contrib/gel/gevd/gevd_region_edge.h File Reference

An edge with extract information to support constructing regions from an edgel segmentation. More...

#include <vtol/vtol_edge_2d_sptr.h>
#include <vbl/vbl_ref_count.h>
#include <vcl_stlfwd.h>

Classes
class	gevd_region_edge

Detailed Description

An edge with extract information to support constructing regions from an edgel segmentation.

This class supports tracing of region boundaries in conjunction with the class EdgelIntensity. The gevd_region_edge maintains a list of region labels which the edge is adjacent to. Ideally, the edge is adjacent to only two regions, left and right, as shown below.

                      left_region_
             V1------------------------V2
                      right_region_

In practice, this restriction is too limiting. It is possible for an edge to be adjacent to more than two regions. For example:

      c c c
     o----\ c
    E  b b  \ c
     o------+ \ c
      c c c | a \ c
          c +----+ c
            c c c c

Note that edge E is adjacent to both regions a and b even though there is no intervening vertex at the transition between a and b. In order to preserve a separation between regions b and c, it is necessary to allow more than two labels (a,b) for a given edge.

Author:

J. L. Mundy - January 24, 1999

    Modifications
     Feb 10, 1999  - JLM Extended the concept of a gevd_region_edge
                         to represent a vertex, where the edge is NULL.
                         This extension permits the propagation of region labels
                         across junctions.
     March 7, 1999 - JLM Allowed more than two regions per edge.
     Sept 10, 2004 - PVr Added copy ctor with explicit vbl_ref_count init

Definition in file gevd_region_edge.h.

Classes

Detailed Description