Used to work fine, now only outputs black pixels

[marsupilamiimalipusram]

Hello,

I tried the code on colab a few weeks ago (only changing a few lines for compatibility), and it worked perfectly fine.
Now, it only outputs black images. The images have the correct dimensions, but they contain only black pixels.

Compatibility change in 'main.py':

# ~ import tensorflow as tf  # here
import tensorflow.compat.v1 as tf; tf.disable_v2_behavior()  # here
import numpy as np
from imageio import imread, imsave
import os, glob, cv2
imsave = cv2.imwrite  # and here

As I said, it worked after I made the changes, so these are not responsible for the strange behavior.
Would you have any idea?

Best regards.