Dappled photography

Abstract

We describe a theoretical framework for reversibly modulating 4D light fields using an attenuating mask in the optical path of a lens based camera. Based on this framework, we present a novel design to reconstruct the 4D light field from a 2D camera image without any additional refractive elements as required by previous light field cameras. The patterned mask attenuates light rays inside the camera instead of bending them, and the attenuation recoverably encodes the rays on the 2D sensor. Our mask-equipped camera focuses just as a traditional camera to capture conventional 2D photos at full sensor resolution, but the raw pixel values also hold a modulated 4D light field. The light field can be recovered by rearranging the tiles of the 2D Fourier transform of sensor values into 4D planes and computing the inverse Fourier transform. In addition, one can also recover the full resolution image information for the in-focus parts of the scene.

3D Imaging based on Depth Measurement Technologies

“…Various light ray field acquisition methods have been developed, including complicated setups such as camera arrays [33,34], compact designs that utilize micro-lens arrays [30,35], frequency domain multiplexing [35], amplitude masks [36,37], and well-designed mirrors [38,39]. Among these techniques, a camera with a micro-lens array in front of its sensor [30, 40,41] is well-known and widely used due to its single-shot convenience, as Fig.…”

Analyzing computational imaging systems

“…Several CI techniques have been introduced that produce well-conditioned blur without sacrificing light. For defocus deblurring, extended depth-of-field (EDOF) systems have been proposed that encode defocus blur using attenuation masks, [17][18][19] refractive masks, 20 or motion. 21,22 Motion deblurring cameras have been proposed that encode motion blur using either a fluttered shutter 23 or camera motion.…”

Dual light field and polarization imaging using CMOS diffractive image sensors

“…Applications of light field imaging include synthetic aperture refocusing to extend the depth of field, passive depth from defocus, and glare reduction [3,4]. Methods for capturing light fields have included camera arrays [5] and plenoptic cameras that place optical elements such as microlenses [6], transmission masks [7], or diffraction gratings in front of the sensor [8,9].…”