From 23fd53cf1b2fb15fb8c846fff1d84f413c4364ba Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 15 Jun 2016 08:06:05 +0530
Subject: [PATCH] Fix typo that broke grayscaling of images in the previous
 release

---
 src/calibre/utils/img.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/calibre/utils/img.py b/src/calibre/utils/img.py
index af153536e4..2e181105ab 100644
--- a/src/calibre/utils/img.py
+++ b/src/calibre/utils/img.py
@@ -309,7 +309,7 @@ def crop_image(img, x, y, width, height):
 # Image transformations {{{
 
 def grayscale_image(img):
-    return img
+    return imageops.grayscale(image_from_data(img))
 
 def set_image_opacity(img, alpha=0.5):
     ''' Change the opacity of `img`. Note that the alpha value is multiplied to