skel3d_tp.m

java与matlab编程的例题。想要做类似工程项目的人员可以参考哦。

% Skeleton in 3d - 
% Ref. N.Gagvani & D.Silver Tech.Rep.CAIP-TR-216
% Parameter Controlled skeletonization of 3D Objects
%
% http://www.caip.rutgers.edu/~gagvani/skel/
close all , clear all , % initialization 
D = ones(70,70,50); % object background
D(25:50,25:50,25:35) = 0; % Tetrahedre definition (simple object)
%D(35:40,25:40,30:60)=0; % 

Dst = bwdist(D); % Distance Transform (Euclidean) ref. p.6
DstPos = Dst>0;

H = fspecial3('average',[3 3 3]); % Author: Damien Garcia 
%FSPECIAL3 (from matlab central) creates a 3-dimensional filter H of the 
%specified type and size  

H(2,2,2)=0; % mask ; try to comment-out this statement !!! 

DFlt = imfilter(Dst,H); % filtered distance, ref. p.8 Note: 3d mean flt not available in matlab

tp=0.45 % Thinness parameter control tp ref. p.8 
% An high (a low) tp value results in a thinner (thick) skeletron
DSk = DFlt<(Dst-tp); % Skeleton , ref. p.9 

% visualize results . see also ref. pp.12-
% Alternative : 
% Flux Driven Medial Surface
% Average Outward Flux via  divergence & gradient (author K. Siddiqi)
% Ref. Sylvain Bouix  , Kaleem Siddiqi , Allen Tanneubaum
% http://sylvain.homelinux.org/~sylvain/research/projects/endoscopy/
% and related papers (e.g. Proc. of 2003 IEEE Com. Soc. Conf. on CVPR)
[GrDx, GrDy, GrDz] = gradient(Dst); % ref CVPR eq 3
Flux = divergence(GrDx, GrDy, GrDz);
Eps=-0.9 % threshold
Med_Surf = logical((Flux<Eps)) & DstPos ;
% end alternative 

% intersect Skeletons calculated according to the 2 methods
Sk_AND_MS= (Med_Surf & DSk);

figure
        subplot(3,2,1), isosurface(D,0), axis equal, view(3)
        camlight, lighting gouraud, title('3D Object')
        
        subplot(3,2,2), isosurface(DSk,0), axis equal, view(3)
        tit_SK=['3D Skeleton (Tp= ' num2str(tp) ' )']
        camlight, lighting gouraud, title(tit_SK)
        
        subplot(3,2,3), isosurface(Med_Surf,0), axis equal, view(3)
        tit_MS=['Medial Surface Outward Flux (Eps= ' num2str(Eps) ' )']
        camlight, lighting gouraud, title(tit_MS)

        subplot(3,2,4), isosurface(Sk_AND_MS,0), axis equal, view(3)
        camlight, lighting gouraud, title(' Medial Surf & Skeleton ')
return
       
% use camera toolbar to explore che data (object) and results (skeleton)
% Gianni Schena Univ. Trieste 34127 trieste Italy - [e-mail]