Shape Context is a method to get an unique descriptor (feature vector) for every point of an object contour or surface. This descriptor is used in combination with a b-spline free form deformation grid, for fully automatic creation of point mappings between surfaces of patient datasets (2D/3D).
The 2D Example will create a corresponding point model (PCM) for a set of 10 2D hand contours.
The 3D Example will create a PCM for a set of 10 3D jaw triangulated surfaces.
There are also examples using the PCM's to train and use 2D/3D Active Shape Models (ASM) and Active Appearance Models (AAM). (folder "ActiveModels_version7")
The 2D example takes a couple of minutes. The 3D-example about 7 hours, and requires 64bit Matlab.
The non-rigid mapping between datasets is kept Diffeomorphic to prevent mesh folding. But the optimizer doesn't succeeded in all cases of the 3D-example (maybe in next update)
- The examples, will compile some c-coded functions into MEX files. In case of failure slower Matlab coded functions will be used.
- Most functions in this zip-archive are also available as standalone files on the File-Exchange, and can be newer/updated.