opencv学习笔记9 查找绘制轮廓

一。查找绘制轮廓

1.查找轮廓

 

 2.绘制轮廓

 1 #include<opencv.hpp>
 2 #include<iostream>
 3 #include<vector>
 4 using namespace std;
 5 using namespace cv;
 6 int main()
 7 {
 8     Mat srcImg = imread("F:/opencv/lena.jpg", 0);
 9     imshow("yuantu", srcImg);
10     Mat dstImg = Mat::zeros(srcImg.rows, srcImg.cols, srcImg.type());
11     threshold(srcImg, srcImg, 119, 255, THRESH_BINARY);//通过threshold进行二值化
12     imshow("二值图", srcImg);
13     vector<vector<Point>>contours; //每个轮廓由多个Point组成，有多个轮廓
14     vector<Vec4i>hierarchy; //保存每个轮廓的4个信息，hierarchy[i]代表第i个轮廓 hierarchy[i][0]表示第i个轮廓的后一个轮廓
15     findContours(srcImg, contours, hierarchy, RETR_CCOMP, CHAIN_APPROX_SIMPLE); //寻找轮廓，保存轮廓信息，和轮廓的索引信息
16     int index = 0; //第1个轮廓的索引
17     for (; index >= 0; index = hierarchy[index][0]) //index++，若index后面没有对应项，为-1
18     {
19         Scalar color(rand() % 255, rand() % 255, rand() % 255);
20         drawContours(dstImg, contours, index, color, FILLED, 8, hierarchy);//画轮廓
21     }
22     imshow("轮廓", dstImg);
23     waitKey();
24     return 0;
25 }