if image is None:
             return
 
-        bmp = image.ConvertToBitmap()
+        try:
+            bmp = image.ConvertToBitmap()
+        except:
+            return
 
         iwidth = bmp.GetWidth()   # dimensions of image file
         iheight = bmp.GetHeight()
             if pattern.match(value) != None:
                 filelist.append(i)
 
-            self.files = filelist
+        self.files = filelist
 
     def MakeRegex(self, pattern):
         import re