Optimize images a bit before serving

trans/views/charts.py

@@ -94,7 +94,7 @@ def render_activity(activity):
 
     # Render surface to PNG
     out = StringIO()
-    image.save(out, 'PNG')
+    image.convert('P', palette=Image.ADAPTIVE).save(out, 'PNG')
 
     # Return response
     return HttpResponse(content_type='image/png', content=out.getvalue())

trans/widgets.py

@@ -220,7 +220,7 @@ class Widget(object):
         Returns PNG data.
         '''
         out = StringIO()
-        self.image.save(out, 'PNG')
+        self.image.convert('P', palette=Image.ADAPTIVE).save(out, 'PNG')
         return out.getvalue()