/** create_mask.cpp** Author:* Siddharth Kherada <siddharthkherada27[at]gmail[dot]com>** This tutorial demonstrates how to make mask image (black and white).* The program takes as input a source image and ouputs its corresponding* mask image.*/#include "opencv2/imgproc.hpp"#include "opencv2/imgcodecs.hpp"#include "opencv2/highgui.hpp"#include "opencv2/core.hpp"#include <iostream>#include <stdlib.h>using namespace std;using namespace cv;Mat img0, img1, res1, final;Point point;int drag = 0;int numpts = 100;Point* pts = new Point[100];int var = 0;int flag = 0;int flag1 = 0;int minx,miny,maxx,maxy,lenx,leny;int channel;void mouseHandler(int, int, int, int, void*);void mouseHandler(int event, int x, int y, int, void*){    // Jeff --> Click Left button: status down.    if (event == EVENT_LBUTTONDOWN && !drag)    {        if(flag1 == 0)        {            if(var==0)                img1 = img0.clone();            point = Point(x, y);            circle(img1,point,2,Scalar(0, 0, 255),-1, 8, 0);            pts[var] = point;            var++;            drag  = 1;            if(var>1)                line(img1,pts[var-2], point, Scalar(0, 0, 255), 2, 8, 0);            imshow("Source", img1);        }    }    // Jeff --> Click Left button: status up.    if (event == EVENT_LBUTTONUP && drag)    {        imshow("Source", img1);        drag = 0;    }    /*     * Jeff --> Click Right button.     */    if (event == EVENT_RBUTTONDOWN)    {        flag1 = 1;        img1 = img0.clone();        for(int i = var; i < numpts ; i++)            pts[i] = point;        if(var!=0)        {            const Point* pts3[1] = {&pts[0]};            polylines( img1, pts3, &numpts,1, 1, Scalar(0,0,0), 2, 8, 0);        }        for(int i=0;i<var;i++)        {            minx = min(minx,pts[i].x);            maxx = max(maxx,pts[i].x);            miny = min(miny,pts[i].y);            maxy = max(maxy,pts[i].y);        }        lenx = maxx - minx;        leny = maxy - miny;        imshow("Source", img1);    }    if (event == EVENT_RBUTTONUP)    {        flag = var;        final = Mat::zeros(img0.size(),CV_8UC3);        res1 = Mat::zeros(img0.size(),CV_8UC1);        const Point* pts4[1] = {&pts[0]};        fillPoly(res1, pts4,&numpts, 1, Scalar(255, 255, 255), 8, 0);        bitwise_and(img0, img0, final,res1);        imshow("mask",res1);        imwrite("mask.png",res1);        imshow("Source", img1);    }    if (event == EVENT_MBUTTONDOWN)    {        for(int i = 0; i < numpts ; i++)        {            pts[i].x=0;            pts[i].y=0;        }        var = 0;        flag1 = 0;        minx = INT_MAX; miny = INT_MAX; maxx = INT_MIN; maxy = INT_MIN;        imshow("Source", img0);        drag = 0;    }}int main(int argc, char **argv){    cv::CommandLineParser parser(argc, argv, "{help h | | show help message}{@input | | input image}");    if (parser.has("help"))    {        parser.printMessage();        return 0;    }    string input_image = parser.get<string>("@input");    if (input_image.empty())    {        parser.printMessage();        parser.printErrors();        return 0;    }    Mat src = http://www.mamicode.com/imread(input_image);"channel = " << channel << endl;    res1 = Mat::zeros(img0.size(),CV_8UC1);    final = Mat::zeros(img0.size(),CV_8UC3);    //////////// source image ///////////////////    namedWindow("Source", 1);    /*     * Jeff --> listen to mouse event.     */    setMouseCallback("Source", mouseHandler, NULL);    imshow("Source", img0);    waitKey(0);    img0.release();    img1.release();}