QLabel QPixmap Antialiasing

[great_newbie]

Hi, Guys!
I am attempting to draw an image with rounded corners in a QLabel. I have tried using QPainter to draw the image and set the QPainter::Antialiasing property in an effort to eliminate the jagged edges of the corners, but it doesn't seem to be working. Here is my code:

QPixmap QLabelUtils::pixmapToRound(QPixmap& src, int x, int y, int width, int height, int radius) {
    if (src.isNull()) {
        return QPixmap();
    }

    QSize size(width, height);
    QBitmap mask(size);
    QPainter painter(&mask);
    painter.setRenderHints(QPainter::Antialiasing|QPainter::SmoothPixmapTransform);
    painter.fillRect(x, y, size.width(), size.height(), Qt::white);
    painter.setBrush(QColor(0, 0, 0));

    QPainterPath path;
    path.addRoundedRect(x, y, size.width()-1, size.height()-1, radius, radius);
    path.translate(0.5, 0.5);
    painter.drawPath(path);

    QPixmap image = src.scaled(size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
    image.setMask(mask);
    return image;
}

my Qt version is 6.4.
Please help me solve this problem, it's really bothering me. Thank you very much.