Merge branch 'feature/use-exif-to-determine-rotation' into 'master'

Use Orientation EXIF tag in photo to determine orientation on upload

Closes #591

See merge request !730

website/photos/models.py

@@ -2,17 +2,29 @@ import hashlib
 import os
 import random
 
+from PIL.JpegImagePlugin import JpegImageFile
 from django.conf import settings
 from django.db import models
 from django.urls import reverse
 from django.utils.functional import cached_property
 from django.utils.translation import ugettext_lazy as _
-from PIL import Image
+from PIL import Image, ExifTags
 
 from utils.translation import ModelTranslateMeta, MultilingualField
 
 COVER_FILENAME = 'cover.jpg'
 
+EXIF_ORIENTATION = {
+    1: 0,
+    2: 0,
+    3: 180,
+    4: 180,
+    5: 90,
+    6: 90,
+    7: 270,
+    8: 270,
+}
+
 
 def photo_uploadto(instance, filename):
     num = instance.album.photo_set.count()
@@ -21,7 +33,20 @@ def photo_uploadto(instance, filename):
     return os.path.join(Album.photosdir, instance.album.dirname, new_filename)
 
 
+def determine_rotation(pil_image):
+    if isinstance(pil_image, JpegImageFile) and pil_image._getexif():
+        exif = {
+            ExifTags.TAGS[k]: v
+            for k, v in pil_image._getexif().items()
+            if k in ExifTags.TAGS
+        }
+        if exif.get('Orientation'):
+            return EXIF_ORIENTATION[exif.get('Orientation')]
+    return 0
+
+
 class Photo(models.Model):
+
     album = models.ForeignKey(
         'Album',
         on_delete=models.CASCADE,
@@ -61,11 +86,14 @@ class Photo(models.Model):
         return self.file.name
 
     def save(self, *args, **kwargs):
-        super(Photo, self).save(*args, **kwargs)
+        super().save(*args, **kwargs)
 
         if self._orig_file != self.file.path:
             image_path = self.file.path
             image = Image.open(image_path)
+
+            self.rotation = determine_rotation(image)
+
             # Image.thumbnail does not upscale an image that is smaller
             image.thumbnail(settings.PHOTO_UPLOAD_SIZE, Image.ANTIALIAS)
             image.save(image_path, "JPEG")
@@ -77,6 +105,9 @@ class Photo(models.Model):
             self.file.close()
             self._digest = hash_sha1.hexdigest()
 
+            # Save again, to update changes in digest and rotation
+            super().save(*args, **kwargs)
+
     class Meta:
         ordering = ('file', )
 
@@ -143,7 +174,7 @@ class Album(models.Model, metaclass=ModelTranslateMeta):
         # dirname is only set for new objects, to avoid ever changing it
         if self.pk is None:
             self.dirname = self.slug
-        super(Album, self).save(*args, **kwargs)
+        super().save(*args, **kwargs)
 
     @property
     def access_token(self):

website/photos/tests.py

-from zipfile import ZipFile
 from io import BytesIO
+from zipfile import ZipFile
 
+from PIL import Image
 from django.test import Client, TestCase
 
 from members.models import Member
-from photos.models import Photo, Album
+from .models import Photo, Album, determine_rotation
 
 
 def create_zip(photos):
@@ -16,6 +17,27 @@ def create_zip(photos):
     return output_file
 
 
+class PhotoRotationTest(TestCase):
+
+    fixtures = ['members.json']
+
+    @classmethod
+    def setUpTestData(cls):
+        cls.member = Member.objects.filter(last_name="Wiggers").first()
+
+    def setUp(self):
+        self.client = Client()
+        self.client.force_login(self.member)
+
+    def test_rotation_detection(self):
+        orientations = [0, 0, 180, 180, 90, 90, 270, 270]
+        for i in range(1, 9):
+            with self.subTest(orentation=i):
+                with open('photos/fixtures/poker_{}.jpg'.format(i), 'rb') as f:
+                    rot = determine_rotation(Image.open(f))
+                    self.assertEqual(orientations[i - 1], rot)
+
+
 class AlbumUploadTest(TestCase):
     """Tests album uploads in the admin."""
 
@@ -102,3 +124,15 @@ class AlbumUploadTest(TestCase):
 
         self.assertEqual(Album.objects.all().count(), 1)
         self.assertEqual(Photo.objects.all().count(), 2)
+
+    def test_album_upload_rotated_photo_in_album(self):
+        output_file = create_zip(["photos/fixtures/rotated_janbeleid.jpg"])
+        self.client.post('/admin/photos/album/add/',
+                         {"title_nl": "test album",
+                          "title_en": "test album",
+                          "date": "2017-04-12",
+                          "slug": "2017-04-12-test-album",
+                          "album_archive": output_file},
+                         follow=True)
+
+        self.assertEqual(Photo.objects.first().rotation, 90)