On the sensitivity analysis of camera calibration from images of spheres

This paper presents a novel sensitivity analysis of camera calibration from images of spheres. We improve the accuracy of a conic matrix and hence the accuracy of calibration results by eliminating the ambiguity of the conic orientation that arises from the nature of a circular-ellipse. In addition, relationships between the difference in length of the long and short axes of a conic and other parameters of the conic and the camera are investigated and demonstrated through parametric study and experimental analysis. By utilizing these relationships, we establish novel guidelines that can be followed to obtain better calibration results.