Slides (ppt, pdf). Videos (.zip, 81Mb)
The light field is a 4D representation of radiance as a function of position and direction in space. In computer graphics, light fields have been used to fly through scenes without the use of geometric models. In this talk, I explore three ways to capture and use light fields that fall outside this paradigm. Specifically, I describe:
1. A new photographic technique called dual photography, which exploits Helmholtz reciprocity to interchange the lights and cameras in a scene. The technique lets us take photographs using a projector and a photocell, and points to efficient ways of measuring 4D, 6D, and 8D reflectance fields.
2. A compact handheld camera capable of capturing a light field in a single exposure. By capturing directional as well as spatial information about the light entering the camera, we can refocus a photograph after it has been taken.
3. New applications for the Stanford multi-camera array, including a 30-megapixel tiled video camera with independent exposure metering in each tile. This lets us record dynamic environments with very high spatial resolution and dynamic range.
I will end with some observations about the relationship between photography and computational imaging in other fields, and then make some unfounded predictions about the future.
Marc Levoy is an Associate Professor of Computer Science and Electrical Engineering at Stanford University. He received his PhD in Computer Science from the University of North Carolina in 1989. In the 1970's Levoy worked on computer animation, developing an early computer-assisted cartoon animation system. In the 1980's Levoy worked on volume rendering, a family of techniques for displaying sampled three-dimensional functions, such as CT and MR data. In the 1990's he worked on technology and algorithms for 3D scanning. This led to the Digital Michelangelo Project, in which he and a team of researchers spent a year in Italy digitizing the statues of Michelangelo using laser rangefinders. His current interests include light field sensing and display, computational imaging, and digital photography. Levoy received the NSF Presidential Young Investigator Award in 1991 and the SIGGRAPH Computer Graphics Achievement Award in 1996 for his work in volume rendering.