OpenCV利用鼠标在如下图所示的MFC视频图像上画直线？

您好，您这样：

#include <cv.h>

#include <highgui.h>

#include <stdio.h>

#pragma comment( lib, "cv.lib" )

#pragma comment( lib, "cxcore.lib" )

#pragma comment( lib, "highgui.lib" )

IplImage* src = 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}

CvFont font

cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 0.5, 0.5, 0, 1, CV_AA)

char temp[16]

if( event == CV_EVENT_LBUTTONDOWN )

{

cvCopy(dst,src)

sprintf(temp,"(%d,%d)",x,y)

pre_pt = cvPoint(x,y)

cvPutText(src,temp, pre_pt, &font, cvScalar(0,0, 0, 255))

cvCircle( src, pre_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 )

cvShowImage( "src", src )

cvCopy(src,dst)

}

else if( event == CV_EVENT_MOUSEMOVE &&(flags &CV_EVENT_FLAG_LBUTTON))

{

cvCopy(dst,src)

sprintf(temp,"(%d,%d)",x,y)

cur_pt = cvPoint(x,y)

cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255))

cvLine(src, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, CV_AA, 0 )

cvShowImage( "src", src )

}

else if( event == CV_EVENT_LBUTTONUP )

{

sprintf(temp,"(%d,%d)",x,y)

cur_pt = cvPoint(x,y)

cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255))

cvCircle( src, cur_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 )

cvLine( src, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, CV_AA, 0 )

cvShowImage( "src", src )

cvCopy(src,dst)

}

}

int main()

{

src=cvLoadImage("lena.jpg",1)

dst=cvCloneImage(src)

cvNamedWindow("src",1)

cvSetMouseCallback( "src", on_mouse, 0 )

cvShowImage("src",src)

cvWaitKey(0)

cvDestroyAllWindows()

cvReleaseImage(&src)

cvReleaseImage(&dst)

return 0

}

可以通过一个bool全局变量指示划线菜单项是否被选中，首先用类向导在view类中为划线菜单项添加消息响应函数，在该函数中为该全局变量赋值指示开始划线

可以这样赋值

m_bline=true

然后通过类向导向view类添加OnLButtonDown()函数以响应鼠标按下消息，该消息中首先判断m_bline是否为true，若为true，可通过一个全局CPoint变量记录鼠标按下的位置

OnLButtonUp(UINT,

CPoint

point)

{

if(m_bline)m_oripoint=point

}

相同方法添加OnLButtonUp()函数响应鼠标释放消息

if(m_bline)

{

ClientDC

dc(this)//获取设备描述表句柄

dc.MoveTo(m_oripoint)//画笔移动到第一点

dc.LineTo(point)//划线至第二点

}

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