鼠标绘制矩形
程序之一，在OpenCV中利用鼠标绘制矩形
#include <cv.h>
#include <highgui.h>
#include <stdio.h>
IplImage* org = 0;
IplImage* img = 0;
IplImage* tmp = 0;
IplImage* dst = 0;
void on_mouse(int event, int x, int y, int flags, void* ustc)
{
static CvPoint pre_pt = { -1, -1 };
static CvPoint cur_pt = { -1, -1 }; //初始化鼠标窗口的选择的坐标
CvFont font;
cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 0.5, 0.5, 0, 1, CV_AA); //表示书写文字的操作
char temp[16];
if (event == CV_EVENT_LBUTTONDOWN) //当鼠标按下时，输出当前的坐标位置，用圆点表示
{
cvCopy(org, img);
sprintf(temp, "(%d,%d)", x, y);
pre_pt = cvPoint(x, y);
cvPutText(img, temp, pre_pt, &font, cvScalar(0, 0, 0, 255));
cvCircle(img, pre_pt, 3, cvScalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);
cvShowImage("img", img);
cvCopy(img, tmp);
}
else if (event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON)) //当鼠标移动，并且向左边拖拽的时候，输出鼠标点的位置信息
{
cvCopy(tmp, img);
sprintf(temp, "(%d,%d)", x, y);
cur_pt = cvPoint(x, y);
cvPutText(img, temp, cur_pt, &font, cvScalar(0, 0, 0, 255));
cvShowImage("img", img);
}
else if (event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))
{
cvCopy(tmp, img);
sprintf(temp, "(%d,%d)", x, y);
cur_pt = cvPoint(x, y);
cvPutText(img, temp, cur_pt, &font, cvScalar(0, 0, 0, 255));
cvRectangle(img, pre_pt, cur_pt, cvScalar(0, 255, 0, 0), 1, 8, 0);
cvShowImage("img", img);
} //当鼠标移动，并且向左边拖拽的时候，画出拖拽的矩形
else if (event == CV_EVENT_LBUTTONUP)
{
cvCopy(tmp, img);
sprintf(temp, "(%d,%d)", x, y);
cur_pt = cvPoint(x, y);
cvPutText(img, temp, cur_pt, &font, cvScalar(0, 0, 0, 255));
cvCircle(img, cur_pt, 3, cvScalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);
cvRectangle(img, pre_pt, cur_pt, cvScalar(0, 255, 0, 0), 1, 8, 0);
cvShowImage("img", img); //当鼠标按键放开时，画出鼠标点的坐标，并且画出鼠标画出的矩形
cvCopy(img, tmp);
int width = abs(pre_pt.x - cur_pt.x);
int height = abs(pre_pt.y - cur_pt.y);
if (width == 0 || height == 0)
{
cvDestroyWindow("dst");
return;
} //查看鼠标画出的矩形的大小，并用改大小表示这一区域的图像
dst = cvCreateImage(cvSize(width, height), org->depth, org->nChannels);
CvRect rect;
if (pre_pt.x<cur_pt.x && pre_pt.y<cur_pt.y)
{
rect = cvRect(pre_pt.x, pre_pt.y, width, height);
}
else if (pre_pt.x>cur_pt.x && pre_pt.y<cur_pt.y)
{
rect = cvRect(cur_pt.x, pre_pt.y, width, height);
}
else if (pre_pt.x>cur_pt.x && pre_pt.y>cur_pt.y)
{
rect = cvRect(cur_pt.x, cur_pt.y, width, height);
}
else if (pre_pt.x<cur_pt.x && pre_pt.y>cur_pt.y)
{
rect = cvRect(pre_pt.x, cur_pt.y, width, height);
}
cvSetImageROI(org, rect); //取图像感兴趣区域的图像，rect里的图像
cvCopy(org, dst);
cvResetImageROI(org);
cvDestroyWindow("dst");
cvNamedWindow("dst", 1);
cvShowImage("dst", dst);
cvSaveImage("dst.jpg", dst);
}
}
int main()
{
org = cvLoadImage("D:6.jpg", 1);
img = cvCloneImage(org);
tmp = cvCloneImage(org);
cvNamedWindow("img", 1);
cvSetMouseCallback("img", on_mouse, 0);
cvShowImage("img", img);
cvWaitKey(0);
cvDestroyAllWindows();
cvReleaseImage(&org);
cvReleaseImage(&img);
cvReleaseImage(&tmp);
cvReleaseImage(&dst);
return 0;
}
效果图如下
程序之二，在OpenCV中利用鼠标绘制矩形并截取该矩形区域的图像
效果图如下
