Half-sweep imaging for depth from defocus

Abstract

Depth from defocus (DFD) is a technique to recover the scene depth from defocusing in images. DFD usually involves two differently focused images (near-focused and far-focused) and calculates the size of the depth blur in the captured images. In recent years, the coded aperture technique, which uses a special pattern for the aperture to engineer the point spread function (PSF), has been used to improve the accuracy of DFD estimation. However, coded aperture sacrifices an incident light and loses a SNR of captured images which is needed for the accurate estimation. In this paper, we propose a new computational imaging, called half-sweep imaging. Half-sweep imaging engineers PSFs for improving DFD and maintaining the SNR of captured images. We confirmed the advantage of the imaging in comparison with conventional DFD and coded aperture in experiments. © 2011 Springer-Verlag.