text: #define CV_NO_BACKWARD_COMPATIBILITY
  
  #include "opencv2/imgproc/imgproc.hpp"
  #include "opencv2/highgui/highgui.hpp"
  #include <stdlib.h>
  #include <stdio.h>
  
  using namespace cv;
  
  static void help()
  {
  
  printf("\nShow off image morphology: erosion, dialation, open and close\n"
      "Call:\n   morphology2 [image]\n"
      "This program also shows use of rect, elipse and cross kernels\n\n");
  printf( "Hot keys: \n"
      "\tESC - quit the program\n"
      "\tr - use rectangle structuring element\n"
      "\te - use elliptic structuring element\n"
      "\tc - use cross-shaped structuring element\n"
      "\tSPACE - loop through all the options\n" );
  }
  
  Mat src, dst;
  
  int element_shape = MORPH_RECT;
  
  //the address of variable which receives trackbar position update
  int max_iters = 10;
  int open_close_pos = 0;
  int erode_dilate_pos = 0;
  
  // callback function for open/close trackbar
  static void OpenClose(int, void*)
  {
      int n = open_close_pos - max_iters;
      int an = n > 0 ? n : -n;
      Mat element = getStructuringElement(element_shape, Size(an*2+1, an*2+1), Point(an, an) );
      if( n < 0 )
          morphologyEx(src, dst, CV_MOP_OPEN, element);
      else
          morphologyEx(src, dst, CV_MOP_CLOSE, element);
      imshow("Open/Close",dst);
  }
  
  // callback function for erode/dilate trackbar
  static void ErodeDilate(int, void*)
  {
      int n = erode_dilate_pos - max_iters;
      int an = n > 0 ? n : -n;
      Mat element = getStructuringElement(element_shape, Size(an*2+1, an*2+1), Point(an, an) );
      if( n < 0 )
          erode(src, dst, element);
      else
          dilate(src, dst, element);
      imshow("Erode/Dilate",dst);
  }
  
  
  int main( int argc, char** argv )
  {
      char* filename = argc == 2 ? argv[1] : (char*)"baboon.jpg";
      if( (src = imread(filename,1)).data == 0 )
          return -1;
  
      help();
  
      //create windows for output images
      namedWindow("Open/Close",1);
      namedWindow("Erode/Dilate",1);
  
      open_close_pos = erode_dilate_pos = max_iters;
      createTrackbar("iterations", "Open/Close",&open_close_pos,max_iters*2+1,OpenClose);
      createTrackbar("iterations", "Erode/Dilate",&erode_dilate_pos,max_iters*2+1,ErodeDilate);
  
      for(;;)
      {
          int c;
  
          OpenClose(open_close_pos, 0);
          ErodeDilate(erode_dilate_pos, 0);
          c = cvWaitKey(0);
  
          if( (char)c == 27 )
              break;
          if( (char)c == 'e' )
              element_shape = MORPH_ELLIPSE;
          else if( (char)c == 'r' )
              element_shape = MORPH_RECT;
          else if( (char)c == 'c' )
              element_shape = MORPH_CROSS;
          else if( (char)c == ' ' )
              element_shape = (element_shape + 1) % 3;
      }
  
      return 0;
  }
  