Add default JPEG optimisation, progressive JPEGs and set quality to high_profile

requirements-dev.txt

@@ -1,6 +1,5 @@
 -e .
 coverage==4.3.1
-django-coverage-plugin==1.3.1
 flake8==3.2.1
 isort==4.2.5
 mccabe==0.5.3

setup.cfg

@@ -17,8 +17,6 @@ match = (?!setup).*.py
 
 [coverage:run]
 source = .
-plugins =
-    django_coverage_plugin
 omit =
   */migrations/*
   */tests/*

stdimage/models.py

@@ -74,6 +74,7 @@ def render_variation(cls, file_name, variation, replace=False,
 
         with storage.open(file_name) as f:
             with Image.open(f) as img:
+                save_kargs = {}
                 file_format = img.format
 
                 if cls.is_smaller(img, variation):
@@ -93,6 +94,15 @@ def render_variation(cls, file_name, variation, replace=False,
                     size = variation['width'], variation['height']
                     size = tuple(int(i) if i != float('inf') else i
                                  for i in size)
+
+                    if file_format == 'JPEG':
+                        # http://stackoverflow.com/a/21669827
+                        img = img.convert('RGB')
+                        save_kargs['optimize'] = True
+                        save_kargs['quality'] = 'web_high'
+                        if size[0] * size[1] > 10000:  # roughly <10kb
+                            save_kargs['progressive'] = True
+
                     if variation['crop']:
                         img = ImageOps.fit(
                             img,
@@ -106,7 +116,7 @@ def render_variation(cls, file_name, variation, replace=False,
                         )
 
                 with BytesIO() as file_buffer:
-                    img.save(file_buffer, file_format)
+                    img.save(file_buffer, file_format, **save_kargs)
                     f = ContentFile(file_buffer.getvalue())
                     storage.save(variation_name, f)
         return variation_name

tox.ini

@@ -9,10 +9,11 @@ deps=
     dj110: https://github.com/django/django/archive/stable/1.10.x.tar.gz#egg=django
     djmaster: https://github.com/django/django/archive/master.tar.gz#egg=django
 commands=
-    py.test \
+    coverage run --source=stdimage -m 'pytest' \
         --basetemp={envtmpdir} \
         --ignore=.tox \
         {posargs}
+    coverage report
 
 [testenv:qa]
 changedir={toxinidir}