共查询到20条相似文献,搜索用时 15 毫秒
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The author details the development of an industrial training curriculum at Albany International (a textile company which makes paper-machine clothing, huge ruglike belts used to convey paper on paper machines), including the development of technical video as an important part of the program. Specifically, the production of a technical video for the warp yarn dresser is examined. The role of the video in the manufacturing segment of the curriculum is explained. Details of the video development and a variety of its educational uses in the company are discussed 相似文献
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Television transmission to small inexpensive earth stations is now being explored using conventional domestic satellites. A number of alternatives exist for the technical formatting of the television signal. Some of the tradeoffs in video deviation, bandwidth, and location of the television sound for frequency modulated television are discussed in this paper. The paper is concluded with an example of a system design for the Alaskan Bush communities. 相似文献
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为了增强节目的可看性,我们在节目的制作过程中会从引用大量的视音频素材,这些素材的格式是多种多样的,但是可以让大洋D3-cube EDIT非编软件可以识别并且导入的非常少,本文运用多种技术手段实现了多样化素材的综合利用,丰富了节目的制作表现形式。 相似文献
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《Signal Processing: Image Communication》2014,29(1):1-22
In video communication systems, the video signals are typically compressed and sent to the decoder through an error-prone transmission channel that may corrupt the compressed signal, causing the degradation of the final decoded video quality. In this context, it is possible to enhance the error resilience of typical predictive video coding schemes using as inspiration principles and tools from an alternative video coding approach, the so-called Distributed Video Coding (DVC), based on the Distributed Source Coding (DSC) theory. Further improvements in the decoded video quality after error-prone transmission may also be obtained by considering the perceptual relevance of the video content, as distortions occurring in different regions of a picture have a different impact on the user's final experience. In this context, this paper proposes a Perceptually Driven Error Protection (PDEP) video coding solution that enhances the error resilience of a state-of-the-art H.264/AVC predictive video codec using DSC principles and perceptual considerations. To increase the H.264/AVC error resilience performance, the main technical novelties brought by the proposed video coding solution are: (i) design of an improved compressed domain perceptual classification mechanism; (ii) design of an improved transcoding tool for the DSC-based protection mechanism; and (iii) integration of a perceptual classification mechanism in an H.264/AVC compliant codec with a DSC-based error protection mechanism. The performance results obtained show that the proposed PDEP video codec provides a better performing alternative to traditional error protection video coding schemes, notably Forward Error Correction (FEC)-based schemes. 相似文献
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AVS中的音视频编码压缩技术 总被引:7,自引:1,他引:6
介绍了音视频编码标准AVS中的主要技术特点,对AVS标准所采用的主要技术进行了综述,给出了AVS视频标准与MPEG-4 AVC/H.264编码器性能的比较和分析,讨论了AVS的发展前景. 相似文献
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Automated camerawork for capturing desktop presentations 总被引:1,自引:0,他引:1
Ozeki M. Nakamura Y. Ohta Y. 《Vision, Image and Signal Processing, IEE Proceedings -》2005,152(4):437-447
A novel automated camera control method for capturing desktop presentations is introduced. Typical features and the camerawork of shots that appear frequently in TV programs are discussed. To realise those features in this automated video capturing system, the purpose of camerawork is classified from two points of view: target and aspect-of-target. Then, the correspondence between the classification and typical shots and camerawork is considered. A virtual-frame control algorithm based on this idea is proposed, and its implementation in a video production system. Results are shown that verify this method through two kinds of experiments, virtual video capturing using CG animations and real video capturing of real presentations. 相似文献
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凭借对数变换、信号压缩、瞬时处理的功能和特点,对数视频放大器在雷达、电子对抗、声纳系统中得到了较多应用。由于专业性强、应用面窄、资料匮乏,因而在工程使用中存在认识模糊的情况。从解析概念入手,重点分析了对数视频放大器主要技术参数,最后给出了选择对数视频放大器的原则和方法。 相似文献
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Pritchard W.L. Ogata M. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1990,78(7):1116-1140
A brief history and commentary on the development of satellite direct broadcast (direct broadcast satellite, or DBS) to small user terminals is given, and the interrelations among the technical, economic, and political aspects are discussed. The fundamental technical problems in the transmission of video and audio directly to small user terminals are reviewed at a basic level, and points of particular interest relating to DBS are highlighted. The effects of improved transmission systems using multiplexed analog components and of high-definition television are related to the satellite transmission problems. The conflicting requirements of performance, compatibility with existing equipment, competition with other means of transmission, and vested political interests are pointed out. A reasonably complete summary of existing programs, both true DBS and near DBS, is given 相似文献
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The research of video-based sports movement analysis technology has an important application value. The introduction of digital video, human–computer interaction and other technologies in sports training can greatly improve training efficiency. This paper studies the technical characteristics of the players in the basketball game video and proposes a behavior analysis method based on deep learning. We first design a method to automatically extract the basketball court and stadium marking line. Subsequently, key frames in the video are captured using a spatiotemporal scoring mechanism. Afterward, we develop a behavior recognition and prediction method based on an encoder–decoder framework. The analysis results can be fed back to coaches and data analysts in real-time to help them analyze the tactics and technical choices. Experiments on the proposed method are carried out on a large basketball video dataset. The results show that the proposed method can effectively identify the motion of video characters while achieving high behavior analysis accuracy. 相似文献
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Shane J. Shklov 《International Journal of Communication Systems》1990,3(4):319-325
Over the past year the Manitoba Telephone System, working with both Catel in California and Cabletel in Toronto has developed a unique optical architecture. In comparison to conventional fibre architectures, this structure has reduced the cost and complexity while increasing the reliability and capacity without sacrificing technical performance. This multinode, multichannel, bi-directional, single wavelength video conference structure is in use between hospitals in the province of Manitoba. Details of this configuration along with its performance are discussed. 相似文献
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Weidong Mao 《The Journal of VLSI Signal Processing》1997,17(2-3):255-268
The integrated digital multimedia video service can be delivered via different network media such as Hybrid Fiber Coax (HFC) and Fiber to the Curb (FTTC). Asynchronous Transfer Mode (ATM) can be used as an effective transport mechanism for the digital video services, such as MPEG-2. Both the lower layer physical network topology/characteristics and network protocols impose special technical constraints on the overall digital video system design.The system issues on network delivery of digital video discussed in this paper include: (1) Overall network impact and system protocol stack for HFC and FTTC video delivery; (2) Interactivity of digital video and its signaling; (3) Quality of Service (QoS) impact on digital video coding algorithm.Finally, the future directions on the networked video field are discussed and implementation choice and migration strategy are briefly analyzed. 相似文献
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Jieying Zhou Guangzhao Zhang Zhisheng Lin 《Journal of Infrared, Millimeter and Terahertz Waves》2002,23(9):1385-1398
LMDS is one kind of fixed broadband wireless access network. It uses radio spectrum between 10GHz and 40GHz to transmit voice, video, and data signals within small cell 3-10 miles in diameter. This paper proposes some key technical scenarios to support videoconferencing services transported on LMDS. Firstly, two kinds of typical LMDS lower layer standards made by DAVIC and 802.16 separately are discussed from the angle of supporting video conferencing services. Then, H.323 is studied and recommended as the standard of LMDS video conferencing system. And some strategies are proposed to support H.323 services on LMDS. After that, IP multicast technology, the key supporting technology of H.323, is studied from the angle of running on LMDS. Scenarios for IGMP, RMTP protocol running on LMDS are suggested and analyzed with Markov network queuing theory. The technical scenarios proposed by this paper make use of the transporting property of LMDS to support LMDS videoconferencing system more effectively. 相似文献
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Now that the US standard for digital TV has set technical parameters, equipment has to be built for production, editing and broadcast. The full-production HDTV facility must support existing NTSC equipment. When possible, it also must allow compressed operations (like storage and splicing) to avoid encoding and decoding penalties. The configuration resembles that being created as part of the NIST HDBT project. In this setup, a high-speed ATM computer network routes the compressed bit-stream around the studio. Besides the compressed video, the ATM net routes intercom, digital audio (compressed or not), and data. All the equipment (servers, encoders, and the off-line transcoder) interfaces to the ATM router, which is the studio's central switch, replacing the router of conventional studios. The transcoder's job is to convert one compressed format into another. All the devices on the computer network are controlled by the studio control workstation. This architecture also allows connection to be made to other TV studios over existing telecommunications networks. A network interface device has this job. In the early stages, video production will be performed on uncompressed video. As compressed technology advances, more production will be done on compressed video. Most studios will probably transition to compressed production but retain uncompressed elements to take advantage of some of its features 相似文献