« Ivars Peterson: En matematisk analys av tennis | Main | Artikelserie om forskare och bloggar från Umeå Centrum för Interaktionsteknik »
juni 13, 2005
Dual photography
Titeln på New Scientist-artikeln Card trick holds promise for movie effects fångade naturligtvis mitt intresse. Korttrick och filmeffekter?
Det visade sig handla om en fotografisk teknik "Dual Photography" som möjliggör en massa roliga saker (som en som jag icke insatt i dessa saker benämner det). Från New Scientist-artikeln:
A card trick to flummox even the most expert of conjurers could hold the key to unparalleled trick photography and special effects.Researchers from Stanford University in California and Cornell University, New York, both in the US, have demonstrated a way to identify a playing card whose face is turned away from the camera. They did it by measuring projected light as it bounced off the face of the card and one other surface before reaching a camera.
Key to the conjuring trick is a technique known as "dual photography". This involves retracing the path light takes as it bounces off different surfaces, pixel by pixel. A light projector - with millions of controllable pixels which are switched on in turn - illuminates the scene. The reflected light from each pixel is recorded sequentially by a digital camera.
Papret som refereras är
Pradeep Sen, Billy Chen, Gaurav Garg, Stephen R. Marschner, Mark Horowitz, Marc Levoy, Hendrik P. A. Lensch: Dual Photography (stor fet PDF, cirka 20Mb).
Det finns även en MP4-fil (cirka 63 Mb). Det omtalade "korttricket" är det sista som visas.
Posted by hakank at juni 13, 2005 09:05 EM Posted to Diverse vetenskap