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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]> 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]>> 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> > > 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] >