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An Improved Rate Control Method Based on Modification at Scene Change for H.264
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作者 RU Guobao GAO Wenli FU Jianfeng 《Wuhan University Journal of Natural Sciences》 CAS 2007年第6期1047-1050,共4页
This paper presents an improved rate control method for H.264. First, the scene changes are detected by the average absolute difference of the brightness histograms between the adjacent frames. Then, the bit allocatio... This paper presents an improved rate control method for H.264. First, the scene changes are detected by the average absolute difference of the brightness histograms between the adjacent frames. Then, the bit allocation and quantization parameters are adjusted, using a certain threshold. In addition, the calculation of the mean absolute difference (MAD) is modified in an alternative way, which makes the rate distortion optimization (RDO) more accurate. Extensive simulation results show that the proposed method, compared with G012, can improve the average peak signal-to-noise ratio (PSNR) and moderate the image quality. 展开更多
关键词 brightness histogram mean absolute difference (MAD) rate distortion optimization (RDO) rate control scene change
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Bandwidth-Efficient Transmission Method for User View-Oriented Video Services
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作者 Minjae Seo Jong-Ho Paik 《Computers, Materials & Continua》 SCIE EI 2020年第12期2571-2589,共19页
The trend in video viewing has been evolving beyond simply providing a multi-view option.Recently,a function that allows selection and viewing of a clip from a multi-view service that captures a specific range or obje... The trend in video viewing has been evolving beyond simply providing a multi-view option.Recently,a function that allows selection and viewing of a clip from a multi-view service that captures a specific range or object has been added.In particular,the free-view service is an extended concept of multi-view and provides a freer viewpoint.However,since numerous videos and additional data are required for its construction,all of the clips constituting the content cannot be simultaneously provided.Only certain clips are selected and provided to the user.If the video is not the preferred video,change request is made,and a delay occurs during retransmission from the server.Delays due to frequent re-requests degrade the overall quality of service.For free-view services,selectively transmitting the video according to the user’s desired viewpoint and region of interest within the limited network of available videos is important.In this study,we propose a method of screening and providing the correct video based on objects in the contents.Based on the method of recognizing the object in each clip,we designed a method of setting its priority based on information about the object’s location for each viewpoint.During the transmission and receiving process using this information,the selected video can be rapidly recognized and changed.Herein,we present a service system configuration method and propose video selection examples for free-view services. 展开更多
关键词 Free-viewpoint video multi-view video coding scene change object co-detection transmission method
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The Changing Linguistic Scene in Britain 被引量:1
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作者 Randolph Quirk 《外语教学与研究》 1985年第3期25-33,共9页
此文是现任伦敦大学副校长夸克教授于1982年所作的一篇讲演。讲演概述近75年来英语的变化,作者以1982年为基点,上推75年至1907年,文章追述此75年时代和语言的变化。1907年,伦敦大学荣休教授艾弗·伊凡思8岁,已故辞典学家A.S 霍恩比... 此文是现任伦敦大学副校长夸克教授于1982年所作的一篇讲演。讲演概述近75年来英语的变化,作者以1982年为基点,上推75年至1907年,文章追述此75年时代和语言的变化。1907年,伦敦大学荣休教授艾弗·伊凡思8岁,已故辞典学家A.S 霍恩比之夫人玛丽恩·霍恩比8岁,二人均为夸克友,为述当时语词与今不同的意义,可称信史。英帝国盛时,英语多殖民地语词,今不复用,这是一种明显的变化。此外,汽车、无线电问世,新语词随之而来。教育普及,大学教育不再为中产者与贵族所独享,于是牛津学生厌弃牛津音,而以民间音为时髦。英国书刊素以用词纯正自居,今则不得不接受美国语词的影响;过去只许在闲叙琐谈中出现之词,今则亦见于正式文体。男女平等的观念,使过去父系社会习用的称呼增加新的形式;种族平等的观念,使歧视性称呼遭受淘汰;国家平等的观念,使不同英语国家采取自己的发音;英国国内各民族平等的观念,使威尔士语、苏格兰语在学校里的地位得到承认。文章作者有传统语文学的学养,又有语言学的审察,释义析例精到,起讫都成文章。1984年夏许国璋教授访英,晤夸克于堂前石阶三层之伦敦大学评议楼,许索稿,夸克出数稿应,此即其一。 展开更多
关键词 The Changing Linguistic scene in Britain
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