Visualizing and Alleviating the Effect of Radial Distortion on Camera Calibration Using Principal Lines

TL;DR

This paper proposes new methods to prepare images for camera calibration that reduce radial distortion effects, leading to more robust calibration results by analyzing principal lines and their symmetries.

Contribution

It introduces a novel approach using principal lines and their symmetry properties to improve camera calibration accuracy under radial distortion.

Findings

More robust calibration results compared to algebraic methods

Identification of principal line directions affecting calibration accuracy

Effective estimation of principal points using nearly parallel principal lines

Abstract

Preparing appropriate images for camera calibration is crucial to obtain accurate results. In this paper, new suggestions for preparing such data to alleviate the adverse effect of radial distortion for a calibration procedure using principal lines are developed through the investigations of: (i) identifying directions of checkerboard movements in an image which will result in maximum (and minimum) influence on the calibration results, and (ii) inspecting symmetry and monotonicity of such effect in (i) using the above principal lines. Accordingly, it is suggested that the estimation of principal point should based on linearly independent pairs of nearly parallel principal lines, with a member in each pair corresponds to a near 180-degree rotation (in the image plane) of the other. Experimental results show that more robust and consistent calibration results for the foregoing estimation can actually be obtained, compared with the renowned algebraic methods which estimate distortion parameters explicitly.