Index: /trunk/ppStack/src/ppStackTarget.c
===================================================================
--- /trunk/ppStack/src/ppStackTarget.c	(revision 28253)
+++ /trunk/ppStack/src/ppStackTarget.c	(revision 28254)
@@ -144,10 +144,10 @@
 
         if (numCols == 0 && numRows == 0) {
-            numCols = readout->image->numCols;
-            numRows = readout->image->numRows;
-        } else if (numCols != readout->image->numCols ||
-                   numRows != readout->image->numRows) {
+            numCols = readout->variance->numCols;
+            numRows = readout->variance->numRows;
+        } else if (numCols != readout->variance->numCols ||
+                   numRows != readout->variance->numRows) {
             psError(PPSTACK_ERR_ARGUMENTS, true, "Sizes of input images don't match: %dx%d vs %dx%d",
-                    readout->image->numCols, readout->image->numRows, numCols, numRows);
+                    readout->variance->numCols, readout->variance->numRows, numCols, numRows);
             psFree(rng);
             return NULL;