Depth from defocus and rapid autofocusing: a practical approach

Author

Subbarao, Murali ; Wei, Tse-Chung

Author_Institution

Dept. of Electr. Eng.. State Univ. of New York, Stony Brook, NY, USA

fYear

1992

fDate

15-18 Jun 1992

Firstpage

773

Lastpage

776

Abstract

A method for determining depth (range) from image defocus and rapid autofocusing of a camera named DFD1F, is presented. It requires only two images in theory, but three images in the present implementation. DFD1F is based on computing only one-dimensional Fourier coefficients as opposed to two-dimensional Fourier coefficients for a related prior method, thus providing not only computational advantage but also robustness in practical applications. DFD1F is independent of the form of the modulation transfer function of the camera. DFD1F has been successfully implemented and tested on an actual camera system named SPARCS. SPARCS can determine the distance of an object placed in front of it at any distance in the range of 0.5 m to infinity, and can successfully focus the object by moving the lens with a root-mean-square error of less than 6% in terms of lens position

Keywords

cameras; computer vision; image recognition; DFD1F; SPARCS; camera; depth; image defocus; modulation transfer function; one-dimensional Fourier coefficients; rapid autofocusing; Acoustic noise; Cameras; Colored noise; Design for disassembly; Focusing; H infinity control; Lenses; Noise robustness; System testing; Transfer functions;

fLanguage

English

Publisher

ieee

Conference_Titel

Computer Vision and Pattern Recognition, 1992. Proceedings CVPR '92., 1992 IEEE Computer Society Conference on

Conference_Location

Champaign, IL

ISSN

1063-6919

Print_ISBN

0-8186-2855-3

Type

conf

DOI

10.1109/CVPR.1992.223176

Filename

223176