@InCollection{sommer04kluwer, author = {G. Sommer and B. Rosenhahn and C. Perwass}, title = {The twist representation of free-form objects}, booktitle = {Geometric Properties from Incomplete Data}, pages = {3-22}, publisher = {Springer-Verlag}, series = {Computational Imaging and Vision}, volume = {31}, year = 2006 editor = {R. Klette and R. Kozera and L. Noakes and J. Weickert} }