Accession Number : ADP000131

Title :   Depth of Scene from Depth of Field,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Pentland,Alex P.

Report Date : 1982

Pagination or Media Count : 7

Abstract : Image focus is a simple function of distawnce to the imaged point (an effect commonly referred to as depth of field) and the parameters of the lens. Therefore, by measuring focus we can determine distance to the imaged object. Two algorithms are presented. The first determines lens-to-object distance at points of discontinuity in the scene, using one image acquired with a standard lens sytstem. The second algorithm determines distance for all regions of the image that contain high-frequency information, using a single view acquired with a special lens system. The distance estimate produced by the second algorithm is overconstrained; thus, the accuracy of the estimate can be checked internally. These results show that single-view measurement of focus provides information comparable to measurement of stereo disparity or motion, while avoiding image-to-image-matching problems. A simple experiment is described showing that focus information is important in human perception. (Author)

Descriptors :   *Image processing, Optical images, Algorithms, Focusing, Optical lenses

Distribution Statement : APPROVED FOR PUBLIC RELEASE