鼠标选取ROI区域

来源：互联网发布：火星网络加速器编辑：程序博客网时间：2024/04/27 18:52

这里实现一个简单的功能：在一幅完整的图中用鼠标拖出一个矩形框，然后把这个矩形框区域存储为一幅图片

这里有个十分值得警惕的地方，就是你在选择方框的时候必须沿着向右、向下拖动，否则报错。我用泪水得来的教训

#include "opencv2/core/core.hpp"
#include<cv.h>
#include<highgui.h>
using namespace cv;
using namespace std;

CvPoint pt1 = Point(0, 0);
CvPoint pt2 = Point(0, 0);
bool is_selecting = false;
void cvMouseCallback(int mouseEvent, int x, int y, int flags, void* param)
{
switch (mouseEvent)
{
case CV_EVENT_LBUTTONDOWN:
pt1 = Point(x, y);
pt2 = Point(x, y);
is_selecting = true;
break;
case CV_EVENT_MOUSEMOVE:
if (is_selecting)
pt2 = Point(x, y);
break;
case CV_EVENT_LBUTTONUP:
pt2 = Point(x, y);
is_selecting = false;
break;
}
}

int main()
{
IplImage* img = cvLoadImage("photo.jpg");
IplImage* img_show = cvCreateImage(cvGetSize(img), IPL_DEPTH_8U, 3);
cvNamedWindow("img", CV_WINDOW_AUTOSIZE);
cvSetMouseCallback("img", cvMouseCallback);
bool shift_on = false;
while (true)
{
cvCopy(img, img_show);
cvRectangle(img_show, pt1, pt2, Scalar(0, 255, 0));
cvShowImage("img", img_show);
char key = cvWaitKey(10);
cvSetImageROI(img_show,cvRect(pt1.x, pt1.y, abs(pt2.x - pt1.x), abs(pt2.y - pt1.y)));
IplImage* roi = cvCreateImage(cvSize(abs(pt2.x - pt1.x), abs(pt2.y - pt1.y)), IPL_DEPTH_8U, 3);
cvCopy(img_show, roi);
cvResetImageROI(img_show);
cvSaveImage("ROI.jpg", roi);
if (key == 27) break;
}
return 0;
}

原图：

选择的矩形区域：

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