opencv图像边界提取

#include <stdio.h>
#include <cv.h>
#include <highgui.h>
#include <cvaux.h>

int intersection(IplImage *img_in,IplImage *img_in2,IplImage *img_out);
int differencing(IplImage *img_in,IplImage *img_in2,IplImage *img_out);
int complementation(IplImage *img_in,IplImage *img_out);

int main( int argc, char** argv )
{
        IplImage *img = cvLoadImage("F:/Works/Qt/20140520/EXP12/EXP12B/Fig0914(a)(licoln from penny).tif",0);
        if(img == NULL)
        {
                printf("img load failed!\n");
                return 0;
        }
        IplImage *img_erode = cvCreateImage(cvGetSize(img), 8, 1);
        IplImage *img_out = cvCreateImage(cvGetSize(img), 8, 1);
        IplConvKernel* element = cvCreateStructuringElementEx(3,3,1,1,CV_SHAPE_RECT,NULL);
        cvErode( img,img_erode, element,1); //腐蚀
        //intersection(img_erode,img_dilate,img_out);//交集
        differencing(img,img_erode,img_out);
        //complementation(img_erode,img_out);//补集

        cvNamedWindow("originpic");
        cvNamedWindow("img_erode");
        cvNamedWindow("img_out");

        cvShowImage("originpic",img);