Incorrect variable reference in param.image alpha

lucid/optvis/param/images.py

@@ -35,10 +35,10 @@ def image(w, h=None, batch=None, sd=None, decorrelate=True, fft=True, alpha=Fals
         output = to_valid_rgb(t[..., :3], decorrelate=decorrelate, sigmoid=True)
         if alpha:
             a = tf.nn.sigmoid(t[..., 3:])
-            return tf.concat([rgb, a], -1)
+            return tf.concat([output, a], -1)
     return output
 
 def grayscale_image_rgb(*args, **kwargs):
   """Takes same arguments as image"""
   output = image(*args, channels=1, **kwargs)
-  return tf.tile(output, (1,1,1,3))
+  return tf.tile(output, (1,1,1,3))