3dBllurToFWHM within small masks (ROIs)

Dear AFNI team,

I am working with small ROIs and I am interested to smooth the data within the limit of a specific mask. The problem is that the majority of these masks have less than 333 voxels, which means that the program will show the error “Mask is too small to process”.
I found the source code of the function in GitHub and the line in which I could modify the value (limit amount of voxels permitted in the mask) here .

But, then I can not compile the file to make it binary and replace it the AFNI binaries on my computer.

Is there any way in which I could change that value?

Thanks in advance,
Karel

There is a reason that blurring to a given FWHM is not allowed inside small masks. Estimating the FWHM accurately requires a decent number of voxels, and blurring to FWHM requires doing that estimate over and over as the blurring magnitude is increased.

That make sense. Thank you so much Robert.

Best regards,
Karel