python - 使用乘法和减法加密和解密图像

Question

我使用加法和减法在 Python 中对图像进行编码和解码，但我无法通过乘法和除法来完成。任何人都可以吗？
加密代码部分:

for  i in range(image.shape[0]):
    for j in range(image.shape[1]):
        temp=image[i, j] + key[i,j]
        if temp > 255:
            temp = image[i, j] + key[i,j] - 255
        result[i,j]=temp

解密代码部分:

for i in range(image.shape[0]):
    for j in range(image.shape[1]):
        temp = image[i, j]-key[i,j]
        if temp < 0:
            temp = 255 + temp
        result[i, j] = temp

Answer 1

你可以试试这种方式:

from cv2 import *
import numpy as np

image_input = imread('image_input.jpeg', IMREAD_GRAYSCALE)
(x, y) = image_input.shape
image_input = image_input.astype(float) / 255.0

加密

mu, sigma = 0, 0.1 # mean and standard deviation
key = np.random.normal(mu, sigma, (x, y)) + np.finfo(float).eps
image_encrypted = image_input / key
imwrite('image_encrypted.jpg', image_encrypted * 255)

解密

image_output = image_encrypted * key
image_output *= 255.0
imwrite('image_output.jpg', image_output)