本文是对OpenCV2.4.13文档的部分翻译，作个人学习之用，并不完整。
#include "opencv2/highgui/highgui.hpp" #include "opencv2/imgproc/imgproc.hpp" #include <iostream> #include <stdio.h> #include <stdlib.h> using namespace cv; using namespace std; Mat src; Mat src_gray; int thresh = 100; int max_thresh = 255; RNG rng(12345); /// Function header void thresh_callback(int, void* ); /** * @function main */ int main() { /// 载入图像 src = imread("HappyFish.jpg"); if (src.empty()) { cerr << "No image supplied ..." << endl; return -1; } /// 将图像转换成灰度图并将其模糊 cvtColor( src, src_gray, COLOR_BGR2GRAY ); blur( src_gray, src_gray, Size(3,3) ); /// 创建窗口 const char* source_window = "Source"; namedWindow( source_window, WINDOW_AUTOSIZE ); imshow( source_window, src ); createTrackbar( " Canny thresh:", "Source", &thresh, max_thresh, thresh_callback ); thresh_callback( 0, 0 ); waitKey(0); return(0); } /** * @function thresh_callback */ void thresh_callback(int, void* ) { Mat canny_output; vector<vector<Point> > contours; vector<Vec4i> hierarchy; /// 用Canny检测边缘 Canny( src_gray, canny_output, thresh, thresh*2, 3 ); /// 找到轮廓 findContours( canny_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) ); /// 画出轮廓 Mat drawing = Mat::zeros( canny_output.size(), CV_8UC3 ); for( size_t i = 0; i< contours.size(); i++ ) { Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) ); drawContours( drawing, contours, (int)i, color, 2, 8, hierarchy, 0, Point() ); } /// 显示图像 namedWindow( "Contours", WINDOW_AUTOSIZE ); imshow( "Contours", drawing ); } 结果：
