Index: trunk/psModules/src/camera/pmReadoutStack.c
===================================================================
--- trunk/psModules/src/camera/pmReadoutStack.c	(revision 16600)
+++ trunk/psModules/src/camera/pmReadoutStack.c	(revision 16680)
@@ -25,4 +25,5 @@
     if (!readout->image) {
         readout->image = psImageAlloc(numCols, numRows, PS_TYPE_F32);
+        psImageInit(readout->image, NAN);
     }
     if (readout->image->numCols < numCols || readout->image->numRows < numRows) {
@@ -38,4 +39,5 @@
         if (!readout->mask) {
             readout->mask = psImageAlloc(numCols, numRows, PS_TYPE_MASK);
+            psImageInit(readout->mask, blank);
         }
         if (readout->mask->numCols < numCols || readout->mask->numRows < numRows) {
@@ -51,4 +53,5 @@
         if (!readout->weight) {
             readout->weight = psImageAlloc(numCols, numRows, PS_TYPE_F32);
+            psImageInit(readout->weight, NAN);
         }
         if (readout->weight->numCols < numCols || readout->weight->numRows < numRows) {