【OpenCv】QImage 与 cv::Mat 之间的相互转换

转换代码：

cv::Mat QImageToMat(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.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;  
}  

QImage MatToQImage(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();    
    }    
}  

测试代码：

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;  
}

void test1()  
{  
    cv::Mat mat = cv::imread("Q:\\Koala.jpg", cv::IMREAD_UNCHANGED);  
    cv::cvtColor(mat, mat, CV_BGR2BGRA);  
    QImage image = cvMat2QImage(mat);  
    qDebug() << (mat.type() == CV_8UC4);  
    cvNamedWindow("cvMat2QImage RGB32", CV_WINDOW_AUTOSIZE);  
    imshow("cvMat2QImage RGB32", mat);  
    QLabel label;  
    label.setPixmap(QPixmap::fromImage(image));  
    label.show();  
    cv::waitKey(10000);  
}  
void test2()  
{  
    cv::Mat mat = cv::imread("Q:\\Koala.jpg", cv::IMREAD_UNCHANGED);  
    cv::cvtColor(mat, mat, CV_BGR2GRAY);  
    QImage image = cvMat2QImage(mat);  
    cvNamedWindow("cvMat2QImage gray", CV_WINDOW_AUTOSIZE);  
    imshow("cvMat2QImage gray", mat);  
    QLabel label;  
    label.setPixmap(QPixmap::fromImage(image));  
    label.show();  
    cv::waitKey(10000);  
}  
void test3()  
{  
    QImage image("Q:\\Koala.jpg");  
    image = image.convertToFormat(QImage::Format_RGB32);  
    cv::Mat mat = QImage2cvMat(image);  
    //cv::cvtColor(mat, mat, CV_BGR2RGB);  
    imshow("QImage2cvMat RGB32", mat);  
    cv::waitKey(10000);  
}  
  
void test4()  
{  
    QImage image("Q:\\Koala.jpg");  
    image = image.convertToFormat(QImage::Format_RGB888);  
    cv::Mat mat = QImage2cvMat(image);  
    imshow("QImage2cvMat RGB24", mat);  
    cv::waitKey(10000);  
}  
void test5()  
{  
    QImage image("Q:\\Koala.jpg");  
    image = image.convertToFormat(QImage::Format_Indexed8);  
    cv::Mat mat = QImage2cvMat(image);  
    imshow("QImage2cvMat Indexed8", mat);  
    cv::waitKey(10000);  
}  
int main(int argc, char *argv[])  
{  
    QApplication a(argc, argv);  
    //test1();  
    //test2();  
    //test3();  
    //test4();  
    //test5();  
    test1();  
    return a.exec();  
}  

参考博客：

http://blog.csdn.net/dancing_night/article/details/51545524

http://blog.csdn.net/liyuanbhu/article/details/46662115

转换代码：