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;}