增强视觉 | 计算机视觉 增强现实

Paul Debevec, Tim Hawkins, John Monosand Mark Sagar以他们创造的light stage获得了2010的奥斯卡sci-tech奖。light stage为本杰明巴顿奇事，阿凡达， 哈利波特等等电影贡献良多。

light stage是以Paul Debevec在2000年的siggraph的研究基础上发展起来的捕捉重建技术，目标是通过计算机图形，计算机图像等重建出有着高度真实感的人脸。主要思路是通过不同方向，强度的光照照亮的演员的脸部图像，来重建以假乱真的虚拟人脸。下面是lightstage 1的样子，现在看来很山寨。

下面是siggraph论文链接和项目主页。

Acquiring the Reflectance Field of a Human Face:
(Research Paper) (Project Web Page)

在light stage 1的基础上，相继发展出了light stage 2， 3， 4， 5，6代！下面是light stage 家谱。

• Light Stage 1:
  • Acquiring the Reflectance Field of a Human Face, SIGGRAPH 2000
  • Facial Reflectance Field Demo, SIGGRAPH 2000 Creative Applications Laboratory
  • Realistic Human Face Scanning and Rendering, ICT Graphics Lab 2001
• Light Stage 2:
  • A Photometric Approach to Digitizing Cultural Artifacts, VAST 2001
  • Reflectance Field Rendering of Human Faces for “Spider-Man 2″, SIGGRAPH 2004 Sketch
• Light Stage 3:
  • A Lighting Reproduction Approach to Live-Action Compositing, SIGGRAPH 2002
  • Optimizing Color Matching in a Lighting Reproduction System for Complex Subject and Illuminant Spectra, EGSR 2003
• Light Stage 5:
  • Postproduction Re-Illumination of Live Action Using Interleaved Lighting, SIGGRAPH 2004 Poster
  • Rapid Acquisition of Specular and Diffuse Normal Maps from Polarized Spherical Gradient Illumination, EGSR 2007
• Light Stage 6:
  • Relighting Human Locomotion with Flowed Reflectance Fields, EGSR 2006 Paper
  • A Reflective Light Stage, ICT Technical Report 2006 Paper
  • A Dual Light Stage , EGSR 2005 Paper

到了light stage 5已经酷多了。看图。

avatar中逼真的外星人就是weta digital和ict light stage 5合力打造的。（插一句，weta digitall是新西兰导演peter jackson，也就是指环王，金刚的导演效仿前辈卢卡斯创建的视觉特效公司）。

现在的state of art是light stage 6，看下图，光装置就够炫了。目标是从人脸扩展到人体。看下图。

下面是Paul Debevec在TED上面的演讲。

来源：HDRI，fxguide，ict light stage 主页