parallel 3D binary skeleton
Usage: skelpar3d in.pgm algorithm nsteps [inhibit] out.pgm
Description:
Parallel 3D binary thinning or skeleton.
The parameter nsteps gives, if positive, the number of parallel thinning steps to be processed. If the value given for nsteps equals -1, the thinning is continued until stability.
For some algorithms (16 to ??), the parameter nsteps has a different meaning which is related to the notion of persistence (see [REF A AJOUTER]). It plays the role of a filtering parameter.
The parameter algorithm is a numerical code indicating which method will be used for the thinning. The possible choices are:
- 0: ultimate, without constraint (MK3a)
- 1: curvilinear, symmetric, based on 1D isthmus (CK3a)
- 2: medial axis preservation (AK3) - parameter inhibit represents the minimal radius of medial axis balls which are considered
- 3: ultimate (MK3) - if nsteps = -2, returns the topological distance
- 4: curvilinear based on ends (EK3)
- 5: curvilinear based on ends, with end reconstruction (CK3b)
- 6: topological axis (not homotopic)
- 7: curvilinear, based on residual points and 2D isthmus (CK3)
- 8: ultimate, asymmetric (AMK3)
- 9: curvilinear, asymmetric, based on thin 1D isthmus (ACK3a)
- 10: curvilinear, asymmetric, based on 3D and 2D residuals (ACK3)
- 11: surface, symmetric, based on residual points (RK3)
- 12: surface, symmetric, based on 2D isthmuses (SK3)
- 13: ultimate, directional, (DK3)
- 14: surface, directional, based on residual points (DRK3)
- 15: surface, directional, based on 2D isthmuses (DSK3)
- 16: curvilinear, asymmetric, based on thin 1D isthmus with persistence (ACK3p)
- 17: surface, asymmetric, based on thin 2D isthmus with persistence (ASK3p)
- 18: curvilinear, symmetric, based on 1D isthmus with persistence (CK3p)
- 19: surface, symmetric, based on 2D isthmus with persistence (SK3p)
- 20: surface and curvilinear, symmetric, based on 1D and 2D isthmus with persistence (SCK3p)
In modes other than 2, if the parameter inhibit is given and is a binary image name, then the points of this image will be left unchanged.
The following codes give access to auxiliary functions, for isthmus detection. Parameter nsteps will not be used in this case (any value can be given).
Warning: The object must not have any point on the frame of the image.
Types supported: byte 3d
Category: topobin
- Author:
- Michel Couprie
