Hi Ged,
It is perfect. Thanks a lot.
Amir
PS: any idea about my deformation field question I posted before?
Ged Ridgway wrote:
> Hi Amir,
>
>> I was wondering if there is a function in SPM for zero padding a
>> series of images. For instance, changing the size from 128x128 to
>> 256x256 only by adding zeros around while keeping the image centered.
>> Thanks.
>
> I think you should be able to do something like this with:
>
> resize_img('blah.img', nan(1,3), 2*world_bb('blah.img'));
>
> which should increase the bounding box by 2 while keeping the image
> fixed in world-space. To get exactly 128->256 or exactly symmetric
> padding might be tricky, but should be possible if you experiment with
> the BB values until you get the result you want.
>
> SPM's bounding box is specified as a 2-by-3 matrix, in world/mm
> coordinates, [Xmin Ymin Zmin; Xmax Ymax Zmax]. So e.g. instead of
> 2*world_bb(), if you have 2mm square pixels you might try:
> [-128 -128 0; 128 128 0]+world_bb()
> to pad by 64 pixels symmetrically either side of the image in the x
> and y directions.
>
> Hope that helps,
> Ged.
>
> http://www.cs.ucl.ac.uk/staff/gridgway/vbm/resize_img.m
> http://www.cs.ucl.ac.uk/staff/gridgway/vbm/world_bb.m
>
> P.S. I don't think I ever tested these functions on 2D images, please
> let me know if they don't work!
>
--
________________________________
Amir M. Tahmasebi
Ph.D. Student,
Medical Image Analysis Lab.
School of Computing,
Queen's University,
Kingston, Ontario
CANADA
K7L 3N6
________________________________
Tel: (613) 533-2797
Web: www.cs.queensu.ca/~tahmaseb
|