Hi,
I'm trying to better understand the implementation of the Unified
Segementation rotine in SPM5 and I've been unable to figure out how the
number of DCTs is computed.
I understand that the default is 7x8x7, which fits the 91x109x91
dimensions of the prior volumes. Nonetheless, when I run spm_preproc.m, I
get a Twarp of 9x7x9(x3), which fits (given the cutoff of 25mm) the
256x124x256 (raw) volume of input. Is this supposed to be like this? Is
the reference 7x8x7 outdated when talking about SPM5?
Finally, when I run spm_prep2sn (and then spm_preproc_write), the
resulting sn.mat file will have a transformation Tr 11x9x11(x3) because of
the reparametrisation. What does this final value mean?
Thank you for your help!
Regards,
Joao Pereira
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