- Plenoptic camera
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 alenticular lens array) to capture4D light field 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". [ [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.]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. [ [http://graphics.stanford.edu/papers/lfcamera/lfcamera-150dpi.pdf 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.]
The microlens array 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. [ [http://www.cfar.umd.edu/~jneumann/videogeometry/polydioptric.htm "Polydioptric" cameras] , says 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. [ [http://news-service.stanford.edu/news/2005/november9/camera-110205.html Computer scientists create a 'light field camera' that banishes fuzzy photos] , BY ANNE STREHLOW. Stanford Report. November 3, 2005.]
References
* [http://graphics.stanford.edu/papers/lfcamera Article by Ren Ng of Stanford] (now at Refocus Imaging)
* [http://www.refocusimaging.com Refocus Imaging] , a Stanford spinoff.
* [http://www.wired.com/news/technology/0,69594-0.html Say Sayonara to Blurry Pics] . Wired.
* [http://graphics.stanford.edu/papers/fourierphoto Fourier slice photography]
Wikimedia Foundation. 2010.
