[MINC-development] nu_correct on linux

[Richard Boyes]

hi all,

we have a SUN file server here that stores all our
analyze images as hilo endian. i'm trying to run nu_correct
on a linux machine (lohi endian) using these files,
byte swapping them beforehand using dd conv=swab
and then converting them to minc using the rawtominc
command.
the converted minc files appear fine in mincview and i can
run all the minc* utilities on them without a problem.

when i try nu_correct, it jumps out straight away,
saying the field change is 1E-27. this has happened
for multiple images with bad bias fields, which doesn't
seem correct.

dd conv=swab if=/tmp/0_0_1071834373.img |
rawtominc -oshort -clobber -mri -coronal -short -xstep 0.9766 -ystep
1.8000 -zstep 0.9766 -scan_range ./00000.mnc 120 256 256
#Mask file - no need to swap bytes
rawtominc -byte -obyte -clobber -input ./bmask00000.img -coronal -xstep
0.9766 -ystep 1.8000 -zstep 0.9766 -orange 0 255 ./bmask00000.mnc 120 256
256
nu_correct -clobber -mask ./bmask00000.mnc ./00000.mnc
/correct00000.mnc  -stop 0.0005 -fwhm 0.075 -distance 100 -iterations
250 -mapping_dir . -shrink 3
Transforming slices:.........................................Done
Processing:.........................................Done
Not implemented yet in cache_volume_range_has_changed()
Not implemented yet in cache_volume_range_has_changed()
Number of iterations: 1
CV of field change: 9.80328e-27
Transforming slices:.........................................Done
256+0 records in
256+0 records out
Not implemented yet in cache_volume_range_has_changed()
Not implemented yet in cache_volume_range_has_changed()
Transforming
slices:.....................................................................
...................................................Done

At which point it finishes, without really finding a bias field. Any
ideas? Is there a test suite or something i could try my build of
nu_correct/MINC/netCDF on?