Parse exif for rotation infobetter-scaling

1 files changed, 114 insertions, 18 deletions

diff --git a/thumbnail/action/Thumbnail.py b/thumbnail/action/Thumbnail.py
index 3ff1f42..b3118e0 100644
--- a/thumbnail/action/Thumbnail.py
+++ b/thumbnail/action/Thumbnail.py
@@ -1,5 +1,7 @@
 import os
 import hashlib
+import exifread
+from collections import namedtuple
 from PIL import Image, ImageOps
 from PIL.ImageFileIO import ImageFileIO
 
@@ -13,22 +15,117 @@ from MoinMoin.caching import CacheEntry
 logging = log.getLogger(__name__)
 
 
+class ExifWrapper(object):
+
+    ROTATED = (5, 6, 7, 8)
+
+    def __init__(self, exif_data):
+        self.exif_data = exif_data
+
+    @classmethod
+    def from_fp(cls, fp):
+        return cls(exifread.process_file(fp))
+
+    def _get_first_value(self, tag):
+        value = self.exif_data.get(tag)
+
+        if value and len(value.values) >= 1:
+            return value.values[0]
+
+    @property
+    def image_width(self):
+        return self._get_first_value('EXIF ExifImageWidth')
+
+    @property
+    def image_length(self):
+        return self._get_first_value('EXIF ExifImageLength')
+
+    @property
+    def is_rotated(self):
+        value = self._get_first_value('Image Orientation')
+        return value in self.ROTATED
+
+
+class ImageWrapper(object):
+
+    _IMG_WIDTH = 0
+    _IMG_HEIGHT = 1
+
+    def __init__(self, filename, img, exif):
+        self.filename = filename
+        self.exif = exif
+        self.img = img
+
+    @classmethod
+    def from_fp(cls, fp):
+        img = Image.open(fp)
+        img.load()
+        fp.seek(0)
+
+        return cls(fp.name, img, ExifWrapper.from_fp(fp))
+
+    @property
+    def _width(self):
+        return float(self.img.size[self._IMG_WIDTH])
+
+    @property
+    def _height(self):
+        return float(self.img.size[self._IMG_HEIGHT])
+
+    @property
+    def is_landscape(self):
+        return self.width > self.height
+
+    @property
+    def height(self):
+        if self.exif.is_rotated:
+            return self._width
+        else:
+            return self._height
+
+    @property
+    def width(self):
+        if self.exif.is_rotated:
+            return self._height
+        else:
+            return self._width 
+
+    def to_jpeg_data(self):
+        return self.img.tostring('jpeg', self.img.mode)
+
+    def content_type(self):
+        mt = wikiutil.MimeType(filename=self.filename)
+        return mt.content_type()
+
+    def crop(self, *args, **kwargs):
+        self.img = self.img.crop(*args, **kwargs)
+
+    def thumbnail(self, *args, **kwargs):
+        self.img.thumbnail(*args, **kwargs)
+
+    def grayscale(self):
+        self.img = ImageOps.grayscale(self.img)
+
+
+def grayscale(img):
+    img.grayscale()
+
+
 def crop(img, width, height):
-    src_width, src_height = img.size
-    src_ratio = float(src_width) / float(src_height)
+    src_ratio = float(img.width) / float(img.height)
     dst_width, dst_height = int(width), int(height)
     dst_ratio = float(dst_width) / float(dst_height)
 
     if dst_ratio < src_ratio:
-        crop_height = src_height
+        crop_height = img.height
         crop_width = crop_height * dst_ratio
-        x_offset = float(src_width - crop_width) / 2
+        x_offset = float(img.width - crop_width) / 2
         y_offset = 0
     else:
-        crop_width = src_width
+        crop_width = img.width
         crop_height = crop_width / dst_ratio
         x_offset = 0
-        y_offset = float(src_height - crop_height) / 3
+        y_offset = float(img.height - crop_height) / 3
 
     return img.crop((
         x_offset,
@@ -40,13 +137,12 @@ def crop(img, width, height):
 
 def thumbnail(img, long_side):
     long_side = int(long_side)
-    width, height = [float(d) for d in img.size]
 
-    if height > width:
-        width = (width / height) * long_side
+    if img.is_landscape:
+        width = (img.width / img.height) * long_side
         height = long_side
     else:
-        height = (height / width) * long_side
+        height = (img.height / img.width) * long_side
         width = long_side
 
     img.thumbnail((width, height), Image.ANTIALIAS)
@@ -55,12 +151,11 @@ def thumbnail(img, long_side):
 
 def thumbnail_constrain(img, size, dimension):
     size = int(size)
-    width, height = [float(d) for d in img.size]
 
     if dimension.lower() == "h":
-        height, width = size, ((width * size) / height)
+        height, width = size, ((img.width * size) / img.height)
     elif dimension.lower() == "w":
-        width, height = size, ((height * size) / width)
+        width, height = size, ((img.height * size) / img.width)
     else:
         raise Exception("Must contrain valid dimension")
 
@@ -94,22 +189,24 @@ def execute(pagename, request):
     cache = CacheEntry(request, page,
         get_cache_key(request, filename), scope="item")
 
+    """
     if cache.exists() and (cache.mtime() >= os.path.getmtime(fpath)):
         logging.info("Using cache for %s", fpath)
         cache.open(mode="r")
         request.write(cache.read())
         cache.close()
         return
+    """
 
     action_map = {
-        'ds': ImageOps.grayscale,
+        'ds': grayscale,
         'cr': crop,
         'th': thumbnail,
         'tc': thumbnail_constrain,
     }
 
     with open(fpath) as fp:
-        img = Image.open(fp)
+        img = ImageWrapper.from_fp(fp)
 
         for action in request.values.getlist("do"):
             action = action.split(":")
@@ -122,9 +219,8 @@ def execute(pagename, request):
                 request.write("Error: {}".format(e))
                 return
 
-    mt = wikiutil.MimeType(filename=filename)
-    request.headers['Content-Type'] = mt.content_type()
-    data = img.tostring('jpeg', img.mode)
+    request.headers['Content-Type'] = img.content_type()
+    data = img.to_jpeg_data()
 
     try:
         cache.lock("w")