Depth Detection of Light Field

We propose an algorithm to detect depths in a light field. Specifically, given a 4D light field, we find all planes at which objects are located. Although the exact depth of each pixel in the space is left unknown, the partial information obtained is very useful for many applications, such as synthetic aperture photography and all-focused rendering. Our algorithm measures the degree of focus of different planes by calculating the ratio of high frequencies to the low frequencies. To handle different depth distributions, we reformulate the maximum detection problem to a maximum-cover problem that can be solved efficiently by dynamic programming. Compared with auto-focusing and per-pixel depth estimation, our algorithm is much faster yet sufficiently accurate.