左鍵紅右鍵藍，保存為k

#include "opencv2\imgproc\imgproc.hpp"  // Gaussian Blur
#include "opencv2\core\core.hpp"        // Basic OpenCV structures (cv::Mat, Scalar)
#include <opencv2\highgui\highgui.hpp> // OpenCV window I/O
#include <iostream> // for standard I/O
#include <string>   // for strings
#include <iomanip>  // for controlling float print precision
#include <sstream>  // string to number conversion
using namespace  cv;
using namespace  std;

bool rButtonDown = false;
bool lButtonDown = false;
int numUsedBins = 0;
float varianceSquared = 0;
int scribbleRadius = 10;
Mat inputImg = imread("0.jpg", 3), showImg = imread("0.jpg", 3);
Mat fgScribbleMask;
Mat bgScribbleMask;

static void onMouse(int event, int x, int y, int, void*)
{
	cout << "On Mouse: (" << x << "," << y << ")" <<endl;


	if (event == CV_EVENT_LBUTTONDOWN)
	{
		lButtonDown = true;

	}
	else if (event == CV_EVENT_RBUTTONDOWN)
	{
		rButtonDown = true;

	}
	else if (event == CV_EVENT_LBUTTONUP)
	{
		lButtonDown = false;
	}
	else if (event == CV_EVENT_RBUTTONUP)
	{
		rButtonDown = false;
	}
	else if (event == CV_EVENT_MOUSEMOVE)
	{
		if (rButtonDown)
		{
			// scribble the background
			circle(bgScribbleMask, Point(x, y), scribbleRadius, 255, -1);
			circle(showImg, Point(x, y), scribbleRadius, CV_RGB(0, 0, 255), -1);

		}
		else if (lButtonDown)
		{
			// scribble the foreground
			circle(showImg, Point(x, y), scribbleRadius, CV_RGB(255, 0, 0), -1);
			circle(fgScribbleMask, Point(x, y), scribbleRadius, 255, -1);

		}

	}


	imshow("draw", showImg);
	imshow("fg mask", fgScribbleMask);
	imshow("bg mask", bgScribbleMask);
}
int main() {
	bgScribbleMask.create(2, inputImg.size, CV_8UC1);
	bgScribbleMask = 0; 
	fgScribbleMask.create(2, inputImg.size, CV_8UC1);
	fgScribbleMask = 0;
	namedWindow("draw");
	imshow("draw", showImg);
	namedWindow("input");
	imshow("input", inputImg);


	setMouseCallback("draw", onMouse, 0); 
	while (1) {
	　　char key = waitKey(0);
	　　if (key == ‘k‘) { imwrite("1123.jpg", fgScribbleMask); cout << "successed"; }
	}
}

opencv3.3.1+vs2015+c++實現直接在圖像上畫掩碼，保存掩碼圖片