競技場に塗布されているラインの幾何学的特性と計測範囲外の既知点 を利用したカメラパラメータ算出法の開発

抄録

　The purpose of this study was to develop a calculation method (CL method) for camera parameters using feature points (known three-dimensional coordinates) outside the control volume, one feature point, and the geometric property of lines inside the control volume. The film process in this study was as follows: (1) the camera platform position and focal length that filmed the control volume well were selected; (2) without changing the camera platform position and focal length, cameras were panned and tilted to film the feature points outside the control volume (number of pictures = 5); (3) the camera platform joints were adjusted and fixed to the film control volume; and (4) the control volume was filmed by the cameras. From the pictures, the digitizer coordinates of the feature points and line edges were collected. Focal length and camera platform parameters (such as position and lean) were estimated with particle swarm optimization to minimize the sum of the reprojective errors of the feature points outside the control volume, one feature point inside the control volume, and the lines inside the control volume. The camera parameters at the moment of filming the control volume were calculated using the focal length and camera platform parameters. Three-dimensional coordinates as accuracy verification points (135 points) were reconstructed using the estimated camera parameters. RMS errors of the accuracy verification points in the CL method and a method developed in a previous study were 11.1 and 7.9 mm, respectively. These results show that the CL method can be adapted for the collection of three-dimensional coordinates.