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( "stuff.jpg", 1 ); /// 将图像转换为灰度图并模糊处理 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( " Threshold:", "Source", &thresh, max_thresh, thresh_callback ); thresh_callback( 0, 0 ); waitKey(0); return(0); } /** * @function thresh_callback */ void thresh_callback(int, void* ) { Mat threshold_output; vector<vector<Point> > contours; vector<Vec4i> hierarchy; /// 用阈值检测边缘 threshold( src_gray, threshold_output, thresh, 255, THRESH_BINARY ); /// Find contours findContours( threshold_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) ); /// 逼近多边形轮廓 + 获取环绕的矩形和圆形 vector<vector<Point> > contours_poly( contours.size() ); vector<Rect> boundRect( contours.size() ); vector<Point2f>center( contours.size() ); vector<float>radius( contours.size() ); for( size_t i = 0; i < contours.size(); i++ ) { approxPolyDP( Mat(contours[i]), contours_poly[i], 3, true ); boundRect[i] = boundingRect( Mat(contours_poly[i]) ); minEnclosingCircle( contours_poly[i], center[i], radius[i] ); } /// 画出多边形轮廓 + 廉洁矩形和圆形 Mat drawing = Mat::zeros( threshold_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_poly, (int)i, color, 1, 8, vector<Vec4i>(), 0, Point() ); rectangle( drawing, boundRect[i].tl(), boundRect[i].br(), color, 2, 8, 0 ); circle( drawing, center[i], (int)radius[i], color, 2, 8, 0 ); } /// 在窗口中显示 namedWindow( "Contours", WINDOW_AUTOSIZE ); imshow( "Contours", drawing ); } 结果：
