小记录：关于opencv3.X中的gauss滤波和图像类型转换

我的开发环境：windows下opencv3.2，QT4.8.6。
遇到的问题是： smooth = cvCreateImage(cvGetSize(iplImg),IPL_DEPTH_8U,1); cvSmooth(iplImg,smooth,CV_GAUSSIAN,3,0,0);
所报错误为：OpenCV Error: Assertion failed (dst.size() == src.size() && (smooth_type == CV_BLUR_NO_SCALE || dst.type() == src.type()))。程序执行后卡死退出，但是同样的代码在Linux中却可以执行。
  应该不是申请内存那块。同样的方式做“灰度化”就没有问题。初步怀疑是编译器问题。同时也请看到这篇文章的大牛们回复具体讨论。
  为了达到Gauss滤波的目的先用GaussianBlur函数代替cvSmooth平滑滤波，没有问题。

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  opencv中的转换挺重要，2.X和3.X有的会有些差别,而且方法不局限一种。因为我的环境是QT，在这里对QImage Mat IplImage转换记录下：
QImage—>IplImage:

QImage* img;
IplImage *iplImg;
int nChannel = 0;
    nChannel = img->format();
    qDebug()<<"img format is:"<<img->format();
    if( nChannel==0 )
    {
        return;
    }
    else
    {
        iplImg=cvCreateImageHeader(cvSize(img->width(),img->height()),8,nChannel);
        iplImg->imageData=(char*)img->bits();
        if(nChannel==3)
        {
            cvConvertImage(iplImg,iplImg,CV_CVTIMG_SWAP_RB);
        }

IplImage—>QImage: 摘自

QImage* CjwIplToQImg(const IplImage *cvImg)
{
if(!cvImg)
return NULL;
IplImage* temp=NULL;
temp=cvCloneImage(cvImg);
cvCvtColor(cvImg,temp,CV_BGR2RGB);
uchar* imgData = (uchar*)(temp->imageData);
QImage *qImg=new QImage(imgData,temp->width,temp->height,QImage::Format_RGB888);
return qImg;
cvReleaseImage(&temp);
delete imgData;
}

IplImage—>Mat:

  IplImage iplImg;
  Mat matimg;
    matimg = cvarrToMat(iplImg);

Mat—>IplImage:

iplImg= IplImage(matimg);

Mat—>QImage:摘自

QImage cvMat2QImage(const cv::Mat& mat)
{
    // 8-bits unsigned, NO. OF CHANNELS = 1
    if(mat.type() == CV_8UC1)
    {
        QImage image(mat.cols, mat.rows, QImage::Format_Indexed8);
        // Set the color table (used to translate colour indexes to qRgb values)
        image.setNumColors(256);
        for(int i = 0; i < 256; i++)
        {
            image.setColor(i, qRgb(i, i, i));
        }
        // Copy input Mat
        uchar *pSrc = mat.data;
        for(int row = 0; row < mat.rows; row ++)
        {
            uchar *pDest = image.scanLine(row);
            memcpy(pDest, pSrc, mat.cols);
            pSrc += mat.step;
        }
        return image;
    }
    // 8-bits unsigned, NO. OF CHANNELS = 3
    else if(mat.type() == CV_8UC3)
    {
        // Copy input Mat
        const uchar *pSrc = (const uchar*)mat.data;
        // Create QImage with same dimensions as input Mat
        QImage image(pSrc, mat.cols, mat.rows, mat.step, QImage::Format_RGB888);
        return image.rgbSwapped();
    }
    else if(mat.type() == CV_8UC4)
    {
        // Copy input Mat
        const uchar *pSrc = (const uchar*)mat.data;
        // Create QImage with same dimensions as input Mat
        QImage image(pSrc, mat.cols, mat.rows, mat.step, QImage::Format_ARGB32);
        return image.copy();
    }
    else
    {
        return QImage();
    }
}

QImage—>Mat:摘自

Mat QImage2cvMat(QImage image)
{
    cv::Mat mat;
    switch(image.format())
    {
    case QImage::Format_ARGB32:
    case QImage::Format_RGB32:
    case QImage::Format_ARGB32_Premultiplied:
        mat = cv::Mat(image.height(), image.width(), CV_8UC4, (void*)image.bits(), image.bytesPerLine());
        break;
    case QImage::Format_RGB888:
        mat = cv::Mat(image.height(), image.width(), CV_8UC3, (void*)image.bits(), image.bytesPerLine());
        cv::cvtColor(mat, mat, CV_BGR2RGB);
        break;
    case QImage::Format_Indexed8:
        mat = cv::Mat(image.height(), image.width(), CV_8UC1, (void*)image.bits(), image.bytesPerLine());
        break;
    }
    return mat;
}