Index: /trunk/src/org/openstreetmap/josm/io/imagery/ImageryReader.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/io/imagery/ImageryReader.java	(revision 16558)
+++ /trunk/src/org/openstreetmap/josm/io/imagery/ImageryReader.java	(revision 16559)
@@ -7,4 +7,5 @@
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -132,4 +133,5 @@
         private ImageryInfo mirrorEntry;
         private ImageryBounds bounds;
+        private Map<ImageryBounds, ImageryBounds> boundsInterner = new HashMap<>();
         private Shape shape;
         // language of last element, does only work for simple ENTRY_ATTRIBUTE's
@@ -542,5 +544,5 @@
                 break;
             case BOUNDS:
-                entry.setBounds(bounds);
+                entry.setBounds(intern(bounds));
                 bounds = null;
                 break;
@@ -567,4 +569,8 @@
                 // nothing to do for these or the unknown type
             }
+        }
+
+        private ImageryBounds intern(ImageryBounds imageryBounds) {
+            return boundsInterner.computeIfAbsent(imageryBounds, ignore -> imageryBounds);
         }
     }