This program demonstrates connected components and use of the trackbar
#include <iostream>
int threshval = 100;
static void on_trackbar(int, void*)
{
Mat bw = threshval < 128 ? (img < threshval) : (img > threshval); std::vector<Vec3b> colors(nLabels);
colors[0] = Vec3b(0, 0, 0); for(int label = 1; label < nLabels; ++label){
colors[label] = Vec3b( (rand()&255), (rand()&255), (rand()&255) ); }
for(int r = 0; r < dst.rows; ++r){
for(int c = 0; c < dst.cols; ++c){
int label = labelImage.at<int>(r, c); pixel = colors[label];
}
}
imshow( "Connected Components", dst ); }
int main( int argc, const char** argv )
{
CommandLineParser parser(argc, argv, "{@image|stuff.jpg|image for converting to a grayscale}"); parser.about("\nThis program demonstrates connected components and use of the trackbar\n"); cout << "\nThe 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";
if(img.empty())
{
cout << "Could not read input image file: " << inputImage << endl;
return EXIT_FAILURE;
}
createTrackbar( "Threshold", "Connected Components", &threshval, 255, on_trackbar ); on_trackbar(threshval, 0);
return EXIT_SUCCESS;
}