[Insight-users] Question about image origin

[Somer, Edward]

Hi,

I have a 1000x1000 image with a spacing of 0.5\0.5 and I wish to 
resample it to 125x125 with spacing 4.0\4.0 but I wish the centre of 
each field of view to be coincident. On writing the data my "Image 
Position (Patient)" goes from 249.75\249.75 to 248.0\248.0, being the 
centre of the top left pixel.

If I set the input and output origin to 0.0\0.0 are the FoV aligned or 
should I set the input origin to 0.25/0.25 and the output origin to 
2.0/2.0? Looking at the manual the origin at 0.0\0.0 looks like it's at 
the centre of the 0th pixel but if I resize the pixels the centre of the 
pixel (hence the origin) will move.

I'm trying to evaluate display image alignment so it needs to be as 
accurate as possible.

Thanks,

Ed

-- 
Edward Somer, PhD.
Senior PET Methodologist
The PET Imaging Centre 
St Thomas' Hospital
London, UK
SE1 7EH

work tel: +44 (0) 20 7188 1497
work fax: +44 (0) 20 7620 0790
e-mail: Edward.Somer at kcl.ac.uk / Edward.Somer at googlemail.com