Index: trunk/ppBackground/src/ppBackgroundCamera.c
===================================================================
--- trunk/ppBackground/src/ppBackgroundCamera.c	(revision 28288)
+++ trunk/ppBackground/src/ppBackgroundCamera.c	(revision 28289)
@@ -32,16 +32,20 @@
     bool status;                        // Status of file definition
 
-    fileArguments("PATTERN", data->patternName, "Input pattern", data->config);
-    pmFPAfileDefineFromArgs(&status, data->config, "PPBACKGROUND.PATTERN", "PATTERN"); // File
-    if (!status) {
-        psError(psErrorCodeLast(), false, "Failed to build file from PPBACKGROUND.PATTERN");
-        return false;
+    if (data->patternName) {
+        fileArguments("PATTERN", data->patternName, "Input pattern", data->config);
+        pmFPAfileDefineFromArgs(&status, data->config, "PPBACKGROUND.PATTERN", "PATTERN"); // File
+        if (!status) {
+            psError(psErrorCodeLast(), false, "Failed to build file from PPBACKGROUND.PATTERN");
+            return false;
+        }
     }
 
-    fileArguments("BACKGROUND", data->backgroundName, "Input background model", data->config);
-    pmFPAfileDefineFromArgs(&status, data->config, "PPBACKGROUND.BACKGROUND", "BACKGROUND"); // File
-    if (!status) {
-        psError(psErrorCodeLast(), false, "Failed to build file from PPBACKGROUND.BACKGROUND");
-        return false;
+    if (data->backgroundName) {
+        fileArguments("BACKGROUND", data->backgroundName, "Input background model", data->config);
+        pmFPAfileDefineFromArgs(&status, data->config, "PPBACKGROUND.BACKGROUND", "BACKGROUND"); // File
+        if (!status) {
+            psError(psErrorCodeLast(), false, "Failed to build file from PPBACKGROUND.BACKGROUND");
+            return false;
+        }
     }