OpenCV——查找、绘制轮廓

 1 #include <opencv2/opencv.hpp>
 2 #include <iostream>
 3 
 4 using namespace cv;
 5 using namespace std;
 6 
 7 
 8 int main(int argc, char** argv)
 9 { 
10     Mat src = imread("test.jpg");
11     Mat src_gray,binary,dst=Mat::zeros(src.size(),CV_8UC3);
12     if (src.empty()) {
13         printf("Could not load image...");
14         return -1;
15     }
16     imshow("Input Image",src);
17       
18     //二值化
19     cvtColor(src, src_gray, COLOR_BGR2GRAY);
20     threshold(src_gray, binary, 0, 255, THRESH_BINARY | THRESH_OTSU);
21     //binary = ~binary;//取反
22     imshow("binary", binary);
23     
24     //发现轮廓
25     vector<vector<Point>> contours;
26     vector<Vec4i> hireachy;
27     findContours(binary, contours, hireachy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point());
28 
29     //绘制所有轮廓
30     for (size_t t = 0; t < contours.size(); t++) 
31     {
32         drawContours(dst, contours, t, Scalar(0, 0, 255), 2, 8, Mat(), 0, Point());//dst必须先初始化
33     }
34 
35     imshow("contours", dst);
36 
37     waitKey(0);
38 
39     return 0;
40 }