改变ROI区域进行操作学习

#include "highgui.h"
#include "cv.h"
#include <iostream>
using namespace std;
void main()
{
IplImage *src=cvLoadImage("small.jpg",-1);//读入图像
//IplImage *dst;
CvRect ROI_rect_src;
CvRect ROI_rect_dst;

ROI_rect_src.x=0;
ROI_rect_src.y=0;
ROI_rect_src.width=src->width;
ROI_rect_src.height=src->height;
cvSetImageROI(src,ROI_rect_src);
IplImage *dst = cvCloneImage(src);//复制出ROI区域的图像
CvScalar pixel;
for (int i = src->height/2; i < src->height*0.8; ++i)
{
for (int j = src->width/2; j < src->width*0.8; ++j)
{
//获得像素的RGB值并显示, 注意内存中存储顺序是BGR
pixel = cvGet2D(dst, i, j);
//printf("B=%f,G=%f,R=%f/t", pixel.val[0], pixel.val[1], pixel.val[2]);
//修改各点的值
pixel.val[0] = 0;
pixel.val[1] = 0;
pixel.val[2] = 0;
cvSet2D(dst, i, j, pixel);
}
}
cvShowImage("ROI像素改变后",dst);//输出设定ROI以后的图像
cvWaitKey(0);
cvResetImageROI(dst);//释放目标图像的ROI
cvShowImage("源图像",src);//输出设定ROI以后的图像
cvWaitKey(0);
cvReleaseImage(&src);
cvReleaseImage(&dst);
}