Novel Calibration Method for the Multi-Camera Measurement System

Abstract

In a multi-camera measurement system, the determination of the external parameters is one of the vital tasks, referred to as the calibration of the system. In this paper, a new geometrical calibration method, which is based on the theory of the vanishing line, is proposed. Using a planar target with three equally spaced parallel lines, the normal vector of the target plane can be confirmed easily in every camera coordinate system of the measurement system. By moving the target into more than two different positions, the rotation matrix can be determined from related theory, i.e., the expression of the same vector in different coordinate systems. Moreover, the translation matrix can be derived from the known distance between the adjacent parallel lines. In this paper, the main factors effecting the calibration are analyzed. Simulations show that the proposed method achieves robustness and accuracy. Experimental results show that the calibration can reach 1.25 mm with the range about 0.5m. Furthermore, this calibration method also can be used for auto-calibration of the multi-camera measurement system as the feature of parallels exists widely.

Global calibration of non-overlapping cameras: State of the art

“…A calibration target is a workpiece with high precision and can be used for feature extraction and precision verification in camera calibration [14,15,[19][20][21]23,[25][26][27][28]32,81]. Planar calibration target is the most widely used calibration target, whose plane consistency is good, and features are easy to extract.…”

Three Degrees of Freedom Global Calibration Method for Measurement Systems with Binocular Vision

“…It provides flourishing developments in motion parameters testing, measurement of machine parts, parameter detection of micro-operating systems, 3D profile reconstruction [4][5][6][7], etc. It also gradually permeates into the aerospace, robot navigation, industrial measurement and bio-medical areas [8][9][10][11][12][13]. System calibration is the basis for binocular vision to obtain 3D coordinates.…”

A Global Calibration Method for Widely Distributed Cameras Based on Vanishing Features

“…Xu et al [ 19 ] proposed a pose estimation method based on vanishing lines of a T-shaped target. Wang [ 20 ] used a target with three equally spaced parallel lines to estimate the rotation matrix by moving the target into at least three different positions. Wei et al [ 21 , 22 ] calibrated a line-structured vision sensor and a binocular vision sensor by a planar target with several parallel lines.…”