> > Because the images are scaled according to the maximum value
> > in the volume,
>
> Hang on, is that actually desired? Are you saying that if one image
> has a bright flow-artefact then its GM/WM intensities will be scaled
> down? Doesn't one generally want the bias correction to give similar
> GM/WM intensities across the set of images?
I'm referring to the scaling used for display, not the way the data are
stored. This autoscaling can be disabled in CheckReg by clicking the right
mouse button on one of the images. This brings up a pulldown menu, where you
can go through: image->window->(local/global)->manual and enter a range of
intensity values for displaying.
>
> I know this is what I want here, but I guessing that SPM doesn't mind
> what the GM/WM intensities are among images, as long as they are
> uniform within images, right?
The important thing is that they are uniform within the image, but the
regularisation tends to keep the scaling not too far from a value of 1.
Best regards,
-John
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