opencv/samples/cpp/tutorial_code/ImgProc/Morphology_2.cpp

/**
 * @file Morphology_2.cpp
 * @brief Advanced morphology Transformations sample code
 * @author OpenCV team
 */

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <stdlib.h>
#include <stdio.h>

using namespace cv;

/// Global variables
Mat src, dst;

int morph_elem = 0;
int morph_size = 0;
int morph_operator = 0;
int const max_operator = 4;
int const max_elem = 2;
int const max_kernel_size = 21;

char* window_name = "Morphology Transformations Demo";


/** Function Headers */
void Morphology_Operations( int, void* );

/**
 * @function main
 */
int main( int argc, char** argv )
{
  /// Load an image
  src = imread( argv[1] );

  if( !src.data )
    { return -1; }

  /// Create window
  namedWindow( window_name, CV_WINDOW_AUTOSIZE );

  /// Create Trackbar to select Morphology operation
  createTrackbar("Operator:\n 0: Opening - 1: Closing  \n 2: Gradient - 3: Top Hat \n 4: Black Hat", window_name, &morph_operator, max_operator, Morphology_Operations );

  /// Create Trackbar to select kernel type
  createTrackbar( "Element:\n 0: Rect - 1: Cross - 2: Ellipse", window_name,
          &morph_elem, max_elem,
          Morphology_Operations );

  /// Create Trackbar to choose kernel size
  createTrackbar( "Kernel size:\n 2n +1", window_name,
          &morph_size, max_kernel_size,
          Morphology_Operations );

  /// Default start
  Morphology_Operations( 0, 0 );

  waitKey(0);
  return 0;
}

/**
 * @function Morphology_Operations
 */
void Morphology_Operations( int, void* )
{

  // Since MORPH_X : 2,3,4,5 and 6
  int operation = morph_operator + 2;

  Mat element = getStructuringElement( morph_elem, Size( 2*morph_size + 1, 2*morph_size+1 ), Point( morph_size, morph_size ) );

  /// Apply the specified morphology operation
  morphologyEx( src, dst, operation, element );
  imshow( window_name, dst );
}