Index: /trunk/psModules/src/camera/pmFPAMaskWeight.c
===================================================================
--- /trunk/psModules/src/camera/pmFPAMaskWeight.c	(revision 17691)
+++ /trunk/psModules/src/camera/pmFPAMaskWeight.c	(revision 17692)
@@ -378,2 +378,28 @@
     return true;
 }
+
+
+bool pmReadoutMaskNonfinite(pmReadout *readout, psMaskType maskVal)
+{
+    PM_ASSERT_READOUT_NON_NULL(readout, false);
+    PM_ASSERT_READOUT_IMAGE(readout, false);
+
+    psImage *image = readout->image;    // Readout's image
+    psImage *weight = readout->weight;  // Readout's weight
+    int numCols = image->numCols, numRows = image->numRows; // Size of image
+
+    if (!readout->mask) {
+        readout->mask = psImageAlloc(numCols, numRows, PS_TYPE_MASK);
+    }
+    psImage *mask = readout->mask;      // Readout's mask
+
+    for (int y = 0; y < numRows; y++) {
+        for (int x = 0; x < numCols; x++) {
+            if (!isfinite(image->data.F32[y][x]) || (weight && !isfinite(weight->data.F32[y][x]))) {
+                mask->data.PS_TYPE_MASK_DATA[y][x] |= maskVal;
+            }
+        }
+    }
+
+    return true;
+}
Index: /trunk/psModules/src/camera/pmFPAMaskWeight.h
===================================================================
--- /trunk/psModules/src/camera/pmFPAMaskWeight.h	(revision 17691)
+++ /trunk/psModules/src/camera/pmFPAMaskWeight.h	(revision 17692)
@@ -5,6 +5,6 @@
  * @author Eugene Magnier, IfA
  *
- * @version $Revision: 1.10 $ $Name: not supported by cvs2svn $
- * @date $Date: 2008-03-31 22:39:06 $
+ * @version $Revision: 1.11 $ $Name: not supported by cvs2svn $
+ * @date $Date: 2008-05-15 03:25:10 $
  * Copyright 2005-2006 Institute for Astronomy, University of Hawaii
  */
@@ -106,5 +106,12 @@
     );
 
-
+/// Explicitly mask non-finite pixels
+///
+/// Since unmasked non-finite pixels can occur (e.g., by out-of-range in quantisation), it is sometimes
+/// necessary to mask them explicitly.  Non-finite pixels in the image or weight have their mask OR-ed with
+/// the provided value.
+bool pmReadoutMaskNonfinite(pmReadout *readout, ///< Readout to mask
+                            psMaskType maskVal ///< Mask value to give non-finite pixels
+    );
 
 /// @}