checkimg-methods: Force object to filename
Description
Ensures the output to be a character filename (or vector) from an input
image or nifti.
Usage
checkimg(file, ...)
"checkimg"(file, ...)
"checkimg"(file, ...)
"checkimg"(file, ...)
Arguments
file
character or nifti object
Value
character filename of image or temporary nii,
with .nii extension