def read(self):
        """https://picamera.readthedocs.io/en/release-1.13/recipes1.html#capturing-to-a-pil-image"""
        stream = BytesIO()
        self.cam.capture(stream, format='png')
        # "Rewind" the stream to the beginning so we can read its content
        stream.seek(0)
        return Image.open(stream)
https://picamera.readthedocs.io/en/release-1.13/recipes1.html#capturing-to-a-pil-image