This program will modify the voxel sizes in the specified image header
(.hdr file) and will set any illegal negative dimensions
or sizes to their absolute values.
Warning: If you have moved data from a big-endian machine to a little-endian machine (e.g., from a Sun to a PC) or vice versa,
applying this program to the header file of such data will result in a failure to byte-swap
the image data when loading it into AIR and other programs that use the header information
to detect the need to byte-swap. You may be able to work around this problem by using the
AIR program reorient to make a copy of the data (which will
be fully byte-swapped during copying) and then applying this program the resulting header file.
- where the following definitions apply:
- the name of the header file to be modified
- the x-dimensional size of a voxel
- the y-dimensional size of a voxel
- the z-dimensional size of a voxel
fixheader mri .975 .975 1.2
- This command will set any illegal negative values for dimensions or sizes in the
file mrix.hdr to their absolute values
- This command will reset the voxel x_size to .975, the y_size to .975 and the
z_size to 1.2
- Some image display packages and file format converters may not always preserve the
voxel dimensions. Correct voxel dimensions are critical for image registration. You
should use the program scanheader frequently to make sure
that the image dimensions have not become corrupted by other routines that you use to
manipulate files and use this program to repair them if they have.
- If voxel sizes have to be rounded-off, the smallest voxel size should be rounded
downwards and all other voxel sizes should be rounded upwards to assure that
interpolation to cubic voxels will generate the
correct interpolated dimensions.
- See the warning above regarding the use of this program on data that has been moved
from big-endian to little-endian machines or vice versa.
See also: Generic error messages
- x_size must be a positive number
- y_size must be a positive number
- z_size must be a positive number
Modified: July 22, 2002
© 2001-2002 Roger P. Woods, M.D.(email@example.com)