Qlabel显示mat类型的图像大小改变不了

Question

ui.artwork->setScaledContents(true);
ui.artwork->setPixmap(QPixmap::fromImage(image_mat(camera.get_img())));

QImage Skinmesh::image_mat(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();
}

}

Mat里面装的是2560*1400大小的图片

布局是Qlabel放在Qwidget上面用的Horizontal Layout

现在是label跟着图片大小在变化不是图片跟着label变化

有什么好的方法让图片跟随label大小变化的吗