error fix

app.py

@@ -121,14 +121,12 @@ def predict(input_img, ver):
     # Making image darker
     source = drawing.split()
 
-    R, G, B = 0, 1, 2
+    W = 0
     # constant by which each pixel is divided
 
-    Red = source[R].point(lambda i: i / 2.0)
-    Green = source[G].point(lambda i: i / 2.0)
-    Blue = source[B].point(lambda i: i / 2.0)
+    White = source[W].point(lambda i: darken_pixel(i))
 
-    im_output = Image.merge(im_output.mode, (Red, Green, Blue))
+    im_output = Image.merge(im_output.mode, (White))
     return im_output