72 lines
2.0 KiB
C++
72 lines
2.0 KiB
C++
#include <opencv2/core/utility.hpp>
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#include "opencv2/imgproc.hpp"
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#include "opencv2/imgcodecs.hpp"
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#include "opencv2/highgui.hpp"
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#include <iostream>
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using namespace cv;
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using namespace std;
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Mat img;
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int threshval = 100;
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static void on_trackbar(int, void*)
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{
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Mat bw = threshval < 128 ? (img < threshval) : (img > threshval);
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Mat labelImage(img.size(), CV_32S);
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int nLabels = connectedComponents(bw, labelImage, 8);
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std::vector<Vec3b> colors(nLabels);
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colors[0] = Vec3b(0, 0, 0);//background
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for(int label = 1; label < nLabels; ++label){
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colors[label] = Vec3b( (rand()&255), (rand()&255), (rand()&255) );
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}
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Mat dst(img.size(), CV_8UC3);
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for(int r = 0; r < dst.rows; ++r){
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for(int c = 0; c < dst.cols; ++c){
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int label = labelImage.at<int>(r, c);
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Vec3b &pixel = dst.at<Vec3b>(r, c);
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pixel = colors[label];
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}
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}
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imshow( "Connected Components", dst );
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}
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static void help()
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{
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cout << "\n This program demonstrates connected components and use of the trackbar\n"
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"Usage: \n"
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" ./connected_components <image(stuff.jpg as default)>\n"
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"The image is converted to grayscale and displayed, another image has a trackbar\n"
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"that controls thresholding and thereby the extracted contours which are drawn in color\n";
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}
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const char* keys =
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{
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"{@image|stuff.jpg|image for converting to a grayscale}"
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};
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int main( int argc, const char** argv )
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{
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help();
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CommandLineParser parser(argc, argv, keys);
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string inputImage = parser.get<string>(0);
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img = imread(inputImage.c_str(), 0);
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if(img.empty())
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{
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cout << "Could not read input image file: " << inputImage << endl;
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return -1;
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}
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namedWindow( "Image", 1 );
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imshow( "Image", img );
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namedWindow( "Connected Components", 1 );
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createTrackbar( "Threshold", "Connected Components", &threshval, 255, on_trackbar );
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on_trackbar(threshval, 0);
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waitKey(0);
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return 0;
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}
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