Hi
check the file type (using avwhd) - I suspect your input file is
stored as 16 bit integer?
The output file type of slicetimer will be saved as 32bit floats
(necessary due to the fact that slice timing correction involves
interpolation) - when using any uncompressed file type this means
that the file size increases.
I suspect that in SPM the slice-timing corrected data will internally
be represented as doubles (within matlab) so I guess it will have
increased in size as well. What happened when you wrote this out to
disc I don't know, maybe you've cast these non-integers to integer
again.
If you're concerned about file size use one of the compressed formats.
cheers
christian
On 20 Mar 2006, at 22:43, Todd Penney wrote:
> Hi FSLers,
>
> Does anyone know why the size of the file doubles when only the
> preprocessing step of doing a slice timing adjustment on your fMRI
> data files is done in FSL? SPM5 does not double the size of the
> file when you only want slice timing to be adjusted, so why does FSL?
>
> Thanks
>
> Todd Penney
--
Christian F. Beckmann
Oxford University Centre for Functional
Magnetic Resonance Imaging of the Brain,
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
Email: [log in to unmask] - http://www.fmrib.ox.ac.uk/~beckmann/
Phone: +44(0)1865 222551 Fax: +44(0)1865 222717
|