From 9dc6fbc6b99e767e4e2bbf56d942e1c50fea5dfe Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 9 May 2016 19:36:13 +0530
Subject: [PATCH] ...

---
 src/calibre/utils/img.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/calibre/utils/img.py b/src/calibre/utils/img.py
index 747a9ac8d0..d55ff4e9ce 100644
--- a/src/calibre/utils/img.py
+++ b/src/calibre/utils/img.py
@@ -277,10 +277,14 @@ def normalize(img):
         raise RuntimeError(imageops_err)
     return imageops.normalize(image_from_data(img))
 
-def quantize(img, colors=256, dither=True, palette=''):
-    ''' Quantize the image to contain a maximum of `colors` colors. By default a palette is chosen automatically,
-    if you want to use a fixed palette, then pass in a list of color names in the `palette` variable. If you,
-    specify a palette `colors` is ignored. For example: palette='red green blue #eee' '''
+def quantize(img, max_colors=256, dither=True, palette=''):
+    ''' Quantize the image to contain a maximum of `max_colors` colors. By
+    default a palette is chosen automatically, if you want to use a fixed
+    palette, then pass in a list of color names in the `palette` variable. If
+    you, specify a palette `max_colors` is ignored. Note that it is possible
+    for the actual number of colors used to be less than max_colors.
+
+    For example: palette='red green blue #eee' '''
     if imageops is None:
         raise RuntimeError(imageops_err)
     img = image_from_data(img)
@@ -288,7 +292,7 @@ def quantize(img, colors=256, dither=True, palette=''):
         img = blend_image(img)
     if palette and isinstance(palette, basestring):
         palette = palette.split()
-    return imageops.quantize(img, colors, dither, [QColor(x).rgb() for x in palette])
+    return imageops.quantize(img, max_colors, dither, [QColor(x).rgb() for x in palette])
 
 # Optimization of images {{{