Name: WlzDefGrdTensorFeatures - computes features of deformation gradient tensor fields.

Synopsis

WlzDefGrdTensorFeatures [-d <x>,<y>,<z>] [-f <feature list>]
                        [-g <x>,<y>,<z>] [-h] [-o<out file>]
                        [-p] [-s <dst>] [-u] [-x] [<input file>]

Options

-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.

Description

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 character	property name	feature
d	eigen vectors	eigen (principle direction) vectors
j	jacobian	determinant of Jacobian tensor
s	eigen values	eigen (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.

Examples

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.

File: WlzDefGrdTensorFeatures.c

See Also: WlzIntro(1) WlzDGTensorFeatures(3) WlzCMeshStrainTensor(3)