Broad Area Colloquium For AI-Geometry-Graphics-Robotics-Vision
(CS 528)

Light field microscopy

Marc Levoy
Computer Science Department
Stanford University

November 13, 2006, 4:15PM
TCSeq 200


The light field is a four-dimensional function representing radiance along rays as a function of position and direction in space. By inserting a microlens array into the optical train of a conventional microscope, light fields can be captured of biological (or other) specimens in a single snapshot. We can then employ light field rendering to generate perspective flyarounds, at least up to the angular limit of rays we have captured, and we can use synthetic focusing to generate a focal stack, a set of images each focused on a different plane. Since microscopes are inherently orthographic devices, perspective flyarounds represent a new way to look at microscopic specimens. Focal stacks are not new, but manual techniques for capturing them are time-consuming and hence not applicable to moving or light-sensitive specimens. Applying 3D deconvolution to these focal stacks, we can produce a set of cross sections, which can be visualized using volume rendering. Ours is the first technology (of which we are aware) that can produce volumetric models from a single photograph. In this talk, I will describe a prototype light field microscope and show perspective views, focal stacks, and reconstructed volumes for a variety of biological specimens. I will also survey some promising directions for this technology. For example, by introducing a second microlens array and a video projector, we can control the light field arriving at a specimen as well as the light field leaving it. Potential applications of this idea include microscope scatterometry - measuring reflectance as a function of incident and reflected angle, and "designer illumination" - illuminating one part of a microscopic object while avoiding illuminating another.

About the Speaker

Marc Levoy is a Professor of Computer Science and Electrical Engineering at Stanford University. He received degrees in Architecture from Cornell University in 1976 and 1978 and a PhD in Computer Science from the University of North Carolina in 1989. His research interests include computer-assisted cartoon animation, volume rendering (for which he won the SIGGRAPH Computer Graphics Achievement Award in 1996), 3D scanning, light field sensing and display, computational imaging, digital photography, and microscopy.


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