[Python] Convert boolean numpy array to pillow image

I'm currently working with image processing in python using the scikit-image library. I'm trying to make a binary image using sauvola thresholding with the following code:

from PIL import Image
import numpy
from skimage.color import rgb2gray
from skimage.filters import threshold_sauvola

im = Image.open("test.jpg")
pix = numpy.array(im)
img = rgb2gray(pix)

window_size = 25
thresh_sauvola = threshold_sauvola(img, window_size=window_size)
binary_sauvola = img > thresh_sauvola


Which gives the following result:

the output is a numpy array with data type of this image is a bool

[[ True True True ... True True True]
[ True True True ... True True True]
[ True True True ... True True True]
...
[ True True True ... True True True]
[ True True True ... True True True]
[ True True True ... True True True]]


The problem is that I need to convert this array back to a PIL image using the following line of code:

image = Image.fromarray(binary_sauvola)


which makes the image look like this:



I also tried to change the data type from bool to uint8 but then I'll get the following exception:

AttributeError: 'numpy.ndarray' object has no attribute 'mask'


So far I haven't found a solution to get a PIL image which looks like the result of the thresholding.

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