我想通过下面的代码对Keras（像素值只有0和1）的8*8像素灰度图像进行数据扩增：

from ctypes import sizeof
from re import X
from turtle import shape
from keras.preprocessing.image import ImageDataGenerator
from skimage import io
import numpy as np
from PIL import Image

datagen = ImageDataGenerator(
        rotation_range=45,     #Random rotation between 0 and 45
        width_shift_range=0.2,   #% shift
        height_shift_range=0.2,
        shear_range=0.2,
        zoom_range=0.2,
        horizontal_flip=True,
        fill_mode='nearest')    #Also try nearest, constant, reflect, wrap

    
# forming a binary 8*8 array
array = np.array([[0,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,0],[0,0,1,1,1,0,0,0], 
 [0,0,0,1,1,1,0,0],[0,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,0],[0,0,0,0,0,0,1,0],[0,0,0,0,0,0,0,0]])

# scale values to uint8 maximum 255, and convert it to greyscale image
array = ((array) * 255).astype(np.uint8)
x = Image.fromarray(array)

i = 0
for batch in datagen.flow(x, batch_size=16,  
                          save_to_dir='augmented', 
                          save_prefix='aug', 
                          save_format='png'):
i += 1
if i > 20:
    break  # otherwise the generator would loop indefinitely

但是我在输出中得到这个错误（当我有.flow函数时）：

ValueError: ('Input data in `NumpyArrayIterator` should have rank 4. You passed an array with shape', (8, 8))

有人能给予我一下吗？