| OpenCV 3.4.1 Open Source Computer Vision

morphology2.cpp

Advanced morphology Transformations sample code

Sample screenshot

Check the corresponding tutorial for more details

#include "opencv2/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include <stdlib.h>
#include <stdio.h>
#include <string>
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, ellipse 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, MORPH_OPEN, element);
else
morphologyEx(src, dst, MORPH_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 )
{
cv::CommandLineParser parser(argc, argv, "{help h||}{ @image | ../data/baboon.jpg | }");
if (parser.has("help"))
{
help();
return 0;
}
std::string filename = parser.get<std::string>("@image");
if( (src = imread(filename,IMREAD_COLOR)).empty() )
{
help();
return -1;
}
//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(;;)
{
OpenClose(open_close_pos, 0);
ErodeDilate(erode_dilate_pos, 0);
char c = (char)waitKey(0);
if( c == 27 )
break;
if( c == 'e' )
element_shape = MORPH_ELLIPSE;
else if( c == 'r' )
element_shape = MORPH_RECT;
else if( c == 'c' )
element_shape = MORPH_CROSS;
else if( c == ' ' )
element_shape = (element_shape + 1) % 3;
}
return 0;
}