Plenoptic camera
From Wikipedia, the free encyclopedia
A plenoptic camera, also called a light-field camera, and more correctly called a "polydioptric" camera, is a camera that uses a microlens array (also known as a lenticular lens array) to capture 3D information about a scene. According to John Y. A. Wang, "The novel optics eliminates spatial aliasing, correspondence and aperture problems, and temporal aliasing problems present in conventional stereo and structure from motion".
A team at Stanford University used a 16 megapixel camera with a 90,000-microlens array (meaning that each microlens covers about 175 pixels, and the final resolution is 90 kilopixels) to demonstrate that pictures can be refocused after they are taken, including bringing the entire image into focus.
The microlens sits between the lens of the camera and the image sensor. It refocuses light onto the image sensor to create many small images taken from slightly different viewpoints, which are manipulated by software to extract depth information.
Plenoptic cameras are good for following moving objects. A recording from a security camera based upon this technology could be used to produce an accurate 3D model of a suspect.
[edit] References
- [http://www-bcs.mit.edu/people/jyawang/demos/plenoptic/plenoptic.html Article by John Y. A. Wang of MIT discussing research by E. H. Adelson and John Y. A. Wang on creating 3D images with a modified standard digital camera. The relative order of objects can be calculated. The article includes references and US patent information.
- [1] Article by Ren Ng of Stanford (now at Refocus Imaging)
- [2] Report by Ren Ng, Marc Levoy, Mathieu Brédif, Mark Horowitz, and Pat Hanrahan of Stanford and Gene Duval of Duval Design on processing plenoptic camera images to refocus the images after the picture has been taken. The team used a 16 megapixel camera with 90,000 microlenses.
- http://www.cfar.umd.edu/~jneumann/videogeometry/polydioptric.htm Refers to "Polydioptric" cameras, says good for following moving objects.
- Refocus Imaging, a Stanford spinoff.
- Wired article
- Stanford news article
- Fourier slice photography
