avoid catch-all except

src/img2pdf.py

@@ -233,11 +233,10 @@ def convert(images, dpi=None, pagesize=(None, None, None), title=None,
         debug_out("Reading %s"%imfilename, verbose)
         try:
             rawdata = imfilename.read()
-            im = cStringIO(rawdata)
+        except AttributeError:
-        except:
             with open(imfilename, "rb") as im:
                 rawdata = im.read()
-                im = cStringIO(rawdata)
+        im = cStringIO(rawdata)
         try:
             imgdata = Image.open(im)
         except IOError as e: