make retinaface compatible with tf2.16 and later

Author: serengil

retinaface/RetinaFace.py

@@ -3,13 +3,21 @@
 import logging
 from typing import Union, Any, Optional, Dict
 
+# this has to be set before importing tf
+os.environ["TF_USE_LEGACY_KERAS"] = "1"
+
+# pylint: disable=wrong-import-position
 import numpy as np
 import tensorflow as tf
 
 from retinaface import __version__
 from retinaface.model import retinaface_model
 from retinaface.commons import preprocess, postprocess
 from retinaface.commons.logger import Logger
+from retinaface.commons import package_utils
+
+# users should install tf_keras package if they are using tf 2.16 or later versions
+package_utils.validate_for_keras3()
 
 logger = Logger(module="retinaface/RetinaFace.py")
 

retinaface/commons/package_utils.py

@@ -0,0 +1,28 @@
+# 3rd party dependencies
+import tensorflow as tf
+
+# project dependencies
+from retinaface.commons.logger import Logger
+
+logger = Logger(module="retinaface/commons/package_utils.py")
+
+
+def validate_for_keras3():
+    tf_major = int(tf.__version__.split(".", maxsplit=1)[0])
+    tf_minor = int(tf.__version__.split(".", maxsplit=-1)[1])
+
+    # tf_keras is a must dependency after tf 2.16
+    if tf_major == 1 or (tf_major == 2 and tf_minor < 16):
+        return
+
+    try:
+        import tf_keras
+
+        logger.debug(f"tf_keras is already available - {tf_keras.__version__}")
+    except ImportError as err:
+        # you may consider to install that package here
+        raise ValueError(
+            f"You have tensorflow {tf.__version__} and this requires "
+            "tf-keras package. Please run `pip install tf-keras` "
+            "or downgrade your tensorflow."
+        ) from err