Index: /trunk/psphot/src/psModulesUtils.c
===================================================================
--- /trunk/psphot/src/psModulesUtils.c	(revision 5124)
+++ /trunk/psphot/src/psModulesUtils.c	(revision 5125)
@@ -82,2 +82,21 @@
 } 
 
+// force the fitted sky to meet the source flux at outer radius 
+bool pmModelSkyOffset (pmModel *model, float x, float y, float radius) {
+
+    float flux;
+
+    psVector *coord = psVectorAlloc(2, PS_TYPE_F32);
+
+    pmModelFunc modelFunc = pmModelFunc_GetFunction (model->type);
+    psVector *params = model->params;
+  
+    coord->data.F32[0] = x + radius;
+    coord->data.F32[1] = y;
+    flux = modelFunc (NULL, params, coord);
+    params->data.F32[0] = flux;
+
+    psFree (coord);
+
+    return true;
+}
Index: /trunk/psphot/src/psModulesUtils.h
===================================================================
--- /trunk/psphot/src/psModulesUtils.h	(revision 5124)
+++ /trunk/psphot/src/psModulesUtils.h	(revision 5125)
@@ -14,4 +14,5 @@
 int	     pmSourceDophotType (pmSource *source);
 bool	     pmSourcePhotometry (float *fitMag, float *obsMag, pmModel *model, psImage *image, psImage *mask);
+bool         pmModelSkyOffset (pmModel *model, float x, float y, float radius);
 
 // unify with paul's image/header/metadata functions