diff --git a/rtengine/rawimagesource.cc b/rtengine/rawimagesource.cc
index 392c81de1..232747439 100644
--- a/rtengine/rawimagesource.cc
+++ b/rtengine/rawimagesource.cc
@@ -5322,8 +5322,17 @@ void RawImageSource::getrgbloc(int begx, int begy, int yEn, int xEn, int cx, int
 {
 //    BENCHFUN
     //used by auto WB local to calculate red, green, blue in local region
-    const int bfw = W / 9 + ((W % 9) > 0 ? 1 : 0);//10 arbitrary value  ; perhaps 4 or 5 or 20
-    const int bfh = H / 9 + ((H % 9) > 0 ? 1 : 0);
+    int precision = 5;
+    if (settings->itcwb_precis == 5) {
+        precision = 5;
+    } else if (settings->itcwb_precis < 5) {
+        precision = 3; 
+    } else if (settings->itcwb_precis > 5) {
+        precision = 9;
+    }
+
+    const int bfw = W / precision + ((W % precision) > 0 ? 1 : 0);// 5 arbitrary value can be change to 3 or 9 ;
+    const int bfh = H / precision + ((H % precision) > 0 ? 1 : 0);
 
     if (! greenloc) {
         greenloc(bfw, bfh);
@@ -5373,9 +5382,9 @@ void RawImageSource::getrgbloc(int begx, int begy, int yEn, int xEn, int cx, int
     #pragma omp parallel for
 #endif
     for (int i = 0; i < bfh; ++i) {
-        const int ii = i * 9;
+        const int ii = i * precision;
         if (ii < H) {
-            for (int j = 0, jj = 0; j < bfw; ++j, jj += 9) {
+            for (int j = 0, jj = 0; j < bfw; ++j, jj += precision) {
                 redloc[i][j] = red[ii][jj] * multip;
                 greenloc[i][j] = green[ii][jj] * multip;
                 blueloc[i][j] = blue[ii][jj] * multip;
@@ -5575,8 +5584,17 @@ void RawImageSource::getAutoWBMultipliersitc(double & tempref, double & greenref
 
     if (wbpar.method == "autitcgreen") {
         bool twotimes = false;
-        const int bfw = W / 9 + ((W % 9) > 0 ? 1 : 0);// 10 arbitrary value  ; perhaps 4 or 5 or 20
-        const int bfh = H / 9 + ((H % 9) > 0 ? 1 : 0);
+        int precision = 5;
+        if (settings->itcwb_precis == 5) {
+            precision = 5;
+        } else if (settings->itcwb_precis < 5) {
+            precision = 3; 
+        } else if (settings->itcwb_precis > 5) {
+            precision = 9;
+        }
+        
+        const int bfw = W / precision + ((W % precision) > 0 ? 1 : 0);// 5 arbitrary value can be change to 3 or 9 ;
+        const int bfh = H / precision + ((H % precision) > 0 ? 1 : 0);
         WBauto(tempref, greenref, redloc, greenloc, blueloc, bfw, bfh, avg_rm, avg_gm, avg_bm, tempitc, greenitc, studgood, twotimes, wbpar, begx, begy, yEn,  xEn,  cx,  cy, cmp, raw);
     }
 
diff --git a/rtengine/settings.h b/rtengine/settings.h
index 4d3131695..529336cbc 100644
--- a/rtengine/settings.h
+++ b/rtengine/settings.h
@@ -89,6 +89,7 @@ public:
     int             itcwb_sizereference;
     int             itcwb_delta;
     bool            itcwb_stdobserver10;
+    int             itcwb_precis;
 
 
     enum class ThumbnailInspectorMode {
diff --git a/rtgui/options.cc b/rtgui/options.cc
index 4a21fd8c0..7ae6c24aa 100644
--- a/rtgui/options.cc
+++ b/rtgui/options.cc
@@ -598,7 +598,8 @@ void Options::setDefaults()
     rtSettings.itcwb_sizereference = 3;//between 1 and 5
     rtSettings.itcwb_delta = 1;//between 0 and 5
     rtSettings.itcwb_stdobserver10 = true;
-    
+    rtSettings.itcwb_precis = 5;//3  or 5 or 9
+
     rtSettings.protectred = 60;
     rtSettings.protectredh = 0.3;
     rtSettings.CRI_color = 0;
@@ -1534,6 +1535,9 @@ void Options::readFromFile(Glib::ustring fname)
                     rtSettings.itcwb_delta = keyFile.get_integer("Color Management", "Itcwb_delta");
                 }
 
+                if (keyFile.has_key("Color Management", "Itcwb_precis")) {
+                    rtSettings.itcwb_precis = keyFile.get_integer("Color Management", "Itcwb_precis");
+                }
 
                 //if (keyFile.has_key ("Color Management", "Colortoningab")) rtSettings.colortoningab = keyFile.get_double("Color Management", "Colortoningab");
                 //if (keyFile.has_key ("Color Management", "Decaction")) rtSettings.decaction = keyFile.get_double("Color Management", "Decaction");
@@ -2207,6 +2211,7 @@ void Options::saveToFile(Glib::ustring fname)
         keyFile.set_integer("Color Management", "Itcwb_sizereference", rtSettings.itcwb_sizereference);
         keyFile.set_integer("Color Management", "Itcwb_delta", rtSettings.itcwb_delta);
         keyFile.set_boolean("Color Management", "Itcwb_stdobserver10", rtSettings.itcwb_stdobserver10);
+        keyFile.set_integer("Color Management", "Itcwb_precis", rtSettings.itcwb_precis);
 
         //keyFile.set_double  ("Color Management", "Colortoningab", rtSettings.colortoningab);
         //keyFile.set_double  ("Color Management", "Decaction", rtSettings.decaction);