Got the connected_components to finally work using a vecS for the vertex list in the adjacency list. In this case, the component map is simply a vector of ints (which is the type of UndirectedGraph::vextex_descriptor (=graph_traits<FeatureGraph>::vertex_descriptor) and probably UndirectedGraph::vertices_size_type). To use listS, I was told on the Boost mailing list: >> If you truly need listS, you will need to create a vertex index >> map, fill it in before you create the property map, and pass it to the >> vector_property_map constructor (and as a type argument to that class). It may be feasible with a component map like shared_array_property_map< graph_traits<FeatureGraph>::vertex_descriptor, property_map<FeatureGraph, vertex_index_t>::const_type > components(num_vertices(g), get(vertex_index, g));

#include "cvutils.hpp"

#include "opencv/cv.h"
#include "opencv/highgui.h"

#include <iostream>

using namespace std;


int main(int argc, char *argv[]) {
  //cout << "Hello World" << endl;

  CvCapture *inputVideo = cvCaptureFromFile(argv[1]);

  IplImage* frame = cvQueryFrame(inputVideo);
  IplImage* bwFrame = allocateImage(frame->width, frame->height, IPL_DEPTH_8U, 1);

  int frameNum = 0;
  while (frame) {
    if (frameNum%10 == 0)
      cout << frameNum << endl;
    cvConvertImage(frame, bwFrame);
    
    for (int i=0; i<frame->height; ++i)
      for (int j=0; j<frame->width; ++j)
	int gray = cvGetReal2D(bwFrame, i, j);

    frame = cvQueryFrame(inputVideo);
    frameNum++;
  }

  return 1;
}