Transpose processor now supports auto EXIF orientation.

Replaced calls to Image.open with an open_image utility function.
The open_image utility calls Image.open, but then wraps the opened Image's
copy method with a version that preserves EXIF data. This allows an
ImageSpec to copy the original image, yet still provide all the original
image's exif data to the processor pipeline.

imagekit/models.py

@@ -2,7 +2,7 @@ import os
 import datetime
 from StringIO import StringIO
 from imagekit.lib import *
-from imagekit.utils import img_to_fobj, get_spec_files
+from imagekit.utils import img_to_fobj, get_spec_files, open_image
 from imagekit.processors import ProcessorPipeline
 from django.conf import settings
 from django.core.files.base import ContentFile
@@ -93,7 +93,7 @@ def _get_suggested_extension(name, format):
 class _ImageSpecFileMixin(object):
 
     def _process_content(self, filename, content):
-        img = Image.open(content)
+        img = open_image(content)
         original_format = img.format
         img = self.field.process(img, self)
 
@@ -138,7 +138,7 @@ class ImageSpecFile(_ImageSpecFileMixin):
         if lazy:
             img = self._img
             if not img and self.storage.exists(self.name):
-                img = Image.open(self.file)
+                img = open_image(self.file)
         if not img and self.source_file:
             # Process the original image file
             try:

imagekit/processors.py

@@ -224,11 +224,9 @@ class Transpose(ImageProcessor):
 
     def process(self, img):
         if self.AUTO in self.methods:
-            raise Exception("AUTO is not yet supported. Sorry!")
             try:
                 orientation = img._getexif()[0x0112]
                 ops = self._EXIF_ORIENTATION_STEPS[orientation]
-                print 'GOT %s >>>> %s' % (orientation, ops)
             except AttributeError:
                 ops = []
         else:

imagekit/utils.py

@@ -1,6 +1,9 @@
 """ ImageKit utility functions """
 
-import tempfile
+import tempfile, types
+from django.utils.functional import wraps
+from lib import Image
+
 
 def img_to_fobj(img, format, **kwargs):
     tmp = tempfile.TemporaryFile()
@@ -20,3 +23,26 @@ def get_spec_files(instance):
         if isinstance(value, ImageSpecFile):
             spec_files.append(value)
     return spec_files
+
+
+def open_image(target):
+    img = Image.open(target)
+    img.copy = types.MethodType(_wrap_copy(img.copy), img, img.__class__)
+    return img
+
+
+def _wrap_copy(f):
+    @wraps(f)
+    def copy(self):
+        img = f()
+        try:
+            img.app = self.app
+        except AttributeError:
+            pass
+        try:
+            img._getexif = self._getexif
+        except AttributeError:
+            pass
+        return img
+    return copy
+