Index: trunk/pswarp/src/pswarpTransformReadout.c
===================================================================
--- trunk/pswarp/src/pswarpTransformReadout.c	(revision 18967)
+++ trunk/pswarp/src/pswarpTransformReadout.c	(revision 19391)
@@ -49,4 +49,14 @@
         output->mask = psImageAlloc(output->image->numCols, output->image->numRows, PS_TYPE_MASK);
         psImageInit(output->mask, maskBad);
+    }
+
+    static int maskNum = 0;
+    {
+        psString name = NULL;
+        psStringAppend(&name, "mask_%d.fits", maskNum++);
+        psFits *fits = psFitsOpen(name, "w");
+        psFree(name);
+        psFitsWriteImage(fits, NULL, output->mask, 0, NULL);
+        psFitsClose(fits);
     }
 
@@ -146,4 +156,13 @@
     output->parent->parent->data_exists = true;
 
+    {
+        psString name = NULL;
+        psStringAppend(&name, "mask_%d.fits", maskNum++);
+        psFits *fits = psFitsOpen(name, "w");
+        psFree(name);
+        psFitsWriteImage(fits, NULL, output->mask, 0, NULL);
+        psFitsClose(fits);
+    }
+
     psLogMsg ("pswarp", 3, "warping analysis: %f sec\n", psTimerMark ("warp"));