python从二维数组生成位图数据

import numpy as np
from PIL import Image

array_2d = [[0, 1, 0, 1],
            [1, 0, 1, 0],
            [0, 1, 0, 1],
            [1, 0, 1, 0]]

array_np = np.array(array_2d)

image = Image.new('1', (array_np.shape[1], array_np.shape[0]))

for i in range(array_np.shape[0]):
    for j in range(array_np.shape[1]):
        pixel_value = array_np[i, j]
        image.putpixel((j, i), pixel_value)

image.save('bitmap.bmp')