diff --git a/PhotoAlbum.py b/PhotoAlbum.py
index 0bbbb09..a8fe71d 100644
--- a/PhotoAlbum.py
+++ b/PhotoAlbum.py
@@ -6,6 +6,8 @@ from PIL.ExifTags import TAGS
 
 def set_cache_path_base(base):
 	trim_base.base = base
+def untrim_base(path):
+	return os.path.join(trim_base.base, path)
 def trim_base(path):
 	if path.startswith(trim_base.base):
 		path = path[len(trim_base.base):]
@@ -41,7 +43,7 @@ class Album(object):
 	def date(self):
 		self._sort()
 		if len(self._photos) == 0 and len(self._albums) == 0:
-			return datetime.min
+			return datetime(1900, 1, 1)
 		elif len(self._photos) == 0:
 			return self._albums[-1].date
 		elif len(self._albums) == 0:
@@ -77,7 +79,7 @@ class Album(object):
 	def from_dict(dictionary, cripple=True):
 		album = Album(dictionary["path"])
 		for photo in dictionary["photos"]:
-			album.add_photo(Photo.from_dict(photo, album.path))
+			album.add_photo(Photo.from_dict(photo, untrim_base(album.path)))
 		if not cripple:
 			for subalbum in dictionary["albums"]:
 				album.add_album(Album.from_dict(subalbum), cripple)
@@ -90,46 +92,104 @@ class Album(object):
 		else:
 			subalbums = self._albums
 		return { "path": self.path, "date": self.date, "albums": subalbums, "photos": self._photos }
+	def photo_from_path(self, path):
+		for photo in self._photos:
+			if trim_base(path) == photo._path:
+				print "cache hit %s" % path
+				return photo
+		return None
 	
 class Photo(object):
-	def __init__(self, path, attributes=None):
+	def __init__(self, path, thumb_path=None, attributes=None):
 		self._path = trim_base(path)
 		self.is_valid = True
 		mtime = datetime.fromtimestamp(os.path.getmtime(path))
-		if attributes is not None and attributes["FileTime"] >= mtime:
+		if attributes is not None and attributes["DateTimeFile"] >= mtime:
 			self._attributes = attributes
 			return
 		self._attributes = {}
-		self._attributes["FileTime"] = mtime
+		self._attributes["DateTimeFile"] = mtime
 		
 		try:
-			i = Image.open(path)
+			image = Image.open(path)
 		except:
 			self.is_valid = False
 			return
+		self._metadata(image)
+		self._thumbnails(image, thumb_path)
+	def _metadata(self, image):
 		try:
-			info = i._getexif()
+			info = image._getexif()
 		except:
-			info = None
-		if info:
-			for tag, value in info.items():
-				decoded = TAGS.get(tag, tag)
-				if not isinstance(decoded, int) and decoded not in ['JPEGThumbnail', 'TIFFThumbnail', 'Filename', 'FileSource', 'MakerNote', 'UserComment', 'ImageDescription', 'ComponentsConfiguration']:
-					if isinstance(value, str):
-						value = value.strip()
-						if decoded.startswith("DateTime"):
-							try:
-								value = datetime.strptime(value, '%Y:%m:%d %H:%M:%S')
-							except:
-								pass			
-					self._attributes[decoded] = value
+			return
+		for tag, value in info.items():
+			decoded = TAGS.get(tag, tag)
+			if not isinstance(decoded, int) and decoded not in ['JPEGThumbnail', 'TIFFThumbnail', 'Filename', 'FileSource', 'MakerNote', 'UserComment', 'ImageDescription', 'ComponentsConfiguration']:
+				if isinstance(value, str):
+					value = value.strip()
+					if decoded.startswith("DateTime"):
+						try:
+							value = datetime.strptime(value, '%Y:%m:%d %H:%M:%S')
+						except:
+							pass			
+				self._attributes[decoded] = value
+	def _thumbnail(self, image, thumb_path, size, square=False):
+		if square:
+			suffix = str(size) + "s"
+		else:
+			suffix = str(size)
+		thumb_path = os.path.join(thumb_path, image_cache(self._path, suffix))
+		if os.path.exists(thumb_path) and datetime.fromtimestamp(os.path.getmtime(thumb_path)) >= self._attributes["DateTimeFile"]:
+			return
+		image = image.copy()
+		if square:
+			if image.size[0] > image.size[1]:
+				left = (image.size[0] - image.size[1]) / 2
+				top = 0
+				right = image.size[0] - ((image.size[0] - image.size[1]) / 2)
+				bottom = image.size[1]
+			else:
+				left = 0
+				top = (image.size[1] - image.size[0]) / 2
+				right = image.size[0]
+				bottom = image.size[1] - ((image.size[1] - image.size[0]) / 2)
+			image = image.crop((left, top, right, bottom))
+		image.thumbnail((size, size), Image.ANTIALIAS)
+		image.save(thumb_path, "JPEG")
+		print "saving %s" % thumb_path
+		
+	def _thumbnails(self, image, thumb_path):
+		orientation = self._attributes["Orientation"]
+		mirror = image
+		if orientation == 2:
+			# Vertical Mirror
+			mirror = image.transpose(Image.FLIP_LEFT_RIGHT)
+		elif orientation == 3:
+			# Rotation 180
+			mirror = image.transpose(Image.ROTATE_180)
+		elif orientation == 4:
+			# Horizontal Mirror
+			mirror = image.transpose(Image.FLIP_TOP_BOTTOM)
+		elif orientation == 5:
+			# Horizontal Mirror + Rotation 270
+			mirror = image.transpose(Image.FLIP_TOP_BOTTOM).transpose(Image.ROTATE_270)
+		elif orientation == 6:
+			# Rotation 270
+			mirror = image.transpose(Image.ROTATE_270)
+		elif orientation == 7:
+			# Vertical Mirror + Rotation 270
+			mirror = image.transpose(Image.FLIP_LEFT_RIGHT).transpose(Image.ROTATE_270)
+		elif orientation == 8:
+			# Rotation 90
+			mirror = image.transpose(Image.ROTATE_90)
+		self._thumbnail(mirror, thumb_path, 100, True)
+		self._thumbnail(mirror, thumb_path, 640)
+		self._thumbnail(mirror, thumb_path, 1024)
 	@property
 	def name(self):
 		return os.path.basename(self._path)
 	def __str__(self):
 		return self.name
-	def cache_path(self, size):
-		return image_cache(self.path, size)
 	@property
 	def date(self):
 		if "DateTimeOriginal" in self._attributes:
@@ -137,7 +197,7 @@ class Photo(object):
 		elif "DateTime" in self._attributes:
 			return self._attributes["DateTime"]
 		else:
-			return self._attributes["FileTime"]
+			return self._attributes["DateTimeFile"]
 	def __cmp__(self, other):
 		return cmp(self.date, other.date)
 	@property
@@ -148,6 +208,12 @@ class Photo(object):
 		del dictionary["date"]
 		path = os.path.join(basepath, dictionary["name"])
 		del dictionary["name"]
+		for key, value in dictionary.items():
+			if key.startswith("DateTime"):
+				try:
+					dictionary[key] = datetime.strptime(dictionary[key], "%a %b %d %H:%M:%S %Y")
+				except:
+					pass
 		return Photo(path, dictionary)
 	def to_dict(self):
 		photo = { "name": self.name, "date": self.date }
@@ -157,7 +223,7 @@ class Photo(object):
 class PhotoAlbumEncoder(json.JSONEncoder):
 	def default(self, obj):
 		if isinstance(obj, datetime):
-			return obj.isoformat()
+			return obj.strftime("%a %b %d %H:%M:%S %Y")
 		if isinstance(obj, Album) or isinstance(obj, Photo):
 			return obj.to_dict()
 		return json.JSONEncoder.default(self, obj)
diff --git a/TreeWalker.py b/TreeWalker.py
index 1ec1cba..e8b9e76 100644
--- a/TreeWalker.py
+++ b/TreeWalker.py
@@ -1,5 +1,6 @@
 import os
 import os.path
+from datetime import datetime
 from PhotoAlbum import Photo, Album, json_cache, set_cache_path_base
 
 class TreeWalker:
@@ -14,17 +15,27 @@ class TreeWalker:
 	def walk(self, path):
 		cache = os.path.join(self.cache_path, json_cache(path))
 		cached = False
-		if os.path.exists(cache) and os.path.getmtime(path) <= os.path.getmtime(cache):
-			album = Album.from_cache(cache)
-			cached = True
-		else:
+		cached_album = None
+		if os.path.exists(cache):
+			cached_album = Album.from_cache(cache)
+			if os.path.getmtime(path) <= os.path.getmtime(cache):
+				cached = True
+				album = cached_album
+		if not cached:
 			album = Album(path)
 		for entry in os.listdir(path):
 			entry = os.path.join(path, entry)
 			if os.path.isdir(entry):
 				album.add_album(self.walk(entry))
 			elif not cached and os.path.isfile(entry):
-				photo = Photo(entry)
+				cache_hit = False
+				if cached_album:
+					cached_photo = cached_album.photo_from_path(entry)
+					if cached_photo and datetime.fromtimestamp(os.path.getmtime(entry)) <= cached_photo.attributes["DateTimeFile"]:
+						cache_hit = True
+						photo = cached_photo
+				if not cache_hit:
+					photo = Photo(entry, self.cache_path)
 				if photo.is_valid:
 					self.all_photos.append(photo)
 					album.add_photo(photo)