Index: trunk/psModules/src/camera/pmHDU.c
===================================================================
--- trunk/psModules/src/camera/pmHDU.c	(revision 21183)
+++ trunk/psModules/src/camera/pmHDU.c	(revision 21279)
@@ -243,2 +243,26 @@
     return hduWrite(hdu, hdu->weights, hdu->masks, maskVal, fits);
 }
+
+bool pmHDUWriteIdentifiers(pmHDU *hdu, psS64 imageId, psS64 sourceId)
+{
+    PS_ASSERT_PTR_NON_NULL(hdu, false);
+
+    // XXX Get header keyword name from camera configuration
+
+    psMetadataAddS64(hdu->header, PS_LIST_TAIL, "IMAGEID", PS_META_REPLACE, "Image identifier", imageId);
+    psMetadataAddS64(hdu->header, PS_LIST_TAIL, "SOURCEID", PS_META_REPLACE, "Source identifier", sourceId);
+    return true;
+}
+
+bool pmHDUReadIdentifiers(psS64 *imageId, psS64 *sourceId, const pmHDU *hdu)
+{
+    PS_ASSERT_PTR_NON_NULL(hdu, false);
+
+    // XXX Get header keyword name from camera configuration
+
+    bool imageOK, sourceOK;             // Status of MD lookups
+    *imageId = psMetadataLookupS64(&imageOK, hdu->header, "IMAGEID");
+    *sourceId = psMetadataLookupS64(&sourceOK, hdu->header, "SOURCEID");
+
+    return imageOK && sourceOK;
+}