diff --git a/demo.py b/demo.py
index c5950c9..8125fac 100644
--- a/demo.py
+++ b/demo.py
@@ -50,7 +50,10 @@ def main(args):
         if args.isDlib:
             max_size = max(image.shape[0], image.shape[1])
             if max_size> 1000:
-                image = rescale(image, 1000./max_size)
+                try:
+                    image = rescale(image, 1000./max_size,multichannel=True)
+                except:
+                    image = rescale(image, 1000./max_size)
                 image = (image*255).astype(np.uint8)
             pos = prn.process(image) # use dlib to detect face
         else:
diff --git a/requirements.txt b/requirements.txt
index 5ba7442..a1d9364 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 numpy>=1.14.3
 scikit-image
 scipy
-tensorflow
+tensorflow<2.0.0