minor fixes

app.py

@@ -53,7 +53,9 @@ def predict(image):
         mask *= 255
 
     mask = np.array(Image.fromarray(mask).convert("L"))
-    mask = np.resize(mask, original_shape)
+    mask = tf.image.resize(mask[..., tf.newaxis], original_shape)
+    mask = tf.cast(mask, tf.uint8)
+    mask = mask.numpy().squeeze()
 
     return mask