In pure Python, the results of realign and reslice are significantly different from those produced by SPM 12.

[balabalabs]

In pure Python, the results obtained by realign.py and reslice.py differ significantly from those produced by SPM 12. I would like to know what the main differences are between the algorithms used in realign.py and reslice.py and those used in SPM 12.Can you help me with this problem? Thanks。