虚拟演播室技术

计算机技术应用到电视演播室之后,出现了虚拟演播室系统(简称VSS)。这二年来,VSS技术已成为电视领域中的一个热点,被业内人士称为极顶制作工具。虚拟演播室技术以计算机和相应的三维图形处理软件为技术基础,要求所使用的计算机有强大的计算能力及三维图形处理能力,目前通常以性能优越的SGI Onyx Reali-ty Engine超级图形计算机作为硬件平台。我们知道在演播室制作节目时布景及道具是必不可少的,而虚拟演播室技术完全抛弃人工布景和道具,将电视摄像机拍摄到的图像(如人物)实时地与计算机三维图形进行合成,从而形成一种新的电视节目制作系统。虚拟演播室系统的优势在于:(1)演播室设计小型化;(2)演播室内只需蓝色     

增强现实技术在虚拟演播室系统中的应用

虚拟演播室是虚拟现实技术和视频合成技术相结合的产物,其场景是计算机生成的三维场景,由于人们对虚拟场景和复杂度的无限要求,使得场景的实时显示十分困难,使用基于图像的绘制技术构造虚拟空间能够较好地解决这个问题。在虚拟演播室中,演员需要与三维运动虚拟物体进行交互,运用增强现实技术,可以将三维虚拟物体与基于图象绘制的虚拟场景融合在一起。     

虚拟演播室系统

虚拟演播室技术是近年发展起来的一种独特的电视节目制作技术,它是色键技术、计算机软件、三维建模、音视频数字化合成处理、摄像机跟踪等技术综合的产物。介绍了虚拟演播室的关键技术和基本构成,同时提出了相应的建设建议。     

虚拟演播室:结构及关键技术

色键是传统电视节目制作中常用的技术,虚拟演播室是在此基础上发展而来的,它是用计算机生成的替换蓝色背景,并运用计算机技术和视频合成技术,使演可可以在虚拟的场景中“表演”,与虚拟对象（如卡通动物等）“交互”,真正实现虚实结合,这时 重讨论虚拟演播室系统的结构以及关键技术。     

浅析虚拟演播室系统的应用

虚拟演播室作为一种新事物,它的出现是电视节目制作方式的一次变革。它基于传统的色键抠像技术,利用现代图形处理技术实现摄像机实时拍摄的前景画面与计算机构建的三维背景画面完美结合,这为电视节目的制作提供了无限的发展空间。     

虚拟演播室—虚拟现实技术的新应用

虚拟演播室——虚拟现实技术的新应用闫宏伟闫宏伟，１９９３～１９９６年就读于清华大学，主要从事多媒体技术的研究与应用，获硕士学位。现就读于北京大学计算机研究所，攻读博士学位。主要从事数字视频三维图形及虚拟现实技术的研究与应用。１虚拟演播室概述在现代信息...     

基于VRML的虚拟场景的设计与实现

文章结合VRML的功能,具体分析了基于VRML的三维交互式虚拟场景设计的关键技术,并以虚拟演播室系统为应用背景,给出了用VRML开发三维交互式虚拟场景的整体解决方案。     

幻景成真:虚拟演播室技术

所谓虚拟演播室,就是利用计算机产生出虚拟的三维背景和道具,然后通过视频合成系统将演员与其进行合成,最后生成全三维、真人与虚拟布景和道具融合的效果。采用虚拟演播室技术,可以制作出任何想象中的布景和道具。虚拟演播室的产生,给视频节目制作、电视广播带来了一场革命。但目前系统应用还存在着一定的局限性。     

基于虚拟演播室的Motion Capture研究

在介绍虚拟演播室的基础上，分析了Motion Capture的技术和应用，提出了一种基于虚拟演播室的系统实现，并探讨了其在节目制作中的应用。     

虚拟演播室系统分析及应用

虚拟演播室是由传统的色键技术发展而来。它可以把现场视频与计算机影像实时地无缝地合成在一起,它不仅为视频节目制作提供了高科技的制作手段和无限自由的创作空间,而且在丰富节目包装方式、降低节目制作费用等方面也显示出其巨大的优势。文章分析了虚拟演播室系统的原理、技术途径以及实际应用。     

A sensor-based SLAM algorithm for camera tracking in virtual studio

This paper addresses a sensor-based simultaneous localization and mapping （SLAM） algorithm for camera tracking in a virtual studio environment. The traditional camera tracking methods in virtual studios are vision-based or sensor-based. However, the chroma keying process in virtual studios requires color cues, such as blue background, to segment foreground objects to be inserted into images and videos. Chroma keying limits the application of vision-based tracking methods in virtual studios since the background cannot provide enough feature information. Furthermore, the conventional sensor-based tracking approaches suffer from the jitter, drift or expensive computation due to the characteristics of individual sensor system. Therefore, the SLAM techniques from the mobile robot area are first investigated and adapted to the camera tracking area. Then, a sensor-based SLAM extension algorithm for two dimensional （2D） camera tracking in virtual studio is described. Also, a technique called map adjustment is proposed to increase the accuracy＇ and efficiency of the algorithm. The feasibility and robustness of the algorithm is shown by experiments. The simulation results demonstrate that the sensor-based SLAM algorithm can satisfy the fundamental 2D camera tracking requirement in virtual studio environment.     

Movie Texture节点在虚拟演播室场景开发中应用

VRML是一种用来描述交互式3D对象和环境的语言,也是用于开发虚拟演播室场景的语言之一。该文讨论使用Movie Texture节点实现虚拟演播室场景中常用的虚拟视频面板效果。     

The reality of virtual TV studios

Virtual television took a step closer to reality when BBC TV'sTomorrow's World demonstrated a new technology which will allow TV programme makers to stretch the limits of their artistic imagination. The technique enables programme makers to create imaginative studio sets with limitless perspectives, sweeping camera shots, and where the quality of imagery is almost indistinguishable from the real thing, but at a fraction of the cost. Tomorrow's World viewers saw the result when presenter Howard Stableford stepped onto a ‘virtual set’ depicting a Roman Bath, in which he sees himself playing characters in a pastiche ofJulius Caesar andUp Pompeii. In reality Stableford was filmed in a conventional TV studio, but the set was created artificially using technology which combines computer graphics and a motion controlled camera. Unlike other attempts at virtual sets, where only the virtual set, or the actor, or the camera is in motion, this technique allows simultaneous motion of all three. The resulting sequence of just over two minutes was broadcast on BBC TV as part of theTomorrow's World-Christmas Special on 22 December 1995.     

A Sensor-based SLAM Algorithm for Camera Tracking vin Virtual Studio

This paper addresses a sensor-based simultaneous localization and mapping (SLAM) algorithm for camera tracking in a virtual studio environment. The traditional camera tracking methods in virtual studios are vision-based or sensor-based. However, the chroma keying process in virtual studios requires color cues, such as blue background, to segment foreground objects to be inserted into images and videos. Chroma keying limits the application of vision-based tracking methods in virtual studios since the background cannot provide enough feature information. Furthermore, the conventional sensor-based tracking approaches suffer from the jitter, drift or expensive computation due to the characteristics of individual sensor system. Therefore, the SLAM techniques from the mobile robot area are first investigated and adapted to the camera tracking area. Then, a sensor-based SLAM extension algorithm for two dimensional (2D) camera tracking in virtual studio is described. Also, a technique called map adjustment is proposed to increase the accuracy and efficiency of the algorithm. The feasibility and robustness of the algorithm is shown by experiments. The simulation results demonstrate that the sensor-based SLAM algorithm can satisfy the fundamental 2D camera tracking requirement in virtual studio environment.     

影视制作中HDRI技术的应用与研究

当前的影视创作中,电脑三维、模型、实拍多元素结合一张画面中来增强视觉感染力,在此创作中使画面看的更为真实,天衣无缝,是影视后期制作者一直在研究的内容。HDRI高动态环境贴图的制作是摹拟真实环境、电脑三维中物体质感体现重要的环节,是影视创作中画面真实与细腻重要的手段。     

一种高性价比虚拟演播室系统设计与实现

针对目前国内需求和产品现状 ,量体设计开发了一种低价位、高性价比的虚拟演播室系统。系统选用了高精度的光学旋转编码器跟踪技术、性能卓越的专业视频处理板卡、成熟稳定的数字图像处理技术 ,在高性能PC工作站上的 Windows2 0 0 0操作系统下开发。系统实现了现代虚拟演播室的基本功能 ,其出色的技术指标 ,稳定可靠的性能 ,人性化的操作界面 ,赢得了电视行业的青睐     

Real-Time Camera Calibration for Virtual Studio

In this paper, we present an overall algorithm for real-time camera parameter extraction, which is one of the key elements in implementing virtual studio, and we also present a new method for calculating the lens distortion parameter in real time. In a virtual studio, the motion of a virtual camera generating a graphic studio must follow the motion of the real camera in order to generate a realistic video product. This requires the calculation of camera parameters in real-time by analyzing the positions of feature points in the input video. Towards this goal, we first design a special calibration pattern utilizing the concept of cross-ratio, which makes it easy to extract and identify feature points, so that we can calculate the camera parameters from the visible portion of the pattern in real-time. It is important to consider the lens distortion when zoom lenses are used because it causes nonnegligible errors in the computation of the camera parameters. However, the Tsai algorithm, adopted for camera calibration, calculates the lens distortion through nonlinear optimization in triple parameter space, which is inappropriate for our real-time system. Thus, we propose a new linear method by calculating the lens distortion parameter independently, which can be computed fast enough for our real-time application. We implement the whole algorithm using a Pentium PC and Matrox Genesis boards with five processing nodes in order to obtain the processing rate of 30 frames per second, which is the minimum requirement for TV broadcasting. Experimental results show this system can be used practically for realizing a virtual studio.     

New distributed virtual TV set architecture for a synergistic operation of sensors and improved interaction between real and virtual worlds

A virtual TV set is a studio that is able to combine recorded actors and objects with computer generated virtual environments in real time. In order to achieve this combination seamlessly, in an ideal configuration, several elements such as cameras, objects and people should be tracked so that all their actions on the stage have a corresponding effect in the virtual world. However, in the actual professional virtual TV sets, the tracking possibilities are quite limited because of the hardware and software architecture used, which has not had a major evolution since the first prototypes presented in the nineties. This traditional architecture uses to be rigid, including just one monolithic tracking system and low levels of interactivity. In this paper, a new distributed, flexible and scalable hardware and software architecture that allows the inclusion of multiple kinds of devices in parallel is introduced. It breaks with the traditional structure of the virtual TV sets, opening the technology to an easier inclusion of new devices without the need of updating the proprietary software of the set, thus facilitating its future evolution. The design, implementation and test of this architecture, through the adaptation of a traditional virtual TV set, is presented. The tests are developed through the inclusion of modern devices (in our case Optitrack infrared cameras, Microsoft Kinect V2 and Leap Motion) that, through a synergistic operation, allow the system to solve some traditional drawbacks of this technology such as free and multiple object and camera tracking, presenter natural interaction and automatic distance keying.     

Stereo Matching with Transparency and Matting

This paper formulates and solves a new variant of the stereo correspondence problem: simultaneously recovering the disparities, true colors, and opacities of visible surface elements. This problem arises in newer applications of stereo reconstruction, such as view interpolation and the layering of real imagery with synthetic graphics for special effects and virtual studio applications. While this problem is intrinsically more difficult than traditional stereo correspondence, where only the disparities are being recovered, it provides a principled way of dealing with commonly occurring problems such as occlusions and the handling of mixed (foreground/background) pixels near depth discontinuities. It also provides a novel means for separating foreground and background objects (matting), without the use of a special blue screen. We formulate the problem as the recovery of colors and opacities in a generalized 3D (x, y, d) disparity space, and solve the problem using a combination of initial evidence aggregation followed by iterative energy minimization.     

PLC以及变频器在电视演播工艺中的应用

本文通过分析电视演播工艺中的功能要求．介绍利用PLC以及变频器实现电视演播技术与楼宇空调设备自动控制技术的融合方案，提高了电视演播的节目质量。