Keep ICC profile when saving image, if present

README.rst

@@ -134,7 +134,14 @@ during scaling.
 Changes the quality of the output JPEG thumbnail. Defaults to ``85``.
 
 In Python code, this is given as a separate option to the ``get_thumbnail``
-method rather than just alter the other
+method rather than just alter the other.
+
+``keep_icc_profile``
+--------------------
+
+If `True`, when saving a thumbnail with the alias that defines this option, the
+ICC profile of the image will be preserved in the thumbnail, if present in the first place.
+
 
 Other options
 -------------

easy_thumbnails/engine.py

@@ -1,4 +1,5 @@
 import os
+
 from io import BytesIO
 
 from PIL import Image
@@ -57,6 +58,8 @@ def save_image(image, destination=None, filename=None, **options):
                 max(image.size) >= settings.THUMBNAIL_PROGRESSIVE):
             options['progressive'] = True
         try:
+            if options.pop('keep_icc_profile', False):
+                options['icc_profile'] = image.info.get('icc_profile')
             image.save(destination, format=format, optimize=1, **options)
             saved = True
         except IOError:

easy_thumbnails/files.py

@@ -150,6 +150,7 @@ class ThumbnailFile(ImageFieldFile):
     This can be used just like a Django model instance's property for a file
     field (i.e. an ``ImageFieldFile`` object).
     """
+
     def __init__(self, name, file=None, storage=None, thumbnail_options=None,
                  *args, **kwargs):
         fake_field = FakeField(storage=storage)
@@ -400,7 +401,7 @@ def generate_thumbnail(self, thumbnail_options, high_resolution=False,
 
         img = engine.save_image(
             thumbnail_image, filename=filename, quality=quality,
-            subsampling=subsampling)
+            subsampling=subsampling, keep_icc_profile=thumbnail_options.get('keep_icc_profile', False))
         data = img.read()
 
         thumbnail = ThumbnailFile(
@@ -653,6 +654,7 @@ class ThumbnailerFieldFile(FieldFile, Thumbnailer):
     A field file which provides some methods for generating (and returning)
     thumbnail images.
     """
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.source_storage = self.field.storage

easy_thumbnails/tests/test_engine.py

@@ -1,5 +1,5 @@
 from unittest import TestCase
-from PIL import Image
+from PIL import Image, ImageCms
 
 from easy_thumbnails import engine
 
@@ -17,3 +17,14 @@ def test_save_jpeg_la(self):
         data = engine.save_image(source, filename='test.jpg')
         with Image.open(data) as img:
             self.assertEqual(img.mode, 'L')
+
+    def test_save_with_icc_profile(self):
+        source = Image.new('RGB', (100, 100), (255, 255, 255))
+        profile = ImageCms.createProfile('sRGB')
+        source.save('source.jpg', icc_profile=ImageCms.ImageCmsProfile(profile).tobytes())
+        source = Image.open('source.jpg')
+
+        data = engine.save_image(source, filename='test.jpg', keep_icc_profile=True)
+        img = Image.open(data)
+
+        self.assertNotEqual(img.info.get('icc_profile'), None)