Index: trunk/psModules/src/imcombine/pmReadoutCombine.c
===================================================================
--- trunk/psModules/src/imcombine/pmReadoutCombine.c	(revision 24906)
+++ trunk/psModules/src/imcombine/pmReadoutCombine.c	(revision 24907)
@@ -281,4 +281,7 @@
     #endif
 
+    // set up windows for visualization (if selected)
+    pmReadoutCombineVisualInit();
+
     // Dereference output products
     psF32 **outputImage  = output->image->data.F32; // Output image
@@ -397,4 +400,8 @@
 	    outputImage[yOut][xOut] = psStatsGetValue(stats, params->combine);
 
+	    if (!isfinite(outputImage[yOut][xOut])) {
+		pmReadoutCombineVisualPixels(pixels, mask, outputImage[yOut][xOut]);
+	    }
+
 	    if (isnan(outputImage[yOut][xOut])) {
                 outputImage[yOut][xOut] = NAN;
@@ -434,2 +441,106 @@
 }
 
+#if (HAVE_KAPA)
+#include <kapa.h>
+#include "pmKapaPlots.h"
+#include "pmVisual.h"
+
+static int kapa = -1;
+static bool plotFlag = true;
+
+// this init function only gets the ordinates for the first readout...
+bool pmReadoutCombineVisualInit(void) {
+    
+    if (!pmVisualIsVisual()) return true;
+
+    // skip if we have already opened the windows (or if none are requested...)
+    if (kapa != -1) return true;
+
+    pmVisualInitWindow(&kapa, "ppmerge");
+    return true;
+}
+
+bool pmReadoutCombineVisualPixels(psVector *pixels, psVector *mask, float mean) {
+
+    Graphdata graphdata;
+    float xline[2], yline[2];
+    
+    if (!pmVisualIsVisual()) return true;
+
+    if (!plotFlag) return true;
+
+    KapaInitGraph(&graphdata);
+
+    psVector *xAll = psVectorAlloc(pixels->n, PS_TYPE_F32);
+    psVector *xSub = psVectorAlloc(pixels->n, PS_TYPE_F32);
+    psVector *ySub = psVectorAlloc(pixels->n, PS_TYPE_F32);
+
+    // generate vectors of the unmasked values
+    int nSub = 0;
+    for (int j = 0; j < pixels->n; j++) {
+	xAll->data.F32[j] = j;
+	if (mask && mask->data.PS_TYPE_VECTOR_MASK_DATA[j]) continue;
+	xSub->data.F32[nSub] = j;
+	ySub->data.F32[nSub] = pixels->data.F32[j];
+	nSub ++;
+    }
+    xSub->n = ySub->n = nSub;
+    xAll->n = pixels->n;
+	
+    xline[0] = 0;
+    xline[1] = pixels->n;
+    yline[0] = mean;
+    yline[1] = mean;
+
+    // plot the unmasked values
+    pmVisualScaleGraphdata (&graphdata, xAll, pixels, false);
+    KapaSetGraphData(kapa, &graphdata);
+    KapaSetLimits(kapa, &graphdata);
+    KapaClearPlots (kapa);
+
+    KapaSetFont (kapa, "courier", 14);
+    KapaBox (kapa, &graphdata);
+    KapaSendLabel (kapa, "ordinate", KAPA_LABEL_XM);
+    KapaSendLabel (kapa, "pixel values", KAPA_LABEL_YM);
+
+    graphdata.color = KapaColorByName("black");
+    graphdata.style = 2;
+    graphdata.ptype = 2;
+    KapaPrepPlot  (kapa, xSub->n, &graphdata);
+    KapaPlotVector(kapa, xSub->n, xSub->data.F32, "x");
+    KapaPlotVector(kapa, xSub->n, ySub->data.F32, "y");
+
+    graphdata.color = KapaColorByName("red");
+    graphdata.style = 2;
+    graphdata.ptype = 7;
+    KapaPrepPlot  (kapa, xAll->n, &graphdata);
+    KapaPlotVector(kapa, xAll->n, xAll->data.F32, "x");
+    KapaPlotVector(kapa, xAll->n, pixels->data.F32, "y");
+
+    graphdata.color = KapaColorByName("blue");
+    graphdata.style = 0;
+    graphdata.ptype = 7;
+    KapaPrepPlot  (kapa, 2, &graphdata);
+    KapaPlotVector(kapa, 2, xline, "x");
+    KapaPlotVector(kapa, 2, yline, "y");
+
+    pmVisualAskUser (&plotFlag);
+    return true;
+}
+
+bool pmReadoutCombineVisualCleanup(void) {
+
+    if (!pmVisualIsVisual()) return true;
+    if (kapa == -1) return true;
+
+    KapaClose(kapa);
+    return true;
+}
+
+# else
+
+bool pmReadoutCombineVisualInit(void) { return true; }
+bool pmReadoutCombineVisualPixels(psVector *pixels, psVector *mask, float mean) { return true; }
+bool pmReadoutCombineVisualCleanup(void) { return true; }
+
+# endif
Index: trunk/psModules/src/imcombine/pmReadoutCombine.h
===================================================================
--- trunk/psModules/src/imcombine/pmReadoutCombine.h	(revision 24906)
+++ trunk/psModules/src/imcombine/pmReadoutCombine.h	(revision 24907)
@@ -47,4 +47,8 @@
                      );
 
+bool pmReadoutCombineVisualInit(void);
+bool pmReadoutCombineVisualPixels(psVector *pixels, psVector *mask, float mean);
+bool pmReadoutCombineVisualCleanup(void);
+
 /// @}
 #endif