Add a config option to change Pearson's factor in background mode estimation.

configure.ac

@@ -7,7 +7,7 @@
 #
 #	This file part of:	SExtractor
 #
-#	Copyright:		(C) 2002-2023 IAP/CNRS/SorbonneU
+#	Copyright:		(C) 2002-2023 CFHT/IAP/CNRS/SorbonneU
 #
 #	License:		GNU General Public License
 #
@@ -22,7 +22,7 @@
 #	You should have received a copy of the GNU General Public License
 #	along with SExtractor. If not, see <http://www.gnu.org/licenses/>.
 #
-#	Last modified:		26/02/2023
+#	Last modified:		07/03/2023
 #
 #%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
@@ -31,7 +31,7 @@ define([AC_CACHE_LOAD],)
 define([AC_CACHE_SAVE],)
 
 # This is your standard AstrOmatic source code...
-AC_INIT([SExtractor],[2.27.1],[astromatic@astromatic.iap.fr],
+AC_INIT([SExtractor],[2.28.0],[astromatic@astromatic.iap.fr],
         [sextractor],[http://astromatic.net/software/sextractor])
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_AUX_DIR(autoconf)

doc/src/conf.py

@@ -67,9 +67,9 @@ author = u'E. Bertin'
 # built documents.
 #
 # The short X.Y version.
-version = '2.27.1'
+version = '2.28.0'
 # The full version, including alpha/beta/rc tags.
-release = '2.27.1'
+release = '2.28.0'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -144,7 +144,7 @@ html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 # The name for this set of Sphinx documents.
 # "<project> v<release> documentation" by default.
 #
-# html_title = u'SExtractor v2.27.1'
+# html_title = u'SExtractor v2.28.0'
 
 # A shorter title for the navigation bar.  Default is the same as html_title.
 #

src/back.c

@@ -673,7 +673,7 @@ float	backguess(backstruct *bkg, float *mean, float *sigma)
   {
    LONG		*histo, *hilow, *hihigh, *histot;
    unsigned long lowsum, highsum, sum;
-   double	ftemp, mea, sig, sig1, med, dpix;
+   double	ftemp, mea,meafac, sig, sig1, med,medfac, dpix;
    int		i, n, lcut,hcut, nlevelsm1, pix;
 
 /* Leave here if the mesh is already classified as `bad' */
@@ -689,6 +689,8 @@ float	backguess(backstruct *bkg, float *mean, float *sigma)
 
   sig = 10.0*nlevelsm1;
   sig1 = 1.0;
+  medfac = prefs.back_pearsons;
+  meafac = prefs.back_pearsons - 1.0;
   mea = med = bkg->mean;
   for (n=100; n-- && (sig>=0.1) && (fabs(sig/sig1-1.0)>EPS);)
     {
@@ -725,7 +727,7 @@ float	backguess(backstruct *bkg, float *mean, float *sigma)
   *mean = fabs(sig)>0.0? (fabs(bkg->sigma/(sig*bkg->qscale)-1) < 0.0 ?
 			    bkg->qzero+mea*bkg->qscale
 			    :(fabs((mea-med)/sig)< 0.3 ?
-			      bkg->qzero+(2.5*med-1.5*mea)*bkg->qscale
+			      bkg->qzero+(medfac*med - meafac*mea)*bkg->qscale
 			     :bkg->qzero+med*bkg->qscale))
                        :bkg->qzero+mea*bkg->qscale;
 

src/preflist.h

@@ -22,7 +22,7 @@
 *	You should have received a copy of the GNU General Public License
 *	along with SExtractor. If not, see <http://www.gnu.org/licenses/>.
 *
-*	Last modified:		15/07/2020
+*	Last modified:		07/03/2023
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
@@ -61,6 +61,7 @@
   {"BACK_FILTERSIZE", P_INTLIST, prefs.backfsize, 1,11, 0.0,0.0,
     {""}, 1,2, &prefs.nbackfsize},
   {"BACK_FILTTHRESH", P_FLOAT, &prefs.backfthresh, 0,0, 0.0,BIG},
+  {"BACK_PEARSONS", P_FLOAT, &prefs.back_pearsons, 0,0, 1.0,BIG},
   {"BACKPHOTO_THICK", P_INT, &prefs.pback_size, 1, 256},
   {"BACKPHOTO_TYPE", P_KEY, &prefs.pback_type, 0,0, 0.0,0.0,
    {"GLOBAL","LOCAL",""}},
@@ -261,6 +262,9 @@ char *default_prefs[] =
 " ",
 "*BACK_TYPE        AUTO           # AUTO or MANUAL",
 "*BACK_VALUE       0.0            # Default background value in MANUAL mode",
+"*BACK_PEARSONS    2.5            # Pearson's factor P >= 1 with",
+"*                                # (mean - mode) ~ P * (mean - median)",
+"*                                # Legacy value is 2.5, but 3.5 is more accurate",
 "BACK_SIZE        64             # Background mesh: <size> or <width>,<height>",
 "BACK_FILTERSIZE  3              # Background filter: <size> or <width>,<height>",
 " ",

src/prefs.h

@@ -7,7 +7,7 @@
 *
 *	This file part of:	SExtractor
 *
-*	Copyright:		(C) 1993-2020 IAP/CNRS/SorbonneU
+*	Copyright:		(C) 1993-2023 IAP/CNRS/SorbonneU
 *
 *	License:		GNU General Public License
 *
@@ -22,7 +22,7 @@
 *	You should have received a copy of the GNU General Public License
 *	along with SExtractor. If not, see <http://www.gnu.org/licenses/>.
 *
-*	Last modified:		15/07/2020
+*	Last modified:		07/03/2023
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
@@ -136,6 +136,7 @@ typedef struct
   int		backfsize[2];				/* bkgnd filt. size */
   int		nbackfsize;				/* nb of params */
   double	backfthresh;				/* bkgnd fil. thresh */
+  double	back_pearsons;				/* Pearson's factor */
   enum	{GLOBAL, LOCAL}			pback_type;	/* phot. bkgnd type */
   int		pback_size;				/* rect. ann. width */
 /*----- memory */