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.setColorCount(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)

    {

        qDebug() << "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

    {

        qDebug() << "ERROR: Mat could not be converted to QImage.";

        return QImage();

    }

}

cv::Mat QImage2cvMat(QImage image)

{

    cv::Mat mat;

    qDebug() << image.format();

    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.constBits(), image.bytesPerLine());

        break;

    case QImage::Format_RGB888:

        mat = cv::Mat(image.height(), image.width(), CV_8UC3, (void*)image.constBits(), image.bytesPerLine());

        cv::cvtColor(mat, mat, CV_BGR2RGB);

        break;

    case QImage::Format_Indexed8:

        mat = cv::Mat(image.height(), image.width(), CV_8UC1, (void*)image.constBits(), image.bytesPerLine());

        break;

    }

    return mat;

}