Refactoring Level-Set framework - V4

This page outlines the proposed changes to the current Level-Set framework. A number of these changes will break backwards compatibility.

Authors

The proposed changes for the Level-Set framework are being proposed by the Megason-Lab, Systems Biology Department, Harvard Medical School.

Questions and comments regarding these changes should be sent to

• Arnaud Gelas (arnaud_gelas -at- hms.harvard.edu)
• Sean Megason (sean_megason -at- hms.harvard.edu)

Other team members include:

• Kishore Mosaliganti (kishore_mosaliganti -at- hms.harvard.edu)
• Nicolas Rannou (nicolas_rannou -at- hms.harvard.edu)

Tcons

• 29 July. Attendees: Karthik Krishnan (Kitware), Lucas Antiga (Orobix), Kishore Mosaliganti (Harvard), Arnaud Gelas (Harvard)
• 11 August. Attendees: Luis Ibanez (Kitware), Ivo Sbalzarini (ETH), Kishore Mosaliganti (Harvard), Arnaud Gelas (Harvard)
• 18 August. Attendees: Gregory Paul (ETH), Kishore Mosaliganti (Harvard), Arnaud Gelas (Harvard)
• 1 September. Attendees: Olivier Bernard (Creatis), Joel Schaerer (Creatis), Kishore Mosaliganti (Harvard), Arnaud Gelas (Harvard)

Ideas

Term class

Represent on term of the PDE. First example of implementation (not complete) located at http://github.com/lantiga/ModularLevelSets.

• One weight (scalar)
• One Level Set Function
• virtual GetCFLContribution() = 0;
• virtual Value() = 0;
• virtual bool IsStreamable() = 0

Term Container class

• std::map< id, Term > to be able to dynamically add/remove terms at any time during the evolution
• Virtual Value() = 0;
• bool IsStreamable(); // iterate on all term elements as long as there is streamable element.

Term Sum Container

• Inherit form Term Container
• Implement Value as sum of all elements from the container

Term Product Container

(Don't know yet the application, but it is theoretically possible to implement it as noticed by Joel Schaerer).

• Inherit form Term Container
• Implement Value as product of all elements from the container

LevelSetFunctionBase

The level set function representation could be discrete, parametric (continuous)

• Virtual Value() = 0;
• Virtual Grad() = 0;
• Virtual Hessian() = 0;
• Virtual bool IsStreamable() = 0;

LocalStructure

This structure will be used to pass information add each step for a single location x

• Location x
• std::pair< bool, xxx > value (bool encode if its characteristics has already been computed)
• std::pair< bool, xxx > grad
• Etc…

Reinitialization Filter

• Input: one level set function
• Output: one level set function
• Virtual void GenerateData() = 0; // processing

Stopping criterion

• Functor?
• Inputs: Phi^{n}, Phi^{n-1}, Number of iterations
• Check for additional values that can be passed (to avoid as much as possible explosion of computational cost!!!)

SamplingDomain

• Represents the domain where the level set PDE is sampled, and thus used to solve the PDE equation.
• Iterator Begin();
• Iterator End();
• Iterator Iterator::operator ++ ( -- ? )