如何从opencv image_hash模块PHashImpl中获取哈希值

import cv2
from PIL import Image
from io import BytesIO

image_path = "path_to_image.jpg"  # 图像路径
image = cv2.imread(image_path)
gray_image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

hash_impl = cv2.img_hash.PHashImpl_create()
hash_value = hash_impl.compute(gray_image)

hash_str = hash_value.flatten().tolist()
hash_str = ''.join(map(str, hash_str))