OPENCV学习笔记1-7_定义感兴趣区域

　　Sometimes, a processing function(处理函数) needs to be applied only to a portion(部分) of an image. OpenCV incorporates (内嵌)an elegant(精致) and simple mechanism(机制) to define a subregion(子区域) in an image and manipulate(操作) it as a regular image(普通图像).

　　The key(关键在于) is that the ROI is indeed(实际上) a cv::Mat object that points to the same data buffer as its parent image（指向与父图像相同的数据缓冲区） and has a header that specifies the coordinates（指定坐标） of the ROI.

#include <iostream>
#include <opencv2/opencv.hpp>
using namespace cv;
int main() {
namedWindow("YunFung Image");
Mat image = imread("test.jpg");
Mat logo  = imread("yunfung.png");
// define image ROI at image top-right
Mat imageROI(image,    Rect(image.cols - logo.cols, 0,        // ROI coordinates
logo.cols, logo.rows));           // ROI size
// insert logo
logo.copyTo(imageROI);
// not imwrite
imshow("YunFung Image", image);
waitKey(0);
return 0;
}