如何在图像中添加20%的最大像素强度的噪声？

import cv2
import numpy as np

def add_noise(image):
    # 转换为灰度图像
    gray_image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    
    # 计算最大像素强度
    max_intensity = np.max(gray_image)
    
    # 计算20%最大像素强度
    noise_intensity = int(0.2 * max_intensity)
    
    # 添加噪声
    noisy_image = gray_image + np.random.randint(-noise_intensity, noise_intensity, size=gray_image.shape)
    
    # 确保像素值不超过最大像素强度
    noisy_image = np.clip(noisy_image, 0, max_intensity)
    
    # 转换回彩色图像
    noisy_image = cv2.cvtColor(noisy_image.astype(np.uint8), cv2.COLOR_GRAY2BGR)
    
    return noisy_image

# 读取图像
image = cv2.imread('image.jpg')

# 添加噪声
noisy_image = add_noise(image)

# 显示原始图像和添加噪声后的图像
cv2.imshow('Original Image', image)
cv2.imshow('Noisy Image', noisy_image)
cv2.waitKey(0)
cv2.destroyAllWindows()