Update app.py

app.py

@@ -2,13 +2,29 @@ import gradio as gr
 import tensorflow as tf
 from PIL import Image
 import numpy as np
+import tensorflow as tf
+import keras.backend as K
+
+
+# Define focal loss
+def focal_loss(gamma=2., alpha=0.25):
+    def focal_loss_fixed(y_true, y_pred):
+        y_pred = tf.clip_by_value(y_pred, K.epsilon(), 1. - K.epsilon())
+        cross_entropy = -y_true * tf.math.log(y_pred)
+        weight = alpha * y_true * tf.math.pow((1 - y_pred), gamma)
+        loss = weight * cross_entropy
+        return tf.reduce_sum(loss, axis=-1)
+    return focal_loss_fixed
+
 
 # Load models
 vgg16_model = tf.keras.models.load_model(
     "vgg16_best_model.keras"
 )
+
 xception_model = tf.keras.models.load_model(
-    "xception_best.keras"
+    'xception_best.keras',
+    custom_objects={'focal_loss_fixed': focal_loss()}
 )