Index: /trunk/ppSub/src/ppSubCamera.c
===================================================================
--- /trunk/ppSub/src/ppSubCamera.c	(revision 23308)
+++ /trunk/ppSub/src/ppSubCamera.c	(revision 23309)
@@ -180,15 +180,33 @@
 
     // Convolved input image
-    defineOutputFile(config, input, "PPSUB.INPUT.CONV", PM_FPA_FILE_IMAGE);
-    defineOutputFile(config, input, "PPSUB.INPUT.CONV.MASK", PM_FPA_FILE_MASK);
+    pmFPAfile *inConvImage = defineOutputFile(config, input, "PPSUB.INPUT.CONV", PM_FPA_FILE_IMAGE);
+    pmFPAfile *inConvMask = defineOutputFile(config, input, "PPSUB.INPUT.CONV.MASK", PM_FPA_FILE_MASK);
+    if (!inConvImage || !inConvMask) {
+        psError(PS_ERR_UNKNOWN, false, "Unable to define output files");
+        return false;
+    }
     if (inVar) {
-        defineOutputFile(config, input, "PPSUB.INPUT.CONV.VARIANCE", PM_FPA_FILE_VARIANCE);
+        pmFPAfile *inConvVar = defineOutputFile(config, input, "PPSUB.INPUT.CONV.VARIANCE",
+                                                PM_FPA_FILE_VARIANCE);
+        if (!inConvVar) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to define output files");
+            return false;
+        }
     }
 
     // Convolved ref image
-    defineOutputFile(config, input, "PPSUB.REF.CONV", PM_FPA_FILE_IMAGE);
-    defineOutputFile(config, input, "PPSUB.REF.CONV.MASK", PM_FPA_FILE_MASK);
+    pmFPAfile *refConvImage = defineOutputFile(config, input, "PPSUB.REF.CONV", PM_FPA_FILE_IMAGE);
+    pmFPAfile *refConvMask = defineOutputFile(config, input, "PPSUB.REF.CONV.MASK", PM_FPA_FILE_MASK);
+    if (!refConvImage || !refConvMask) {
+        psError(PS_ERR_UNKNOWN, false, "Unable to define output files");
+        return false;
+    }
     if (refVar) {
-        defineOutputFile(config, input, "PPSUB.REF.CONV.VARIANCE", PM_FPA_FILE_VARIANCE);
+        pmFPAfile *refConvVar = defineOutputFile(config, input, "PPSUB.REF.CONV.VARIANCE",
+                                                 PM_FPA_FILE_VARIANCE);
+        if (!refConvVar) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to define output files");
+            return false;
+        }
     }
 
Index: /trunk/ppSub/src/ppSubMatchPSFs.c
===================================================================
--- /trunk/ppSub/src/ppSubMatchPSFs.c	(revision 23308)
+++ /trunk/ppSub/src/ppSubMatchPSFs.c	(revision 23309)
@@ -48,4 +48,7 @@
 
     bool mdok;                          // Status of MD lookup
+
+    // Load pre-calculated kernel, if available
+    pmReadout *kernelRO = pmFPAfileThisReadout(config->files, view, "PPSUB.OUTPUT.KERNEL"); // RO with kernel
 
     // Sources in image, used for stamps: these must be loaded from previous analysis stages
@@ -134,10 +137,18 @@
 
     // Match the PSFs
-    if (!pmSubtractionMatch(inConv, refConv, inRO, refRO, footprint, stride, regionSize, spacing, threshold,
-                            sources, stampsName, type, size, order, widths, orders, inner, ringsOrder,
-                            binning, penalty, optimum, optWidths, optOrder, optThresh, iter, rej, sys,
-                            maskVal, maskBad, maskPoor, poorFrac, badFrac, subMode)) {
-        psError(PS_ERR_UNKNOWN, false, "Unable to match images.");
-        return false;
+    if (kernelRO) {
+        if (!pmSubtractionMatchPrecalc(inConv, refConv, inRO, refRO, kernelRO->analysis,
+                                       stride, sys, maskVal, maskBad, maskPoor, poorFrac, badFrac)) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to convolve images.");
+            return false;
+        }
+    } else {
+        if (!pmSubtractionMatch(inConv, refConv, inRO, refRO, footprint, stride, regionSize, spacing,
+                                threshold, sources, stampsName, type, size, order, widths, orders, inner,
+                                ringsOrder, binning, penalty, optimum, optWidths, optOrder, optThresh, iter,
+                                rej, sys, maskVal, maskBad, maskPoor, poorFrac, badFrac, subMode)) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to match images.");
+            return false;
+        }
     }