From 48340fe6eff473093ea88e0a50ea53acc7b92f55 Mon Sep 17 00:00:00 2001
From: "Marshall T. Vandegrift" <llasram@gmail.com>
Date: Mon, 19 Jan 2009 21:32:03 -0500
Subject: [PATCH] Fix #1654:   - Convert image format to full-color when
 forcing large-pixel area     lossless image formats to JPEG

---
 src/calibre/ebooks/mobi/writer.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/calibre/ebooks/mobi/writer.py b/src/calibre/ebooks/mobi/writer.py
index 4fb080801e..306f097c90 100644
--- a/src/calibre/ebooks/mobi/writer.py
+++ b/src/calibre/ebooks/mobi/writer.py
@@ -364,7 +364,11 @@ class MobiWriter(object):
         if image.format not in ('JPEG', 'GIF'):
             width, height = image.size
             area = width * height
-            format = 'GIF' if area <= 40000 else 'JPEG'
+            if area <= 40000:
+                format = 'GIF'
+            else:
+                image = image.convert('RGBA')
+                format = 'JPEG'
             changed = True
         if dimen is not None:
             image.thumbnail(dimen, Image.ANTIALIAS)