Hi,
avscale gives you a whole set of different pieces of information about
the spatial affine transform, including the average scaling (size)
change. It does not tell you anything about intensities. On average,
in general, intensities don't change upon resampling, though of course
any given voxel will change!
Cheers.
On 19 Jan 2008, at 15:12, Li Jiang wrote:
> Dear Steve Smith,
>
> I use fsl to process the functional MR data. It is a great software.
> To process the data, I first transform the EPI (subject image) data
> to T1 volume then to MNI_space with affine transformation. And I'll
> measure the absolute value from the images have been coregistered to
> MNI-space . I learned from the lectures and noticed the avscale for
> Inter-subject Registration. I wonder what's the scale mean. If the
> signal intensity of the subject image will change after affine
> transformation or global intra-subject transformation.
>
>
>
> Best regards.
>
> Li Jiang
>
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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