Some Aspects of Zoom-Lens Camera Calibration

Mengxiang Li and Jean-Marc Lavest

Abstract

Camera calibration has been a studying subject in both photogrammetry and computer vision community for a long time. Most of the previous work has been concerned with algorithms and techniques for geometric properties of CCD camera. Very little attention has been paid on the radiometric properties. Calibration results does not only depend on the mathematical tools used to compute the {\em intrinsic} and {\em extrinsic} parameters. A lot of cares have to be taken in the electronic stability of camera and frame grabber, the construction of a 3D refernada object CVAP/and the way calibration points are measured and detected in images. In this paper we address some practical aspects of camera calibration, in particular, of a {\em zoom lens} system. Through a systematic approach we try to describe all the keys points that have to be checked in order to obtain accurate calibration results. Experimental results on calibrating the KTH head-eye system, which is an active vision system consisting a pair of cameras with motor controlled zooming, focusing and aperture, are presented and annadaed. Full paper: (PostScript 1.3mb)
Mengxiang Li <mxli@bion.kth.se>