Hello everyone,
I have the corrected time series for every voxel from niftiDATA_Subject001_Condition000.nii. I don't want to consider the whole matrix of these values for computational reasons. I want to truncate the matrix to a smaller 4D matrix so that I can easily use it for further computation. Now my problem is

How do I know where I am truncating it? For example, the original denoised matrix is 79x95x68x140
 What does 79, 95 and 68 mean? Are they in mm or in voxel indices. How can I get the original location of the voxels in the brain?

Any help will be greatly appreciated
-Shounak