Application of velocity filtering to optical-flow passive ranging

Author

Barniv, Yair

Author_Institution

NASA Ames Res. Center, Moffett Field, CA, USA

Volume

28

Issue

4

fYear

1992

fDate

10/1/1992 12:00:00 AM

Firstpage

957

Lastpage

969

Abstract

The performance of the velocity filtering method as applied to optical-flow passive ranging under real-world conditions is evaluated. The theory of the 3-D Fourier transform as applied to constant-speed moving points is reviewed, and the space-domain shift-and-add algorithm is derived from the general 3-D matched filtering formulation. The constant-speed algorithm is then modified to fit the actual speed encountered in the optical flow application, and the passband of that filter is found in terms of depth (sensor/object distance) so as to cover any given range of depths. Two algorithmic solutions for the problems associated with pixel interpolation and object expansion are developed, and experimental results are presented

Keywords

Fourier transforms; distance measurement; filtering and prediction theory; image processing; interpolation; 3-D Fourier transform; 3D matched filtering; constant-speed algorithm; constant-speed moving points; helicopter obstacle avoidance; object expansion; optical-flow passive ranging; pixel interpolation; space-domain shift-and-add algorithm; velocity filtering; Filtering algorithms; Filtering theory; Fourier transforms; Image motion analysis; Interpolation; Matched filters; Optical filters; Optical sensors; Passband; Passive filters;

fLanguage

English

Journal_Title

Aerospace and Electronic Systems, IEEE Transactions on

Publisher

ieee

ISSN

0018-9251

Type

jour

DOI

10.1109/7.165359

Filename

165359