change image data format

app/models/merged/card.rb

@@ -5,7 +5,7 @@ module Merged
     belongs_to :section , class_name: "Merged::Section"
 
     fields  :id , :index , :section_id
-    fields  :text , :header, :image
+    fields  :text , :header, :image_name
 
     def move_up
       swap_index_with(next_card)

app/models/merged/section.rb

@@ -5,7 +5,7 @@ module Merged
 
     fields :id , :page_id , :index
     fields :template , :card_template
-    fields :header, :text , :image
+    fields :header, :text , :image_name
 
     def cards
       Card.where(section_id: id).order(index: :asc)

app/models/merged/view_base.rb

@@ -62,7 +62,7 @@ module Merged
     end
 
     def image
-      Image.find_by_name(@attributes[:image])
+      Image.find_by_name(self.image_name)
     end
   end
 end