Index: /branches/eam_branches/ipp-dev-20210817/psModules/src/camera/pmFPAfileIO.c
===================================================================
--- /branches/eam_branches/ipp-dev-20210817/psModules/src/camera/pmFPAfileIO.c	(revision 41842)
+++ /branches/eam_branches/ipp-dev-20210817/psModules/src/camera/pmFPAfileIO.c	(revision 41843)
@@ -145,4 +145,25 @@
 }
 
+// list all defined pmFPAfiles
+bool pmFPAfileIOList (pmConfig *config)
+{
+    PS_ASSERT_PTR_NON_NULL(config, false);
+    PS_ASSERT_PTR_NON_NULL(config->files, false);
+
+    psMetadata *files = config->files;
+
+    // attempt to perform all create, read, write, close operations
+    psMetadataItem *item = NULL;
+    psMetadataIterator *iter = psMetadataIteratorAlloc (files, PS_LIST_HEAD, NULL);
+    while ((item = psMetadataGetAndIncrement (iter)) != NULL) {
+        pmFPAfile *file = item->data.V;
+	
+	fprintf (stderr, "%s : %d %d %d : %d %d %d %d\n", file->name, file->type, file->mode, file->state,
+		 file->fileLevel, file->dataLevel, file->freeLevel, file->mosaicLevel);
+    }
+    psFree (iter);
+    return true;
+}
+
 // read the file, if necessary and possible
 bool pmFPAfileRead(pmFPAfile *file, const pmFPAview *view, pmConfig *config)
@@ -359,5 +380,5 @@
 
     if (file->state & PM_FPA_STATE_INACTIVE) {
-        psTrace("psModules.camera", 6, "skip write for %s, files is inactive", file->name);
+        psTrace("psModules.camera", 6, "skip write for %s, file is inactive", file->name);
         return true;
     }
Index: /branches/eam_branches/ipp-dev-20210817/psModules/src/camera/pmFPAfileIO.h
===================================================================
--- /branches/eam_branches/ipp-dev-20210817/psModules/src/camera/pmFPAfileIO.h	(revision 41842)
+++ /branches/eam_branches/ipp-dev-20210817/psModules/src/camera/pmFPAfileIO.h	(revision 41843)
@@ -55,4 +55,6 @@
 bool pmFPAfileReadPHU (pmFPAfile *file, const pmFPAview *view, pmConfig *config);
 
+bool pmFPAfileIOList (pmConfig *config);
+
 /// @}
 # endif
Index: /branches/eam_branches/ipp-dev-20210817/psModules/src/imcombine/pmStack.c
===================================================================
--- /branches/eam_branches/ipp-dev-20210817/psModules/src/imcombine/pmStack.c	(revision 41842)
+++ /branches/eam_branches/ipp-dev-20210817/psModules/src/imcombine/pmStack.c	(revision 41843)
@@ -961,5 +961,5 @@
 
     // KMM values;
-    float Punimodal = 1.0,KMMmean = NAN,KMMsigma = NAN,KMMpi = NAN;
+    float Punimodal = 1.0, KMMmean = NAN, KMMsigma = NAN, KMMpi = NAN;
     int KMM_MINIMUM_INPUTS = 6;
     bool useKMM = false;
@@ -1510,4 +1510,94 @@
 }
 
+# define MIN_GOOD_PERCENTILE 2
+bool pmStackCombineByPercentile(
+    pmReadout *combined,
+    psArray *stackData,
+    psF64 minRange,
+    psF64 maxRange,
+    psImageMaskType badMaskBits, 	// treat these bits as 'bad'
+    psImageMaskType suspectMaskBits,	// treat these bits as 'suspect'
+    psImageMaskType blankMaskBits       // use this mask value for pixels missing input data (distinguish between Ninput = 0 and Ngood = 0?)
+) {
+    int minInputCols, maxInputCols, minInputRows, maxInputRows; // Smallest and largest values to combine
+    int xSize, ySize;                   // Size of the output image
+
+    // we need to copy the readouts to their own array for validation
+    psArray *stackReadouts = psArrayAlloc(stackData->n);
+    for (int i = 0; i < stackData->n; i++) {
+        pmStackData *data = stackData->data[i]; // Stack data for this input
+        pmReadout *ro = data->readout;  // Readout of interest
+        stackReadouts->data[i] = psMemIncrRefCounter(ro);
+    }
+
+    if (!pmReadoutStackValidate(&minInputCols, &maxInputCols, &minInputRows, &maxInputRows, &xSize, &ySize, stackReadouts)) {
+	psError(psErrorCodeLast(), false, "Input stack is not valid.");
+	psFree(stackReadouts);
+	return false;
+    }
+    psFree(stackReadouts);
+
+    psVector *pixelData = psVectorAlloc(stackData->n, PS_TYPE_F32);
+    psVector *pixelMask = psVectorAlloc(stackData->n, PS_TYPE_VECTOR_MASK);
+
+    for (int y = minInputRows; y < maxInputRows; y++) {
+	for (int x = minInputCols; x < maxInputCols; x++) {
+
+	    int nGood = 0; 
+	    for (int i = 0; i < stackData->n; i++) {
+
+		pmStackData *data = stackData->data[i]; // Stack data for this input
+		pmReadout *ro = data->readout;  // Readout of interest
+		psImage *image = ro->image;
+
+		int xIn = x - data->readout->col0;
+		int yIn = y - data->readout->row0; // Coordinates on input readout
+
+		if (!isfinite(image->data.F32[yIn][xIn])) continue;
+		if (fabs(image->data.F32[yIn][xIn]) > 1e5) continue;
+		// XXX need to test the input mask as well here
+
+		pixelData->data.F32[nGood] = image->data.F32[yIn][xIn];
+		nGood ++;
+	    }
+	    pixelData->n = nGood;
+	    psVectorSortInPlace (pixelData);
+
+	    if (nGood < MIN_GOOD_PERCENTILE) {
+		combined->image->data.F32[y][x] = NAN;
+		combined->variance->data.F32[y][x] = NAN;
+		combined->mask->data.PS_TYPE_IMAGE_MASK_DATA[y][x] = 1;
+		continue;
+	    }
+
+	    int Ns = MIN(MAX(0, minRange * nGood),nGood); // e.g., 0.1 * 50 = 5
+	    int Ne = MIN(MAX(0, maxRange * nGood),nGood); // e.g., 0.9 * 50 = 45 
+	    int Npt = Ne - Ns;
+
+	    float sum = 0.0;
+	    for (int n = Ns; n < Ne; n++) {
+		sum += pixelData->data.F32[n];
+	    }
+	    float mean = sum / (float) Npt;
+
+	    float varSum = 0.0;
+	    for (int n = Ns; n < Ne; n++) {
+		varSum += SQ(pixelData->data.F32[n] - mean);
+	    }
+	    // variance on the mean (stdev / sqrt(N))^2
+	    float varValue = varSum / (Npt - 1) / Npt;
+
+	    combined->image->data.F32[y][x] = mean;
+	    combined->variance->data.F32[y][x] = varValue;
+	    combined->mask->data.PS_TYPE_IMAGE_MASK_DATA[y][x] = 0;
+	}
+    }
+  
+    psFree(pixelData);
+    psFree(pixelMask);
+
+    return (true);
+}
+
 /// Stack input images
 bool pmStackCombine(
@@ -1644,10 +1734,4 @@
         expweight = expmaps->variance;
     }
-
-/*     // Pre-reject inputs using KMM bimodality test. */
-/*     if (1)  { */
-/* /\*       KMMRejectUnpopular(input,x,y); *\/ */
-/*       rejection = true; */
-/*     } */
    
     // Set up rejection list
@@ -1660,20 +1744,6 @@
     for (int y = minInputRows; y < maxInputRows; y++) {
         for (int x = minInputCols; x < maxInputCols; x++) {
+	    // this is only for TESTING:
 	    CHECKPIX(x, y, "Combining pixel %d,%d: %x %x %f %f %f %f %d %d %d\n", x, y, badMaskBits, blankMaskBits, iter, rej, sys, olympic, useVariance, safe, rejection);
-
-/* 	    // Pre-reject inputs using KMM bimodality test. */
-/* 	  if (1)  { */
-/* 	    KMMRejectUnpopular(input,x,y); */
-/* /\* 	    rejection = true; *\/ */
-/* 	  } */
-/* 	  else { */
-/* 	    KMMRejectBright(input,x,y); */
-/* 	  } */
-
-#ifdef TESTING
-	    if (PS_SQR(x - TEST_X) + PS_SQR(y - TEST_Y) <= PS_SQR(TEST_RADIUS)) {
-		fprintf (stderr, "combine\n");
-	    }
-# endif
 
             psVector *reject = NULL; // Images to reject for this pixel
Index: /branches/eam_branches/ipp-dev-20210817/psModules/src/imcombine/pmStack.h
===================================================================
--- /branches/eam_branches/ipp-dev-20210817/psModules/src/imcombine/pmStack.h	(revision 41842)
+++ /branches/eam_branches/ipp-dev-20210817/psModules/src/imcombine/pmStack.h	(revision 41843)
@@ -47,4 +47,14 @@
 				);
 
+bool pmStackCombineByPercentile(
+    pmReadout *combined,
+    psArray *input,
+    psF64 minRange,
+    psF64 maxRange,
+    psImageMaskType badMaskBits, 	// treat these bits as 'bad'
+    psImageMaskType suspectMaskBits,	// treat these bits as 'suspect'
+    psImageMaskType blankMaskBits       // use this mask value for pixels missing input data (distinguish between Ninput = 0 and Ngood = 0?)
+  );
+
 /// Stack input images
 bool pmStackCombine(pmReadout *combined,///< Combined readout (output)