drawContours c++

以下是drawContours函数的C++示例：

#include <opencv2/opencv.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main()
{
    Mat image = imread("example.jpg");
    if (image.empty())
    {
        cout << "Could not open or find the image" << endl;
        return -1;
    }

    Mat gray;
    cvtColor(image, gray, COLOR_BGR2GRAY);

    Mat binary;
    threshold(gray, binary, 0, 255, THRESH_BINARY | THRESH_OTSU);

    vector<vector<Point>> contours;
    vector<Vec4i> hierarchy;
    findContours(binary, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE);

    Mat result = Mat::zeros(image.size(), CV_8UC3);
    for (size_t i = 0; i < contours.size(); i++)
    {
        drawContours(result, contours, i, Scalar(0, 0, 255), 2, LINE_8, hierarchy);
    }

    imshow("Result", result);
    waitKey(0);

    return 0;
}

该示例首先读取一张图像，将其转换为灰度图像并进行二值化处理。然后使用findContours函数查找轮廓，并使用drawContours函数将轮廓绘制在新的图像上。最后显示结果图像并等待用户按下任意键退出程序。