round corners

picture = "snap.png"
if os.path.isfile(picture):
    scaledpicture = QtGui.QPixmap(picture).scaled(238, 174, QtCore.Qt.IgnoreAspectRatio, QtCore.Qt.FastTransformation)
    pixlabel = QtGui.QLabel()
    pixlabel.setPixmap(scaledpicture)
    pixlabel.setStyleSheet("border:2px solid grey; border-radius: 10px;background-color: transparent;");
    picitem = QtGui.QGraphicsPixmapItem(pixlabel.pixmap())
    picitem.setPos((260 * col), lin)
    self.scene.addItem(picitem)

------------------------------------

picture = "snap.png"
if os.path.isfile(picture):
    pixlabel = QtGui.QLabel()
    pixlabel.setPixmap(scaledpicture)
    pixlabel.setMask(scaledpicture.mask())
    pixlabel.setFixedSize(scaledpicture.width(), scaledpicture.height())
    pixlabel.setWindowFlags(QtCore.Qt.FramelessWindowHint)
    pixlabel.move(100, 100)
    picitem = QtGui.QGraphicsPixmapItem(pixlabel.pixmap())
    picitem.setPos((260 * col), lin)
    self.scene.addItem(picitem)

------------------------------------

picture = "snap.png"
if os.path.isfile(picture):
    scaledpicture = QtGui.QPixmap(picture).scaled(238, 174, QtCore.Qt.IgnoreAspectRatio, QtCore.Qt.FastTransformation)
    maskedpicture = maskregion(scaledpicture)
    picitem = QtGui.QGraphicsPixmapItem(maskedpicture)
    self.scene.addItem(picitem)

def maskregion(self, pixmap):
    widget_rect = pixmap.rect()
    painter = QtGui.QPainter(pixmap)
    painter.save()
    painter.setRenderHint(QtGui.QPainter.Antialiasing)
    rounded_rect = QtGui.QPainterPath()
    rounded_rect.addRoundedRect(1, 1, widget_rect.width() - 2, widget_rect.height() - 2, 20, 20, QtCore.Qt.AbsoluteSize)
    painter.setClipPath(rounded_rect)
    maskregion = painter.clipRegion()
    return maskregion