The lens has long been a central element of cameras, since its early use in the mid-19th century by Niepce, Talbot, and Daguerre. The role of the lens, from the Daguerrotype to modern digital cameras, is to refract light to achieve a one-to-one mapping between a point in the scene and a point on the sensor. This effect enables the sensor to compute a particular two-dimensional (2D) integral of the incident 4D light-field. We propose a radical departure from this practice and the many limitations it imposes. In the talk Ashok Veeraraghavan will focus on two inter-related research projects that attempt to go beyond lens-based imaging.
First, Veeraraghavan will discuss his lab’s recent efforts to build flat, extremely thin imaging devices by replacing the lens in a conventional camera with an amplitude mask and computational reconstruction algorithms. These lensless cameras, called FlatCams, can be less than a millimeter in thickness and enable applications where size, weight, thickness or cost are the driving factors. He'll take a brief detour and study an important problem in neuroscience that his team is currently attempting to solve by exploiting the lensless imaging technology.
Second, he will discuss high-resolution, long-distance imaging using Fourier Ptychography, where the need for a large aperture aberration corrected lens is replaced by a camera array and associated phase retrieval algorithms resulting again in order of magnitude reductions in size, weight and cost.
Finally, Veeraraghavan will spend a few minutes highlighting some of the other challenging imaging problems including looking around the corner, imaging at the speed of light, imaging through scattering media and direct brain-brain communication that they are attempting to solve through this holistic approach of jointly designing sensors, optics and computational algorithms.Bio:Ashok Veeraraghavan is currently an associate professor of electrical and computer engineering at Rice University. Before joining Rice University, he spent three wonderful and fun-filled years as a research scientist at Mitsubishi Electric Research Labs in Cambridge, Massachusetts. He received his bachelor's in electrical engineering from the Indian Institute of Technology, Madras, in 2002 and MS and PhD degrees from the Department of Electrical and Computer Engineering at the University of Maryland, College Park, in 2004 and 2008, respectively. His thesis received the doctoral dissertation award from the Department of Electrical and Computer Engineering at the University of Maryland. His work has won numerous awards including the Hershel. M. Rich Invention Award in 2016 and 2017 and an NSF CAREER award in 2017. He loves playing, talking and pretty much anything to do with the slow and boring but enthralling game of cricket.