def connect(self): 
        try:
            self.connection = pymongo.Connection(self.host, self.port)
            self.db = self.connection[self.name]
        except AutoReconnect:
            raise DatabaseException("It's not possible connect to the database")
def _read_img(self, file_name):
        img = Image.open(file_name)
        if img.mode != "RGB":
            img = img.convert("RGB")
        return img