移动监控系统中设备端视频软件的设计与实现

提出了一种移动视频监控系统中视频数据处理软件的设计方案。移动监控系统主要由前端移动监控设备、3G网络、服务器、手机客户端组成。给出了系统总体原理图,主要分析了移动监控系统中视频数据的采集、去抖动处理、压缩以及备份等设备端软件设计部分。在去抖动的过程中使用了改进的灰度投影法,解决了传统投影法中易受到移动前景干扰的问题。通过实际测试验证了方案的可行性。     

Personalized multi-user view and content synchronization and retrieval in real-time mobile social software applications

Past years have witnessed the rapid growth of computer-based social software. Despite the increasing popularity of mobile devices, the choices of social software on these devices are still limited to non-real-time email and social media systems. Real-time social software on mobile devices is virtually non-existent due to the device characteristics such as small screen real estate, limited battery talk time, scarce network resources, and inherent need for personalization, which present challenges to the design and implementation of effective and useful real-time mobile social software. In this article, we present a technical solution to these challenges using a smartphone-based real-time collaborative note-taking system as an example. The solution allows for personalized multi-user view through flexible layout of multiple windows, maximally utilizing the available screen real estate, personalized content synchronization through synchronization protocols and algorithms based on the operational transformation technique and a buffer compression algorithm based on the operational merging technique, maximally utilizing the available battery talk time and network resources, and personalized content retrieval through customizable search methods.     

Using objects to handle complexity in finite element software

Engineering software is becoming ever more complex. Finite element programs have sophisticated graphical input and output facilities, and are increasingly required to be linked to other software such as CAD or databases. The paper shows how an object oriented approach to finite element programming can be used to handle this complexity. This requires an approach that is very different from that adopted in more traditional programming. A foundation finite element class system is developed. This represents the essential data structure of the main finite element classes. It is then shown how this system can be used in a graphical model of two dimensional structures. The finite element system imposed no constraints on the development of the graphical model, yet could still be used easily. An important feature is that the nodes and elements are distributed around the graphical model, rather than being held centrally. For instance nodes may belong to points or lines of the graphical model. This means that the data structure used in the program more closely matches the way that the user of the program is likely to think.     

基于流媒体的移动视频直播系统的设计与实现

视频直播是最能体现媒体信息实时传播的媒体形态,介绍了一个利用3G/4G手机进行视频拍摄和传输的移动直播系统。分析了当今移动直播系统的发展趋势,介绍了如何设计并实现一个基于流媒体技术的移动视频直播系统。实际测试结果表明,用户可以随时随地地利用3G/4G的iPhone手机进行直播,观众可以在远程PC端利用VLC播放器进行观看,提高直播系统的便捷性。     

A robust method for estimating synchronization and delay of audio and video for communication services

One of the main contributions to the quality of experience in streaming services or in two-way communication of audio and video applications is synchronization. This has been shown in several studies and experiments but methods to measure synchronization are less frequent, especially for situations without internal access to the application and independent of platform and device. In this paper we present a method for measuring synchronization skewness as well as delay for audio and video. The solution incorporates audio and video reference streams, where audio and video frames are marked with frame numbers which are decoded on the receiver side to enable calculation of synchronization and delay. The method has been verified in a two-way communication application in a transparent network with and without inserting known delays, as well as in a network with 5 and 10 % packet loss levels. The method can be used for both streaming and two-way communication services, both with and without access to the internal structures, and enables measurements of applications running on e.g. smartphones, tablets, and laptops under various conditions.     

Live mobile collaboration for video production: design,guidelines, and requirements

Traditional cameras and video equipment are gradually losing the race with smart phones and small mobile devices that allow video, photo, and audio capturing on the go. Users are now quickly creating movies and taking photos whenever and wherever they go, particularly at concerts and live events (e.g., shows, sport events). Still, in-situ media capturing with such devices poses constraints to any user, especially amateur ones. In this paper, we present the design and evaluation of a mobile video capture suite that allows for cooperative ad hoc production. Our system relies on ad hoc in-situ collaboration offering users the ability to switch between streams and cooperate with each other in order to capture better media with mobile devices. Our main contribution is the real-time awareness that users gain on media capturing endeavors around them and the possibility to collect that data for personal use once the event is over. This contribution is further emphasized by the geo-referenced cues that support the overall user interface and the management of the different media streams. As a secondary contribution, we report on lessons and design guidelines that emerged and apply to in-situ design of rich video collaborative experiences and with the elicitation of functional and usability requirements related to privacy, social connections, and gamification.     

Improving the development of instructional software: Three building-block solutions to interrelate design and production

Currently, there is a focus on authentic tasks as the driving force for learning in integrated e-learning systems. This sets new criteria for instructional software, which should become much more flexible and allow for domain modeling and pedagogical modeling. A theoretical analysis and a survey (n = 37) amongst experienced developers show that current development methods are insufficient to develop such instructional software. New development methods such as “lean production” promise to satisfy the new criteria as they emphasize mass-customization by rigorously applying a pull-principle throughout the whole development process. However, a potential bottleneck is the lack of design languages to transfer the design outcomes to the production phase. Three building-block solutions are proposed to overcome this transition problem: (1) a 3D-model to support designers in stratifying, elaborating, and formalizing design documents, (2) instructional software templates to support designers in producing software themselves, and (3) an integrative approach to support designers in reusing learning objects.     

VideoAcM: a transitive and temporal access control mechanism for collaborative video database production applications

Access control models play an important role in database management systems. In general, there are three basic access control models: Discretionary Access Control (DAC), Mandatory Access Control (MAC), and Non-Discretionary Access Control (NAC). Currently, the majority of commercial DBMSs provide only DAC, and some temporal access control models have been derived based on either DAC or NAC. In the context of video database applications, since the structure of video data is complex in nature, it requires a specific and tailor-made access control mechanism which should include MAC as well as DAC and NAC. However, only few efforts have been put on access control models for video database systems. In this paper, a transitive and temporal access control mechanism for collaborative video database production applications has been proposed, which subsumes the properties of DAC, MAC, and NAC. Moreover, our proposed mechanism is integrated with the intellectual property concerns by constructing an access control hierarchy of video data with authorization rules. In particular, our mechanism can derive novel authorization rules not only on conventional client-data access control, but also on data–data access control. Besides video data, the proposed model is applicable to other data types which exhibit a hierarchical data structure.     

Primary and secondary context in mobile video communication

The new video capabilities of mobile phones are starting to change the field of mobile communication. It is now dramatically easier to publish video in quasi-real time. We discuss how this change will affect the way people perceive video-recording, in terms of privacy, transparency, and the notion of context. We use a model of primary and secondary contexts to analyze usage situations, highlighting newly relevant research issues.     

Problems and solutions in software maintenance

The software maintenance cost has risen to 70% of the data processing budget in some corporations. Some of the crucial factors contributing to the software maintenance problems are identified and discussed and some management and technical solutions to the pressing problems are proposed.     

Capture and representation of human walking in live video sequences

Extracting human representations from video has vast applications. In this paper, we present a knowledge-based framework to capture metarepresentations for real-life video with human walkers. The system models the human body as an articulated object and the human walking as a cyclic activity with highly correlated temporal patterns. We extract for each of the body parts its motion, shape, and texture. Once available, this structural information can be used to manipulate or synthesize the original video sequence, or animate the walker with a different motion in a new synthesized video     

Integrating XML and CORBA to support collaborative writing using off-the-shelf editing software

In this paper, collaborative writing is modeled as a workflow application comprising a number of activities. Each activity is assigned to a co-author to edit certain part(s) of the shared document. The order of editing is governed by a workflow schedule, which can be modified during execution. To enable concurrent editing, a data definition scheme is proposed whereby documents are transformed into the XML format for internal storage. Effectively, a hierarchical structure is superimposed on each document, allowing it to be broken down into a number of independent parts. These parts may then be separately edited in parallel. Unlike other approaches, the system supports the use of off-the-shelf editor software. Users can thus adapt to the system easily and existing documents can also be re-used rapidly. A prototype has been built which supports collaborative editing of Microsoft Word^TM${}^{\mathrm{TM}}$ documents.     

Real-time image and video processing in portable and mobile devices

Mobile handheld and battery-operated consumer electronic devices such as digital still cameras, personal media players, digital camcorders, camera phones, mobile video telephones, etc. have become very popular and their annual shipments are already in hunderds of millions of units. The ability to carry out image and video processing in real-time has been one of the major reasons for the widespread success of these devices. In this article, the typical components present in such devices and the image and video processing that are carried out are described first. Some of the emerging trends relevant to image and video processing algorithms used on these devices are highlighted next. A brief overview of system requirements and challenges for image and video processing on these devices is then provided. These requirements are driving image and video processing research in new directions.     

Evaluate mobile video quality in hybrid spatial and temporal domain

Mobile video quality assessment plays an essential role in multimedia systems and services. In the case of scalable video coding, which enables dynamic adaptation based on terminal capabilities and heterogeneous network, variable resolution is one of the most prominent types of video distortions. In this paper, we propose a new hybrid spatial and temporal distortion metric for evaluating video streaming quality with variable spatio-temporal resolution. The key idea is to project video sequence into feature domain and calculate the distortion of content information from the projected principal component matrix and its eigenvectors. This metric can measures the degree of content information degradation especially in spatio-temporal resolution scalable video. The performance of the proposed metric is evaluated and compared to some state-of-the-art quality evaluation metrics in the literature. Our results show that the proposed metric achieves good correlations with the subjective evaluations of the EPFL scale video database.     

Intelligent and collaborative Multi-Agent System to generate and schedule production orders

The authors present a Multi-Agent System for constructing and releasing production orders. In a manufacturing enterprise, the generation of production orders consists in a set of coordinated tasks among departments. This has been achieved traditionally as a module of the Production Activity Control (PAC) system. However, classic PAC modules lack collaborative techniques and intelligent behaviour. Moreover, in real-life situations experienced planners take over traditional PAC systems, since the range of possibilities to actually build production orders increases exponentially. To contribute to production planning, we present an intelligent and collaborative Multi-Agent System (MAS), having coordinated two forms to emulate intelligence. The learning capability is achieved by means of a Feed-forward Artificial Neural Network (FANN) with the back-propagation algorithm. The FANN is embedded within a machine agent whose objective is to obtain the appropriate machine in order to comply with requirements coming from the sales department. Also, an expert system is provided to a tool agent, which in turn is in charge of inferring the right tooling. The MAS also consists of a coordinator and a spy. The coordinator agent has the responsibility to control the flow of messages among the agents, whereas the spy agent is constantly reading the Enterprise Information System. Finally, a scheduler agent schedules the production orders. The resultant MAS improves the current form to plan production in a factory dedicated to produce labels.     

多级多域视频监控系统数据同步机制的设计

针对多级多域视频监控系统中多个分布式数据库对数据一致性的要求,提出了基于同步标识轮转的数据同步方法。在对多级多域视频监控系统的结构进行分析后,介绍了同步数据表的设计方法,指出如何利用同步标识字段标识一条记录的同步状态。通过在各区域子系统设置同步模块,完成待同步数据的筛选、封装、解析和处理。上下级同步模块间的通信利用会话初始化协议(SIP),数据格式的转换遵照扩展标记语言(XML)。当发生添加、修改、删除操作时立即进行同步,如果同步失败,可触发批量同步直至所有记录都同步成功。实验结果表明,该方案能够准确地将下级数据的变化情况同步到上级数据库中。