update series to use middle image

generic/tables.py

@@ -7,7 +7,7 @@ from easy_thumbnails.files import get_thumbnailer
 
 from easy_thumbnails.exceptions import InvalidImageFormatError
 
-from generic.models import CidUser, Examination
+from generic.models import CidUser, Examination, findMiddle
 
 from django.contrib.auth.models import User
 
@@ -33,7 +33,15 @@ class BlockImageColumn(tables.Column):
 
 class SeriesImageColumn(tables.Column):
     def render(self, value):
-        obj = value.first()
+        #obj = value.first()
+        images = value.all()
+
+        if not images:
+            return format_html(
+                '<span>None<span><br/>',
+            )
+
+        obj = findMiddle(images)
 
         if obj is None:
             return "None"