opencv对图像进行高斯平滑和边缘提取

高斯平滑：

    //对图像进行平滑处理
    cvNamedWindow( "smooth-out" );
    //当前图像结构的大小,各通道每个像素点的数据类型,通道的总数
    IplImage* out = cvCreateImage(
        cvGetSize(img),
        IPL_DEPTH_8U,
        3
    );
    cvSmooth( img, out, CV_GAUSSIAN, 3, 3 );
    cvShowImage( "smooth-out", out );

边缘检测和缩放，canny

IplImage* doPyrDown(
    IplImage* in,
    bool isPyr,
    double      lowThresh,
    double      highThresh,
    double      aperture)
{

    // Best to make sure input image is divisible by two.
    //
//    assert( in->width%2 == 0 && in->height%2 == 0 );

    IplImage* out = NULL;
    if(isPyr){
        out = cvCreateImage(
                cvSize( in->width/2, in->height/2 ),
                in->depth,
                in->nChannels
            );
        //cvPyrDown() 创建一幅宽度和高度为输入图像一半尺寸的图像
        cvPyrDown( in, out );
    }else{
        if(in->nChannels != 1)
            return(0);
        /*
         * Canny边缘检测将输出写入一个单通道(灰度级)图像*/
        IplImage* out = cvCreateImage(
            cvGetSize(in),
            IPL_DEPTH_8U,
            1
        );
        cvCanny( in, out, lowThresh, highThresh, aperture );
    }

    return( out );
};

转载：http://book.51cto.com/art/200912/172349.htm