Merge pull request #35 from cneud/upgrade_to_tf2_with_tf1.compat_session

fix tf2 with tf1.compat session

requirements.txt

@@ -1,7 +1,6 @@
-numpy >= 1.17.0, < 1.19.0
+numpy
 setuptools >= 41
 opencv-python-headless
 ocrd >= 2.22.3
-keras >= 2.3.1, < 2.4
 h5py < 3
-tensorflow-gpu >= 1.15, < 1.16
+tensorflow-gpu >= 2.4.0

sbb_binarize/sbb_binarize.py

@@ -14,10 +14,11 @@ import cv2
 environ['TF_CPP_MIN_LOG_LEVEL'] = '3'
 stderr = sys.stderr
 sys.stderr = open(devnull, 'w')
-from keras.models import load_model
-from keras.backend import tensorflow_backend
-sys.stderr = stderr
 import tensorflow as tf
+from tensorflow.keras.models import load_model
+from tensorflow.python.keras import backend as tensorflow_backend
+sys.stderr = stderr
+
 
 import logging