图像缩放_OpenCv

图像缩放是一种比较简单的图像处理操作，这里给出opencv中的代码，

opencv的版本C语言接口

int resize_c()
{
    const char *pstrImageName = "lena.jpg";
    const char *pstrSaveImageName = "lena缩放图.jpg";
    const char *pstrWindowsSrcTitle = "原图";
    const char *pstrWindowsDstTitle = "缩放图 ";

    double fScale = 0.8;        //缩放倍数
    CvSize czSize;                //目标图像尺寸

    //从文件中读取图像
    IplImage *pSrcImage = cvLoadImage(pstrImageName, CV_LOAD_IMAGE_UNCHANGED);
    IplImage *pDstImage = NULL;    

    //计算目标图像大小
    czSize.width = pSrcImage->width * fScale;
    czSize.height = pSrcImage->height * fScale;

    //创建图像并缩放
    pDstImage = cvCreateImage(czSize, pSrcImage->depth, pSrcImage->nChannels);
    cvResize(pSrcImage, pDstImage, CV_INTER_AREA);

    //创建窗口
    cvNamedWindow(pstrWindowsSrcTitle, CV_WINDOW_AUTOSIZE);
    cvNamedWindow(pstrWindowsDstTitle, CV_WINDOW_AUTOSIZE);

    //在指定窗口中显示图像
    cvShowImage(pstrWindowsSrcTitle, pSrcImage);
    cvShowImage(pstrWindowsDstTitle, pDstImage);

    //等待按键事件
    cvWaitKey();

    //保存图片
    cvSaveImage(pstrSaveImageName, pDstImage);

    cvDestroyWindow(pstrWindowsSrcTitle);
    cvDestroyWindow(pstrWindowsDstTitle);
    cvReleaseImage(&pSrcImage);
    cvReleaseImage(&pDstImage);
    return 0;
}

C++版本

int resize_cpp()
{
    string pstrImageName = "lena.jpg";
    string pstrSaveImageName = "lena缩放图.jpg";
    string pstrWindowsSrcTitle = "原图";
    string pstrWindowsDstTitle = "缩放图 ";

    double fScale = 0.8;        //缩放倍数
    Size czSize;                //目标图像尺寸

    //从文件中读取图像
    Mat pSrcImage = imread(pstrImageName);

    //计算目标图像大小
    czSize.width = pSrcImage.cols * fScale;
    czSize.height = pSrcImage.rows * fScale;

    //创建图像并缩放
    Mat pDstImage  = Mat(czSize, CV_8UC3);
    resize(pSrcImage, pDstImage, czSize,CV_INTER_AREA);

    //创建窗口
    namedWindow(pstrWindowsSrcTitle, CV_WINDOW_AUTOSIZE);
    namedWindow(pstrWindowsDstTitle, CV_WINDOW_AUTOSIZE);

    //在指定窗口中显示图像
    imshow(pstrWindowsSrcTitle, pSrcImage);
    imshow(pstrWindowsDstTitle, pDstImage);

    //等待按键事件
    waitKey();
    return 0;
}