pythonLSB加密算法代码

Python LSB加密算法是一种基于最低有效位隐写技术的加密算法。该算法可以将一张图片和一段文本进行加密，使得图片看起来并没有发生变化，但是文本已经被嵌入到了图片中。

以下是Python LSB加密算法的实现步骤：
1. 读取原始图片和需要加密的文本
2. 将文本转换成二进制字符串
3. 将二进制字符串嵌入到图片的最低有效位中
4. 保存加密后的图片

下面是Python实现代码：

from PIL import Image

def encode_image(image_name, secret_message):
    # Open image and convert to RGB format
    img = Image.open(image_name).convert('RGB')
    width, height = img.size

    # Convert message to binary
    secret_message = secret_message + "==="  # Add stopping criteria
    secret_message = ''.join([format(ord(i), "08b") for i in secret_message])
    message_length = len(secret_message)

    # Check if the message can be encoded in the image
    if message_length > (width * height * 3) // 8:
        raise ValueError("Error: Message too large to encode in image.")

    # Encode the message in the image
    encoded_img = img.copy()
    index = 0
    for row in range(height):
        for col in range(width):
            r, g, b = img.getpixel((col, row))
            if index < message_length:
                encoded_img.putpixel((col, row), (r - r % 2 + int(secret_message[index]), g - g % 2 + int(secret_message[index + 1]), b - b % 2 + int(secret_message[index + 2])))
                index += 3
            else:
                break

        if index >= message_length:
            break

    return encoded_img

def decode_image(image_name):
    # Open image and get size
    img = Image.open(image_name).convert('RGB')
    width, height = img.size

    # Decode the message from the image
    binary_str = ""
    for row in range(height):
        for col in range(width):
            r, g, b = img.getpixel((col, row))
            binary_str += str(r % 2)
            binary_str += str(g % 2)
            binary_str += str(b % 2)

    # Convert binary string to ASCII message
    message = ""
    for i in range(0, len(binary_str), 8):
        byte = binary_str[i:i+8]
        message += chr(int(byte, 2))
        if message[-3:] == "===":
            break

    return message[:-3]

# Example usage
encoded_img = encode_image("original.png", "This is a secret message.")
encoded_img.save("encoded.png")
decoded_message = decode_image("encoded.png")
print(decoded_message)