sclass FloodFillBWImage_v2 extends FloodFillBWImage {
  Matrix<Region> matrix = new ArrayMatrix;
  
  class Region {
    new PointSetBitMatrix points;
    Rect boundingBox;
    
    void add(Pt p) {
      points.set(p, true);
      boundingBox = rectUnionWithPt(boundingBox, p);
    }
    
    int size() { ret points.nSetBits(); }
    
    toString { ret "Region with " + nPixels(size()) + " within " + boundingBox; }
  }
  
  void visited(Pt p) {
    matrix.put(p, new Region);
  }

  *(IBWImage *img) { super(img); }
  
  bool isConnectable(Pt a, Pt b) {
    float brightnessA = img.getFloatPixel(a);
    float brightnessB = img.getFloatPixel(b);
    ret abs(brightnessA-brightnessB) <= tolerance;
  }
}