Dear Eric,
if you do not require a voxel-by-voxel correspondence between reference and coregistered source image, you may use "coregister" without reslice. This will update the voxel-to-world coordinate mapping of your source image without resampling the data matrix of the image. For most use cases within SPM, this will be sufficient.
If you really need to resample the source image somehow (e.g. for other software that requires images to be in voxelwise correspondence), SPM requires a target data matrix definition. For Reslice, ImageCalculator SPM simply uses the first (reference) image as target. If you need a higher resolution, you should first check whether a higher resolution reference image would be available.
Volkmar
|