Index: /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/Makefile
===================================================================
--- /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/Makefile	(revision 29796)
+++ /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/Makefile	(revision 29797)
@@ -22,11 +22,13 @@
 all: dvomerge dvoconvert dvosecfilt
 
+#  $(SRC)/dvomergeContinue.$(ARCH).o
+
 DVOMERGE = \
 $(SRC)/dvomerge.$(ARCH).o \
 $(SRC)/dvomergeUpdate.$(ARCH).o \
 $(SRC)/dvomergeCreate.$(ARCH).o \
-$(SRC)/dvomergeContinue.$(ARCH).o \
-$(SRC)/dvomergeContinue_threaded.$(ARCH).o \
+$(SRC)/dvomergeUpdate_threaded.$(ARCH).o \
 $(SRC)/dvomergeFromList.$(ARCH).o \
+$(SRC)/dvomergeImageIDs.$(ARCH).o \
 $(SRC)/dvo_image_merge_dbs.$(ARCH).o \
 $(SRC)/SetSignals.$(ARCH).o \
Index: /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/include/dvomerge.h
===================================================================
--- /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/include/dvomerge.h	(revision 29796)
+++ /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/include/dvomerge.h	(revision 29797)
@@ -111,5 +111,4 @@
 int 	   dvo_image_match_dbs    PROTO((IDmapType *IDmap, FITS_DB *tgt, FITS_DB *src));
 int 	   dvomergeImagesGetMap   PROTO((IDmapType *IDmap, char *input, char *output));
-int 	   dvomergeContinue       PROTO((int argc, char **argv));
 int        dvomergeFromList       PROTO((int argc, char **argv));
-int 	   dvomergeContinue_threaded PROTO((int argc, char **argv));
+int 	   dvomergeUpdate_threaded PROTO((int argc, char **argv));
Index: /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomerge.c
===================================================================
--- /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomerge.c	(revision 29796)
+++ /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomerge.c	(revision 29797)
@@ -8,6 +8,4 @@
   dvomerge_args (&argc, argv);
 
-  // XXX require both inputs to be sorted?
-
   if (argc == 6) {
     if (!strcasecmp (argv[2], "and")) {
@@ -17,10 +15,9 @@
     }
   }
-  if (argc == 4) dvomergeUpdate (argc, argv);
-  if (argc == 5) {
+  if ((argc == 4) || (argc == 5)) {
     if (NTHREADS) {
-      dvomergeContinue_threaded (argc, argv);
+      dvomergeUpdate_threaded (argc, argv);
     } else {
-      dvomergeContinue (argc, argv);
+      dvomergeUpdate (argc, argv);
     }
   }
Index: /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeContinue.c
===================================================================
--- /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeContinue.c	(revision 29796)
+++ /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeContinue.c	(revision 29797)
@@ -71,5 +71,5 @@
   }
 
-  // XXX need to determine the mapping from the input to the output images
+  // need to determine the mapping from the input to the output images
   dvomergeImagesGetMap (&IDmap, input, output);
 
@@ -96,5 +96,4 @@
   depth = inlist[0].regions[Ns][0].depth;
   
-  // XXX test: are we using the table (if so, if it is NULL, we should get errors)
   SetPhotcodeTable(NULL);
 
@@ -164,47 +163,2 @@
   exit (0);
 }
-
-/*** update the image table ***/
-int dvomergeImagesGetMap (IDmapType *IDmap, char *input, char *output) { 
-
-  FITS_DB inDB;
-  FITS_DB outDB;
-  int    status;
-
-  /*** load input1/Images.dat ***/
-  sprintf (ImageCat, "%s/Images.dat", input);
-  inDB.mode   = dvo_catalog_catmode (CATMODE);
-  inDB.format = dvo_catalog_catformat (CATFORMAT);
-  status       = dvo_image_lock (&inDB, ImageCat, 3600.0, LCK_XCLD);  // shorter timeout?
-  if (!status) Shutdown ("ERROR: failure to lock image catalog %s", inDB.filename);
-
-  // load the image table 
-  if (inDB.dbstate == LCK_EMPTY) {
-    Shutdown ("only use -continue for an existing, partially merged database");
-  }
-  if (!dvo_image_load (&inDB, VERBOSE, TRUE)) {
-    Shutdown ("can't read input image catalog %s", inDB.filename);
-  }
-
-  /*** load output/Images.dat ***/
-  sprintf (ImageCat, "%s/Images.dat", output);
-  outDB.mode   = dvo_catalog_catmode (CATMODE);
-  outDB.format = dvo_catalog_catformat (CATFORMAT);
-  status       = dvo_image_lock (&outDB, ImageCat, 3600.0, LCK_XCLD);  // shorter timeout?
-  if (!status) Shutdown ("ERROR: failure to lock image catalog %s", outDB.filename);
-
-  /* load the image table */
-  if (outDB.dbstate == LCK_EMPTY) {
-    Shutdown ("only use -continue for an existing, partially merged database");
-  } 
-  if (!dvo_image_load (&outDB, VERBOSE, TRUE)) {
-    Shutdown ("can't read output image catalog %s", outDB.filename);
-  }
-
-  // convert database table to internal structure & add to output image db
-  dvo_image_match_dbs(IDmap, &outDB, &inDB);
-  dvo_image_unlock (&inDB); // unlock input
-  dvo_image_unlock (&outDB); // unlock output
-
-  return TRUE;
-}
Index: /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeContinue_threaded.c
===================================================================
--- /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeContinue_threaded.c	(revision 29796)
+++ /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeContinue_threaded.c	(revision 29797)
@@ -25,5 +25,5 @@
 } ThreadData;
 
-void *dvomergeContinue_threadjob (void *inputData) {
+void *dvomergeUpdate_threadjob (void *inputData) {
 
   off_t j;
@@ -96,5 +96,5 @@
 }
 
-int dvomergeContinue_threaded (int argc, char **argv) {
+int dvomergeUpdate_threaded (int argc, char **argv) {
 
   int j, launched, done, Nwait, Nrun;
@@ -118,6 +118,10 @@
   gettimeofday (&start, NULL);
 
+  CONTINUE = FALSE;
   if (strcasecmp (argv[2], "into")) dvomerge_usage();
-  if (strcasecmp (argv[4], "continue")) dvomerge_usage();
+  if (argc == 5) {
+    if (strcasecmp (argv[4], "continue")) dvomerge_usage();
+    CONTINUE = TRUE;
+  }
 
   input  = argv[1];
@@ -170,6 +174,10 @@
   }
 
-  // XXX need to determine the mapping from the input to the output images
-  dvomergeImagesGetMap (&IDmap, input, output);
+  if (CONTINUE) {
+    // need to determine the mapping from the input to the output images
+    dvomergeImagesGetMap (&IDmap, input, output);
+  } else {
+    dvomergeImagesUpdate (&IDmap, input, output);
+  }
 
   // load the sky table for the existing database
@@ -192,10 +200,9 @@
   // loop over the populatable output tables; check for data in input in the corresponding regions
 
-  // XXX test: are we using the table (if so, if it is NULL, we should get errors)
-  SetPhotcodeTable(NULL);
-
   SkyListPopulatedRange (&Ns, &Ne, inlist, 0);
   depth = inlist[0].regions[Ns][0].depth;
   
+  SetPhotcodeTable(NULL);
+
   ALLOCATE(threads, pthread_t, NTHREADS);
   ALLOCATE(threadData, ThreadData, NTHREADS);
@@ -205,5 +212,5 @@
   }
   for (i = 0; i < NTHREADS; i++) {
-    pthread_create (&threads[i], NULL, &dvomergeContinue_threadjob, (void *) &threadData[i]);
+    pthread_create (&threads[i], NULL, &dvomergeUpdate_threadjob, (void *) &threadData[i]);
   }
 
Index: /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeImageIDs.c
===================================================================
--- /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeImageIDs.c	(revision 29797)
+++ /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeImageIDs.c	(revision 29797)
@@ -0,0 +1,100 @@
+# include "dvomerge.h"
+
+/*** update the image table ***/
+int dvomergeImagesUpdate (IDmapType *IDmap, char *input, char *output) { 
+
+  FITS_DB inDB;
+  FITS_DB outDB;
+  int    status;
+
+  /*** load input1/Images.dat ***/
+  sprintf (ImageCat, "%s/Images.dat", input);
+  inDB.mode   = dvo_catalog_catmode (CATMODE);
+  inDB.format = dvo_catalog_catformat (CATFORMAT);
+  status       = dvo_image_lock (&inDB, ImageCat, 3600.0, LCK_XCLD);  // shorter timeout?
+  if (!status) Shutdown ("ERROR: failure to lock image catalog %s", inDB.filename);
+
+  // load the image table 
+  if (inDB.dbstate == LCK_EMPTY) {
+    IDmap->Nmap = 0;
+    return TRUE;
+  }
+  if (!dvo_image_load (&inDB, VERBOSE, TRUE)) {
+    Shutdown ("can't read input image catalog %s", inDB.filename);
+  }
+
+  /*** load output/Images.dat ***/
+  sprintf (ImageCat, "%s/Images.dat", output);
+  outDB.mode   = dvo_catalog_catmode (CATMODE);
+  outDB.format = dvo_catalog_catformat (CATFORMAT);
+  status       = dvo_image_lock (&outDB, ImageCat, 3600.0, LCK_XCLD);  // shorter timeout?
+  if (!status) Shutdown ("ERROR: failure to lock image catalog %s", outDB.filename);
+
+  /* load the image table */
+  if (outDB.dbstate == LCK_EMPTY) {
+    dvo_image_create (&outDB, GetZeroPoint());
+  } else {
+    if (!dvo_image_load (&outDB, VERBOSE, TRUE)) {
+      Shutdown ("can't read output image catalog %s", outDB.filename);
+    }
+  }
+
+  // convert database table to internal structure & add to output image db
+  dvo_image_merge_dbs(IDmap, &outDB, &inDB);
+  dvo_image_unlock (&inDB); // unlock input
+
+  SetProtect (TRUE);
+  dvo_image_save (&outDB, VERBOSE);
+  SetProtect (FALSE);
+  dvo_image_unlock (&outDB); // unlock output
+
+  return TRUE;
+}
+
+/*** update the image table ***/
+int dvomergeImagesGetMap (IDmapType *IDmap, char *input, char *output) { 
+
+  FITS_DB inDB;
+  FITS_DB outDB;
+  int    status;
+
+  /*** load input1/Images.dat ***/
+  sprintf (ImageCat, "%s/Images.dat", input);
+  inDB.mode   = dvo_catalog_catmode (CATMODE);
+  inDB.format = dvo_catalog_catformat (CATFORMAT);
+  status       = dvo_image_lock (&inDB, ImageCat, 3600.0, LCK_XCLD);  // shorter timeout?
+  if (!status) Shutdown ("ERROR: failure to lock image catalog %s", inDB.filename);
+
+  // load the image table
+  if (inDB.dbstate == LCK_EMPTY) {
+    IDmap->Nmap = 0;
+    return TRUE;
+  }
+
+  // the input database is allowed to have no images 
+  if (!dvo_image_load (&inDB, VERBOSE, TRUE)) {
+    Shutdown ("can't read input image catalog %s", inDB.filename);
+  }
+
+  /*** load output/Images.dat ***/
+  sprintf (ImageCat, "%s/Images.dat", output);
+  outDB.mode   = dvo_catalog_catmode (CATMODE);
+  outDB.format = dvo_catalog_catformat (CATFORMAT);
+  status       = dvo_image_lock (&outDB, ImageCat, 3600.0, LCK_XCLD);  // shorter timeout?
+  if (!status) Shutdown ("ERROR: failure to lock image catalog %s", outDB.filename);
+
+  /* load the image table */
+  if (outDB.dbstate == LCK_EMPTY) {
+    Shutdown ("only use -continue for an existing, partially merged database");
+  } 
+  if (!dvo_image_load (&outDB, VERBOSE, TRUE)) {
+    Shutdown ("can't read output image catalog %s", outDB.filename);
+  }
+
+  // convert database table to internal structure & add to output image db
+  dvo_image_match_dbs(IDmap, &outDB, &inDB);
+  dvo_image_unlock (&inDB); // unlock input
+  dvo_image_unlock (&outDB); // unlock output
+
+  return TRUE;
+}
Index: /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeUpdate.c
===================================================================
--- /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeUpdate.c	(revision 29796)
+++ /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeUpdate.c	(revision 29797)
@@ -3,5 +3,5 @@
 int dvomergeUpdate (int argc, char **argv) {
 
-  int depth;
+  int depth, CONTINUE;
   off_t i, j, Ns, Ne;
   SkyTable *outsky, *insky;
@@ -15,5 +15,14 @@
   int NsecfiltInput, NsecfiltOutput;
 
+  double dtime;
+  struct timeval start, stop;
+  gettimeofday (&start, NULL);
+
+  CONTINUE = FALSE;
   if (strcasecmp (argv[2], "into")) dvomerge_usage();
+  if (argc == 5) {
+    if (strcasecmp (argv[4], "continue")) dvomerge_usage();
+    CONTINUE = TRUE;
+  }
 
   input  = argv[1];
@@ -66,5 +75,10 @@
   }
 
-  dvomergeImagesUpdate (&IDmap, input, output);
+  if (CONTINUE) {
+    // need to determine the mapping from the input to the output images
+    dvomergeImagesGetMap (&IDmap, input, output);
+  } else {
+    dvomergeImagesUpdate (&IDmap, input, output);
+  }
 
   // load the sky table for the existing database
@@ -97,5 +111,4 @@
     if (VERBOSE) fprintf (stderr, "input: %s\n", inlist[0].regions[i][0].name);
 
-    // SetPhotcodeTable(inputPhotcodes);
     // load / create output catalog (if catalog does not exist, it will be created)
     LoadCatalog (&incatalog, &inlist[0].regions[i][0], inlist[0].filename[i], "r", NsecfiltInput);
@@ -118,5 +131,4 @@
 
       // load input catalog
-      // SetPhotcodeTable(outputPhotcodes);
       LoadCatalog (&outcatalog, outlist[0].regions[j], outlist[0].filename[j], "w", NsecfiltOutput);
 
@@ -153,56 +165,8 @@
   }
 
+  gettimeofday (&stop, NULL);
+  dtime = DTIME (stop, start);
+  fprintf (stderr, "SUCCESS: elapsed time %9.4f sec\n", dtime);
+
   exit (0);
 }
-
-/*** update the image table ***/
-int dvomergeImagesUpdate (IDmapType *IDmap, char *input, char *output) { 
-
-  FITS_DB inDB;
-  FITS_DB outDB;
-  int    status;
-
-  /*** load input1/Images.dat ***/
-  sprintf (ImageCat, "%s/Images.dat", input);
-  inDB.mode   = dvo_catalog_catmode (CATMODE);
-  inDB.format = dvo_catalog_catformat (CATFORMAT);
-  status       = dvo_image_lock (&inDB, ImageCat, 3600.0, LCK_XCLD);  // shorter timeout?
-  if (!status) Shutdown ("ERROR: failure to lock image catalog %s", inDB.filename);
-
-  // load the image table 
-  if (inDB.dbstate == LCK_EMPTY) {
-    // Shutdown ("can't find input image catalog %s", inDB.filename);
-    IDmap->Nmap = 0;
-    return TRUE;
-  }
-  if (!dvo_image_load (&inDB, VERBOSE, TRUE)) {
-    Shutdown ("can't read input image catalog %s", inDB.filename);
-  }
-
-  /*** load output/Images.dat ***/
-  sprintf (ImageCat, "%s/Images.dat", output);
-  outDB.mode   = dvo_catalog_catmode (CATMODE);
-  outDB.format = dvo_catalog_catformat (CATFORMAT);
-  status       = dvo_image_lock (&outDB, ImageCat, 3600.0, LCK_XCLD);  // shorter timeout?
-  if (!status) Shutdown ("ERROR: failure to lock image catalog %s", outDB.filename);
-
-  /* load the image table */
-  if (outDB.dbstate == LCK_EMPTY) {
-    dvo_image_create (&outDB, GetZeroPoint());
-  } else {
-    if (!dvo_image_load (&outDB, VERBOSE, TRUE)) {
-      Shutdown ("can't read output image catalog %s", outDB.filename);
-    }
-  }
-
-  // convert database table to internal structure & add to output image db
-  dvo_image_merge_dbs(IDmap, &outDB, &inDB);
-  dvo_image_unlock (&inDB); // unlock input
-
-  SetProtect (TRUE);
-  dvo_image_save (&outDB, VERBOSE);
-  SetProtect (FALSE);
-  dvo_image_unlock (&outDB); // unlock output
-
-  return TRUE;
-}
Index: /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeUpdate_threaded.c
===================================================================
--- /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeUpdate_threaded.c	(revision 29797)
+++ /branches/eam_branches/ipp-20101103/Ohana/src/dvomerge/src/dvomergeUpdate_threaded.c	(revision 29797)
@@ -0,0 +1,313 @@
+# include "dvomerge.h"
+# include <pthread.h>
+
+enum {
+  TS_WAIT,
+  TS_RUN,
+  TS_DONE,
+  TS_FAIL,
+  TS_EXIT,
+};
+
+typedef struct {
+  int iThread;
+  int state;
+  // elements used to carry data to the threadjob
+  char *name;
+  char *filename;
+  SkyRegion *region;
+  int NsecfiltInput;
+  int NsecfiltOutput;
+  IDmapType *IDmap;
+  SkyTable *outsky;
+  int *secfiltMap;
+  int depth;
+} ThreadData;
+
+void *dvomergeUpdate_threadjob (void *inputData) {
+
+  off_t j;
+  Catalog incatalog, outcatalog;
+  SkyList *outlist;
+
+  ThreadData *threadData = (ThreadData *) inputData;
+
+  while (TRUE) {
+
+    while (threadData->state != TS_RUN) {
+      usleep (100);
+    }
+
+    if (VERBOSE) fprintf (stderr, "input: %s\n", threadData->name);
+
+    // load / create output catalog (if catalog does not exist, it will be created)
+    LoadCatalog (&incatalog, threadData->region, threadData->filename, "r", threadData->NsecfiltInput);
+    // skip empty input catalogs
+    if (!incatalog.Naves_disk) {
+      dvo_catalog_unlock (&incatalog);
+      dvo_catalog_free (&incatalog);
+      threadData->state = TS_DONE;
+      continue;
+    }
+
+    // combine only tables at equal or larger depth.
+
+    // NOTE: this requirement is especially important for the threaded version: if the
+    // output catalog is guaranteed to be the same size or finer than the input, then two
+    // input catalogs cannot collide on their target output catalog.
+      
+    // load in all of the tables from input for this region
+    // SkyListByBounds will return neighbor catalogs if the boundaries exactly match (due to rounding).  Since the regions are not infinitely small, 
+    // compare to a slightly reduced footprint
+    float dPos = 2.0/3600.0;
+    outlist = SkyListByBounds (threadData->outsky, threadData->depth, threadData->region->Rmin + dPos, threadData->region->Rmax - dPos, threadData->region->Dmin + dPos, threadData->region->Dmax - dPos);
+    for (j = 0; (j < outlist[0].Nregions) && (threadData->state != TS_FAIL); j++) {
+      if (VERBOSE) fprintf (stderr, "output : %s\n", outlist[0].regions[j][0].name);
+
+      // load input catalog
+      LoadCatalog (&outcatalog, outlist[0].regions[j], outlist[0].filename[j], "w", threadData->NsecfiltOutput);
+
+      dvo_update_image_IDs (threadData->IDmap, &incatalog);
+      merge_catalogs_old (&threadData->outsky->regions[j], &outcatalog, &incatalog, RADIUS, threadData->secfiltMap);
+
+      outcatalog.catflags = LOAD_AVES | LOAD_MEAS | LOAD_MISS | LOAD_SECF;
+
+      // if we receive a signal which would cause us to exit, wait until the full catalog is written
+      SetProtect (TRUE);
+      if (!dvo_catalog_save (&outcatalog, VERBOSE)) {
+	fprintf (stderr, "ERROR: failed to save catalog %s\n", outlist[0].filename[j]);
+	threadData->state = TS_FAIL;
+	continue;
+      }
+      SetProtect (FALSE);
+
+      dvo_catalog_unlock (&outcatalog);
+      dvo_catalog_free (&outcatalog);
+
+      fprintf (stderr, "merged %s into %s\n", threadData->name, outlist[0].regions[j][0].name);
+    }
+    SkyListFree (outlist);
+
+    dvo_catalog_unlock (&incatalog);
+    dvo_catalog_free (&incatalog);
+    threadData->state = TS_DONE;
+  }
+  return NULL;
+}
+
+int dvomergeUpdate_threaded (int argc, char **argv) {
+
+  int j, launched, done, Nwait, Nrun;
+
+  ThreadData *threadData;
+  pthread_t *threads;
+
+  int depth, CONTINUE;
+  off_t i, Ns, Ne;
+  SkyTable *outsky, *insky;
+  SkyList *inlist;
+  char filename[256], *input, *output;
+  IDmapType IDmap;
+  PhotCodeData *inputPhotcodes;
+  PhotCodeData *outputPhotcodes;
+  int *secfiltMap = NULL;
+  int NsecfiltInput, NsecfiltOutput;
+
+  double dtime;
+  struct timeval start, stop;
+  gettimeofday (&start, NULL);
+
+  CONTINUE = FALSE;
+  if (strcasecmp (argv[2], "into")) dvomerge_usage();
+  if (argc == 5) {
+    if (strcasecmp (argv[4], "continue")) dvomerge_usage();
+    CONTINUE = TRUE;
+  }
+
+  input  = argv[1];
+  output = argv[3];
+
+  if (ALTERNATE_PHOTCODE_FILE) {
+    fprintf (stderr, "cannot specify photcodes when merging into an existing catdir\n");
+    exit (1);
+  }
+
+  SetPhotcodeTable(NULL);
+  sprintf (filename, "%s/Photcodes.dat", input);
+  if (!LoadPhotcodes (filename, NULL, FALSE)) {
+    fprintf (stderr, "error reading input database directory %s\n", input);
+    exit (1);
+  }	
+  inputPhotcodes = GetPhotcodeTable();
+  NsecfiltInput = GetPhotcodeNsecfilt();
+
+  // since we are merging the input db into the output db, the output defines the photcode
+  // table & db layout but, this requires the output to exist.  if it does not, instead use the
+  // input.
+
+  SetPhotcodeTable(NULL);
+  sprintf (filename, "%s/Photcodes.dat", output);
+  if (LoadPhotcodes (filename, NULL, FALSE)) {
+
+    outputPhotcodes = GetPhotcodeTable();
+    NsecfiltOutput = GetPhotcodeNsecfilt();
+
+    secfiltMap = GetSecFiltMap(outputPhotcodes, inputPhotcodes);
+    if (!secfiltMap) {
+      fprintf (stderr, "failed to map input secfilt photcodes to output photcodes table\n");
+      exit (1);
+    }
+  } else {
+    fprintf(stderr, "%s not found using photcodes from %s/Photcodes.dat\n", filename, input);
+    outputPhotcodes = inputPhotcodes;
+    NsecfiltOutput = NsecfiltInput;
+
+    if (!check_dir_access (output, VERBOSE)) {
+      fprintf (stderr, "error creating output database directory %s\n", output);
+      exit (1);
+    }
+    SetPhotcodeTable(inputPhotcodes);
+    if (!SavePhotcodesFITS (filename)) {
+      fprintf (stderr, "error saving photcode table in %s/Photcodes.dat\n", output);
+      exit (1);
+    }
+  }
+
+  if (CONTINUE) {
+    // need to determine the mapping from the input to the output images
+    dvomergeImagesGetMap (&IDmap, input, output);
+  } else {
+    dvomergeImagesUpdate (&IDmap, input, output);
+  }
+
+  // load the sky table for the existing database
+  insky = SkyTableLoadOptimal (input, NULL, NULL, FALSE, SKY_DEPTH_HST, VERBOSE);
+  if (!insky) {
+      Shutdown ("can't read SkyTable for %s", input);
+  }
+  SkyTableSetFilenames (insky, input, "cpt");
+
+  // XXX apply this...generate the subset matching the user-selected region
+  inlist = SkyListByPatch (insky, -1, &UserPatch);
+
+  // generate an output table populated at the desired depth
+  outsky = SkyTableLoadOptimal (output, NULL, GSCFILE, TRUE, SKY_DEPTH, VERBOSE);
+  if (!outsky) {
+      Shutdown ("can't read or create SkyTable for %s", output);
+  }
+  SkyTableSetFilenames (outsky, output, "cpt");
+
+  // loop over the populatable output tables; check for data in input in the corresponding regions
+
+  SkyListPopulatedRange (&Ns, &Ne, inlist, 0);
+  depth = inlist[0].regions[Ns][0].depth;
+  
+  SetPhotcodeTable(NULL);
+
+  ALLOCATE(threads, pthread_t, NTHREADS);
+  ALLOCATE(threadData, ThreadData, NTHREADS);
+  for (i = 0; i < NTHREADS; i++) {
+    threadData[i].state = TS_WAIT;
+    threadData[i].iThread = i;
+  }
+  for (i = 0; i < NTHREADS; i++) {
+    pthread_create (&threads[i], NULL, &dvomergeUpdate_threadjob, (void *) &threadData[i]);
+  }
+
+  // loop over the populated input regions
+  for (i = 0; i < inlist[0].Nregions; i++) {
+    if (!inlist[0].regions[i][0].table) continue;
+
+    launched = FALSE;
+    while (!launched) {
+
+      // are any threads done? can we harvest them?
+      for (j = 0; j < NTHREADS; j++) {
+	if (threadData[j].state == TS_FAIL) goto failure;
+	if (threadData[j].state != TS_DONE) continue;
+	// fprintf (stderr, "harvested thread %d\n", threadData[j].iThread);
+	threadData[j].state = TS_WAIT;
+      }
+	
+      // are any threads available? can we launch this job?
+      for (j = 0; !launched && (j < NTHREADS); j++) {
+	if (threadData[j].state == TS_FAIL) goto failure;
+	if (threadData[j].state != TS_WAIT) continue;
+
+	threadData[j].name = inlist[0].regions[i][0].name;
+	threadData[j].filename = inlist[0].filename[i];
+	threadData[j].region = inlist[0].regions[i];
+	threadData[j].NsecfiltInput = NsecfiltInput;
+	threadData[j].NsecfiltOutput = NsecfiltOutput;
+	threadData[j].IDmap = &IDmap;
+	threadData[j].outsky = outsky;
+	threadData[j].secfiltMap = secfiltMap;
+	threadData[j].depth = depth;
+	threadData[j].state = TS_RUN;
+	launched = TRUE;
+      }
+      if (!launched) usleep (100);
+    }
+  }
+
+  // wait for all threads to be done
+  done = FALSE;
+  while (!done) {
+    // are any threads done? can we harvest them?
+    for (j = 0; j < NTHREADS; j++) {
+      if (threadData[j].state == TS_FAIL) goto failure;
+      if (threadData[j].state != TS_DONE) continue;
+      threadData[j].state = TS_WAIT;
+    }
+
+    // how many are waiting now?
+    Nwait = 0;
+    for (j = 0; j < NTHREADS; j++) {
+      if (threadData[j].state == TS_FAIL) goto failure;
+      if (threadData[j].state != TS_WAIT) continue;
+      Nwait ++;
+    }
+
+    if (Nwait < NTHREADS) { 
+      usleep (100); 
+    } else {
+      done = TRUE;
+    }
+  }
+
+  // save the output sky table copy
+  sprintf (filename, "%s/SkyTable.fits", output);
+  check_file_access (filename, TRUE, TRUE, VERBOSE);
+  if (!SkyTableSave (outsky, filename)) {
+    fprintf (stderr, "ERROR: failed to save sky table for %s\n", output);
+    exit (1);
+  }
+
+  gettimeofday (&stop, NULL);
+  dtime = DTIME (stop, start);
+  fprintf (stderr, "SUCCESS: elapsed time %9.4f sec\n", dtime);
+
+  exit (0);
+
+failure:
+
+  // wait for all threads to be done
+  done = FALSE;
+  while (!done) {
+
+    // how many are still running?
+    Nrun = 0;
+    for (j = 0; j < NTHREADS; j++) {
+      if (threadData[j].state != TS_RUN) continue;
+      Nrun ++;
+    }
+
+    if (Nrun) { 
+      usleep (100); 
+    } else {
+      done = TRUE;
+    }
+  }
+  exit (1);
+}
+