title: Depth from diffracted rotation.
abstract: The accuracy of depth estimation based on defocus effects has been essentially limited by the depth of field of the imaging system. We show that depth estimation can be improved significantly relative to classical methods by exploiting three-dimensional diffraction effects. We formulate the problem by using information theory analysis and present, to the best of our knowledge, a new paradigm for depth estimation based on spatially rotating point-spread functions (PSFs). Such PSFs are fundamentally more sensitive to defocus thanks to their first-order axial variation. Our system acquires a frame by using a rotating PSF and jointly processes it with an image acquired by using a standard PSF to recover depth information. Analytical, numerical, and experimental evidence suggest that the approach is suitable for applications such as microscopy and machine vision.
authors.affiliation: Department of Electrical and Computer Engineering, University of Colorado at Boulder, Colorado 80309, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Greengard
authors.forename: Yoav Y
authors.initials: YY
authors.lastname: Schechner
authors.forename: Rafael
authors.initials: R
authors.lastname: Piestun
mesh_terms: D000465:Algorithms; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D012031:Refractometry / Q000379:methods*; D012399:Rotation