Index: branches/pap/psModules/src/imcombine/pmSubtractionStamps.c
===================================================================
--- branches/pap/psModules/src/imcombine/pmSubtractionStamps.c	(revision 26300)
+++ branches/pap/psModules/src/imcombine/pmSubtractionStamps.c	(revision 26321)
@@ -46,4 +46,5 @@
     psFree(list->y);
     psFree(list->flux);
+    psFree(list->window);
 }
 
@@ -220,4 +221,5 @@
     list->y = NULL;
     list->flux = NULL;
+    list->window = NULL;
     list->footprint = footprint;
     list->sysErr = sysErr;
@@ -239,4 +241,5 @@
     out->y = NULL;
     out->flux = NULL;
+    out->window = psMemIncrRefCounter(in->window);
     out->footprint = in->footprint;
 
@@ -606,4 +609,77 @@
 }
 
+
+bool pmSubtractionStampsGetWindow(pmSubtractionStampList *stamps, int kernelSize)
+{
+    PM_ASSERT_SUBTRACTION_STAMP_LIST_NON_NULL(stamps, false);
+    PS_ASSERT_INT_NONNEGATIVE(kernelSize, false);
+
+    int size = kernelSize + stamps->footprint; // Size of postage stamps
+
+    psFree (stamps->window);
+    stamps->window = psKernelAlloc(-size, size, -size, size);
+    psImageInit(stamps->window->image, 0.0);
+
+    // generate normalizations for each stamp
+    psVector *norm1 = psVectorAlloc(stamps->num, PS_TYPE_F32);
+    psVector *norm2 = psVectorAlloc(stamps->num, PS_TYPE_F32);
+    for (int i = 0; i < stamps->num; i++) {
+        pmSubtractionStamp *stamp = stamps->stamps->data[i]; // Stamp of interest
+        if (!stamp) continue;
+	if (!stamp->image1) continue;
+	if (!stamp->image2) continue;
+
+	float sum1 = 0.0;
+	float sum2 = 0.0;
+	for (int y = -size; y <= size; y++) {
+	    for (int x = -size; x <= size; x++) {
+		sum1 += stamp->image1->kernel[y][x];
+		sum2 += stamp->image2->kernel[y][x];
+	    }
+	}
+	norm1->data.F32[i] = sum1;
+	norm2->data.F32[i] = sum2;
+    }
+
+    // storage vector for flux data
+    psStats *stats = psStatsAlloc (PS_STAT_ROBUST_MEDIAN | PS_STAT_ROBUST_STDEV);
+    psVector *flux = psVectorAllocEmpty(2*stamps->num, PS_TYPE_F32);
+
+    // generate the window pixels
+    for (int y = -size; y <= size; y++) {
+	for (int x = -size; x <= size; x++) {
+
+	    flux->n = 0;
+	    for (int i = 0; i < stamps->num; i++) {
+		pmSubtractionStamp *stamp = stamps->stamps->data[i]; // Stamp of interest
+		if (!stamp) continue;
+		if (!stamp->image1) continue;
+		if (!stamp->image2) continue;
+		
+		psVectorAppend (flux, stamp->image1->kernel[y][x] / norm1->data.F32[i]);
+		psVectorAppend (flux, stamp->image2->kernel[y][x] / norm2->data.F32[i]);
+	    }
+
+	    psStatsInit (stats);
+	    if (!psVectorStats (stats, flux, NULL, NULL, 0)) {
+		psAbort ("failed to generate stats");
+	    }
+	    stamps->window->kernel[y][x] = stats->robustMedian;
+	}
+    }
+
+    // XXX TESTING: 
+    {
+	psFits *fits = psFitsOpen ("window.fits", "w");
+	psFitsWriteImage (fits, NULL, stamps->window->image, 0, NULL);
+	psFitsClose (fits);
+    }
+
+    psFree (stats);
+    psFree (flux);
+    psFree (norm1);
+    psFree (norm2);
+    return true;
+}
 
 bool pmSubtractionStampsExtract(pmSubtractionStampList *stamps, psImage *image1, psImage *image2,