Graham, Thanks for pointing these out. We've corrected the page (but it still needs quite a bit more work to make it a true 'file spec').
Nick On Wed, 2006-07-12 at 20:05 -0700, Graham Wideman wrote: > Folks: (Probably Nick S?) > > Comments on the MghFormat wiki doc page: > > https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial_2fMghFormat > > 1. Width/Height/Depth confusion. > -------------------------------- > Doc says... > > width integer first dimension of the image buffer (slowest) > height integer second dimension of the image buffer (2nd slowest) > depth integer fastest dimension when reading the buffer > > ... yet mriio mghWrite(...) source code says... > > for (frame = start_frame ; frame <= end_frame ; frame++) { > for (z = 0 ; z < depth ; z++) { > for (y = 0 ; y < height ; y++) { [...] > for (x = 0 ; x < width ; x++) > > Ie: width should be fastest, and depth slowest, contrary to doc. > > Further, the statement "the bytes being read in the order Z --> Y --> X" is > either incorrect or doesn't have any meaning. > > 2. "image data starts at specified offset, which is currently ???". > -------------------------------------------------------------------- > > Looks like from the source code that the header is padded to 24 + 256, > which means image starting at byte 280 (counting from zero). > > 3. Other Data > -------------- > In the doc, the Other Data section ends at "FoV". Actually the source code > shows that mghWrite writes out other stuff beyond that, which in the > examples I looked at appears to be a history of commands performed on the > image so far, for example (abbreviated [...] and wrapped by me): > > =========================== > [...] > mri_convert /data/[...]/39174a/mri/rawavg.mgz [output filepath] --conform > ProgramVersion: $Name: stable3 > $ TimeStamp: 06/06/07-04:10:32-GMT CVS: > $Id: mri_convert.c,v 1.121 2006/02/22 05:39:36 greve Exp > $ User: graham Machine: gwlin[...] > CompilerName: GCC Compile[...] > > mri_ca_normalize -mask brainmask.mgz nu.mgz [...] norm.mgz > ProgramVersion: $Name: stable3 > $ TimeStamp: 06/06/11-05:41:45-GMT CVS: > $Id: mri_ca_normalize.c,v 1.31 2005/08/15 14:14:22 fischl Exp > $ User: graham Machine: gwlin[...] > GCC CompilerVersion: > [...] > =========================== > > (Plus the source code suggests that if a Talairach transform has been > applied it appears here in some form). > > ----------------------------- > > Graham > > > _______________________________________________ > Freesurfer mailing list > [email protected] > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > _______________________________________________ Freesurfer mailing list [email protected] https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
