Camera calibration with distortion models and accuracy evaluation

Abstract

The objective of stereo camera calibration is to estimate the internal and external parameters of each camera. Using these parameters, the 3-D position of a point in the scene, which is identified and matched in two stereo images, can be determined by the method of triangulation. In this paper, we present a camera model that accounts for major sources of camera distortion, namely, radial, decentering, and thin prism distortions. The proposed calibration procedure consists of two steps. In the first step, the calibration parameters are estimated using a closed-form solution based on a distortion-free camera model. In the second step, the parameters estimated in the first step are improved iteratively through a nonlinear optimization, taking into account camera distortions. According to minimum variance estimation, the objective function to be minimized is the mean-square discrepancy between the observed image points and their inferred image projections computed with the estimated calibration parameters. We introduce a type of measure that can be used to directly evaluate the performance of calibration and compare calibrations among different systems. The validity and performance of our calibration procedure are tested with both synthetic data and real images taken by tele-and wide-angle lenses. The results consistently show significant improvements over less complete camera models.

Technical note: Bathymetry observations of inland water bodies using a tethered single-beam sonar controlled by an unmanned aerial vehicle

“…Lens distortion needs to be corrected for because the SONY RX-100 camera is not a metric camera. Numerous methods have been discussed in the literature to correct for lens distortion (e.g., Brown, 1971;Clarke and Fryer, 1998;Faig, 1975;Weng et al, 1992). In this research the software PTLens was used to remove lens radial distortion because the lens parameters of the SONY RX-100 camera are included in the software database.…”

SVMT: A MATLAB toolbox for stereo-vision motion tracking of motor reactivity

“…see [3,[5][6][7][8]]. In the present application we used a freely available MATLAB Camera Calibration Toolbox developed by Bouguet [6].…”

A review on egomotion by means of differential epipolar geometry applied to the movement of a mobile robot

“…Some years later, work proposed by Faugeras was adaptated to include radial lens distortion [3]. Two other interesting contributions are the widely used method proposed by Tsai [4], is based on a two-step technique modelling only radial lens distortion, and the complete model of Weng [5], proposed in 1992, which includes three di erent types of lens distortion. Research e orts are still being carried out on obtaining new camera models to improve both accuracy in computing the optical ray and in extracting the camera parameters which best model reality.…”