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.<<ETX>>
[1]
Murali Subbarao.
Parallel Depth Recovery By Changing Camera Parameters
,
1988,
[1988 Proceedings] Second International Conference on Computer Vision.
[2]
Murali Subbarao,et al.
Computer modeling and simulation of camera defocus
,
1993,
Other Conferences.
[3]
Murali Subbarao,et al.
Application of spatial-domain convolution/deconvolution transform for determining distance from image defocus
,
1993,
Other Conferences.
[4]
Alex Pentland,et al.
A New Sense for Depth of Field
,
1985,
IEEE Transactions on Pattern Analysis and Machine Intelligence.