Peter J. Olver, Guillermo Sapiro, Allen Tannenbaum.
Caption title.
Includes bibliographical references (p. 6).
Supported by the National Science Foundation. DMS-8901600 DMS-8811084 ECS-9122106 Supported by the Air Force Office of Scientific Research. AFOSR-90-0024 F49620-94-1-00S8DEF Supported by the Army Research Office. DAAL03-92-G-0115 DAAL03-91-G-0019 DAAH04-93-G-0332 Supported by the Rothschild Foundation, Yad Handiv and by Image Evolutions, Ltd.