Relative depth estimation with an uncalibrated camera for image refocus

Built-in post refocus applications begin to appear in cameras of new phone models. Most of them rely on dual or even customized cameras. In this paper, we proposed a solution of post refocus using a single uncalibrated cellphone camera. The input is a short video clip with minor camera movement, which is commonly caused by nature shaking of hand. After using feature matching to find a reference plane, the parallax of multiple frames will be revised based on the transformation of reference plane and a factorization method is used to recover the relative depth map. Finally, plausible refocus images can be obtained according to the relative depth map. Our solution has no reliance on any specialized lens and can generate adjustable refocus effect, in both focal depth and the degree of out-of-focus.