Automatic camera self-calibration for immersive navigation of free viewpoint sports video

In recent years, the demand of immersive experience has triggered a great revolution in the applications and formats of multimedia. Particularly, immersive navigation of free viewpoint sports video has become increasingly popular, and people would like to be able to actively select different viewpoints when watching sports videos to enhance the ultra realistic experience. In the practical realization of immersive navigation of free viewpoint video, the camera calibration is of vital importance. Especially, automatic camera calibration is very significant in real-time implementation and the accuracy of camera parameter directly determines the final experience of free viewpoint navigation. In this paper, we propose an automatic camera self-calibration method based on a field model for free viewpoint navigation in sports events. The proposed method is composed of three parts, namely, extraction of field lines in a camera image, calculation of crossing points, determination of the optimal camera parameter. Experimental results show that the camera parameter can be automatically estimated by the proposed method for a fixed camera, dynamic camera and multi-view cameras with high accuracy. Furthermore, immersive free viewpoint navigation in sports events can also be completely realized based on the camera parameter estimated by the proposed method.