Non-refractive modulators for encoding and capturing scene appearance and depth

We analyze the modulation of a light field via nonrefracting attenuators. In the most general case, any desired modulation can be achieved with attenuators having four degrees of freedom in ray-space. We motivate the discussion with a universal 4D ray modulator (ray-filter) which can attenuate the intensity of each ray independently. We describe operation of such a fantasy ray-filter in the context of altering the 4D light field incident on a 2D camera sensor. Ray-filters are difficult to realize in practice but we can achieve reversible encoding for light field capture using patterned attenuating mask. Two mask-based designs are analyzed in this framework. The first design closely mimics the angle-dependent ray-sorting possible with the ray filter. The second design [17] exploits frequency-domain modulation to achieve a more efficient encoding. We extend these designs for optimal sampling of light field by matching the modulation function to the specific shape of the band-limit frequ...

• Type: Conference
• Year: 2008
• Where: CVPR
• Authors: Ashok Veeraraghavan, Amit K. Agrawal, Ramesh Raskar, Ankit Mohan, Jack Tumblin
• Keywords: Computer Vision, CVPR 2008, Exploits Frequency-domain Modulation, Light Field, Light Field Camera, Light Field Capture, Light Field Incident