OpenCV实现图像物体轮廓，前景背景，标记，并保存。

#include <iostream> // for standard I/O
#include <string>   // for strings
#include <iomanip>  // for controlling float print precision
#include <sstream>  // string to number conversion 

#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

using namespace std;
using namespace cv;

// images
Mat inputImg, showImg, segMask, segShowImg;

// mask
Mat fgScribbleMask, bgScribbleMask;

// user clicked mouse buttons flags
bool rButtonDown = false;
bool lButtonDown = false;
int scribbleRadius = 5;

// mouse listener
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(fgScribbleMask,Point(x,y),scribbleRadius, 255,-1);
			circle(showImg,Point(x,y),scribbleRadius, CV_RGB(255,0,0),-1);

			//fgScribbleMask.at<char>(y,x)=(char)255;
			// set variables using mask
			//showImg.setTo(redColorElement,fgScribbleMask);

			//showImg.at<Vec3b>(y,x)[0] = 0;
			//showImg.at<Vec3b>(y,x)[1] = 0;
			//showImg.at<Vec3b>(y,x)[2] = 255;
		}

	}

	imshow("Scribble Image", showImg);
	imshow("fg mask", fgScribbleMask);
	imshow("bg mask", bgScribbleMask);
}

// clear everything before closing
void destroyAll()
{
	// destroy all windows
	destroyWindow("Input Image");
	destroyWindow("Scribble Image");

	destroyWindow("bg mask");
	destroyWindow("fg mask");
	destroyWindow("Segmentation Mask");
	destroyWindow("Segmentation Image");

	// clear all data
	fgScribbleMask.release();
	bgScribbleMask.release();
	inputImg.release();
	showImg.release();

	segMask.release();
	segShowImg.release();

}

// init all images/vars
int init(char * imgFileName)
{
	// Read the file
	inputImg = imread(imgFileName, CV_LOAD_IMAGE_COLOR);
	showImg = inputImg.clone();
	segShowImg = inputImg.clone();

	// Check for invalid input
	if(!inputImg.data )
	{
		cout <<  "Could not open or find the image: " << imgFileName << std::endl ;
		return -1;
	}

	// this is the mask to keep the user scribbles
	fgScribbleMask.create(2,inputImg.size,CV_8UC1);
	fgScribbleMask = 0;
	bgScribbleMask.create(2,inputImg.size,CV_8UC1);
	bgScribbleMask = 0;
	segMask.create(2,inputImg.size,CV_8UC1);
	segMask = 0;

	// Create a window for display.
	namedWindow( "Input Image", CV_WINDOW_AUTOSIZE );
	namedWindow( "Scribble Image", CV_WINDOW_AUTOSIZE);

	namedWindow( "fg mask", CV_WINDOW_AUTOSIZE );
	namedWindow( "bg mask", CV_WINDOW_AUTOSIZE );

	// Show our image inside it.
	imshow( "Input Image", inputImg );
	imshow( "Scribble Image", showImg );  

	imshow("fg mask", fgScribbleMask);
	imshow("bg mask", bgScribbleMask);

	moveWindow("Scribble Image", 1,1);
	moveWindow("Input Image", inputImg.cols + 50,1);
	moveWindow("Bin Per Pixel", 2*(inputImg.cols + 50),1);
	moveWindow("Edges", 2*(inputImg.cols + 55),1);

	// set the callback on mouse
	setMouseCallback("Scribble Image", onMouse, 0);

	return 0;
}

int main(int argc, char *argv[])
{

	String image_name,numBinsStr,bhaSlopeStr;
	cout<<"input Parameters:"<<endl;
	cout<<"image name: ";
	cin>>image_name;

	// get img name parameter
	char * imgFileName = (char *)image_name.c_str();

	if (init(imgFileName)==-1)
	{
		cout <<  "Could not initialize" << endl ;
		return -1;
	}

	// Wait for a keystroke in the window
	for (;;)
	{
		char key = waitKey(0);
		switch (key)
		{
		case 'q':
			cout << "goodbye" << endl;
			destroyAll();
			return 0;
		case '-':
			//缩小画笔直径
			if (scribbleRadius > 2)
				scribbleRadius --;
			cout << "current radius is " << scribbleRadius << endl;
			break;
		case '+':
			if (scribbleRadius < 100)
				scribbleRadius ++;
			cout << "current radius is " << scribbleRadius << endl;
			break;
		case 's':
			{

				// this is where we store the results
				segMask = 0;
				inputImg.copyTo(segShowImg);
				//inputImg.copyTo(showImg);

				imwrite("bg.bmp",bgScribbleMask);

				break;

			}
		case 'r':
			{
				cout << "resetting" << endl;
				destroyAll();
				if (init(imgFileName)==-1)
				{
					cout <<  "could not initialize" << std::endl ;
					return -1;
				}
				break;
			}
		}
	}

	return 0;
}