We distinguish two general situations: that where individual fibers or fiber bundles can and need to be resolved separately and the inverse. They differ in the types of algorithms that can be employed and the information that can be extracted. If, for instance, one is interested in getting a fiber length distribution, separable fibers are greatly advantageous, but for fiber orientation distribution it is much less required.
The latest version of CTAn offers the possibility to generate colour coded images according a number of morphometric characteristics (size, orientation, major diameter). The orientation in 3D space is determined by the main eigenvalues of the second moments of inertia of the objects. The object colour coding can then be done either by angle or by local thickness.
For more information on the topic of fiber analysis and orientation we kindly refer to ‘MN084 - fiber characterization - orientation in 3D’.