Don't hardcode JPG format for thumbnail save (w/ patch)

[GoogleCodeExporter]

Simple fix to let the thumbnailing code save in the format of the image, 
instead of hardcoding 'JPEG', which 
will fail for any non-JPG thumbnail.

Patch in SVN diff format...

Index: userprofile/templatetags/avatars.py
===================================================================
--- userprofile/templatetags/avatars.py (revision 434)
+++ userprofile/templatetags/avatars.py (working copy)
@@ -84,7 +84,7 @@
             thumb = Image.open(ContentFile(avatar.read()))
             thumb.thumbnail((self.size, self.size), Image.ANTIALIAS)
             f = StringIO()
-            thumb.save(f, "JPEG")
+            thumb.save(f, thumb.format)
             f.seek(0)
             storage.save(filename, ContentFile(f.read()))

Original issue reported on code.google.com by daemianmack@gmail.com on 27 Mar 2010 at 7:39

[GoogleCodeExporter]

When image is saved after the user choose it, it's always in jpg format, so 
when it's
resized, there should be no problem

By the way i made a little patch in [443] to correctly handle non jpg images 
(but
finally always saved as jpg), by changing the mode to RGB (in first uploading or
later in resizing)

I tried with jpg, png and gif, and it was ok.

Could you try with this new trunk ?

Original comment by stephane.angel on 26 Apr 2010 at 4:18

• Changed state: WontFix

[GoogleCodeExporter]

[deleted comment]

[GoogleCodeExporter]

i wanted to say in r443

Original comment by stephane.angel on 26 Apr 2010 at 4:27

[GoogleCodeExporter]

Thanks for looking at this. 

Saving everything as JPG really isn't ideal, as JPG isn't suitable for many 
image types: e.g., GIF is a better format for smaller images, images with a lot 
of text 
or sharp lines, and screenshots. 

A lot of GIFs end up looking worse after being saved to JPG, and end up with a 
larger filesize.

Lastly, any GIFs a user uploads that have transparency will look surprising to 
the user after the save to JPG.

There are additional reasons not to convert all image formats to JPG, but these 
are the ones most compelling to my needs. 

If you agree, the above patch as submitted is pretty incomplete, as there are a 
number of other codepaths that need to be updated to not hardcode JPG; I'll be 
happy to create a diff against my edits and apply here if you're amenable.

Original comment by daemianmack@gmail.com on 26 Apr 2010 at 4:53

[GoogleCodeExporter]

I agree with you, but i have not the time to make patches and tests for this, 
but if
you have a patch... (did you forgot to join it ?)

Original comment by stephane.angel on 26 Apr 2010 at 6:33

• Changed state: Accepted

[GoogleCodeExporter]

Nope, just making sure you were interested. :)

Here's the full patch, inclusive of the single change I submitted above...

Index: views.py                                                                 

===================================================================
--- views.py    (revision 434)                                                  

+++ views.py    (working copy)                                                  

@@ -247,10 +254,11 @@
                 thumb.thumbnail((480, 480), Image.ANTIALIAS)                                                                                                                                                                                 
                 thumb.convert("RGB")                                                                                                                                                                                                         
                 f = StringIO()                                                                                                                                                                                                               
-                thumb.save(f, "JPEG")                                          

+                thumb.save(f, thumb.format)                                    

                 f.seek(0)                                                                                                                                                                                                                    
                 avatar = Avatar(user=request.user, image="", valid=False)                                                                                                                                                                    
-                avatar.image.save("%s.jpg" % request.user.username, 
ContentFile(f.read()))                                                          

+                file_ext = image.content_type.split("/")[1] # "image/gif" => 
"gif"                                                                           

+                avatar.image.save("%s.%s" % (request.user.username, file_ext), 
ContentFile(f.read()))                                                          

                 avatar.save()                                                                                                                                                                                                                

                 signal_responses = signals.post_signal.send(sender=avatarchoose, request=request, form=form)                                                                                                                                 
@@ -310,16 +319,23 @@

             if hasattr(settings, "AWS_SECRET_ACCESS_KEY"):                                                                                                                                                                                   
                 f = StringIO()                                                                                                                                                                                                               
-                image.save(f, "JPEG")                                          

+                image.save(f, image.format)                                    

                 f.seek(0)                                                                                                                                                                                                                    
                 avatar.image.delete()                                                                                                                                                                                                        
-                avatar.image.save("%s.jpg" % request.user.username, 
ContentFile(f.read()))                                                          

+                file_ext = image.content_type.split("/")[1] # "image/gif" => 
"gif"                                                                           

+                avatar.image.save("%s.%s" % (request.user.username, file_ext), 
ContentFile(f.read()))                                                          

             else:                                                                                                                                                                                                                            
                 image.save(avatar.image.path)                                                                                                                                                                                                

             avatar.valid = True                                                                                                                                                                                                              
Index: templatetags/avatars.py                                                  

===================================================================
--- templatetags/avatars.py     (revision 434)                                  

+++ templatetags/avatars.py     (working copy)                                  

@@ -84,7 +87,7 @@
             thumb = Image.open(ContentFile(avatar.read()))                                                                                                                                                                                   
             thumb.thumbnail((self.size, self.size), Image.ANTIALIAS)                                                                                                                                                                         
             f = StringIO()                                                                                                                                                                                                                   
-            thumb.save(f, "JPEG")                                              

+            thumb.save(f, thumb.format)                                        

             f.seek(0)                                                                                                                                                                                                                        
             storage.save(filename, ContentFile(f.read()))                                                                                                                                                                                    

Original comment by daemianmack@gmail.com on 26 Apr 2010 at 11:11

[GoogleCodeExporter]

ok thanks i'll check that

Original comment by stephane.angel on 27 Apr 2010 at 9:19

[GoogleCodeExporter]

it's now ok in r445, thanks a lot for your patch

Original comment by stephane.angel on 29 Apr 2010 at 9:27

• Changed state: Fixed

[GoogleCodeExporter]

Sure thing. Thanks for the app; it's been helpful! 

Time permitting, I've got some other quick fixes I plan to cherry-pick out of 
my repository and submit as patches.

Original comment by daemianmack@gmail.com on 29 Apr 2010 at 9:49

[GoogleCodeExporter]

i'm waiting for them :)

Original comment by stephane.angel on 29 Apr 2010 at 9:51