[Elastix] Coordinates of control points in B-spline transform
Ramón Casero Cañas
rcasero at gmail.com
Wed Apr 15 19:56:53 CEST 2015
I have a couple of questions about B-splines in elastix:
1) What are the coordinates of the control points in a B-spline transform?
After registering an image to itself, the t.TransformParameters are all
zero, as expected for no deformation.
But how's the grid determined, e.g. for a cubic spline?
Let's say e.g. that we have a 1D grid with 5 control points, plus 1 extra
point before the grid, plus 2 extra points after the grid, in each
Are the coordinates of the 5 control points determined by placing one at
the centre of the first pixel, and another at the centre of the last pixel,
and then the other 3 equidistant between those?
2) Are then the extra ones outside the grid, and equidistant too?
3) Is the convention for the TransformParameters [x1 x2 x3...xN y1 y2 ...
Dr. Ramón Casero Cañas
Institute of Biomedical Engineering
Department of Engineering Science, University of Oxford
Old Road Campus Research Building, Headington
tlf +44 (0) 1865 617716
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Elastix