ITK/Release 4 Planning

Wish List

Oriented Images

• Support ND image in N+1 dimension
  • 2D image can have an origin specified in 3D, thus a series of 2D images is not always Z-aligned
• All images are oriented - remove concept of an un-oriented image
• Check use of orientation throughout ITK
• Support re-orientation of ND oriented images
  • Using anything other than 3D images won't compile with itkOrientedImageFilter

• • Spatial Objects
  • Meshes
• Suggestions
  • ITK_Release_4.0_Orientation_by_Kent
  • ITK_Release_4.0_Orientation_by_Torsten
  • ITK_Release_4.0_Orientation_by_Michael

Image Representation

• Allow the use of strides that are not equal to the image width
  • Would ease the collaboration of ITK with opencv
  • Would allow the use of sse operations
  • Might be redundant with correct use of image regions

Statistics

• Complete statistics refactoring (see NAMIC sandbox)

FEM Meshes

• Consolidate FEM Meshes and ITK Meshes

Image Registration

• Set up the infrastructure to ease the implementation of modern optimization schemes for image registration
  • Requires Hessian or pseudo-Hessians of the cost function
  • Requires several types of update rules (additive, compositional, inverse compositional, etc.)
  • References: "Lucas-Kanade 20 years on" by Baker et al.; "Homography-based 2D Visual Tracking and Servoing" by Benhimane and Malis, "Groupwise Geometric and Photometric Direct Image Registration" by Bartoli; etc.
• Clean up the use of parameter scaling in the optimizers
  • One possibility would be that the optimizers only perform unscaled minimization. It would then be up to a cost function wrapper to do the rescaling and potentially return the opposite of the cost function. This is similar to how vnl optimizers are used in ITK
• Optimizers should return the best visited value
  • See Bug 3205
• Modify transforms to support a consistent API across transform types
• Modify order of parameters to be consistent across transforms.

Architecture

• Implement a pure virtual base class for each API to support instantiation of templated filters at run-time with different dimensions.

Proper resampling/consistency in IndexToPhysicalPoint, ContinuousIndexToPhysicalPoint, Point*

• Refactor all the interpolators
  • See Proposals:Refactoring Index Point Coordinate System
  • See ITK Bug 6558
  • Fix bug 0005335 - transform initializer computes geometric center incorrectly

Composite Transform

• Define a composite transform which can contain any number of transforms, composed.
• Only expose the parameters of the last transform for optimization (default)
• Used in multivariate atlas formation (DTI reg with T1 reg with atlas)
• Remove all of the Centered transforms
• Modify the base class for optimizers to support key optimizer API calls such as SetMaximize and SetNumberOfIterations or SetMaximumIteration