OpenCV实现物体的凸包检测的示例代码

void convexHull(InputArray points,OutputArray hull,bool clockwise=false,bool returnPoints=true)

RNG &rng = theRNG();  //用其引用来接收theRNG函数返回的随机数生成器（RNG就是随机数生成器的类）

void circle(CV_IN_OUT Mat& image, Point center, int radius, const Scalar& color, int thickness=1, int lineType=8); 

#include<opencv2/opencv.hpp>
#include<opencv2/imgproc/imgproc.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<iostream>
using namespace std;
using namespace cv;
int main()
{
    //初始化变量和随机值
    Mat image(500, 500, CV_8UC3);
    RNG & rng = theRNG();
    while (1)
    {
        char key;
        int count = (unsigned)rng % 100 + 3;//随机生成点的数量
        cout << count << endl;
        vector<Point> points;//点值
        //随机生成点坐标
        for (int i = 0; i < count; i++)
        {
            Point point;
            point.x = rng.uniform(image.cols / 4, image.cols * 3 / 4);//uniform() 方法将随机生成下一个实数，它在[x,y]范围内。
            point.y = rng.uniform(image.rows / 4, image.rows * 3 / 4);
            if(i<10)
                cout << "(" << point.x << "," << point.y << ")" << endl;
            points.push_back(point);//C++ vector::push_back 会先创建临时对象，然后将临时对象拷贝到容器中
        }
        //检测凸包
        vector<int> hull;
        convexHull(Mat(points), hull, true);    
        //绘制出随机颜色的点
        image = Scalar::all(0);
        for (int i = 0; i < count; i++)
        {
            circle(image, points[i], 3, Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255)), FILLED,LINE_AA);
        }
        //准备参数
        int hullcount = (int)hull.size();//凸包边数
        Point point0 = points[hull[hullcount - 1]];//连接凸包边的坐标点
        //    cout << hull[0] <<":"<< hull.size()<<endl;
        //绘制凸包的边
        for (int i = 0; i < hullcount; i++)
        {
            Point point = points[hull[i]];
            line(image, point0, point, Scalar(255, 255, 255), 2, LINE_AA);
            point0 = point;
        }
        imshow("凸包检测", image);
        key = (char)waitKey();
        if (key == 27 || key == 'q' || key == 'Q')
            break;
    }
    return 0;
}