学习OpenCV——鼠标事件（画框）

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#include "cv.h"

#include "highgui.h"

bool check_line_state=false;

IplImage* workImg;

IplImage* imgshow;

CvRect ROI_rect;

void on_mouse4(int event, int x,int y,int flags,void* param)

{

int thickness=2;

CvPoint p1,p2;

if(event==CV_EVENT_LBUTTONDOWN)

{

//当前鼠标位置（x，y）

ROI_rect.x=x;

ROI_rect.y=y;

check_line_state=true;

}

else if(check_line_state&&event==CV_EVENT_MOUSEMOVE)//鼠标状态

{

cvCopy(workImg,imgshow);//这一步很重要，不断更新显示图像，不然画出的图像如图2所示

p1=cvPoint(ROI_rect.x,ROI_rect.y);

p2=cvPoint(x,y);

cvRectangle(imgshow,p1,p2,CV_RGB(0,255,150),thickness,CV_AA,0);

cvShowImage("image",imgshow);

}

else if(check_line_state&&event==CV_EVENT_LBUTTONUP)

{

check_line_state=false;

cvWaitKey(20);

}

}

int main()

{

workImg=cvLoadImage("D:/Demo.jpg",1);

imgshow=cvCreateImage(cvSize(workImg->width,workImg->height),workImg->depth,workImg->nChannels);

cvCopy(workImg,imgshow);

//cvFlip(imgshow);

ROI_rect.x=ROI_rect.y=0;

cvNamedWindow("image",CV_WINDOW_AUTOSIZE);

cvShowImage("image",imgshow);

cvSetMouseCallback("image",on_mouse4);

cvWaitKey();

cvDestroyWindow("image");

}

图1： 图2：





from: http://blog.csdn.net/yangtrees/article/details/7573919