Camera calibration using property of asymptotes with application to sports scenes

Inspired by Ying's work on the calibration technique, this study proposes a new planar pattern (referred to as the phi-type model hereinafter), which includes a circle and diameter, as the calibration scene. In sports scenarios, such as a soccer match or basketball court, most existing methods require information of the scene points in a three-dimensional space. However, an interesting observation in the midfield is that the centre circle and the halfway line form a phi-type template. A new automatic method using the properties of asymptotes is proposed based on the images of the midfield. All intrinsic parameters of the camera can be determined without any assumptions such as zero skew or unitary aspect ratio. The main advantages of our technique are that it neither involves point or line matching nor does it require the metric information of the model plane. The feasibility and validity of the proposed algorithm were verified by testing the noise sensitivity and performing image metric rectification.