cvBoundingRect

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

using namespace cv;  
using namespace std;  

int main()  
{  
    Mat srcImage(Size(600, 600), CV_8UC3, Scalar(0));  

    RNG &rng = theRNG();  

    char key;  
    while (1)  
    {  
        //随机生成一些点  
        //首先就是随机生成点的总数量  
        int g_nPointCount = rng.uniform(3, 30);  
        //接下来就是随机生成一些点的坐标  
        vector<Point> points;  
        for (int i = 0; i < g_nPointCount; i++)  
        {  
            Point midPoint;  

            midPoint.x = rng.uniform(srcImage.cols / 4, srcImage.cols * 3 / 4);  
            midPoint.y = rng.uniform(srcImage.rows / 4, srcImage.rows * 3 / 4);  

            points.push_back(midPoint);  
        }  

        //显示刚刚随机生成的那些点  
        for (int i = 0; i < g_nPointCount; i++)  
        {  
            circle(srcImage, points[i], 0, Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255)), 3);  
        }  

        //在生成的那些随机点中寻找最小包围矩形  
        //rect变量中得到了矩形  
        Rect rect = boundingRect(points);  

        //根据得到的矩形  绘制矩形  
        rectangle(srcImage, rect, Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255)), 3);  

        imshow("【绘制结束后的图像】", srcImage);  

        key = waitKey();  
        if (key == 27)  
            break;  
        else  
            srcImage = Scalar::all(0);  
    }