-------- Original Message -------- Subject: Re: TPS 3D negative bending energy Date: Mon, 7 Feb 2011 05:56:43 -0500 From: Stefan Schlager <stefan.schla...@uniklinik-freiburg.de> To: morphmet@morphometrics.org but hen again, in the article /Gunz, P.; Mitteroecker, P. & Bookstein, F. 2005. Semilandmarks in three dimensions. In: Slice, D. (Ed.), Modern Morphometrics in Physical Anthropology/, where Booksteinis co-author, U=|r| is used, and as in most papers. But as said before, the only difference seems to be the "negative" bending energy. In the article stated above the bending energy is calculated: t(-H)(L^-1)H - instead of t(H)(L^-1)H as usually - in order to make up for the negative semidefinite bending energy matrix. BTW:/ "FYI Bookstein (1991) - the "orange book" gives -|r| "/ - if the orange book is: /Bookstein F, 1991. Morphometric tools for landmark data/ - I couldn't find it there greetings stefan Stefan Schlager M.A. Anthropologie Medizinische Fakultät der der Albert Ludwigs- Universität Freiburg Hebelstr. 29 79104 Freiburg Anthropology Faculty of Medicine, Albert-Ludwigs-University Freiburg Hebelstr. 29 D- 79104 Freiburg phone +49 (0)761 203-5522 fax +49 (0)761 203-6898 On 06/02/11 17:10, morphmet wrote:
-------- Original Message -------- Subject: Re: TPS 3D negative bending energy Date: Fri, 4 Feb 2011 21:13:03 -0500 From: F. James Rohlf <ro...@life.bio.sunysb.edu> Reply-To: ro...@life.bio.sunysb.edu To: Morphmet <morphmet@morphometrics.org> FYI Bookstein (1991) - the "orange book" gives -|r| ------- Sent remotely by F. James Rohlf, John S. Toll Professor -----Original Message----- From: morphmet <morphmet_modera...@morphometrics.org> Date: Fri, 04 Feb 2011 16:42:51 To: morphmet<morphmet@morphometrics.org> Reply-To: morphmet@morphometrics.org Subject: Re: TPS 3D negative bending energy -------- Original Message -------- Subject: Re: TPS 3D negative bending energy Date: Fri, 4 Feb 2011 15:25:49 -0500 From: Stefan Schlager <stefan.schla...@uniklinik-freiburg.de> To: morphmet@morphometrics.org I found the kernel U=|r| in most computer journals - e.g. in /Claes et al., Statistically deformable face models for craniofacial reconstruction. Journal of Computing and Information Technology - CIT, 14(1):21–30, 2006. / But as it was working excellent (the non-affine part of the spline is t(w)*(r) instead of t(-w)*(-r) - with (w) being my "old" coefficients and (r) the vector of ri=||(x,y,z)-(xi,yi,zi)||) , I never questioned the choice of the kernel (who am to do such a thing as I am quite a novice to this field). Up to this week I never noticed a difference, as the result of the spline is exactly the same. I used TPS only for actual deformation of 3d-meshes. thanks for answering greetings stefan
