Пример #1
0
/****************************** scanimage ************************************
PROTO   void scanimage(picstruct *field, picstruct *dfield, picstruct *ffield,
        picstruct *wfield, picstruct *dwfield)
PURPOSE Scan of the large pixmap(s). Main loop and heart of the program.
INPUT   Measurement field pointer,
        Detection field pointer,
        Flag field pointer,
        Measurement weight-map field pointer,
        Detection weight-map field pointer,
OUTPUT  -.
NOTES   -.
AUTHOR  E. Bertin (IAP)
VERSION 21/12/2011
 ***/
void	scanimage(picstruct *field, picstruct *dfield, picstruct **pffield,
		int nffield, picstruct *wfield, picstruct *dwfield)

  {
   static infostruct	curpixinfo, *info, *store,
			initinfo, freeinfo, *victim;
   picstruct		*ffield;
   checkstruct		*check;
   objliststruct       	objlist;
   objstruct		*cleanobj;
   pliststruct		*pixel, *pixt;
   picstruct		*cfield, *cdwfield;

   char			*marker, newmarker, *blankpad, *bpt,*bpt0;
   int			co, i,j, flag, luflag,pstop, xl,xl2,yl, cn,
			nposize, stacksize, w, h, blankh, maxpixnb,
			varthreshflag, ontotal;
   short	       	trunflag;
   PIXTYPE		thresh, relthresh, cdnewsymbol, cdwthresh,wthresh,
			*scan,*dscan,*cdscan,*dwscan,*dwscanp,*dwscann,
			*cdwscan,*cdwscanp,*cdwscann,*wscand,
			*scant, *wscan,*wscann,*wscanp;
   FLAGTYPE		*pfscan[MAXFLAG];
   status		cs, ps, *psstack;
   int			*start, *end, ymax;

/* Avoid gcc -Wall warnings */
  scan = dscan = cdscan = cdwscan = cdwscann = cdwscanp
	= dwscan = dwscann = dwscanp
	= wscan = wscann = wscanp = NULL;
  victim = NULL;			/* Avoid gcc -Wall warnings */
  blankh = 0;				/* Avoid gcc -Wall warnings */
/*----- Beginning of the main loop: Initialisations  */
  thecat.ntotal = thecat.ndetect = 0;

/* cfield is the detection field in any case */
  cfield = dfield? dfield:field;

/* cdwfield is the detection weight-field if available */
  cdwfield = dwfield? dwfield:(prefs.dweight_flag?wfield:NULL);
  cdwthresh = cdwfield ? cdwfield->weight_thresh : 0.0;
  if (cdwthresh>BIG*WTHRESH_CONVFAC);
    cdwthresh = BIG*WTHRESH_CONVFAC;
  wthresh = wfield? wfield->weight_thresh : 0.0;

/* If WEIGHTing and no absolute thresholding, activate threshold scaling */
  varthreshflag = (cdwfield && prefs.thresh_type[0]!=THRESH_ABSOLUTE);
  relthresh = varthreshflag ? prefs.dthresh[0] : 0.0;/* To avoid gcc warnings*/
  w = cfield->width;
  h = cfield->height;
  objlist.dthresh = cfield->dthresh;
  objlist.thresh = field->thresh;
  cfield->yblank = 1;
  field->y = field->stripy = 0;
  field->ymin = field->stripylim = 0;
  field->stripysclim = 0;
  if (dfield)
    {
    dfield->y = dfield->stripy = 0;
    dfield->ymin = dfield->stripylim = 0;
    dfield->stripysclim = 0;
    }
  if (nffield)
    for (i=0; i<nffield; i++)
      {
      ffield = pffield[i];
      ffield->y = ffield->stripy = 0;
      ffield->ymin = ffield->stripylim = 0;
      ffield->stripysclim = 0;
      }
  if (wfield)
    {
    wfield->y = wfield->stripy = 0;
    wfield->ymin = wfield->stripylim = 0;
    wfield->stripysclim = 0;
    }
  if (dwfield)
    {
    dwfield->y = dwfield->stripy = 0;
    dwfield->ymin = dwfield->stripylim = 0;
    dwfield->stripysclim = 0;
    }

/*Allocate memory for buffers */
  stacksize = w+1;
  QMALLOC(info, infostruct, stacksize);
  QCALLOC(store, infostruct, stacksize);
  QMALLOC(marker, char, stacksize);
  QMALLOC(dumscan, PIXTYPE, stacksize);
  QMALLOC(psstack, status, stacksize);
  QCALLOC(start, int, stacksize);
  QMALLOC(end, int, stacksize);
  blankpad = bpt = NULL;
  lutzalloc(w,h);
  allocparcelout();

/* Some initializations */

  thresh = objlist.dthresh;
  initinfo.pixnb = 0;
  initinfo.flag = 0;
  initinfo.firstpix = initinfo.lastpix = -1;

  for (xl=0; xl<stacksize; xl++)
    {
    marker[xl]  = 0 ;
    dumscan[xl] = -BIG ;
    }

  co = pstop = 0;
  objlist.nobj = 1;
  curpixinfo.pixnb = 1;

/* Init cleaning procedure */
  initclean();

/*----- Allocate memory for the pixel list */
  init_plist();

  if (!(pixel = objlist.plist = malloc(nposize=prefs.mem_pixstack*plistsize)))
    error(EXIT_FAILURE, "Not enough memory to store the pixel stack:\n",
        "           Try to decrease MEMORY_PIXSTACK");

/*----- at the beginning, "free" object fills the whole pixel list */
  freeinfo.firstpix = 0;
  freeinfo.lastpix = nposize-plistsize;
  pixt = pixel;
  for (i=plistsize; i<nposize; i += plistsize, pixt += plistsize)
    PLIST(pixt, nextpix) = i;
  PLIST(pixt, nextpix) = -1;

/* Allocate memory for other buffers */
  if (prefs.filter_flag)
    {
    QMALLOC(cdscan, PIXTYPE, stacksize);
    if (cdwfield)
      {
      QCALLOC(cdwscan, PIXTYPE, stacksize);
      if (PLISTEXIST(wflag))
        {
        QCALLOC(cdwscanp, PIXTYPE, stacksize);
        QCALLOC(cdwscann, PIXTYPE, stacksize);
        }
      }
/*-- One needs a buffer to protect filtering if source-blanking applies */
    if (prefs.blank_flag)
      {
      blankh = thefilter->convh/2+1;
      QMALLOC(blankpad, char, w*blankh);
      cfield->yblank -= blankh;
      if (dfield)
        field->yblank = cfield->yblank;
      bpt = blankpad;
      }
    }

/*----- Here we go */
  for (yl=0; yl<=h;)
    {
    ps = COMPLETE;
    cs = NONOBJECT;
    if (yl==h)
      {
/*---- Need an empty line for Lutz' algorithm to end gracely */
      if (prefs.filter_flag)
        {
        free(cdscan);
        if (cdwfield)
          {
          if (PLISTEXIST(wflag))
            {
            free(cdwscanp);
            free(cdwscann);
            cdwscanp = cdwscan;
            }
          else
            free(cdwscan);
          }
        }
      cdwscan = cdwscann = cdscan = dumscan;
      }
    else
      {
      if (nffield)
        for (i=0; i<nffield; i++)
          {
          ffield = pffield[i];
          pfscan[i] = (ffield->stripy==ffield->stripysclim)?
		  (FLAGTYPE *)loadstrip(ffield, (picstruct *)NULL)
		: &ffield->fstrip[ffield->stripy*ffield->width];
          }
      if (wfield)
        {
/*------ Copy the previous weight line to track bad pixel limits */
        wscan = (wfield->stripy==wfield->stripysclim)?
		  (PIXTYPE *)loadstrip(wfield, (picstruct *)NULL)
		: &wfield->strip[wfield->stripy*wfield->width];
        if (PLISTEXIST(wflag))
          {
          if (yl>0)
            wscanp = &wfield->strip[((yl-1)%wfield->stripheight)*wfield->width];
          if (yl<h-1)
            wscann = &wfield->strip[((yl+1)%wfield->stripheight)*wfield->width];
          }
        }
      scan = (field->stripy==field->stripysclim)?
		  (PIXTYPE *)loadstrip(field, wfield)
		: &field->strip[field->stripy*field->width];
      if (dwfield)
        {
        dwscan = (dwfield->stripy==dwfield->stripysclim)?
		  (PIXTYPE *)loadstrip(dwfield,
				dfield?(picstruct *)NULL:dwfield)
		: &dwfield->strip[dwfield->stripy*dwfield->width];
        if (PLISTEXIST(wflag))
          {
          if (yl>0)
            dwscanp = &dwfield->strip[((yl-1)%dwfield->stripheight)
			*dwfield->width];
          if (yl<h-1)
            dwscann = &dwfield->strip[((yl+1)%dwfield->stripheight)
			*dwfield->width];
          }
        }
      else
        {
        dwscan = wscan;
        if (PLISTEXIST(wflag))
          {
          dwscanp = wscanp;
          dwscann = wscann;
          }
        }
      if (dfield)
        dscan = (dfield->stripy==dfield->stripysclim)?
		  (PIXTYPE *)loadstrip(dfield, dwfield)
		: &dfield->strip[dfield->stripy*dfield->width];
      else
        dscan = scan;

      if (prefs.filter_flag)
        {
        filter(cfield, cdscan, cfield->y);
        if (cdwfield)
          {
          if (PLISTEXIST(wflag))
            {
            if (yl==0)
              filter(cdwfield, cdwscann, yl);
            wscand = cdwscanp;
            cdwscanp = cdwscan;
            cdwscan = cdwscann;
            cdwscann = wscand;
            if (yl < h-1)
              filter(cdwfield, cdwscann, yl + 1);
            }
          else
            filter(cdwfield, cdwscan, yl);
          }
        }
      else
        {
        cdscan = dscan;
        cdwscan = dwscan;
        if (PLISTEXIST(wflag))
          {
          cdwscanp = dwscanp;
          cdwscann = dwscann;
          }
        }

      if ((check=prefs.check[CHECK_FILTERED]))
        writecheck(check, cdscan, w);
      }

    trunflag = (yl==0 || yl==h-1)? OBJ_TRUNC:0;

    for (xl=0; xl<=w; xl++)
      {
      if (xl == w)
        cdnewsymbol = -BIG;
      else
        cdnewsymbol = cdscan[xl];

      newmarker = marker[xl];
      marker[xl] = 0;

      curpixinfo.flag = trunflag;
      if (varthreshflag)
        thresh = relthresh*sqrt((xl==w || yl==h)? 0.0:cdwscan[xl]);
      luflag = cdnewsymbol > thresh?1:0;

      if (luflag)
        {
        if (xl==0 || xl==w-1)
          curpixinfo.flag |= OBJ_TRUNC;
        pixt = pixel + (cn=freeinfo.firstpix);
        freeinfo.firstpix = PLIST(pixt, nextpix);

/*------- Running out of pixels, the largest object becomes a "victim" ------*/

        if (freeinfo.firstpix==freeinfo.lastpix)
          {
          sprintf(gstr, "%d,%d", xl+1, yl+1);
          warning("Pixel stack overflow at position ", gstr);
          maxpixnb = 0;
          for (i=0; i<=w; i++)
            if (store[i].pixnb>maxpixnb)
              if (marker[i]=='S' || (newmarker=='S' && i==xl))
                {
                flag = 0;
                if (i<xl)
                  for (j=0; j<=co; j++)
                    flag |= (start[j]==i);
                if (!flag)
                  maxpixnb = (victim = &store[i])->pixnb;
                }
          for (j=1; j<=co; j++)
            if (info[j].pixnb>maxpixnb)
              maxpixnb = (victim = &info[j])->pixnb;

          if (!maxpixnb)
            error(EXIT_FAILURE, "*Fatal Error*: something is badly bugged in ",
		"scanimage()!");
          if (maxpixnb <= 1)
            error(EXIT_FAILURE, "Pixel stack overflow in ", "scanimage()");
          freeinfo.firstpix = PLIST(pixel+victim->firstpix, nextpix);
          PLIST(pixel+victim->lastpix, nextpix) = freeinfo.lastpix;
          PLIST(pixel+(victim->lastpix=victim->firstpix), nextpix) = -1;
          victim->pixnb = 1;
          victim->flag |= OBJ_OVERFLOW;
          }

/*---------------------------------------------------------------------------*/
        curpixinfo.lastpix = curpixinfo.firstpix = cn;
        PLIST(pixt, nextpix) = -1;
        PLIST(pixt, x) = xl;
        PLIST(pixt, y) = yl;
        PLIST(pixt, value) = scan[xl];
        if (PLISTEXIST(dvalue))
          PLISTPIX(pixt, dvalue) = dscan[xl];
        if (PLISTEXIST(cdvalue))
          PLISTPIX(pixt, cdvalue) = cdnewsymbol;
        if (PLISTEXIST(flag))
          for (i=0; i<nffield; i++)
            PLISTFLAG(pixt, flag[i]) = pfscan[i][xl];
/*--------------------- Detect pixels with a low weight ---------------------*/
        if (PLISTEXIST(wflag) && wscan)
          {
	  PLISTFLAG(pixt, wflag) = 0;
          if (wscan[xl] >= wthresh)
            PLISTFLAG(pixt, wflag) |= OBJ_LOWWEIGHT;
          if (cdwscan[xl] >= cdwthresh)
            PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;

          if (yl>0)
            {
            if (cdwscanp[xl] >= cdwthresh)
              PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;
            if (xl>0 && cdwscanp[xl-1]>=cdwthresh)
              PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;
            if (xl<w-1 && cdwscanp[xl+1]>=cdwthresh)
              PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;
            }
          if (xl>0 && cdwscan[xl-1]>=cdwthresh)
              PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;
          if (xl<w-1 && cdwscan[xl+1]>=cdwthresh)
            PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;
          if (yl<h-1)
            {
            if (cdwscann[xl] >= cdwthresh)
              PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;
            if (xl>0 && cdwscann[xl-1]>=cdwthresh)
              PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;
            if (xl<w-1 && cdwscann[xl+1]>=cdwthresh)
              PLISTFLAG(pixt, wflag) |= OBJ_LOWDWEIGHT;
            }
          }
        if (PLISTEXIST(dthresh))
          PLISTPIX(pixt, dthresh) = thresh;
        if (PLISTEXIST(var))
          PLISTPIX(pixt, var) = wscan[xl];

        if (cs != OBJECT)
/*------------------------------- Start Segment -----------------------------*/

          {
          cs = OBJECT;
          if (ps == OBJECT)
            {
            if (start[co] == UNKNOWN)
              {
              marker[xl] = 'S';
              start[co] = xl;
              }
            else
              marker[xl] = 's';
            }
          else
            {
            psstack[pstop++] = ps;
            marker[xl] = 'S';
            start[++co] = xl;
            ps = COMPLETE;
            info[co] = initinfo;
            }
          }

/*---------------------------------------------------------------------------*/
        }

      if (newmarker)

/*---------------------------- Process New Marker ---------------------------*/

        {
        if (newmarker == 'S')
          {
          psstack[pstop++] = ps;
          if (cs == NONOBJECT)
            {
            psstack[pstop++] = COMPLETE;
            info[++co] = store[xl];
            start[co] = UNKNOWN;
            }
          else
            update (&info[co],&store[xl], pixel);
          ps = OBJECT;
          }
        else if (newmarker == 's')
          {
          if ((cs == OBJECT) && (ps == COMPLETE))
            {
            pstop--;
            xl2 = start[co];
            update (&info[co-1],&info[co], pixel);
            if (start[--co] == UNKNOWN)
              start[co] = xl2;
            else
              marker[xl2] = 's';
            }
          ps = OBJECT;
          }
        else if (newmarker == 'f')
          ps = INCOMPLETE;
        else if (newmarker == 'F')
          {
          ps = psstack[--pstop];
          if ((cs == NONOBJECT) && (ps == COMPLETE))
            {
            if (start[co] == UNKNOWN)
              {
              if ((int)info[co].pixnb >= prefs.ext_minarea)
                {
                sortit(field, dfield, wfield, cdwfield, &info[co], &objlist,
		       cdwscan, wscan);
                }
/* ------------------------------------ free the chain-list */

              PLIST(pixel+info[co].lastpix, nextpix) = freeinfo.firstpix;
              freeinfo.firstpix = info[co].firstpix;
              }
            else
              {
              marker[end[co]] = 'F';
              store[start[co]] = info[co];
              }
            co--;
            ps = psstack[--pstop];
            }
          }
        }
/*---------------------------------------------------------------------------*/

      if (luflag)
        update (&info[co],&curpixinfo, pixel);
      else
        {
        if (cs == OBJECT)
/*-------------------------------- End Segment ------------------------------*/
          {
          cs = NONOBJECT;
          if (ps != COMPLETE)
            {
            marker[xl] = 'f';
            end[co] = xl;
            }
          else
            {
            ps = psstack[--pstop];
            marker[xl] = 'F';
            store[start[co]] = info[co];
            co--;
            }
          }
        }

      if (prefs.blank_flag && xl<w)
        {
        if (prefs.filter_flag)
	  *(bpt++) = (luflag)?1:0;
        else if (luflag)
          dscan[xl] = -BIG;
        if (dfield && luflag)
          scan[xl] = -BIG;
        }
/*--------------------- End of the loop over the x's -----------------------*/
      }

/* Detected pixel removal at the end of each line */
    if (prefs.blank_flag && yl<h)
      {
      if (prefs.filter_flag)
        {
        bpt = bpt0 = blankpad + w*((yl+1)%blankh);
        if (cfield->yblank >= 0)
          {
          scant = &PIX(cfield, 0, cfield->yblank);
          for (i=w; i--; scant++)
            if (*(bpt++))
              *scant = -BIG;
          if (dfield)
            {
            bpt = bpt0;
            scant = &PIX(field, 0, cfield->yblank);
            for (i=w; i--; scant++)
              if (*(bpt++))
                *scant = -BIG;
            }
          bpt = bpt0;
          }
        }
      cfield->yblank++;
      if (dfield)
        field->yblank = cfield->yblank;
      }

/*-- Prepare markers for the next line */
    yl++;
    field->stripy = (field->y=yl)%field->stripheight;
    if (dfield)
      dfield->stripy = (dfield->y=yl)%dfield->stripheight;
    if (nffield)
      for (i=0; i<nffield; i++)
        {
        ffield = pffield[i];
        ffield->stripy = (ffield->y=yl)%ffield->stripheight;
        }
    if (wfield)
      wfield->stripy = (wfield->y=yl)%wfield->stripheight;
    if (dwfield)
      dwfield->stripy = (dwfield->y=yl)%dwfield->stripheight;

/*-- Remove objects close to the ymin limit if ymin is ready to increase */
    if (cfield->stripy==cfield->stripysclim)
      {
      cleanobj = cleanobjlist->obj+cleanobjlist->nobj-1;
      ontotal = 0;
      for (i=cleanobjlist->nobj; i--; cleanobj--)
        {
        if (cleanobj->ycmin <= cfield->ymin)
          {
/*-------- Warn if there is a possibility for any aperture to be truncated */
          if ((ymax=cleanobj->ycmax) > cfield->ymax)
            {
            sprintf(gstr, "Object at position %.0f,%.0f ",
		cleanobj->mx+1, cleanobj->my+1);
            QWARNING(gstr, "may have some apertures truncated:\n"
		"          You might want to increase MEMORY_BUFSIZE");
            }
          else if (ymax>cfield->yblank && prefs.blank_flag)
            {
            sprintf(gstr, "Object at position %.0f,%.0f ",
		cleanobj->mx+1, cleanobj->my+1);
            QWARNING(gstr, "may have some unBLANKed neighbours:\n"
		"          You might want to increase MEMORY_PIXSTACK");
            }
          if ((prefs.prof_flag && !(thecat.ntotal%10)
		&& thecat.ntotal != ontotal)
		|| !(thecat.ntotal%400))
            NPRINTF(OUTPUT, "\33[1M> Line:%5d  "
		"Objects: %8d detected / %8d sextracted\n\33[1A",
		yl>h? h:yl, thecat.ndetect, thecat.ntotal);
          ontotal = thecat.ntotal;
          endobject(field, dfield, wfield, cdwfield, i, cleanobjlist);
          subcleanobj(i);
          cleanobj = cleanobjlist->obj+i;	/* realloc in subcleanobj() */
          }
        }
      }

    if ((prefs.prof_flag && !(thecat.ntotal%10)) || !(yl%25))
      NPRINTF(OUTPUT, "\33[1M> Line:%5d  "
		"Objects: %8d detected / %8d sextracted\n\33[1A",
	yl>h?h:yl, thecat.ndetect, thecat.ntotal);
/*--------------------- End of the loop over the y's -----------------------*/
    }

/* Removal or the remaining pixels */
  if (prefs.blank_flag && prefs.filter_flag && (cfield->yblank >= 0))
    for (j=blankh-1; j--; yl++)
      {
      bpt = bpt0 = blankpad + w*(yl%blankh);
      scant = &PIX(cfield, 0, cfield->yblank);
      for (i=w; i--; scant++)
        if (*(bpt++))
          *scant = -BIG;
      if (dfield)
        {
        bpt = bpt0;
        scant = &PIX(field, 0, cfield->yblank);
        for (i=w; i--; scant++)
          if (*(bpt++))
            *scant = -BIG;
        }
      cfield->yblank++;
      if (dfield)
        field->yblank = cfield->yblank;
      }

/* Now that all "detected" pixels have been removed, analyse detections */
  ontotal = 0;
  for (j=cleanobjlist->nobj; j--;)
    {
    if ((prefs.prof_flag && !(thecat.ntotal%10) && thecat.ntotal != ontotal)
		|| !(thecat.ntotal%400))
      NPRINTF(OUTPUT, "\33[1M> Line:%5d  "
		"Objects: %8d detected / %8d sextracted\n\33[1A",
	h, thecat.ndetect, thecat.ntotal);
    ontotal = thecat.ntotal;
    endobject(field, dfield, wfield, cdwfield, 0, cleanobjlist);
    subcleanobj(0);
    }

  endclean();

/*Free memory */
  if (prefs.filter_flag && cdwfield && PLISTEXIST(wflag))
    free(cdwscanp);
  freeparcelout();
  free(pixel); pixel = NULL;
  lutzfree();
  free(info); info = NULL;
  free(store); store = NULL;
  free(marker); marker = NULL;
  free(dumscan); dumscan = NULL;
  free(psstack); psstack = NULL;
  free(start); start = NULL;
  free(end); end = NULL;
  if (prefs.blank_flag && prefs.filter_flag)
    free(blankpad); blankpad = NULL;

  return;
  }
Пример #2
0
/****************************** extract **************************************/
int sep_extract(PIXTYPE *im, PIXTYPE *var, int w, int h,
	        PIXTYPE thresh, int minarea,
	        float *conv, int convw, int convh,
		int deblend_nthresh, double deblend_mincont,
		int clean_flag, double clean_param,
		int *nobj, sepobj **objects)
{
  static infostruct	curpixinfo, *info, *store, initinfo, freeinfo, *victim;
  objliststruct       	objlist, *finalobjlist;
  pliststruct		*pixel, *pixt; 
  char			*marker, newmarker;
  int			co, i, j, flag, luflag, pstop, xl, xl2, yl, cn,
			nposize, stacksize, maxpixnb, convn, status;
  short	       	        trunflag;
  PIXTYPE		relthresh, cdnewsymbol;
  PIXTYPE               *scan,*cdscan,*cdwscan,*wscan,*dumscan;
  float                 sum, *convnorm;
  pixstatus		cs, ps, *psstack;
  int			*start, *end, *survives;

  status = RETURN_OK;
  char errtext[80];  /* 80 should be more than enough */
  
  pixel = NULL;
  convnorm = NULL;
  scan = wscan = cdscan = cdwscan = dumscan = NULL;
  victim = NULL;
  info = NULL;
  store = NULL;
  marker = NULL;
  psstack = NULL;
  start = end = NULL;
  finalobjlist = NULL; /* final return value */
  convn = 0;
  sum = 0.0;

  /* var is the image variance to use for thresholding, if available */
  relthresh = var? thresh : 0.0;/* To avoid gcc warnings*/

  objlist.dthresh = thresh;
  objlist.thresh = thresh;

  /*Allocate memory for buffers */
  stacksize = w+1;
  QMALLOC(info, infostruct, stacksize, status);
  QCALLOC(store, infostruct, stacksize, status);
  QMALLOC(marker, char, stacksize, status);
  QMALLOC(dumscan, PIXTYPE, stacksize, status);
  QMALLOC(psstack, pixstatus, stacksize, status);
  QCALLOC(start, int, stacksize, status);
  QMALLOC(end, int, stacksize, status);
  if ((status = lutzalloc(w, h)) != RETURN_OK)
    goto exit;
  if ((status = allocdeblend(deblend_nthresh)) != RETURN_OK)
    goto exit;

  /* More initializations */
  initinfo.pixnb = 0;
  initinfo.flag = 0;
  initinfo.firstpix = initinfo.lastpix = -1;

  for (xl=0; xl<stacksize; xl++)
    {
    marker[xl]  = 0 ;
    dumscan[xl] = -BIG ;
    }

  co = pstop = 0;
  objlist.nobj = 1;
  curpixinfo.pixnb = 1;

  /* Init finalobjlist (the return catalog) */
  QMALLOC(finalobjlist, objliststruct, 1, status);
  finalobjlist->obj = NULL;
  finalobjlist->plist = NULL;
  finalobjlist->nobj = finalobjlist->npix = 0;


  /* Allocate memory for the pixel list */
  plistinit(conv, var);
  if (!(pixel = objlist.plist = malloc(nposize=MEMORY_PIXSTACK*plistsize)))
    {
      status = MEMORY_ALLOC_ERROR;
      goto exit;
    }

  /*----- at the beginning, "free" object fills the whole pixel list */
  freeinfo.firstpix = 0;
  freeinfo.lastpix = nposize-plistsize;
  pixt = pixel;
  for (i=plistsize; i<nposize; i += plistsize, pixt += plistsize)
    PLIST(pixt, nextpix) = i;
  PLIST(pixt, nextpix) = -1;

  if (conv)
    {
      /* allocate memory for convolved buffers */
      QMALLOC(cdscan, PIXTYPE, stacksize, status);
      if (var)
	QCALLOC(cdwscan, PIXTYPE, stacksize, status);

      /* normalize the filter */
      convn = convw * convh;
      QMALLOC(convnorm, PIXTYPE, convn, status);
      for (i=0; i<convn; i++)
	sum += fabs(conv[i]);
      for (i=0; i<convn; i++)
	convnorm[i] = conv[i] / sum;
    }

  /*----- MAIN LOOP ------ */
  for (yl=0; yl<=h; yl++)
    {

      ps = COMPLETE;
      cs = NONOBJECT;
    
      /* Need an empty line for Lutz' algorithm to end gracely */
      if (yl==h)
	{
	  if (conv)
	    {
	      free(cdscan);
	      cdscan = NULL;
	      if (var)
		{
		  free(cdwscan);
		  cdwscan = NULL;
		}
	    }
	  cdwscan = cdscan = dumscan;
	}

      else
	{
	  scan = im + yl*w;
	  if (var)
	    wscan = var + yl*w;

	  /* filter the lines */
	  if (conv)
	    {
	      convolve(im, w, h, yl, convnorm, convw, convh, cdscan);
	      if (var)
		convolve(var, w, h, yl, convnorm, convw, convh, cdwscan);
	    }
	  else
	    {
	      cdscan = scan;
	      cdwscan = wscan;
	    }	  
	}
      
      trunflag = (yl==0 || yl==h-1)? SEP_OBJ_TRUNC:0;
      
      for (xl=0; xl<=w; xl++)
	{
	  if (xl == w)
	    cdnewsymbol = -BIG;
	  else
	    cdnewsymbol = cdscan[xl];

	  newmarker = marker[xl];  /* marker at this pixel */
	  marker[xl] = 0;

	  curpixinfo.flag = trunflag;
	  if (var)
	    thresh = relthresh * sqrt((xl==w || yl==h)? 0.0:cdwscan[xl]);
	  luflag = cdnewsymbol > thresh? 1: 0;  /* is pixel above thresh? */

	  if (luflag)
	    {
	      /* flag the current object if we're near the image bounds */
	      if (xl==0 || xl==w-1)
		curpixinfo.flag |= SEP_OBJ_TRUNC;
	      
	      /* point pixt to first free pixel in pixel list */
	      /* and increment the "first free pixel" */
	      pixt = pixel + (cn=freeinfo.firstpix);
	      freeinfo.firstpix = PLIST(pixt, nextpix);
	      curpixinfo.lastpix = curpixinfo.firstpix = cn;

	      /* set values for the new pixel */ 
	      PLIST(pixt, nextpix) = -1;
	      PLIST(pixt, x) = xl;
	      PLIST(pixt, y) = yl;
	      PLIST(pixt, value) = scan[xl];
	      if (PLISTEXIST(cdvalue))
		PLISTPIX(pixt, cdvalue) = cdnewsymbol;
	      if (PLISTEXIST(var))
		PLISTPIX(pixt, var) = wscan[xl];

	      /* Check if we are running out of free pixels in objlist.plist */
	      /* (previously, the largest object became a "victim") */
	      if (freeinfo.firstpix==freeinfo.lastpix)
		{
		  status = SEP_INTERNAL_ERROR;
		  sprintf(errtext, "Pixel stack overflow at position %d,%d.",
			  xl+1, yl+1);
		  put_errdetail(errtext);
		  goto exit;
		  
		  /* NOTE: The above error was originally just a warning.
		     with the change to an error, the following code in this
		     if block is never executed.
		     TODO: should this just be a warning (or nothing?)
		  */

		  /* loop over pixels in row to find largest object */
		  maxpixnb = 0;
		  for (i=0; i<=w; i++)
		    if (store[i].pixnb>maxpixnb)
		      if (marker[i]=='S' || (newmarker=='S' && i==xl))
			{
			  flag = 0;
			  if (i<xl)
			    for (j=0; j<=co; j++)
			      flag |= (start[j]==i);
			  if (!flag)
			    maxpixnb = (victim = &store[i])->pixnb;
			}
		  for (j=1; j<=co; j++)
		    if (info[j].pixnb>maxpixnb)
		      maxpixnb = (victim = &info[j])->pixnb;
		  
		  if ((!maxpixnb) || (maxpixnb <= 1))
		    {
		      status = SEP_INTERNAL_ERROR;
		      goto exit;
		    }
		  freeinfo.firstpix = PLIST(pixel+victim->firstpix, nextpix);
		  PLIST(pixel+victim->lastpix, nextpix) = freeinfo.lastpix;
		  PLIST(pixel+(victim->lastpix=victim->firstpix), nextpix) = -1;
		  victim->pixnb = 1;
		  victim->flag |= SEP_OBJ_OVERFLOW;
		}
	      /*------------------------------------------------------------*/

	      /* if the current status on this line is not already OBJECT... */
	      /* start segment */
	      if (cs != OBJECT)
		{
		  cs = OBJECT;
		  if (ps == OBJECT)
		    {
		      if (start[co] == UNKNOWN)
			{
			  marker[xl] = 'S';
			  start[co] = xl;
			}
		      else
			marker[xl] = 's';
		    }
		  else
		    {
		      psstack[pstop++] = ps;
		      marker[xl] = 'S';
		      start[++co] = xl;
		      ps = COMPLETE;
		      info[co] = initinfo;
		    }
		}

	    } /* closes if pixel above threshold */

	  /* process new marker ---------------------------------------------*/
	  /* newmarker is marker[ ] at this pixel position before we got to
	     it. We'll only enter this if marker[ ] was set on a previous
	     loop iteration.   */
	  if (newmarker)
	    {
	      if (newmarker == 'S')
		{
		  psstack[pstop++] = ps;
		  if (cs == NONOBJECT)
		    {
		      psstack[pstop++] = COMPLETE;
		      info[++co] = store[xl];
		      start[co] = UNKNOWN;
		    }
		  else
		    update(&info[co], &store[xl], pixel);
		  ps = OBJECT;
		}

	      else if (newmarker == 's')
		{
		  if ((cs == OBJECT) && (ps == COMPLETE))
		    {
		      pstop--;
		      xl2 = start[co];
		      update (&info[co-1],&info[co], pixel);
		      if (start[--co] == UNKNOWN)
			start[co] = xl2;
		      else
			marker[xl2] = 's';
		    }
		  ps = OBJECT;
		}

	      else if (newmarker == 'f')
		ps = INCOMPLETE;

	      else if (newmarker == 'F')
		{
		  ps = psstack[--pstop];
		  if ((cs == NONOBJECT) && (ps == COMPLETE))
		    {
		      if (start[co] == UNKNOWN)
			{
			  if ((int)info[co].pixnb >= minarea)
			    {
			      status = sortit(&info[co], &objlist, minarea,
					      finalobjlist,
					      deblend_nthresh,deblend_mincont);
			      if (status != RETURN_OK)
				goto exit;
			    }

			  /* free the chain-list */
			  PLIST(pixel+info[co].lastpix, nextpix) =
			    freeinfo.firstpix;
			  freeinfo.firstpix = info[co].firstpix;
			}
		      else
			{
			  marker[end[co]] = 'F';
			  store[start[co]] = info[co];
			}
		      co--;
		      ps = psstack[--pstop];
		    }
		}
	    }
	  /* end of if (newmarker) ------------------------------------------*/

	  /* update the info or end segment */
	  if (luflag)
	    {
	      update(&info[co], &curpixinfo, pixel);
	    }
	  else if (cs == OBJECT)
	    {
	      cs = NONOBJECT;
	      if (ps != COMPLETE)
		{
		  marker[xl] = 'f';
		  end[co] = xl;
		}
	      else
		{
		  ps = psstack[--pstop];
		  marker[xl] = 'F';
		  store[start[co]] = info[co];
		  co--;
		}
	    }

	} /*------------ End of the loop over the x's -----------------------*/
    } /*---------------- End of the loop over the y's -----------------------*/

  /* convert `finalobjlist` to an array of `sepobj` structs */
  if (clean_flag)
    {
      /* Calculate mthresh for all objects in the list (needed for cleaning) */
      for (i=0; i<finalobjlist->nobj; i++)
	{
	  status = analysemthresh(i, finalobjlist, minarea, thresh);
	  if (status != RETURN_OK)
	    goto exit;
	}

      QMALLOC(survives, int, finalobjlist->nobj, status);
      clean(finalobjlist, clean_param, survives);

      /* count surviving objects and allocate space accordingly*/
      *nobj = 0;
      for (i=0; i<finalobjlist->nobj; i++)
	*nobj += survives[i];
      QMALLOC(*objects, sepobj, *nobj, status);

      /* fill */
      j=0;
      for (i=0; i<finalobjlist->nobj; i++)
	if (survives[i])
	    convertobj(i, finalobjlist, (*objects) + j++, w);
    }
  else
    {