def save_last_sync(self, ids, process):
        try:
            spec = {'_id': 'last_sync'}
            document = {'$set': {process: ids}}
            self.db.internal.update(spec, document, upsert=True)
        except Exception as e:
            raise DatabaseException(e)
def make_grayscale(img):
    ret = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    return ret