the norm is the output of the subcortical intensity (nonuniformity) correction detailed in the 2002 paper On Thu, 11 Jan 2018, Aaron Tanenbaum wrote:
I would like to get a clarification on what some the the files generated by FreeSurfer recon-all
based on the URL https://surfer.nmr.mgh.harvard.edu/fswiki/ReconAllOutputFiles
The web pages says the nu.mgz "This is a intensity normalized volume generated after correcting for non-uniformity in the orig.mgz". I just need a clarification the intensity normalized is just a global scaling and the correction for non-uniformity is the bias field correction. I was wondering if the orig.mgz is bias field corrected to generate the orig_nu.mgz and the intensity normalized to generate the nu.mgz.
Finally what is the norm.mgz image. I cannot final details on how it is created.