Index: trunk/ppSub/src/ppSubMaskStats.c
===================================================================
--- trunk/ppSub/src/ppSubMaskStats.c	(revision 28123)
+++ trunk/ppSub/src/ppSubMaskStats.c	(revision 28131)
@@ -9,7 +9,14 @@
 
 
-bool ppSubMaskStats(pmConfig *config, pmFPAview *view, psMetadata *stats) {
+bool ppSubMaskStats(pmConfig *config, pmFPAview *view, psMetadata *stats)
+{
   PS_ASSERT_PTR_NON_NULL(view, false);
   PS_ASSERT_PTR_NON_NULL(config, false);
+
+  pmReadout *readout = pmFPAfileThisReadout(config->files, view, "PPSUB.OUTPUT");
+  if (!stats || !readout || !readout->data_exists) {
+      // Nothing to process
+      return(true);
+  }
 
   bool status;
@@ -27,9 +34,4 @@
   psS32 Npix_advisory = 0;
 
-  pmReadout *readout = pmFPAfileThisReadout(config->files, view, "PPSUB.OUTPUT");
-  if (!readout || !readout->data_exists) {
-    // Nothing to process
-    return(true);
-  }
   psImage *mask = readout->mask;  // Mask of interest;
   if (!pmSingleImageMaskStats(mask,&Npix_valid,&Npix_static,&Npix_magic,