利用python设计图像加密技术(Arnold算法)

def arnold_encode(image, shuffle_times, a, b):
    """ Arnold shuffle for rgb image
    Args:
        image: input original rgb image
        shuffle_times: how many times to shuffle
    Returns:
        Arnold encode image
    """
    # 1:创建新图像
    arnold_image = np.zeros(shape=image.shape)
    
    # 2：计算N
    h, w = image.shape[0], image.shape[1]
    N = h   # 或N=w
    
    # 3：遍历像素坐标变换
    for time in range(shuffle_times):
        for ori_x in range(h):
            for ori_y in range(w):
                # 按照公式坐标变换
                new_x = (1*ori_x + b*ori_y)% N
                new_y = (a*ori_x + (a*b+1)*ori_y) % N
                
                arnold_image[new_x, new_y, :] = image[ori_x, ori_y, :]
            
    return arnold_image

def arnold_decode(image, shuffle_times, a, b):
    """ decode for rgb image that encoded by Arnold
    Args:
        image: rgb image encoded by Arnold
        shuffle_times: how many times to shuffle
    Returns:
        decode image
    """
    # 1:创建新图像
    decode_image = np.zeros(shape=image.shape)
    
    # 2：计算N
    h, w = image.shape[0], image.shape[1]
    N = h # 或N=w
    
    # 3：遍历像素坐标变换
    for time in range(shuffle_times):
        for ori_x in range(h):
            for ori_y in range(w):
                # 按照公式坐标变换
                new_x = ((a*b+1)*ori_x + (-b)* ori_y)% N
                new_y = ((-a)*ori_x + ori_y) % N
                decode_image[new_x, new_y, :] = image[ori_x, ori_y, :]
    return decode_image