[Insight-users] Definition of Image Origin

[Didier Rajon]

Hello,
I'm a little confused about the definition of the Image Origin.
According to the definition that I found in the ITK Software Guide - 
Second Edition (August 30, 2005); p 40: "the image origin is associated 
with the coordinates of the first pixel of the image".
On page 224 of the same documentation I found Eq. (6.20) that suggests 
that the origin is associated with the coordinates of the pixel indexed 
by (0, 0).
On page 234 of the same documentation I found an expression to calculate 
the image center and that suggests that the origin is associated with 
the coordinates of the first pixel of the image, whatever the index of 
the image.
So, if my image has a LargestPossibleRegion().GetIndex() equal to 
(10,10), is my image origin the coordinates of the pixel indexed by 
(10,10) (my first pixel in this case) or the coordinates of the pixel 
indexed by (0,0) (which is out of my dataset in this case)?
Thanks,

Didier.



-- 
Didier Rajon
Department of Neurological Surgery
University of Florida
MBI, L2100 PO Box 100265
Gainesville, FL, 32610-0265
Tel: (352) 294 0144
Fax: (352) 392 8413