EVALUATION OF PLANAR RECONSTRUCTION ACCURACY FOR TWO TECHNIQUES INCORPORATING CAMERA TILT

  • Mark Brewin
  • David Kerwin
  • Paul McCombie
Keywords: two-dimensional, direct linear transformation, scaling, 2D-DLT, tilt correction

Abstract

Planar analyses of sporting activities routinely employ scaling techniques with the camera elevated above the activity. An alternative technique for planar reconstruction can be derived from the DLT. This study compared reconstruction accuracy for scaling with 2D-DLT for a large field of view as camera tilt increased. Four calibration and 30 reconstruction markers on a vertical plane were recorded at tilt angles from 0° to 6°. Locations for the reconstruction markers were estimated using both techniques and compared to their known values. The smallest reconstruction errors were obtained using 2D- DLT and were unaffected by lilt angle (P<0.01). An increased tilt angle produced significantly larger errors (P