QImage 与 Mat 互转

QImage 转 Mat

Mat QImage2Mat(QImage &img)
{
    cv::Mat mat;
    switch (img.format())
    {
    case QImage::Format_RGB32:  //一般Qt读入彩色图后为此格式
        mat = cv::Mat(img.height(), img.width(), CV_8UC4, (void*)img.constBits(), img.bytesPerLine());
        cv::cvtColor(mat,mat,cv::COLOR_BGRA2BGR);   //转3通道
        break;
    case QImage::Format_RGB888:
        mat = cv::Mat(img.height(), img.width(), CV_8UC3, (void*)img.constBits(), img.bytesPerLine());
        cv::cvtColor(mat,mat,cv::COLOR_RGB2BGR);
        break;
    case QImage::Format_Indexed8:
        mat = cv::Mat(img.height(), img.width(), CV_8UC1, (void*)img.constBits(), img.bytesPerLine());
        break;
    }
    return mat;
}

Mat 转 QImage

QImage Mat2QImage(Mat &img)
{
    if(img.type()==CV_8UC1 || img.type()==CV_8U)
    {
        QImage image((const uchar *)img.data, img.cols, img.rows, img.step, QImage::Format_Grayscale8);
        return image;
    }
    else if(img.type()==CV_8UC3)
    {
        QImage image((const uchar *)img.data, img.cols, img.rows, img.step, QImage::Format_RGB888);
        return image.rgbSwapped(); 
    }
}

转：https://www.cnblogs.com/zzzsj/p/16511888.html