opencv:canny邊緣檢測

    #include "StdAfx.h"  
    #include "cv.h"  
    #include "cxcore.h"  
    #include "highgui.h"  
    int main( int argc, char** argv )  
    {  
        //聲明IplImage指針  
        IplImage* img = NULL;  
        IplImage* cannyImg = NULL;  
        char *filename;  
        filename="lena.png";  
        img=cvLoadImage(filename,1);  
        //載入圖像，強制轉化爲Gray  
        if((img = cvLoadImage(filename, 0)) != 0 )  
        {  
            //爲canny邊緣圖像申請空間  
            cannyImg = cvCreateImage(cvGetSize(img),IPL_DEPTH_8U,1);  
            //canny邊緣檢測  
            cvCanny(img, cannyImg, 50, 150, 3);  
            //創建窗口  
            cvNamedWindow("src", 1);  
            cvNamedWindow("canny",1);  
            //顯示圖像  
            cvShowImage( "src", img );  
            cvShowImage( "canny", cannyImg );  
            cvWaitKey(0); //等待按鍵  
            //銷燬窗口  
            cvDestroyWindow( "src" );  
            cvDestroyWindow( "canny" );  
            //釋放圖像  
            cvReleaseImage( &img );  
            cvReleaseImage( &cannyImg );  
            return 0;  
        }  
        return -1;  
    }