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Got it! Implemented it! Reduced the size to 1.2Gb. I guess I'll have to
live with that. Thanks!

Regards,
Glad

On 10/18/2016 12:09 PM, John Ashburner wrote:
> The bounding box encodes the lower and upper x y and z coordinates in
> MNI space (in mm).
> 
> Best regards,
> -John
> 
> 
> On 18 October 2016 at 10:47, Paul Glad Mihai <[log in to unmask]
> <mailto:[log in to unmask]>> wrote:
> 
>     Hi John,
> 
>     Thanks for the quick reply.
> 
>     Because the template encompasses the whole head, while the functional
>     runs only have a small slab of recorded voxels, new voxels are added, so
>     the file sizes increases drastically.
> 
>     How can I find out the size of my bounding box? I think I would like to
>     reduce it but don't know what the 2x3 matrix represents. Can I click on
>     different parts of the image and select the boundary points that contain
>     all of the image?
> 
>     Regards,
>     Glad
> 
>     On 10/18/2016 11:30 AM, John Ashburner wrote:
>     > It depends on the image dimensions and datatype.  16 bit images require
>     > two bytes per voxel.  Floating point images and 32 bit images require
>     > four bytes per voxel (you can see the data types via the Display
>     > button).  Multiply the number of bytes per voxel by the number of voxels
>     > (by multiplying the image dimensions together).  The .nii files also
>     > have a tiny header of 352 bytes to account for.
>     >
>     > If you want smaller spatially normalised images, you could change the
>     > bounding box (and hence the image dimensions) for them.  You could also
>     > increase the size of the voxels so that fewer of them cover the same
>     > field of view.
>     >
>     > Best regards,
>     > -John
>     >
>     >
>     >
>     >
>     > On 18 October 2016 at 10:10, Paul Glad Mihai <[log in to unmask] <mailto:[log in to unmask]>
>     > <mailto:[log in to unmask] <mailto:[log in to unmask]>>> wrote:
>     >
>     >     Dear subscribers,
>     >
>     >     I was wondering why is there such a huge jump in the file size after I
>     >     normalize my functional data (1.1 mm isovoxel) using a created template
>     >     and corresponding flow field. The jump is from 246 MB to 3.2 GB -- a
>     >     13-fold increase! Is this normal?
>     >
>     >     Regards,
>     >     Glad
>     >     --
>     >     Paul Glad Mihai, PhD
>     >
>     >     Independent Research Group "Neural Mechanisms of Human Communication"
>     >     Max Planck Institute for Human Cognitive and Brain Sciences
>     >     Stephanstraße 1A, 04103 Leipzig, Germany
>     >
>     >     Phone:   +49 (0) 341-9940-2478
>     <tel:%2B49%20%280%29%20341-9940-2478>
>     <tel:%2B49%20%280%29%20341-9940-2478>
>     >     E-mail:  [log in to unmask] <mailto:[log in to unmask]>
>     <mailto:[log in to unmask] <mailto:[log in to unmask]>>
>     >
>     >
> 
>     --
>     Paul Glad Mihai, PhD
> 
>     Independent Research Group "Neural Mechanisms of Human Communication"
>     Max Planck Institute for Human Cognitive and Brain Sciences
>     Stephanstraße 1A, 04103 Leipzig, Germany
> 
>     Phone:   +49 (0) 341-9940-2478 <tel:%2B49%20%280%29%20341-9940-2478>
>     E-mail:  [log in to unmask] <mailto:[log in to unmask]>
> 
> 

-- 
Paul Glad Mihai, PhD

Independent Research Group "Neural Mechanisms of Human Communication"
Max Planck Institute for Human Cognitive and Brain Sciences
Stephanstraße 1A, 04103 Leipzig, Germany

Phone:   +49 (0) 341-9940-2478
E-mail:  [log in to unmask]