74 lines
2.0 KiB
C++
74 lines
2.0 KiB
C++
#include "opencv2/imgproc/imgproc.hpp"
|
|
#include "opencv2/highgui/highgui.hpp"
|
|
#include <iostream>
|
|
|
|
using namespace cv;
|
|
using namespace std;
|
|
|
|
Mat img;
|
|
int threshval = 100;
|
|
|
|
static void on_trackbar(int, void*)
|
|
{
|
|
Mat bw = threshval < 128 ? (img < threshval) : (img > threshval);
|
|
|
|
vector<vector<Point> > contours;
|
|
vector<Vec4i> hierarchy;
|
|
|
|
findContours( bw, contours, hierarchy, CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE );
|
|
|
|
Mat dst = Mat::zeros(img.size(), CV_8UC3);
|
|
|
|
if( !contours.empty() && !hierarchy.empty() )
|
|
{
|
|
// iterate through all the top-level contours,
|
|
// draw each connected component with its own random color
|
|
int idx = 0;
|
|
for( ; idx >= 0; idx = hierarchy[idx][0] )
|
|
{
|
|
Scalar color( (rand()&255), (rand()&255), (rand()&255) );
|
|
drawContours( dst, contours, idx, color, CV_FILLED, 8, hierarchy );
|
|
}
|
|
}
|
|
|
|
imshow( "Connected Components", dst );
|
|
}
|
|
|
|
static void help()
|
|
{
|
|
cout << "\n This program demonstrates connected components and use of the trackbar\n"
|
|
"Usage: \n"
|
|
" ./connected_components <image(stuff.jpg as default)>\n"
|
|
"The image is converted to grayscale and displayed, another image has a trackbar\n"
|
|
"that controls thresholding and thereby the extracted contours which are drawn in color\n";
|
|
}
|
|
|
|
const char* keys =
|
|
{
|
|
"{@image |stuff.jpg|image for converting to a grayscale}"
|
|
};
|
|
|
|
int main( int argc, const char** argv )
|
|
{
|
|
help();
|
|
CommandLineParser parser(argc, argv, keys);
|
|
string inputImage = parser.get<string>(1);
|
|
img = imread(inputImage.c_str(), 0);
|
|
|
|
if(img.empty())
|
|
{
|
|
cout << "Could not read input image file: " << inputImage << endl;
|
|
return -1;
|
|
}
|
|
|
|
namedWindow( "Image", 1 );
|
|
imshow( "Image", img );
|
|
|
|
namedWindow( "Connected Components", 1 );
|
|
createTrackbar( "Threshold", "Connected Components", &threshval, 255, on_trackbar );
|
|
on_trackbar(threshval, 0);
|
|
|
|
waitKey(0);
|
|
return 0;
|
|
}
|