Allow turning batch norm scale off

bob/learn/tensorflow/layers.py

@@ -270,6 +270,7 @@ def add_bottleneck(
     use_bias=True,
     batch_norm_decay=0.99,
     batch_norm_epsilon=1e-3,
+    batch_norm_scale=True,
 ):
     """
     Amend a bottleneck layer to a Keras Model
@@ -293,7 +294,11 @@ def add_bottleneck(
         new_model = model
 
     new_model.add(
-        BatchNormalization(momentum=batch_norm_decay, epsilon=batch_norm_epsilon)
+        BatchNormalization(
+            momentum=batch_norm_decay,
+            epsilon=batch_norm_epsilon,
+            scale=batch_norm_scale,
+        )
     )
     new_model.add(Dropout(dropout_rate, name="Dropout"))
     new_model.add(Flatten())
@@ -308,18 +313,19 @@ def add_bottleneck(
             bottleneck_size,
             use_bias=use_bias,
             kernel_regularizer=regularizer,
+            dtype="float32",
         )
     )
 
     new_model.add(
         BatchNormalization(
-            axis=-1,
             name="embeddings",
             momentum=batch_norm_decay,
             epsilon=batch_norm_epsilon,
+            scale=batch_norm_scale,
+            dtype="float32",
         )
     )
-    # new_model.add(BatchNormalization())
 
     return new_model