Woolz Image Processing  Version 1.7.5
WlzDefGrdTensorFeatures - computes features of deformation gradient tensor fields.
WlzDefGrdTensorFeatures [-d <x>,<y>,<z>] [-f <feature list>]
                        [-g <x>,<y>,<z>] [-h] [-o<out file>]
                        [-p] [-s <dst>] [-u] [-x] [<input file>]
-d Dither range for point positions (default no dithering, dithering implies a points output object).
-g Smooth values using a Gaussian with the given sigma values (default no smoothing).
-f Features for extraction identified by a comma separated list of single characters.
-h Help, prints usage message.
-p Output points objects rather than vector fields.
-o Output object file.
-s Minimum point seperation. If generating points objects then
" this specifies the minimum distance between points.
-u If a single feature is requested do not use a compound object.
-x Use voxel size scaling for points objects.
Computes features of the input object which must be a deformation gradient tensor field. The output is a compound object with a component object per feature, with the features identifiable through their name properties or ordering. The features for extraction may be defined by a comma separated list of single characters. Available features are:
identifying characterproperty namefeature
deigen vectorseigen (principle direction) vectors
jjacobiandeterminant of Jacobian tensor
seigen valueseigen (principle stretch) values Default feature selection is d,j,s.

By default all files are read from the standard input and are written to the standard output.

WlzDefGrdTensorFeatures -f d -p -s 40 -d 20,20,20
                             -g 2,2,2 -o features.wlz dgf.wlz
Creates a compound object with a single component points object in which the point domain locations are scattered over the given field's domain with a separation of 40 voxels but then dithered by an additional range of +/-20 voxels. The principle directions are computed and smoothed using a Gaussian with sigma values of 2,2,2 prior to sampling at the point locations. The associated point values will be vector values with a vector for each principle direction. The points object will also have it's name property set to "eigen vectors". The compound object will be written to the file features.wlz.
See Also
WlzIntro(1) WlzDGTensorFeatures(3) WlzCMeshStrainTensor(3)