TIMIT, FaceForensics++, FFW数据库上进行了实验,与文献中流行的同类方法相比,在保持库内检测的高准确率同时,跨库检测的平均错误率显著下降。在近期发布的合成质量较高的DFD数据库上也获得了很好的检测性能,充分证明了所提出方法的有效性和通用性。     

Tennis Video 2.0: A new presentation of sports videos with content separation and rendering

This paper proposes a new method for presenting sports videos. Tennis videos are used as an example for the implementation of a viewing program called as Tennis Video 2.0. For the methods in video analysis, background generation by considering the pixels in temporal and spatial distribution is proposed; foreground segmentation combining automatic trimap generation and matting model is proposed. To provide more functions in watching videos, the rendering flow of video contents and the semantic Scalability are proposed. With the new analysis and rendering tools, the presentation of sports videos has three properties—Structure, Interactivity, and Scalability. The experiments show that several broadcasting game videos are employed to evaluate the robustness and performance of the proposed system. For user study, 20 evaluators highly identify that Tennis Video 2.0 is a new presentation of sports videos and give people better viewing experience.     

Underwater image processing method for fish localization and detection in submarine environment

Object detection is an important process in image processing, it aims to detect instances of semantic objects of a certain class in digital images and videos. Object detection has applications in many areas of computer vision such as underwater fish detection. In this paper we present a method for preprocessing and fish localization in underwater images. We are based on a Poisson–Gauss theory, because it can accurately describe the noise present in a large variety of imaging systems. In the preprocessing step we denoise and restore the raw images. These images are split into regions utilizing the mean shift algorithm. For each region, statistical estimation is done independently in order to combine regions into objects. The method is tested under different underwater conditions. Experimental results show that the proposed approach outperforms state of the art methods.     

Estimation of generalized mixtures and its application in imagesegmentation

We introduce the notion of a generalized mixture and propose some methods for estimating it, along with applications to unsupervised statistical image segmentation. A distribution mixture is said to be "generalized" when the exact nature of the components is not known, but each belongs to a finite known set of families of distributions. For instance, we can consider a mixture of three distributions, each being exponential or Gaussian. The problem of estimating such a mixture contains thus a new difficulty: we have to label each of three components (there are eight possibilities). We show that the classical mixture estimation algorithms-expectation-maximization (EM), stochastic EM (SEM), and iterative conditional estimation (ICE)-can be adapted to such situations once as we dispose of a method of recognition of each component separately. That is, when we know that a sample proceeds from one family of the set considered, we have a decision rule for what family it belongs to. Considering the Pearson system, which is a set of eight families, the decision rule above is defined by the use of "skewness" and "kurtosis". The different algorithms so obtained are then applied to the problem of unsupervised Bayesian image segmentation, We propose the adaptive versions of SEM, EM, and ICE in the case of "blind", i.e., "pixel by pixel", segmentation. "Global" segmentation methods require modeling by hidden random Markov fields, and we propose adaptations of two traditional parameter estimation algorithms: Gibbsian EM (GEM) and ICE allowing the estimation of generalized mixtures corresponding to Pearson's system. The efficiency of different methods is compared via numerical studies, and the results of unsupervised segmentation of three real radar images by different methods are presented.     

生物医学工程中图像分割的应用

医学图像分割是图像分割的一个重要应用领域，它能够自动或半自动描绘出医学图像中的解剖结构和其它感兴趣的区域，从而有助于诊断，所以它在生物医学图像的应用中起着非常重要的作用。文中对近年来图像分割的新方法或改进算法进行综述，重点放在各种方法对于医学图像应用的优点和不足之处上，揭示了各方法的适应范围和应用重点；展望了医学图像的前景和面临的挑战。     

Image segmentation based on the Poincaré map method

Active contour models (ACMs) integrated with various kinds of external force fields to pull the contours to the exact boundaries have shown their powerful abilities in object segmentation. However, local minimum problems still exist within these models, particularly the vector field's "equilibrium issues." Different from traditional ACMs, within this paper, the task of object segmentation is achieved in a novel manner by the Poincaré map method in a defined vector field in view of dynamical systems. An interpolated swirling and attracting flow (ISAF) vector field is first generated for the observed image. Then, the states on the limit cycles of the ISAF are located by the convergence of Newton-Raphson sequences on the given Poincaré sections. Meanwhile, the periods of limit cycles are determined. Consequently, the objects' boundaries are represented by integral equations with the corresponding converged states and periods. Experiments and comparisons with some traditional external force field methods are done to exhibit the superiority of the proposed method in cases of complex concave boundary segmentation, multiple-object segmentation, and initialization flexibility. In addition, it is more computationally efficient than traditional ACMs by solving the problem in some lower dimensional subspace without using level-set methods.     

自适应特征加权的Gibbs随机场影像分割方法

针对现有分割算法很少同时兼顾不同特征分量区分能力的差异和相邻像素间的相关性的问题,提出了一种结合Gibbs随机场的特征加权遥感影像分割方法.该方法首先依据训练样本计算各特征分量的区分能力,确定不同地物类别相应的特征分量的权重;然后利用加权最小距离分类法对影像进行初始分割,并利用Gibbs随机场来描述像素的空间相关性;最后综合Gibbs随机场描述的标记场和加权最小距离分类法描述的特征场来获取影像的最终分割结果.实验结果表明,Gibbs随机场能够有效地描述空间相关性,根据区分能力确定的权重强化了区分能力强的特征分量.     

An objective and subjective quality assessment study of passive gaming video streaming

Passive gaming video‐streaming applications have recently gained much attention as evident with the rising popularity of many Over The Top (OTT) providers such as Twitch.tv and YouTube Gaming. For the continued success of such services, it is imperative that the user Quality of Experience (QoE) remains high, which is usually assessed using subjective and objective video quality assessment methods. Recent years have seen tremendous advancement in the field of objective video quality assessment (VQA) metrics, with the development of models that can predict the quality of the videos streamed over the Internet. A study on the performance of objective VQA on gaming videos, which are artificial and synthetic and have different streaming requirements than traditionally streamed videos, is still missing. Towards this end, we present in this paper an objective and subjective quality assessment study on gaming videos considering passive streaming applications. Subjective ratings are obtained for 90 stimuli generated by encoding six different video games in multiple resolution‐bitrate pairs. Objective quality performance evaluation considering eight widely used VQA metrics is performed using the subjective test results and on a data set of 24 reference videos and 576 compressed sequences obtained by encoding them in 24 resolution‐bitrate pairs. Our results indicate that Video Multimethod Assessment Fusion (VMAF) predicts subjective video quality ratings the best, while Naturalness Image Quality Evaluator (NIQE) turns out to be a promising alternative as a no‐reference metric in some scenarios.     

Review of vehicular ad hoc network communication models including WVANET (Web VANET) model and WVANET future research directions

The most ever growing research field is vehicular ad hoc network. This prominent research field has the widely known communication models such as RoadSide Unit Communication, Vehicle to Vehicle Communication, and Cluster based Communication models. In addition to that M. Milton Joe and B. Ramakrishnan et al. have proposed a new communication model known as WVANET (Web VANET) for vehicular ad hoc network communication. The authors portray that WVANET will be the everlasting research field in future. This WVANET (Web VANET) communication model is fundamentally different from other communication models as it makes use of web signals to disseminate the messages among vehicles. Of course, each communication model in VANET will have its own various pros and cons. This paper provides the overall review of all the existing communication models in VANET and in addition to that WVANET (Web VANET) communication model is also presented. Further this paper discusses the various future research that can be done in WVANET (Web VANET) communication model.     

Estimating the gradient in the Perona-Malik equation

An impressive and efficient improvement in the classical scale-space analysis was proposed by Perona and Malik (1990) where they describe the diffusion process known as the Perona-Malik (PM) equation. Despite the illposed nature of the PM equation, many of its applications could be carried with success in the signal processing field. On the other hand Weickert and Benamouda (1997) proved the regularization of the PM equation describing and analyzing a model on a semidiscrete system. In this article we present a regularized model of the PM diffusion equation for image segmentation. We start from the hypothesis of well-posedness in the discrete space and the stability conditions. We show two methods for automatic setting of the gradient threshold k, which is changed for each iteration of the partial differential equation (PDE) integration steps. Experimental segmentations are implemented for noise reduction of generic digital images and for segmentation of microcalcifications on X-ray biomedical images.     

Maximum-likelihood techniques for joint segmentation-classification of multispectral chromosome images

Traditional chromosome imaging has been limited to grayscale images, but recently a 5-fluorophore combinatorial labeling technique (M-FISH) was developed wherein each class of chromosomes binds with a different combination of fluorophores. This results in a multispectral image, where each class of chromosomes has distinct spectral components. In this paper, we develop new methods for automatic chromosome identification by exploiting the multispectral information in M-FISH chromosome images and by jointly performing chromosome segmentation and classification. We (1) develop a maximum-likelihood hypothesis test that uses multispectral information, together with conventional criteria, to select the best segmentation possibility; (2) use this likelihood function to combine chromosome segmentation and classification into a robust chromosome identification system; and (3) show that the proposed likelihood function can also be used as a reliable indicator of errors in segmentation, errors in classification, and chromosome anomalies, which can be indicators of radiation damage, cancer, and a wide variety of inherited diseases. We show that the proposed multispectral joint segmentation-classification method outperforms past grayscale segmentation methods when decomposing touching chromosomes. We also show that it outperforms past M-FISH classification techniques that do not use segmentation information.     

Techniques for movie content analysis and skimming: tutorial and overview on video abstraction techniques

With the proliferation of digital video, video summarization and skimming has become an indispensable tool of any practical video content management system. This paper provides a tutorial on the existing abstraction work for generic videos and presents state-of-the-art techniques for feature film skimming. The paper also describes the authors' recent work on movie skimming using audiovisual tempo analysis and specific cinematic rules. With the maturity of the movie genre classification, content understanding and video abstraction techniques, an automatic movie content analysis system that facilitates navigation, browsing, and search of desired movie content is possible in the near future     

改进的分水岭算法在图像分割中的研究

图像分割作为图像处理中最基础的研究领域之一,占有很重要的地位,是大多数图像分析和处理的不可替代并且是首要步骤的一个基础环节,在理论研究和实际应用中都得到了人们广泛指重视,目前已提出了多种不同的图像分割方法,总体上来说这些算法主要建立在基于图像本身的相似性上,在许多应用领域都获得了成功,但是没有一种方法适用于所有的图像。分水岭算法近年来得到比较广泛的应用,此次研究中用基于形态学的分水岭分割方法对图像处理,进行仿真,与其他方法相比可以较好的分割对象。     

基于DCT系数统计特性的HEVC视频双压缩检测算法

功能强大和使用简易的视频编辑软件可能会使数字视频遭受到各种不同形式的篡改,视频的真实性和完整性无法得到保证。双压缩是视频篡改的必要条件,双压缩检测则是视频取证的重要辅助手段。通过分析压缩过程中由量化误差引起的离散余弦变换(DCT)系数变化,提出了一种不同量化参数下的高效视频编码(HEVC)视频双压缩检测算法,利用DCT系数直方图和相邻DCT系数对奇偶组合统计特性构造22维联合特征集,最后将特征集用支持向量机(SVM)进行分类识别。实验结果证明了本文算法的有效性。