해결 완료
def upload_func(self):
fname = QFileDialog.getOpenFileName(self, 'Open file', 'c:\\',"Image files (*.jpg *.gif *.svg *.png)")
imagepath = fname[0] # image
pix = QPixmap(imagepath)
self.upload_Label.setPixmap(QPixmap(pix))
self.upload_Label.setScaledContents(True)
겨우 이걸 못 찾아서 헛짓거리만 해댄 나 또 반성하자..