SCI Home Software Documentation Installation User's Guide Developer's Guide

CIBC:Documentation:SCIRun:Reference:Teem:TendEvq

From SCIRun Documentation Wiki

Jump to: navigation, search

Contents

TendEvq

Information

Package: Teem
Catagory: Tend
Author(s): Darby Van Uitert
Status: Supported in latest version
Version: 3.0

Description

Summary

Quantize directions of diffusion. Because VTK doesn't do multi-dimensional colormaps, we have to quantize directions of diffusion (usually just the principal eigenvector) in order to create the usual XYZ-RGB coloring. Because eigenvector directions are poorly defined in regions of low anisotropy, the length of the vector (pre-quantization) is modulated by anisotropy, requiring the selection of some anisotropy metric.

Detailed Description

Quantize directions of diffusion. Because VTK doesn't do multi-dimensional colormaps, we have to quantize directions of diffusion (usually just the principal eigenvector) in order to create the usual XYZ-RGB coloring. Because eigenvector directions are poorly defined in regions of low anisotropy, the length of the vector (pre-quantization) is modulated by anisotropy, requiring the selection of some anisotropy metric.

Evec Index : Which eigenvector should be quantized: a value of 0 for the direction of fastest diffusion (eigenvector associated with largest eigenvalue), values 1 or 2 for other two eigenvectors (associated with middle and smallest eigenvalue) (integer).

Anisotropy Metric: Which anisotropy metric to plot. All the Westin metrics come in two versions. Currently supported: cl1, cl2: Westin's linear; cp1, cp2: Westin's planar; ca1, ca2: Westin's linear + planar; cs1, cs2: Westin's spherical (1-ca); ct1, ct2: GK's anisotropy type (cp/ca); ra: Basser/Pierpaoli relative anisotropy; fa: Basser/Pierpaoli fractional anisotropy/sqrt(2); vf: volume fraction = 1-(Basser/Pierpaoli volume ratio); tr: trace.

Don't Attenuate the color by Anisotropy : When not selected, regions with low or no anisotropy are very dark colors or black.



Frequently Asked Questions


Known Bugs


Recent Changes


Go back to Documentation:SCIRun:Reference:Teem

Personal tools