BUG: fixed bug related to non INT subsampled labels
BUG: fixed bug related to non INT subsampled labels

Former-commit-id: e23d368a69956ca87b5ce4ca44ae53ce2eedb086
Former-commit-id: 652323e5755efbcec0c1e7cfccf18af7192a79af
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox