Extended depth-of-field imaging and ranging in a snapshot
Harvey, Andrew R.
Carles Santacana, Guillem
- Publisher: Optical Society of America
arxiv: Computer Science::Computer Vision and Pattern Recognition
Traditional approaches to imaging require that an increase in depth of field is associated with a reduction in\ud numerical aperture, and hence with a reduction in resolution and optical throughput. In their seminal\ud work, Dowski and Cathey reported how the asymmetric point-spread function generated by a cubic-phase\ud aberration encodes the detected image such that digital recovery can yield images with an extended depth of\ud field without sacrificing resolution [Appl. Opt. 34, 1859 (1995)]. Unfortunately recovered images are\ud generally visibly degraded by artifacts arising from subtle variations in point-spread functions with defocus.\ud We report a technique that involves determination of the spatially variant translation of image components\ud that accompanies defocus to enable determination of spatially variant defocus. This in turn enables recovery\ud of artifact-free, extended depth-of-field images together with a two-dimensional defocus and range map\ud of the imaged scene. We demonstrate the technique for high-quality macroscopic and microscopic imaging\ud of scenes presenting an extended defocus of up to two waves, and for generation of defocus maps with an\ud uncertainty of 0.036 waves.