OpenCV画直线的问题

采石工 2011-05-07 05:53:11

我想利用下面的代码画动态直线。就是说：鼠标左键按下时记录初始点，然后拖动，拖动的过程中不断地修正直线，显示的是初始点和光标所在点之间的直线，鼠标左键松开时显示初始点和松开点之间的直线。我想大家都尝试过用MFC或SDK实现相似功能的程序，可是在OpenCV中用相似的如下的代码怎么就不行了呢？烦请大侠指正指点！



#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* imgOriginal = 0; 

IplImage* img = 0; 



void on_mouse( int event, int x, int y, int flags, void* ustc)

{

    if( !img )

        return;

	

	CvPoint prev_pt;

	CvPoint pt;



	if( event == CV_EVENT_LBUTTONDOWN )

	{

        prev_pt = cvPoint(x,y);

		pt = cvPoint(x,y);

	}

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

    {

		cvLine( img, prev_pt, pt, cvScalar(255,0,255,0), 3, CV_AA, 0 );

		pt = cvPoint(x,y);



        cvLine( img, prev_pt, pt, cvScalar(0,255,0,0), 8, CV_AA, 0 );

        cvShowImage( "image", img );

    }

}





int main( int argc, char** argv )

{

	printf( "Hotkeys: \n"

		"ESC	- quit the program\n"

		"r	- restore the original image\n");



	imgOriginal=cvCreateImage(cvSize(800,600),IPL_DEPTH_8U,3);

	cvSet(imgOriginal,cvScalar(255,255,255,0));

//	imgOriginal=cvLoadImage("f:\\lena.jpg",1);

	

    img = cvCloneImage( imgOriginal );

	cvNamedWindow( "image", 1 );

    cvShowImage( "image", img );



    cvSetMouseCallback( "image", on_mouse, 0 );

	

	while(true)

    {

        int c = cvWaitKey(0);

		

        if( (char)c == 27 )

            break;

		

        if( (char)c == 'r' )

        {

            cvCopy( imgOriginal, img,0 );

            cvShowImage( "image", img );

        }

    }

	

	cvDestroyWindow("image");

	cvReleaseImage(&imgOriginal);

	cvReleaseImage(&img);

	

    return 0;

}