直接上代码：
#include <highgui.h> #include <cxcore.h> #include "math.h"#include <cv.h> #include "iostream"using namespace std;const char* filename1 = "E:\\projects\\OpenCV\\splitMerge\\splitMerge\\osgEarth.jpg";int main(int argc, char** argv){IplImage* img;IplImage* img1;img = cvLoadImage(filename1, CV_LOAD_IMAGE_COLOR);cvNamedWindow("img", CV_WINDOW_AUTOSIZE);cvShowImage("img", img);CvRect rectInImage;rectInImage = cvRect(0, 0, img->width, img->height*0.2);CvSize size;size.width = rectInImage.width;size.height = rectInImage.height;img1 = cvCreateImage(size, img->depth, img->nChannels);cvSetImageROI(img, rectInImage);//基于给定的矩形设置图像的ROIcvCopy(img, img1);cvNamedWindow("img1", CV_WINDOW_AUTOSIZE);cvShowImage("img1", img1);cvResetImageROI(img);cvWaitKey(0);return 0;}
效果图：
