Creating meshes from CT scan images

MOOSE already possesses the functionality to read a stack of CT scan images and create the corresponding mesh through its ImageReader. But the following paragraph explains why MOOSE's module is limited.

##MOOSE ImageSubdomain Using the function ImageSubdomain, MOOSE creates a mesh of the stack of CT-scan Images with 2 blocks, the pore space and the grains.

Two parameters can be chosen by the user:

• Type of elements meshed
• Level of refinement (different options available)

HOWEVER one important parameter can not be changed, level of coarsening. The mesh created can not have elements coarser than the resolution of the image.

Mesh coarsening is an important aspect in simulation with CT-scan images. We want to refine the mesh at the grain's boundary because this is where the simulation is complex. But we want to coarsen the region away from these boundaries in order to reduce simulation time.

This is why I would recommend to use REDBACK Image Reader in order to get the full panel of functionalities.

##REDBACK Image Reader ###Installation The first step is to [install VTK](Installing VTK). Then you have to run REDBACK's tests to make sure that those for ImageSubdomain are not skipped and do not fail.

###Usage

... (why does Martin have a different version?)

(How to use Martin's version? Compile the right thing, etc.)