check_scale
check and correct the Z-scale of a MNI linear transform
check_scale <input.xfm> <result.xfm> [<file.mnc>]
DESCRIPTION
check_scale reads a linear MNI .xfm transform file, extracts its parameters (translation, rotation, scale, shear), and checks whether the Z-scale is disproportionately large relative to the X and Y scales. If the Z-scale exceeds 1.15 times the average of the X and Y scales, it is clamped to that average value.
The corrected transformation matrix is then rebuilt from the adjusted parameters and written to a new .xfm file.
An optional MINC volume can be provided as a third argument; when given, the center of gravity of the volume is used as the center of rotation and scaling for the decomposition.
This is a quality-control tool for linear registration results where the Z-scale factor may become unreliable, for example due to limited sampling along the Z dimension.
OPTIONS
This tool uses positional arguments only. There are no named options.
AUTHOR
Louis Collins - McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University.
COPYRIGHTS
Copyright © 1993 by Louis Collins