Index: trunk/psLib/src/imageops/psImageCovariance.c
===================================================================
--- trunk/psLib/src/imageops/psImageCovariance.c	(revision 22738)
+++ trunk/psLib/src/imageops/psImageCovariance.c	(revision 23401)
@@ -260,4 +260,8 @@
 {
     PS_ASSERT_IMAGE_NON_NULL(variance, NULL);
+    if (!covar) {
+        // Transferred all we could!
+        return true;
+    }
     PS_ASSERT_KERNEL_NON_NULL(covar, NULL);