--- a/degal/thumbnail.py	Sun Jun 14 18:04:53 2009 +0300
+++ b/degal/thumbnail.py	Sun Jun 14 18:08:55 2009 +0300
@@ -11,12 +11,12 @@
         A Thumbnail is a derivate of an Image, usually resized to some other size.
     """
 
-    def __init__ (self, image, subdir, size) :
+    def __init__ (self, image, subdir, target_size) :
         """
             Initialize to link against the given `image`.
             
             `subdir` specifies the directory to store this thumbnail in.
-            `size` determines the target resolution of the output thumbnail.
+            `target_size` determines the target resolution of the output thumbnail.
         """
 
         # our file path, image name inside of the given subdir
@@ -24,7 +24,7 @@
 
         # store
         self.image = image
-        self.size = size
+        self.target_size = target_size
 
     def stale (self) :
         """
@@ -38,18 +38,40 @@
         else :
             # this thumb doesn't exist or is older
             return True
+    
+    @property
+    def size (self) :
+        """
+            Compute the *real* size of this thumbnail, from the image's actual size and our target size.
+
+            Preserves the aspect ratio etc.
+        """
+        
+        # real image size
+        img_width, img_height = self.image.img_size
+
+        # target size
+        thumb_width, thumb_height = self.target_size
+
+        # calc new size, preserving aspect ratio
+        if img_width > thumb_width : 
+            height = max(img_height * thumb_width / img_width, 1)
+            width = thumb_width
+        
+        if img_height > thumb_height :
+            width = max(img_width * thumb_height / img_height, 1)
+            height = thumb_height
+        
+        return width, height 
 
     def update (self) :
         """
-            Render new output thumbnail
+            Render new output thumbnail.
         """
-        
-        # load a copy of the PIL.Image, as .thumbnail mutates it
-        thumb = self.image.pil_image.copy()
 
-        # resample to given size
-        thumb.thumbnail(self.size, resample=True)
+        # create resized copy of main image, using our size
+        thumb = self.image.img.resize(self.size, resample=PIL.Image.ANTIALIAS)
 
-        # and write out
+        # write it out
         thumb.save(self.path)