#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>class WatershedSegmenter {
private:cv::Mat markers;public:void setMarkers(const cv::Mat &markerImage) {// Convert to image of intsmarkerImage.convertTo(markers, CV_32S);}cv::Mat process(const cv::Mat &image) {// Apply watershedcv::watershed(image, markers);return markers;}// Return result in the form of an imagecv::Mat getSegmentation() {cv::Mat tmp;// all segment with label higher than 255// will be assigned value 255markers.convertTo(tmp, CV_8U);return tmp;}// Return watershed in the form of an imagecv::Mat getWatersheds() {cv::Mat tmp;// Each pixel p is transform into// 255p + 255 befor conversionmarkers.convertTo(tmp, CV_8U, 255, 255);return tmp;}
};

// Read input imagecv::Mat image = cv::imread( "../group.jpg");if (!image.data) {return 0;}// Display the imagecv::namedWindow( "Original Image");cv::imshow( "Original Image", image);// Get the binary imagecv::Mat binary;binary = cv::imread( "../binary.bmp", 0);// Display the binary imagecv::namedWindow( "Binary Image");cv::imshow( "Binary Image", binary);// Eliminate noise and smaller objectscv::Mat fg;cv::erode(binary, fg, cv::Mat(), cv::Point(-1, -1), 6);// Display the foreground imagecv::namedWindow( "Foreground Image");cv::imshow( "Foreground Image", fg);

// Identify image pixels without objectscv::Mat bg;cv::dilate(binary, bg, cv::Mat(), cv::Point(-1, -1), 6);cv::threshold(bg, bg, 1, 128, cv::THRESH_BINARY_INV);// Display the backgroud imagecv::namedWindow( "Background Image");cv::imshow( "Background Image", bg);

// Show markers imagecv::Mat markers(binary.size(), CV_8U, cv::Scalar(0));markers = fg + bg;cv::namedWindow( "Markers");cv::imshow( "Markers", markers);

// Create watershed segmentation objectWatershedSegmenter segmenter;// Set markers and processsegmenter.setMarkers(markers);segmenter.process(image);// Display segmentation resultcv::namedWindow( "Segmentation");cv::imshow( "Segmentation", segmenter.getSegmentation());// Display watershedscv::namedWindow( "Watershed");cv::imshow( "Watershed", segmenter.getWatersheds());

// Open another image------------------------------------image = cv::imread( "../tower.jpg");// Identify background pixelscv::Mat imageMask(image.size(), CV_8U, cv::Scalar(0));cv::rectangle(imageMask, cv::Point(5, 5), cv::Point(image.cols - 5, image.rows - 5), cv::Scalar(255), 3);// Identify forground pixels (in the middle of the image)cv::rectangle(imageMask, cv::Point(image.cols / 2 - 10, image.rows / 2 - 10),cv::Point(image.cols / 2 + 10, image.rows / 2 + 10), cv::Scalar(1), 10);// Set markers and processsegmenter.setMarkers(imageMask);segmenter.process(image);// Display the image with markerscv::rectangle(image, cv::Point(5, 5), cv::Point(image.cols - 5, image.rows - 5), cv::Scalar(255, 255, 255), 3);cv::rectangle(image, cv::Point(image.cols / 2 - 10, image.rows / 2 - 10),cv::Point(image.cols / 2 + 10, image.rows / 2 + 10), cv::Scalar(1, 1, 1), 10);cv::namedWindow( "Image with marker");cv::imshow( "Image with marker", image);// Display watershedscv::namedWindow( "Watersheds of foreground object");cv::imshow( "Watersheds of foreground object", segmenter.getWatersheds());