population_template voxel size handling
The voxel size of the template produced by population_template was previously automatically determined from the input images. However, this resulted in suboptimal outcomes under some circumstances, particularly when large rotations exist between the different input images. Furthermore, it became apparent that different voxel sizes were required in different scenarios. To deal with these issues, a new option has been added to population_template to allow the output voxel size to be set manually. We encourage users to set the desired voxel size of their template manually, as is now recommended in the fixel-based analysis documentation.