diff --git a/openerp/tools/image.py b/openerp/tools/image.py
index 251569c7247..ce50298b094 100644
--- a/openerp/tools/image.py
+++ b/openerp/tools/image.py
@@ -93,7 +93,7 @@ def image_resize_image(base64_source, size=(1024, 1024), encoding='base64', file
 
     if image.size != size:
         image = image_resize_and_sharpen(image, size)
-    if image.mode not in ["1", "L", "P", "RGB", "RGBA"]:
+    if image.mode not in ["1", "L", "P", "RGB", "RGBA"] or (filetype == 'JPEG' and image.mode == 'RGBA'):
         image = image.convert("RGB")
 
     background_stream = StringIO.StringIO()
@@ -110,6 +110,7 @@ def image_resize_and_sharpen(image, size, preserve_aspect_ratio=False, factor=2.
         :param preserve_aspect_ratio: boolean (default: False)
         :param factor: Sharpen factor (default: 2.0)
     """
+    origin_mode = image.mode
     if image.mode != 'RGBA':
         image = image.convert('RGBA')
     image.thumbnail(size, Image.ANTIALIAS)
@@ -120,6 +121,8 @@ def image_resize_and_sharpen(image, size, preserve_aspect_ratio=False, factor=2.
     # create a transparent image for background and paste the image on it
     image = Image.new('RGBA', size, (255, 255, 255, 0))
     image.paste(resized_image, ((size[0] - resized_image.size[0]) / 2, (size[1] - resized_image.size[1]) / 2))
+    if image.mode != origin_mode:
+        image = image.convert(origin_mode)
     return image
 
 def image_save_for_web(image, fp=None, format=None):