diff --git a/oml/item/models.py b/oml/item/models.py
index 193cb48..708a5b9 100644
--- a/oml/item/models.py
+++ b/oml/item/models.py
@@ -311,8 +311,11 @@ class Item(db.Model):
 
     def update_icons(self):
         def get_ratio(data):
-            img = Image.open(BytesIO(data))
-            return img.size[0]/img.size[1]
+            try:
+                img = Image.open(BytesIO(data))
+                return img.size[0]/img.size[1]
+            except:
+                return 1
         key = 'cover:%s'%self.id
         cover = None
         if 'cover' in self.meta and self.meta['cover']:
diff --git a/oml/media/epub.py b/oml/media/epub.py
index ed5c2da..9cf35ae 100644
--- a/oml/media/epub.py
+++ b/oml/media/epub.py
@@ -8,6 +8,9 @@ import zipfile
 import re
 from urllib.parse import unquote
 import lxml.html
+from io import BytesIO
+
+from PIL import Image
 
 from ox import strip_tags, decode_html
 
@@ -16,6 +19,13 @@ from utils import find_isbns, get_language, to_isbn13
 import logging
 logger = logging.getLogger(__name__)
 
+def get_ratio(data):
+    try:
+        img = Image.open(BytesIO(data))
+        return img.size[0]/img.size[1]
+    except:
+        return -1
+
 def cover(path):
     logger.debug('cover %s', path)
     data = None
@@ -27,12 +37,19 @@ def cover(path):
 
     def use(filename):
         logger.debug('using %s', filename)
-        return z.read(filename)
-
+        data = z.read(filename)
+        r = get_ratio(data)
+        if r < 0.3 or r > 2:
+            return None
+        return data
+    
+    files = []
     for f in z.filelist:
+        if f.filename == 'calibre-logo.png':
+            continue
         if 'cover' in f.filename.lower() and f.filename.split('.')[-1] in ('jpg', 'jpeg', 'png'):
             return use(f.filename)
-    files = [f.filename for f in z.filelist]
+        files.append(f.filename)
     opf = [f for f in files if f.endswith('opf')]
     if opf:
         #logger.debug('opf: %s', z.read(opf[0]).decode())