Update app.py

app.py

@@ -25,9 +25,9 @@ def dice_metric(y_pred, y_true):
 
 def focal_loss(predict, true):
     error = tf.keras.losses.binary_crossentropy(predict, true)
-    pt = tf.exp(error)
-    focal_loss = (1 - pt) ** 2 * error
-    return dice_metric(predict, true) + (1*tf.reduce_mean(focal_loss))
+    pt = tf.exp(-error)
+    focal_loss_ = (1 - pt) ** 2 * error
+    return dice_metric(predict, true) + (1*tf.reduce_mean(focal_loss_))
 
 def focal_iou(y_true, y_pred):
     return focal_loss(y_true, y_pred) - K.log(jacard(y_true, y_pred))