Coded Aperture for Light Field Acquisition and Digital Refocusing
We propose a new class of "Mask-enhanced" cameras for capturing scene properties beyond conventional 2D cameras. The new camera simply holds a transmissive mask inside a conventional camera. The modification is cheap and easy to install. Applications are show in image restoration due to out of focus blur, digital refocusing and computing the 4D light field of the scene.
Background & Objective: Capture scene properties beyond conventional pixel intensities and recoverably encode scene information.
Technical Discussion: A new Fourier domain theory is developed that describe the effect of placing a single transmissive mask in the optical path of a conventional camera. Two designs are proposed. In the first design, a broadband mask is placed in the aperture to preserve high spatial frequencies. This allows full resolution digital refocusing and extended depth of field. In the second design, a narrowband mask is placed close to the sensor which allows capturing the 4D light field inside the camera. The narrowband mask acts as a carrier to modulate the 4D light field on to the 2D sensor, similar to heterodyning in radio communications.
Outside Collaborations: Prof. Jack Tumblin, Dept of Computer Science, Northwestern University.
Future Direction: Investigate mask installation in a hand-held digital camera for commercial purpose and investigate general ray modulators beyond 2D masks for encoding scene properties in other dimensions such as wavelength, time etc.
Contacts:
Ramesh Raskar
Amit Agrawal
Technology Area: Imaging
Modification Date: September 12, 2007
