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.     

Mobile cinema: canonical processes for video adaptation

Nowadays, users not only want to watch digital videos on a PC but also use mobile devices to play back multimedia content. Video adaptation algorithms enable the visualization of recorded videos on mobile devices. Based on our Mobile Business system, we have developed a video adaptation application called Mobile Cinema which considers several characteristic features of mobile devices like screen resolution, bit rate or color depth of a display. The functionality of this system is high and it would be much easier to understand the system if the analysis and the design of the algorithms and the communication interfaces are based on predefined processes which we call canonical processes for media production. The definition of these processes would also make the comparison of two video adaptation applications or the exchange of modules between different systems much easier. In this paper, we describe the functionality and requirements of our existing video adaptation application and map them to the canonical processes for media production.     

VIDOS, a system for video editing and format conversion over the Internet

VIDOS is a Java-based server–client video management system that permits one to customize a personal version of any downloadable digital video file over the Internet or local intranet. It enables one, without purchasing expensive video editing software, to edit the video spatially and temporally, to specify the desired zoom factor, frame rate and video format, and to choose the nature and quality of digital compression before downloading the edited video. VIDOS permits videos to be adapted to suit their end uses. By potentially reducing their size, it can improve corporate and personal efficiency by speeding network transfers and cutting disc storage requirements.     

Practical mini-PACS based on a hybrid video and digital network.

The Department of Radiology of the Shinshu University Hospital is presently in the process of developing a new type of mini-PACS with a hybrid architecture consisting of a video and a digital image archiving network. The video block consists of a server station with a video write-once optical disk (LD) and three workstations which are connected to two ultrasound imaging devices and an MRI device. The video images from any of these imaging devices are transferred immediately onto an LD. The examiner can observe the archived images immediately without any interruption of the examination. The image transmission time, including the record and play-back, is within 3 s. The digital block consists of a personal computer server and various workstations linked to the ETHERNET. This digital system supports database management, and archives digital images. This prototype system was used for daily clinical examinations from February 1989 to January 1990 and 31,366 images from 1561 patients were stored on the video disk. This one year experience suggests that a hybrid mini-PACS system is practical for total image archiving when the image matrix is less than 512 x 512 and selected digital image archiving.     

数字家庭网络上视频点播系统的实现

数字家庭网络是家庭范围内多个设备之间的信息流通网络,视频点播系统是集通信网络技术、多媒体技术、计算机和数据库技术于一体的崭新的视频服务系统.本文给出了在数字家庭网络上构建视频点播系统的架构模式,并在理论上阐述了系统的实现过程.     

基于无线传感器网络的湿地水环境数据视频监测系统

对湿地水环境监测技术的研究现状与进展进行了概述.提出了基于无线传感器网络的实时数据视频监测系统的设计方案,介绍了系统架构,并详述了基于ZigBee无线技术的数据监测节点、基于ZigBee无线技术和CDMA无线技术的数据视频基站、水环境数据和视频监测中心等各个部分的功能特点及设计方法.     

矿用实时视频传输系统设计

针对现有煤矿井下视频传输系统存在视频清晰度低、传输速率不稳定、兼容性差等问题,设计了一种矿用实时视频传输系统。该系统采用960 nm红外激光作为辅助光源,利用MCCD图像传感器采集视频信号,提高了低光照强度或黑暗环境下视频清晰度;通过视频解码模块TVP5150将采集的PAL制式模拟视频信号转换为YUV数字信号,数字信号经多格式编码器进行H.264压缩编码,并在此基础上添加UDP报文头进行RTP封装,提高了视频数据传输的时效性;通过Live555流媒体服务器进行数据流化,使用ONVIF标准封装RTSP视频流,通过Socket网络编程实现实时视频流数据网络传输,提高了系统兼容性和传输速率稳定性。测试结果表明,该系统视频传输速率为2.190 Mbit/s,丢包率约为1.256%,达到实时视频传输要求。     

Usage derived recommendations for a video digital library

We describe a minimalist methodology to develop usage-based recommender systems for multimedia digital libraries. A prototype recommender system based on this strategy was implemented for the Open Video Project, a digital library of videos that are freely available for download. Sequential patterns of video retrievals are extracted from the project's web download logs and analyzed to generate a network of video relationships. A spreading activation algorithm locates video recommendations by searching for associative paths connecting query-related videos. We evaluate the performance of the resulting system relative to an item-based collaborative filtering technique operating on user profiles extracted from the same log data.     

基于MAP-CA的视频多点处理系统的研究与实现

文中介绍了一种高性能媒体信号处理器MAP-CA，它具备对视音频信号进行压缩处理的优化结构和多种方便的标准音视频接口。针对视频会议中视频信息的处理需求，以MAP—CA为核心处理器，设计了一个基于PC机的插卡式视频多点处理子系统，可应用于视频会议中多路码流的实时合成和转换，并且不会增加PC机负担。     

X射线探测用SSPA器件的数据采集系统

设计了一种供Ｘ射线ＳＳＰＡ（Ｓｅｌｆ ｓｃａｎｎｅｄ ｐｈｏｔｏｄｉｏｄｅ ａｒｒａｙ）器件使用的８位高速数据采集系统。Ｘ射线ＳＳＰＡ的视频信号是窄脉冲,所以必须采用峰值保持,同时为了在同一系统中测量多路信号,设计了一多路开关。在使用Ｘ射线ＳＳＰＡ器件时需对视频信号进行逐位高速采集,因此所有视频信号在一次逐位转 换完毕,存储在帧存储器中,然后再逐位读出。所以本系统主要包括多通道开关、峰值保持、高速     

基于DSP与CPLD的图像压缩编码系统设计

提供了一套利用TMS320VC54x和CPLD实现图像采集与压缩编码系统的通用设计方法。阐述了压缩编码系统的设计和其中的关键技术问题，并结合图像编码算法和DSP流水线的特点进行程序优化。设计结果表明：在系统功能和结构方面，完全满足低速率数字视频通信系统的要求；在实现和应用方面，由于所选用的都是通用器件，成本低廉．对于数字视频监控领域有很高的实用价值．     

3D Video Recorder: a System for Recording and Playing Free‐Viewpoint Video†

We present the 3D Video Recorder, a system capable of recording, processing, and playing three‐dimensional video from multiple points of view. We first record 2D video streams from several synchronized digital video cameras and store pre‐processed images to disk. An off‐line processing stage converts these images into a time‐varying 3D hierarchical point‐based data structure and stores this 3D video to disk. We show how we can trade‐off 3D video quality with processing performance and devise efficient compression and coding schemes for our novel 3D video representation. A typical sequence is encoded at less than 7 Mbps at a frame rate of 8.5 frames per second. The 3D video player decodes and renders 3D videos from hard‐disk in real‐time, providing interaction features known from common video cassette recorders, like variable‐speed forward and reverse, and slow motion. 3D video playback can be enhanced with novel 3D video effects such as freeze‐and‐rotate and arbitrary scaling. The player builds upon point‐based rendering techniques and is thus capable of rendering high‐quality images in real‐time. Finally, we demonstrate the 3D Video Recorder on multiple real‐life video sequences. ACM CSS: I.3.2 Computer Graphics—Graphics Systems, I.3.5 Computer Graphics—Computational Geometry and Object Modelling, I.3.7 Computer Graphics—Three‐Dimensional Graphics and Realism     

多媒体技术环境下嵌入式网络视频监控系统研究

随着视频技术、网络技术与数字技术的飞速发展,多媒体混合应用向数字化与网络化转变。嵌入式网络与多媒体技术二者相结合的优势愈加明显。现代日常生活工作中,视频监控系统已成为保障生活、工作、学习安全、维护正常秩序的重要组成部分。传统的视频监控系统采用原始的视频编码与网络传输技术,存在视频数据噪点高、数据源封装包资源大、网络交互资源消耗大、延迟高等问题,不利于多群组大面积监控系统架构。根据问题产生的原因,提出多媒体技术环境下嵌入式网络视频监控系统的研究。通过采用视频编码单元、网络编码单元与储存压缩算法,对传统视频监控系统进行整体修复改进。仿真实验表明,提出的多媒体技术环境下嵌入式网络视频监控系统研究方法,具有视频清晰度高、视频源封装资源小、网络传输速度快、延迟小的优点。     

一种基于节的视频服务器允许接纳控制算法

提出了一种基于“服务器节”的支持压缩多媒体流的服务器中CPU、磁盘、网络和内存等资源管理的方法和允许接纳控制算法。“服务器节”概念定义了一组客户视频服务特性,如播放、快进、慢进和暂停等,并且确定了视频服务所需资源的分配参。一个“服务器节”包括视频服务器、磁盘设备、网络设备和允许接纳控制。它不但能优化使用单个资源,对于给定系统支持最大数量的客户端,保证其服务质量（QoS),而且其允许接纳控制算法能根据系统所有资源的状况,在不影响原有的视频服务基础上,确定对客户端新提出的视频服务是否接受。     

一种采用带外虚拟化技术的网络存储系统

介绍一种基于带外虚拟化技术的网络存储系统,简称BW-VSDS,它具有以下特点:(1)采用两级带外虚拟化数据管理模型以充分发挥单个存储节点的I/O能力并释放存储网络的承载能力;(2)采用分布式数据存储管理协议以协同多个存储节点有效实现高级数据存储语义;(3)支持多种数据传输协议以适用于不同的应用环境.目前该系统已应用于视频监控、信息处理和企业办公等多个领域.     

Evaluation of video payload over low latency networks: Flexilink

ABSTRACT

Broadcast organisations need to handle both time deterministic traffic and best effort traffic. The adoption of packet networks allows a single converged network for handling both real-time (RT) media traffic as well as data traffic. Due to the historic pervasive growth of IP network, they are widely used to realise this converged network. However, they do have several drawbacks like big header size, software switching delays and inability to support multiple addressing schemes. To overcome these issues, solutions like traffic engineering, quality of service and over-provisioning are implemented in IP networks but has resulted in higher cost, power and system requirements. Flexilink network has been tested for audio payloads using simulation model and outperforms any existing RT network by providing an exceptional average end-to-end delay of microsecond range and a jitter below the audible threshold for live digital audio streaming. However, it is not tested for video payloads. A review of various networks used RT media distribution is included in this paper. The Flexilink architecture design modification to support the most widely used video formats such as MPEG-TS, MPEG-PS and SDI streams is explained. The average delay for multiple video streams over Flexilink is provided using simulation model. The recommendation for testing Flexilink using hardware is also explained in this paper.

The Flexilink Mac design uses dual-buffer system to handle AF (asynchronous flow) and SF (synchronous flow) separately, with the Frame structure that supports current Ethernet frames.     

一个数字视频监控系统的设计与实现

本文以中山移动营业厅视频监控服务为应用背景,通过对数字视频监控中的数字视频压缩、网络传输等相关技术进行分析研究,设计实现了一个集成式、多功能、综合性的数字视频监控系统。测试结果和实际应用表明,系统运行稳定可靠。     

新一代网络视频监控系统在气象部门的应用

新一代网络视频监控系统是一个集多媒体技术、数字图像处理、存储、通信、计算机等新技术于一体的新型视频监控系统.随着全球对气候变化关注的增强,对气象探测数据的要求也越来越高.为保证各类气象观测数据具有代表性、准确性和连续性,需要随时掌握气象探测环境的变化情况,提高观测数据质量,将计算机、通讯、网络、多媒体、存储等技术应用到...