#include <iostream>
#include <opencv2/opencv.hpp>
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"

using namespace std;
using namespace cv;

int main()
{
	Mat srcImg = imread("..\\src.jpg");
	if (srcImg.empty())
	{
		cout<<"Read Image Failed!"<<endl;
		return -1;
	}
	resize(srcImg, srcImg, Size(700, 500));

	Point root_points[1][6];
	root_points[0][0] = Point(100, 100);
	root_points[0][1] = Point(200, 100);
	root_points[0][2] = Point(300, 200);
	root_points[0][3] = Point(200, 300);
	root_points[0][4] = Point(100, 300);
	root_points[0][5] = Point(0, 200);
	
	const Point* ppt[1] = { root_points[0] };
	int npt[] = { 6 };

	Mat dstImg = srcImg.clone();
	polylines(dstImg, ppt, npt, 1, 1, Scalar(0,0,0), 1, 8, 0);
	fillPoly(dstImg, ppt, npt, 1, Scalar(0, 0, 0));

	imshow("srcImg", srcImg);
	imshow("dstImg", dstImg);
	waitKey(0);

	return 0;
}
 

效果如下：

#include <iostream>
#include <opencv2/opencv.hpp>
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"

using namespace std;
using namespace cv;

int main()
{
	Mat srcImg = imread("..\\src.jpg");
	if (srcImg.empty())
	{
		cout<<"Read Image Failed!"<<endl;
		return -1;
	}
	resize(srcImg, srcImg, Size(700, 500));
	Mat dstImg = srcImg.clone();

	Rect targetRect(100,100,150,200);
	Mat allZeroZone(targetRect.height, targetRect.width, CV_8UC3, Scalar(0));
	Mat tmpMat = dstImg(targetRect);
	allZeroZone.copyTo(tmpMat);
	imshow("srcImg", srcImg);
	imshow("dstImg", dstImg);
	waitKey(0);

	return 0;
}
 

效果如下：