High-rank coded aperture projection for extended depth of field

Projectors require large apertures to maximize light throughput. Unfortunately, this leads to shallow depths of field (DOF), hence blurry images, when projecting on non-planar surfaces, such as cultural heritage sites, curved screens, or when sharing visual information in everyday environments. We introduce high-rank coded aperture projectors - a new computational display technology that combines optical designs with computational processing to overcome depth of field limitations of conventional devices. In particular, we employ high-speed spatial light modulators (SLMs) on the image plane and in the aperture of modified projectors. The patterns displayed on these SLMs are computed with a new mathematical framework that uses high-rank light field factorizations and directly exploits the limited temporal resolution and contrast sensitivity of the human visual system. With an experimental prototype projector, we demonstrate significantly increased DOF as compared to conventional technology.