opencv鼠标回调函数实现ROI区域像素值相同化

该代码通过鼠标选取左上角和右下角两个点，并基于这两个点实现ROI区域的选取，ROI区域内所有像素值被赋予左上角选取点的像素值。

源代码

#include <opencv2/core/core.hpp>  
#include <opencv2/highgui/highgui.hpp>  
#include <stdio.h>  
#include<opencv.hpp>
#include<cmath>

using namespace cv;
using namespace std;

cv::Mat org_, dst_, img_, tmp_;
int pointValue;
void on_mouse(int event, int x, int y, int flags, void *ustc)//event鼠标事件代号，x,y鼠标坐标，flags拖拽和键盘操作的代号  
{
    static Point pre_pt = (-1, -1);//初始坐标  
    static Point cur_pt = (-1, -1);//实时坐标  

    char temp[16];

    if (event == CV_EVENT_LBUTTONDOWN)//左键按下，读取初始坐标，并在图像上该点处划圆  
    {
        pointValue=0;
        org_.copyTo(img_);//将原始图片复制到img中  
        cout << img_.rows << "  " << img_.cols << endl;
        sprintf(temp, "(%d,%d)", x, y);
        pre_pt = Point(x, y);
        pointValue = img_.at<Vec3b>(pre_pt)[0];
        cout << pointValue<<endl;
    /*  cout << org.at<Vec3b>(pre_pt)[1];
        cout << org.at<Vec3b>(pre_pt)[2];*/
        //初始坐标
        //putText(org_, temp, pre_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255), 1, 8);//在窗口上显示坐标  
        //circle(org_, pre_pt, 2, Scalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);//划圆  
        imshow("img", org_);
    }
    else if (event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))//左键没有按下的情况下鼠标移动的处理函数  
    {
        img_.copyTo(tmp_);//将img复制到临时图像tmp上，用于显示实时坐标  
        sprintf(temp, "(%d,%d)", x, y);
        cur_pt = Point(x, y);
        //putText(org_, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));//只是实时显示鼠标移动的坐标  
        imshow("img", org_);
    }
    else if (event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))//左键按下时，鼠标移动，则在图像上划矩形  
    {
        img_.copyTo(tmp_);
        sprintf(temp, "(%d,%d)", x, y);
        cur_pt = Point(x, y);
        //putText(org_, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));
        rectangle(tmp_, pre_pt, cur_pt, Scalar(0, 255, 0, 0), 1, 8, 0);//在临时图像上实时显示鼠标拖动时形成的矩形  
        imshow("img", tmp_);
    }
    else if (event == CV_EVENT_LBUTTONUP)//左键松开，将在图像上划矩形  
    {

        org_.copyTo(img_);
        sprintf(temp, "(%d,%d)", x, y);
        cur_pt = Point(x, y);
        int height_ = abs(cur_pt.x - pre_pt.x);
        int width_ = abs(cur_pt.y - pre_pt.y);
        //Mat imageBlue, imageGreen, imageRed;
        Mat imageBlue = Mat::zeros(img_.rows, img_.cols, CV_8UC1);
        Mat imageGreen = Mat::zeros(img_.rows, img_.cols, CV_8UC1);
        Mat imageRed = Mat::zeros(img_.rows, img_.cols, CV_8UC1);
        Mat mergeImage;
        Mat test0,test1,test2;
        vector<Mat> channelrgb;
        Mat mer;
        //putText(org_, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));
        //circle(org_, pre_pt, 2, Scalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);
        split(img_, channelrgb);
        imageBlue = channelrgb.at(0);
        imageGreen = channelrgb.at(1);
        imageRed = channelrgb.at(2);
        cout << imageRed.rows<<"   "<<imageRed.cols<< endl;
        if ((cur_pt.x > pre_pt.x) && (cur_pt.y > pre_pt.y))
        {
            for (int i = 0; i < (cur_pt.x - pre_pt.x); i++)
            {
                for (int j = 0; j <(cur_pt.y - pre_pt.y); j++)
                {
                    imageBlue.at<uchar>(j + pre_pt.y, i + pre_pt.x) = pointValue;
                    imageGreen.at<uchar>(j + pre_pt.y, i + pre_pt.x) = pointValue;
                    imageRed.at<uchar>(j + pre_pt.y, i + pre_pt.x) = pointValue;
                }
            }
        }
        channelrgb.at(0) = imageBlue;
        channelrgb.at(1) = imageGreen;
        channelrgb.at(2) = imageRed;
        test0 = channelrgb.at(0);
        test1 = channelrgb.at(1);
        test2 = channelrgb.at(2);
        merge(channelrgb, org_);
        cout << "cui" << endl;
        //截取矩形包围的图像，并保存到dst中  
        int width = abs(pre_pt.x - cur_pt.x);
        int height = abs(pre_pt.y - cur_pt.y);
        if (width == 0 || height == 0)
        {
            printf("width == 0 || height == 0");
            return;
        }
        dst_ = org_(Rect(min(cur_pt.x, pre_pt.x), min(cur_pt.y, pre_pt.y), width, height));
        //namedWindow("merge", 0);
        //imshow("merge", org_);
        imwrite("C:\\Users\\new\\Desktop\\test.bmp", org_);
        waitKey(0);
    }
}

void main()
{

    org_ = imread("C:/Users/new/Desktop/1.bmp");
    namedWindow("img",0);//定义一个img窗口  
    setMouseCallback("img", on_mouse, 0);//调用回调函数  
    //imshow("img", img_);

    cv::waitKey(0);
}

实验结果