Effective Annotation and Search for Video Blogs with Integration of Context and Content Analysis

In recent years, weblogs (or blogs) have received great popularity worldwide, among which video blogs (or vlogs) are playing an increasingly important role. However, research on vlog analysis is still in the early stage, and how to manage vlogs effectively so that they can be more easily accessible is a challenging problem. In this paper, we propose a novel vlog management model which is comprised of automatic vlog annotation and user-oriented vlog search. For vlog annotation, we extract informative keywords from both the target vlog itself and relevant external resources; besides semantic annotation, we perform sentiment analysis on comments to obtain the overall evaluation. For vlog search, we present saliency-based matching to simulate human perception of similarity, and organize the results by personalized ranking and category-based clustering. An evaluation criterion is also proposed for vlog annotation, which assigns a score to an annotation according to its accuracy and completeness in representing the vlog's semantics. Experimental results demonstrate the effectiveness of the proposed management model for vlogs.     

用于网络搜索引擎的中文分词消岐算法

在正向最大匹配法的基础上,提出了一种便于在网络搜索引擎上使用的消除歧义的方法.通过利用单字词和二字词的高频特性以及不同词条的词频特点,再加上长词优先的原则,来消除在分词中可能会出现的交集型歧义和组合型歧义.实验结果表明:改进的回溯算法,比最大正向匹配法和回溯法的消歧更加有效.对高频交集型歧义字段取样分析结果表明,改进的...     

视频实时传输中的速率控制研究

视频在互联网上的实时传输常因其要求高带宽、低延迟而造成网络拥塞。传统TCP基于窗口的拥塞控制已经不适用于实时传输中的拥塞控制,该文讨论了基于速率的网络拥塞控制方法,它采用自适应码率和分层的视频编码技术,详细说明了基于源端和收端的各种速率控制方法。     

在线视频分割实时后处理

在线视频分割的应用通常都需要对分割结果进行后处理,以消除误分割和边沿闪烁.基于图像抠图的方法太慢,而简单的对(前/背景)边界进行模糊不仅不能消除误分割,而且会导致清晰的边界被过度模糊.为了解决上述问题,文中提出了一种新的后处理方法.对边界附近的每一像素,首先通过一种新的专门用于颜色聚类的快速聚类算法得到该像素周围的局部颜色模型,并用来重新估计像素的alpha值,以消除误分割.为了改善结果的一致性,再采用一种自适应的边界函数作光滑性约束.边界函数可根据像素的局部属性自适应地调整过渡区域的中心和宽度,这样就防止了将清晰的边界过度模糊.文中的算法速度很快,可以很好地满足在线视频分割的要求.     

一种高质量的实时视频压缩后处理算法

针对各种视频应用领域的实际要求，提出了一种新颖的视频压缩后处理算法．该算法将自适应邻域的思想引入到视频信号的后处理中，能够同时高效地抑制采用基于块的变换编码和基于块的运动补偿技术的视频压缩算法产生的振铃噪声和块效应，并能出色地保存图像的边缘．大量的实验数据和实际应用的效果都显示，本算法不仅获得了良好的主观视觉效果，而且在客观评价方面比现有的各种方法都有显著的提高．     

Searching for Flash Movies on the Web: A Content and Context Based Framework

The phenomenal growth of online Flash movies in recent years has made Flash one of the most prevalent media formats on the Web. The retrieval and management issues of Flash, vital to the utilization of the enormous Flash resource, are unfortunately overlooked by the research community. This paper presents the first piece of work (to the best of our knowledge) in this domain by suggesting an integrated framework for the retrieval of Flash movies based on their content characteristics as well as contextual information. The proposed approach consists of two major components: (1) a content-based retrieval component, which explores the characteristics of Flash movie content at compositional and semantic levels; and (2) a context-based retrieval component, which explores the contextual information including the texts and hyperlinks surrounding the movies. An experimental Flash search engine system has been implemented to demonstrate the feasibility of the suggested framework. The work described in this paper was supported substantially by a grant (Project No. 7001457), and partially by another grant (Project No. 7001564), both from CityU of Hong Kong.     

Web实时环境两级过滤中文文本内容自学习算法

用户在互联网发布信息的自由性对Web信息内容过滤提出新的挑战。为此,给出一种自学习的两级内容过滤算法SAFE(self-study algorithm of filtering Chinese text content)。SAFE以数据流的方式处理文本,并根据Apriori性质,在不依赖词典的情况下,通过挖掘关键字和关键词实现对文档的两级内容过滤。利用真实世界Web文档验证了SAFE的有效性,实验表明对给定的主题进行文本内容过滤,SAFE的查全率达到93.75%以上,查准率达到100%,执行时间能够满足Web应用的实时性要求。     

Real-Time Search for Autonomous Agents and Multiagent Systems

Since real-time search provides an attractive framework for resource-bounded problem solving, this paper extends the framework for autonomous agents and for a multiagent world. To adaptively control search processes, we propose -search which allows suboptimal solutions with error, and -search which balances the tradeoff between exploration and exploitation. We then consider search in uncertain situations, where the goal may change during the course of the search, and propose a moving target search (MTS) algorithm. We also investigate real-time bidirectional search (RTBS) algorithms, where two problem solvers cooperatively achieve a shared goal. Finally, we introduce a new problem solving paradigm, called organizational problem solving, for multiagent systems.     

机载视频空中目标实时优化稳像算法

针对机载飞机视频摄取与监视中,由于背景稀疏和前景的大幅度快速运动,造成实时稳像算法存在的画面不稳定的问题,提出了自适应Shi-Tomasi机载视频空中目标实时优化稳像算法。根据提取特征点分布自适应地改变Shi-Tomasi角点检测阈值,解决单一阈值不能适应空中复杂稀疏背景特征点提取的问题。构建带约束的实时优化算法,计算平滑的视频路径,解决基于滤波的算法缺少约束导致画面偏移过大的问题。比对实验结果表明,自适应Shi-Tomasi优化稳像算法能够应对各类机载稀疏背景视频的稳像,解决了快速运动目标稳像后画面大幅偏移的问题,稳定性提高,速度达到20?frame/s以上,满足实时处理需求。     

Real-Time Model-Based Video Stabilization for Microaerial Vehicles

The emerging branch of micro aerial vehicles (MAVs) has attracted a great interest for their indoor navigation capabilities, but they require a high quality video for tele-operated or autonomous tasks. A common problem of on-board video quality is the effect of undesired movements, so different approaches solve it with both mechanical stabilizers or video stabilizer software. Very few video stabilizer algorithms in the literature can be applied in real-time but they do not discriminate at all between intentional movements of the tele-operator and undesired ones. In this paper, a novel technique is introduced for real-time video stabilization with low computational cost, without generating false movements or decreasing the performance of the stabilized video sequence. Our proposal uses a combination of geometric transformations and outliers rejection to obtain a robust inter-frame motion estimation, and a Kalman filter based on an ANN learned model of the MAV that includes the control action for motion intention estimation.     

An Optimal Mechanism for Sponsored Search Auctions on the Web and Comparison With Other Mechanisms

In this paper, we first describe a framework to model the sponsored search auction on the Web as a mechanism design problem. Using this framework, we describe two well-known mechanisms for sponsored search auction - generalized second price (GSP) and Vickrey-Clarke-Groves (VCG). We then derive a new mechanism for sponsored search auction which we call optimal (OPT) mechanism. The OPT mechanism maximizes the search engine's expected revenue, while achieving Bayesian incentive compatibility and individual rationality of the advertisers. We then undertake a detailed comparative study of the mechanisms GSP, VCG, and OPT. We compute and compare the expected revenue earned by the search engine under the three mechanisms when the advertisers are symmetric and some special conditions are satisfied. We also compare the three mechanisms in terms of incentive compatibility, individual rationality, and computational complexity.     

Video Data Conversion and Real-Time Tracking

Recent developments in pattern recognition and image processing are bringing about a new generation of real-time trackers. The RTV system described here is an example.     

Web服务组合上下文模型

基于上下文感知计算,提出一种新颖的Web服务组合上下文模型.一方面,服务组合中的信息被定义为服务和用户上下文,前者又被区分为概要、会话和填充上下文;另一方面,采用多策略机制管理上下文.为此,定义了一种基于ECA规则的语言-服务扩展策略描述语言(PDL-S).采用以上语言描述上下文管理策略和组合服务.该模型不但充分利用了上下文感知计算,而且具有良好的协作性、扩展性和灵活性.     

基于Web内容挖掘的搜索引擎页面等级改进算法

针对PageRank算法忽略了页面内容的不足，根据用户浏览页面的习惯，将Web内容挖掘的页面相似度引入到算法中，对其进行改进。实验结果表明，改进后的算法可以使页面的PageRank值依据页面相似度发生变化，符合人们的一般期望，效果明显有效。     

多组视频流的实时图象拼接

此文介绍了一个实时图象拼接系统.该系统从多个录像设备(如网络摄像头)采集的视频流中实时拼接出全景图象.本系统由两个主要摸块组成实时视频采集,实时图象拼接以及自动更新.为有效地实现图象匹配,该系统运用了基于多分辨率特征的方法.此算法较之传统的基于亮度的方法有着更多优点.实验结果显示上述系统实现了高质量图象拼接并明显地提高了实时处理的速度.本系统适合于如视频监控以及虚拟现实等应用.     

实时视频流自适应速率传输策略

本文提出了一种实时视频流自适应速率传输策略ARTS,该策略通过丢包率和网络传输延迟抖动两种参数对发送端输出速率进行动态调整,以迭到拥塞控制的目的。实验证明,ARTS是TCP友好的,能够降低丢包率,有效地减少了客户端图像质量的震荡幅度,保持了网络带宽的高使用率。     

JMF视频传输技术在Wbe机器人中的应用

本文提出了一种JMF(Jave Media Framework)视频传输技术在基于网络遥操作机器人中的应用,实现 了图像的实时传输.实验表明了这个解决方案的先进性和有效性,它为基于Internet的机器人的远程控制提供了强 有力的支撑技术.􀁱     

视频数据的错误隐藏算法研究

由于实时视频数据流在存储或传输中的错误、丢包等原因,解码器接收到的数据流可能不完整,无法正常解码。错误隐藏是解决这个问题的方法之一,文章回顾了当前的主要错误隐藏算法。根据视频编码的特点,对传输信道的错误隐藏算法进行了分类,包括时间、空间、时-空结合以及频域的相关算法,并对它们进行了比较和评述;同时对存储系统的错误隐藏算法也进行了分类比较和评述。最后对未来研究方向进行了展望,给出了若干值得研究的问题。     

FaceSeg: Automatic Face Segmentation for Real-Time Video

Segmenting human faces automatically is very important for face recognition and verification, security system, and computer vision. In this paper, we present an accurate segmentation system for cutting human faces out from video sequences in real-time. First, a learning based face detector is developed to rapidly find human faces. To speed up the detection process, a face rejection cascade is constructed to remove most of negative samples while retaining all the face samples. Then, we develop a coarse-to-fine segmentation approach to extract the faces based on a min-cut optimization. Finally, a new matting algorithm is proposed to estimate the alpha-matte based on an adaptive trimap generation method. Experimental results demonstrate the effectiveness and robustness of our proposed method that can compete with the well-known interactive methods in real-time.