TY - CONF T1 - View independent human body pose estimation from a single perspective image T2 - Computer Vision and Pattern Recognition, 2004. CVPR 2004. Proceedings of the 2004 IEEE Computer Society Conference on Y1 - 2004 A1 - Parameswaran, V. A1 - Chellapa, Rama KW - 3D KW - analysis; KW - biomechanics; KW - body KW - body-centric KW - camera; KW - capture KW - coordinate KW - coordinates; KW - detection; KW - epipolar KW - equation KW - estimation; KW - geometry; KW - human KW - image KW - image; KW - images; KW - model-based KW - models; KW - MOTION KW - object KW - optical KW - perspective KW - physiological KW - polynomial KW - polynomials; KW - pose KW - real KW - single KW - synthetic KW - system; KW - systems; KW - torso KW - tracking; KW - twist; KW - uncalibrated AB - Recovering the 3D coordinates of various joints of the human body from an image is a critical first step for several model-based human tracking and optical motion capture systems. Unlike previous approaches that have used a restrictive camera model or assumed a calibrated camera, our work deals with the general case of a perspective uncalibrated camera and is thus well suited for archived video. The input to the system is an image of the human body and correspondences of several body landmarks, while the output is the set of 3D coordinates of the landmarks in a body-centric coordinate system. Using ideas from 3D model based invariants, we set up a polynomial system of equations in the unknown head pitch, yaw and roll angles. If we are able to make the often-valid assumption that the torso twist is small, there are finite numbers of solutions to the head-orientation that can be computed readily. Once the head orientation is computed, the epipolar geometry of the camera is recovered, leading to solutions to the 3D joint positions. Results are presented on synthetic and real images. JA - Computer Vision and Pattern Recognition, 2004. CVPR 2004. Proceedings of the 2004 IEEE Computer Society Conference on VL - 2 M3 - 10.1109/CVPR.2004.1315139 ER -