3Yah S,Wang C, Ye M. A method based on moving least squares for XR Ⅱ image distortion correction. Med Phys, 2007,34:4194- 4206.
4Cosby NS,Leszczynski KW. Computer-aided radiation therapy simulation : image intensifier spatial distortion correction for large field of view digital fluoroscopy. Phys Med Biol, 1998,43:2265-2278.