之前学过的简单绘图方法，例如矩形，椭圆等，今天试着在视频图像中用矩形标注感兴趣区域（ROI）

<----图像篇---->

#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
using namespace std;
using namespace cv;

bool draw;  
Mat src;//原始图像  
Mat roi;//ROI图像
Point cursor;//初始坐标   
Rect rect;//标记ROI的矩形框

void onm ouse(int event, int x, int y, int flags, void *param)  
{  
    Mat img = src.clone();
    switch (event)  
    { 
    //按下鼠标左键,点击鼠标图像时，清除之前ROI图像的显示窗口
    case CV_EVENT_LBUTTONDOWN:          
        cvDestroyWindow("ROI");   
        //存放起始坐标  
        cursor = Point(x, y);  
        //初始化起始矩形框  
        rect = Rect(x, y, 0, 0);  
        draw = true;  
        break;  
    //松开鼠标左键      
    case CV_EVENT_LBUTTONUP:           
        if (rect.height > 0 && rect.width > 0)  
        {  
            roi = img(Rect(rect.x, rect.y, rect.width, rect.height));  
            rectangle(img, rect, Scalar(255, 255, 255),2);  
            namedWindow("SignROI");  
            imshow("SignROI", img);  

            //将画过矩形框的图像用原图像还原  
            src.copyTo(img);  
            imshow("SrcImage", img);  

            //显示ROI图像
            namedWindow("ROI");  
            imshow("ROI", roi);    
            waitKey(0);  
        }  
        draw = false;  
        break;  
    //移动光标
    case CV_EVENT_MOUSEMOVE:  
        if (draw)
        {  
            //用MIN得到左上点作为矩形框的起始坐标，如果不加这个，画矩形时只能向一个方向进行  
            rect.x = MIN(x, cursor.x);  
            rect.y = MIN(y, cursor.y);  
            rect.width = abs(cursor.x - x);  
            rect.height = abs(cursor.y - y);  
            //防止矩形区域超出图像的范围  
            rect &= Rect(0, 0, src.cols, src.rows);  
        }  
        break;  
    }  
}  

int main()
{
    src=http://www.mamicode.com/imread("E://IM_VIDEO//kobe.jpg");>运行结果如下：


<---视频篇--->
#include<opencv2\core\core.hpp>  
#include<opencv2\highgui\highgui.hpp>  
#include<opencv2\imgproc\imgproc.hpp>  
#include<iostream>  
#include<vector>  
using namespace cv;
using namespace std;  

bool drawing_box = false;  
bool gotBox =  false;  
Rect box;  
Point downPoint;  
  
void mouseRectHandler(int event, int x, int y, int flags, void *param)  
{  
    switch (event)  
    {  
    case CV_EVENT_MOUSEMOVE:  
        if (drawing_box)  
        {  
            //鼠标的移动到downPoint的右下角  
            if( x >=downPoint.x && y >= downPoint.y)  
            {  
                box.x = downPoint.x;  
                box.y = downPoint.y;  
                box.width = x - downPoint.x;  
                box.height =  y -  downPoint.y;  
            }  
            //鼠标的移动到downPoint的右上角  
            if( x >= downPoint.x && y <= downPoint.y)  
            {  
                box.x =  downPoint.x;  
                box.y = y;  
                box.width = x - downPoint.x;  
                box.height = downPoint.y - y;  
            }  
            //鼠标的移动到downPoint的左上角  
            if( x <= downPoint.x && y <= downPoint.y)  
            {  
                box.x = x;  
                box.y = y;  
                box.width = downPoint.x - x;  
                box.height = downPoint.y - y;  
            }  
            //鼠标的移动到downPoint的左下角  
            if( x <= downPoint.x && y >= downPoint.y)  
            {  
                box.x = x;  
                box.y = downPoint.y;  
                box.width = downPoint.x -x;  
                box.height = y - downPoint.y;  
            }  
        }  
        break;  
  
    case CV_EVENT_LBUTTONDOWN:  
        drawing_box = true;  
        //起点  
        downPoint = Point(x,y);  
        break;  
  
    case CV_EVENT_LBUTTONUP:  
       //松开鼠标，结束画矩形  
        drawing_box = false;  
        gotBox = true;  
        break;  
    default:  
        break;  
    }  
}  
  
int main(int argc,char*argv[])    
 {        
     VideoCapture video("E://IM_VIDEO//xxx.mp4"); 
     if( !video.isOpened())    
         return 0;    
     Mat frame;       
     namedWindow("face",1);    
     setMouseCallback("face",mouseRectHandler,NULL);    
        
     //画感兴趣区域   
    for(;;)    
     {    
        video>>frame;  
        if(!frame.data)  
            break;  
         rectangle(frame,box,Scalar(255,255,255),2);//参见绘图介绍  
         imshow("face",frame);   
        if(waitKey(50) == ‘c‘)
            break;    
     }    
    
     return 0;    
 }    
运行结果如下：




参考：
http://blog.csdn.net/zhangping1987/article/details/51880098
http://blog.csdn.net/qq_23968185/article/details/51335291
opencv图像及视频感兴趣区域设置