We are encountering an issue with getting non-integer values (input file has all integers) when using the “nearest” interpolation method in mri_vol2surf. Here is the command we ran:

mri_vol2surf --mov ${anatIn} --regheader ${REG} --hemi lh --projfrac 0.5 --trgsubject fsaverage6 --o $Limg --reshape --interp nearest

The input file ${anatIn} has values ranging from 0 to 255 and are all integers. The ${REG} folder is created during recon-All. 

We expected the output to be all integers, given the interpolation method, but we see non-integer values. 

Do you know why this is the case and how to fix it?

Thank you,

Wendy