brede_vol_vol2sur

 brede_vol_vol2sur    - Convert volume to surface

       S = brede_vol_vol2sur(V, 'PropertyName', 'PropertyValue') 

       Input:    V    'Vol' structure

       Property: Type [ {Isosurface} | Octahedron | Sphere ] 

       Output:   S    'Sur' structure
 
       Convert a volume represented in a 'vol' structure to a surface
       represented in a 'sur' structure. 

       With 'type' as 'isosurface' the isosurface matlab function with
       the marching cube algorithm is used to construct a surface. 

       When 'type' is either 'octahedron' or 'sphere' a crude
       representation of the volume will be made, e.g., the sphere
       will have a center a the center of gravity of the volume and
       the range determined from brede_vol_range function.

       Ref: EEG Toolbox, mesh_shrinkwrap.m, http://eeg.sourceforge.net/

       Example:
         % An example white matter segmentation 
         f = 'single_subj_T1_seg2';
         V = brede_read_analyze(f);
         V = brede_vol_threshold(V, 0.5);
         Vright = brede_vol_zero(V, 'type', 'left0');

         % Simple crude surface
         S = brede_vol_vol2sur(Vright, 'type', 'Sphere')
         figure, brede_ta3_frame, brede_ta3_sur(S);

         % Convex hull
         S = brede_vol_vol2sur(Vright, 'type', 'isosurface', 'isoabsolute', 0.5)
         S = brede_sur_convhull(S);
         figure, brede_ta3_frame, brede_ta3_sur(S);

       See also BREDE, BREDE_VOL, BREDE_SUR, BREDE_VOL_VOL2SUR,
                BREDE_SUR_SPHERE, BREDE_TA3_SUR, BREDE_TA3_VOLSURF,
                ISOSURFACE.

 $Id: brede_vol_vol2sur.m,v 1.4 2005/10/13 17:46:22 fnielsen Exp $