diff --git a/rtgui/curveeditor.cc b/rtgui/curveeditor.cc
index 09c7b0cd7..645b67f3b 100644
--- a/rtgui/curveeditor.cc
+++ b/rtgui/curveeditor.cc
@@ -22,6 +22,7 @@
 #include <string>
 #include <guiutils.h>
 #include <multilangmgr.h>
+#include <LUT.h>
 
 extern Glib::ustring argv0;
 
@@ -89,7 +90,7 @@ CurveEditor::CurveEditor (Glib::ustring text, CurveEditorGroup* ceGroup, CurveEd
 	bgHistValid = false;
 	selected = DCT_Linear;
 
-    histogram = new unsigned int[256];	// histogram values
+    histogram(256);	// histogram values
 
 	group = ceGroup;
 	subGroup = ceSubGroup;
@@ -107,7 +108,6 @@ CurveEditor::CurveEditor (Glib::ustring text, CurveEditorGroup* ceGroup, CurveEd
 
 CurveEditor::~CurveEditor () {
 
-	delete [] histogram;
 }
 
 void CurveEditor::setCurve (const std::vector<double>& p) {
@@ -134,15 +134,15 @@ void CurveEditor::setUnChanged (bool uc) {
 /*
  * Update the backgrounds histograms
  */
-void CurveEditor::updateBackgroundHistogram (unsigned int* hist) {
+void CurveEditor::updateBackgroundHistogram (LUTu & hist) {
 	// Copy the histogram in the curve editor cache
-	if (hist!=NULL) {
-		memcpy (histogram, hist, 256*sizeof(unsigned int));
+	if (hist) {
+		histogram=hist;
 		bgHistValid = true;
 	}
 	else
 		bgHistValid = false;
-
+	
 	// Then call the curve editor group to eventually update the histogram
 	subGroup->updateBackgroundHistogram (this);
 }
diff --git a/rtgui/curveeditor.h b/rtgui/curveeditor.h
index 66c6c999a..4028ff9b1 100644
--- a/rtgui/curveeditor.h
+++ b/rtgui/curveeditor.h
@@ -20,6 +20,7 @@
 #define _CURVEEDITOR_
 
 #include <popuptogglebutton.h>
+#include <LUT.h>
 
 class CurveEditorGroup;
 class CurveEditorSubGroup;
@@ -32,7 +33,7 @@ class CurveEditorSubGroup;
 
 /*
  * This class is an interface between RT and the curve editor group ; it handles the methods
- * related to a specific curve. It is created by CurveEditorGroup::addCurve
+ * related to a specific curve. It is created by CurveEditorGroup::addCurve
  */
 class CurveEditor {
 
@@ -51,7 +52,7 @@ class CurveEditor {
 		*/
 
 		PopUpToggleButton* curveType;
-		unsigned int* histogram;	// histogram values
+		LUTu histogram;	// histogram values
 		bool bgHistValid;
 
 		int selected;
@@ -70,7 +71,7 @@ class CurveEditor {
 		void curveTypeToggled();
 		bool isUnChanged ();
 		void setUnChanged (bool uc);
-		void updateBackgroundHistogram (unsigned int* hist);
+		void updateBackgroundHistogram (LUTu & hist);
 		void setCurve (const std::vector<double>& p);
 		virtual std::vector<double> getCurve () = 0;
 };
@@ -98,7 +99,7 @@ class DiagonalCurveEditor : public CurveEditor {
 
 
 /*
- ********************** Flat Curve Editor **********************
+ ********************** Flat Curve Editor **********************
  */
 
 
diff --git a/rtgui/diagonalcurveeditorsubgroup.cc b/rtgui/diagonalcurveeditorsubgroup.cc
index 497243bf8..be11431d6 100644
--- a/rtgui/diagonalcurveeditorsubgroup.cc
+++ b/rtgui/diagonalcurveeditorsubgroup.cc
@@ -323,12 +323,12 @@ void DiagonalCurveEditorSubGroup::storeDisplayedCurve() {
  * Restore the histogram to all types from the CurveEditor object to the widgets
  */
 void DiagonalCurveEditorSubGroup::restoreDisplayedHistogram() {
-	if (parent->displayedCurve) {
-		paramCurve->updateBackgroundHistogram (parent->displayedCurve->bgHistValid ? parent->displayedCurve->histogram : NULL);
-		customCurve->updateBackgroundHistogram (parent->displayedCurve->bgHistValid ? parent->displayedCurve->histogram : NULL);
-		NURBSCurve->updateBackgroundHistogram (parent->displayedCurve->bgHistValid ? parent->displayedCurve->histogram : NULL);
+	if (parent->displayedCurve /*&& initslope==1*/) {
+		paramCurve->updateBackgroundHistogram (parent->displayedCurve->histogram);
+		customCurve->updateBackgroundHistogram (parent->displayedCurve->histogram);
+		NURBSCurve->updateBackgroundHistogram (parent->displayedCurve->histogram);
 	}
-
+	
 }
 
 void DiagonalCurveEditorSubGroup::storeCurveValues (CurveEditor* ce, const std::vector<double>& p) {
@@ -465,9 +465,9 @@ bool DiagonalCurveEditorSubGroup::adjusterLeft (GdkEventCrossing* ev, int ac) {
 }
 
 void DiagonalCurveEditorSubGroup::updateBackgroundHistogram (CurveEditor* ce) {
-	if (ce==parent->displayedCurve) {
-		paramCurve->updateBackgroundHistogram (ce->bgHistValid ? ce->histogram : NULL);
-		customCurve->updateBackgroundHistogram (ce->bgHistValid ? ce->histogram : NULL);
-		NURBSCurve->updateBackgroundHistogram (ce->bgHistValid ? ce->histogram : NULL);
+	if (ce==parent->displayedCurve /*&&  initslope==1*/) {
+		paramCurve->updateBackgroundHistogram (ce->histogram);
+		customCurve->updateBackgroundHistogram (ce->histogram);
+		NURBSCurve->updateBackgroundHistogram (ce->histogram);
 	}
 }
diff --git a/rtgui/editorpanel.cc b/rtgui/editorpanel.cc
index c7b6db864..dc2d99ec3 100644
--- a/rtgui/editorpanel.cc
+++ b/rtgui/editorpanel.cc
@@ -1275,7 +1275,7 @@ void EditorPanel::beforeAfterToggled () {
     }
 }
 
-void EditorPanel::histogramChanged (unsigned int* rh, unsigned int* gh, unsigned int* bh, unsigned int* lh, unsigned int* bcrgb, unsigned int* bcl) {
+void EditorPanel::histogramChanged (LUTu & rh, LUTu & gh, LUTu & bh, LUTu & lh, LUTu & bcrgb, LUTu & bcl) {
 
     histogramPanel->histogramChanged (rh, gh, bh, lh);
     tpc->updateCurveBackgroundHistogram (bcrgb, bcl);
diff --git a/rtgui/editorpanel.h b/rtgui/editorpanel.h
index 8eeeba0eb..270b004f0 100644
--- a/rtgui/editorpanel.h
+++ b/rtgui/editorpanel.h
@@ -149,7 +149,7 @@ class EditorPanel : public Gtk::VBox,
         void historyBeforeLineChanged (const rtengine::procparams::ProcParams& params);
         
         // HistogramListener
-        void histogramChanged (unsigned int* rh, unsigned int* gh, unsigned int* bh, unsigned int* lh, unsigned int* bcrgb, unsigned int* bcl);
+		void histogramChanged (LUTu & rh, LUTu & gh, LUTu & bh, LUTu & lh, LUTu & bcrgb, LUTu & bcl);
 
         // event handlers
         void info_toggled ();
diff --git a/rtgui/flatcurveeditorsubgroup.cc b/rtgui/flatcurveeditorsubgroup.cc
index c564395db..860b3a42d 100644
--- a/rtgui/flatcurveeditorsubgroup.cc
+++ b/rtgui/flatcurveeditorsubgroup.cc
@@ -193,10 +193,10 @@ void FlatCurveEditorSubGroup::storeDisplayedCurve() {
  */
 void FlatCurveEditorSubGroup::restoreDisplayedHistogram() {
 	if (parent->displayedCurve) {
-		//paramCurve->updateBackgroundHistogram (parent->displayedCurve->bgHistValid ? parent->displayedCurve->histogram : NULL);
-		CPointsCurve->updateBackgroundHistogram (parent->displayedCurve->bgHistValid ? parent->displayedCurve->histogram : NULL);
+		//paramCurve->updateBackgroundHistogram (parent->displayedCurve->histogram);
+		CPointsCurve->updateBackgroundHistogram (parent->displayedCurve->histogram);
 	}
-
+	
 }
 
 void FlatCurveEditorSubGroup::storeCurveValues (CurveEditor* ce, const std::vector<double>& p) {
diff --git a/rtgui/histogrampanel.cc b/rtgui/histogrampanel.cc
index 3c240d5bc..2b3461440 100644
--- a/rtgui/histogrampanel.cc
+++ b/rtgui/histogrampanel.cc
@@ -19,6 +19,8 @@
 #include <histogrampanel.h>
 #include <multilangmgr.h>
 #include <string.h>
+#include <LUT.h>
+
 
 HistogramPanel::HistogramPanel () {
 
@@ -77,10 +79,10 @@ void HistogramPanel::rgbv_toggled () {
 HistogramArea::HistogramArea () : 
       valid(false), showFull(true), oldwidth(-1), needVal(true), needRed(true), needGreen(true), needBlue(true) {
 
-    lhist = new unsigned int[256];
-    rhist = new unsigned int[256];
-    ghist = new unsigned int[256];
-    bhist = new unsigned int[256];
+	lhist(256);
+	rhist(256);
+	ghist(256);
+	bhist(256);
 
     haih = new HistogramAreaIdleHelper;
     haih->harea = this;
@@ -97,10 +99,6 @@ HistogramArea::~HistogramArea () {
     else
         delete haih;
 
-    delete [] lhist;
-    delete [] rhist;
-    delete [] ghist;
-    delete [] bhist;
 }
 
 void HistogramArea::updateOptions (bool r, bool g, bool b, bool v) {
@@ -136,18 +134,18 @@ int histupdate (void* data) {
     return 0;
 }
 
-void HistogramArea::update (unsigned int* rh, unsigned int* gh, unsigned int* bh, unsigned int* lh) {
-
-    if (rh!=NULL) {
-        memcpy (lhist, lh, 256*sizeof(unsigned int));
-        memcpy (rhist, rh, 256*sizeof(unsigned int));
-        memcpy (ghist, gh, 256*sizeof(unsigned int));
-        memcpy (bhist, bh, 256*sizeof(unsigned int));
+void HistogramArea::update (LUTu & rh, LUTu & gh, LUTu & bh, LUTu & lh) {
+	
+    if (rh) {
+        lhist=lh;
+        rhist=rh;
+        ghist=gh;
+        bhist=bh;
         valid = true;
     }
     else
         valid = false;
-
+	
     haih->pending++;
     g_idle_add (histupdate, haih);
 }
@@ -427,7 +425,7 @@ void HistogramArea::on_realize () {
 }
 
 void HistogramArea::drawCurve(Cairo::RefPtr<Cairo::Context> &cr,
-    unsigned int * data, double scale, int hsize, int vsize)
+    LUTu & data, double scale, int hsize, int vsize)
 {
     cr->move_to (0, vsize-1);
     for (int i = 0; i < 256; i++) {
@@ -440,7 +438,7 @@ void HistogramArea::drawCurve(Cairo::RefPtr<Cairo::Context> &cr,
 }
 
 void HistogramArea::drawMarks(Cairo::RefPtr<Cairo::Context> &cr,
-    unsigned int * data, double scale, int hsize, int & ui, int & oi)
+    LUTu & data, double scale, int hsize, int & ui, int & oi)
 {
     int s = 8;
     
diff --git a/rtgui/histogrampanel.h b/rtgui/histogrampanel.h
index 43d96928f..467088542 100644
--- a/rtgui/histogrampanel.h
+++ b/rtgui/histogrampanel.h
@@ -21,6 +21,7 @@
 
 #include <gtkmm.h>
 #include <glibmm.h>
+#include <LUT.h>
 
 class HistogramArea;
 struct HistogramAreaIdleHelper {
@@ -44,10 +45,10 @@ class HistogramArea : public Gtk::DrawingArea {
     Gdk::Color lgray;
     Gdk::Color mgray;
     Gdk::Color dgray;
-    unsigned int* lhist;
-    unsigned int* rhist;
-    unsigned int* ghist;
-    unsigned int* bhist;
+    LUTu lhist;
+    LUTu rhist;
+    LUTu ghist;
+    LUTu bhist;
     bool valid;
     bool showFull;
     int oldwidth, oldheight;
@@ -65,7 +66,7 @@ class HistogramArea : public Gtk::DrawingArea {
     ~HistogramArea();
 
     void renderHistogram ();
-    void update (unsigned int* rh, unsigned int* gh, unsigned int* bh, unsigned int* lh);
+    void update (LUTu &rh, LUTu &gh, LUTu &bh, LUTu &lh);
     void updateOptions (bool r, bool g, bool b, bool v);
     void on_realize();
     bool on_expose_event(GdkEventExpose* event);
@@ -73,9 +74,9 @@ class HistogramArea : public Gtk::DrawingArea {
     void styleChanged (const Glib::RefPtr<Gtk::Style>& style);
   private:
     void drawCurve(Cairo::RefPtr<Cairo::Context> &cr,
-        unsigned int * data, double scale, int hsize, int vsize);
+				   LUTu & data, double scale, int hsize, int vsize);
     void drawMarks(Cairo::RefPtr<Cairo::Context> &cr,
-        unsigned int * data, double scale, int hsize, int & ui, int & oi);
+				   LUTu & data, double scale, int hsize, int & ui, int & oi);
 };
 
 class HistogramPanel : public Gtk::HBox {
@@ -94,7 +95,7 @@ class HistogramPanel : public Gtk::HBox {
 
     HistogramPanel ();
 
-    void histogramChanged (unsigned int* rh, unsigned int* gh, unsigned int* bh, unsigned int* lh) { histogramArea->update (rh, gh, bh, lh); }
+    void histogramChanged (LUTu &rh, LUTu &gh, LUTu &bh, LUTu &lh) { histogramArea->update (rh, gh, bh, lh); }
     void rgbv_toggled ();
     void resized (Gtk::Allocation& req);
 };
diff --git a/rtgui/labcurve.cc b/rtgui/labcurve.cc
index cc847decc..8c01999c3 100644
--- a/rtgui/labcurve.cc
+++ b/rtgui/labcurve.cc
@@ -359,7 +359,7 @@ void LCurve::setAdjusterBehavior (bool bradd, bool contradd, bool satadd) {
 
 }
 
-void LCurve::updateCurveBackgroundHistogram (unsigned* hist) {
+void LCurve::updateCurveBackgroundHistogram (LUTu & hist) {
     
     lshape->updateBackgroundHistogram (hist);
 }
diff --git a/rtgui/labcurve.h b/rtgui/labcurve.h
index 68efe3c7a..a223eb38d 100644
--- a/rtgui/labcurve.h
+++ b/rtgui/labcurve.h
@@ -65,7 +65,7 @@ class LCurve : public Gtk::VBox, public AdjusterListener, public FoldableToolPan
     void adjusterChanged (Adjuster* a, double newval);
 	void avoidclip_toggled ();
     void enablelimiter_toggled ();
-    void updateCurveBackgroundHistogram (unsigned* hist);
+    void updateCurveBackgroundHistogram (LUTu & hist);
 
     virtual void colorForValue (double valX, double valY);
 };
diff --git a/rtgui/mycurve.h b/rtgui/mycurve.h
index e1dfdc91c..2b8c346d6 100644
--- a/rtgui/mycurve.h
+++ b/rtgui/mycurve.h
@@ -24,6 +24,7 @@
 #include <curvelistener.h>
 #include <cursormanager.h>
 #include <colorprovider.h>
+#include <LUT.h>
 
 #define RADIUS			3	/* radius of the control points */
 #define SQUARE			2	/* half length of the square shape of the tangent handles */
@@ -83,7 +84,7 @@ class MyCurve : public Gtk::DrawingArea {
 		void setCurveListener (CurveListener* cl) { listener = cl; }
 		void setColorProvider (ColorProvider* cp) { colorProvider = cp; }
 		void notifyListener ();
-		void updateBackgroundHistogram (unsigned int* hist) {return;} ;
+		void updateBackgroundHistogram (LUTu & hist) {return;} ;
 		void forceResize() { sized = RS_Force; }
 		virtual std::vector<double> getPoints () = 0;
 		virtual void setPoints (const std::vector<double>& p) = 0;
diff --git a/rtgui/mydiagonalcurve.cc b/rtgui/mydiagonalcurve.cc
index 4255be0c1..f8f3d5c4b 100644
--- a/rtgui/mydiagonalcurve.cc
+++ b/rtgui/mydiagonalcurve.cc
@@ -656,18 +656,20 @@ int diagonalmchistupdate (void* data) {
     return 0;
 }
 
-void MyDiagonalCurve::updateBackgroundHistogram (unsigned int* hist) {
-
+void MyDiagonalCurve::updateBackgroundHistogram (LUTu & hist) {
+	
     if (hist!=NULL) {
-        memcpy (bghist, hist, 256*sizeof(unsigned int));
+        //memcpy (bghist, hist, 256*sizeof(unsigned int));
+		for (int i=0; i<256; i++) bghist[i]=hist[i];
+		//hist = bghist;
         bghistvalid = true;
     }
     else
         bghistvalid = false;
-
+	
     mcih->pending++;
     g_idle_add (diagonalmchistupdate, mcih);
-
+	
 }
 
 void MyDiagonalCurve::reset() {
diff --git a/rtgui/mydiagonalcurve.h b/rtgui/mydiagonalcurve.h
index 9aee97358..c130d37c5 100644
--- a/rtgui/mydiagonalcurve.h
+++ b/rtgui/mydiagonalcurve.h
@@ -24,6 +24,8 @@
 #include <curvelistener.h>
 #include <cursormanager.h>
 #include <mycurve.h>
+#include <LUT.h>
+
 
 // For compatibility and simplicity reason, order shouldn't change, and must be identical to the order specified in the curveType widget
 enum DiagonalCurveType {
@@ -76,7 +78,7 @@ class MyDiagonalCurve : public MyCurve {
 		bool handleEvents (GdkEvent* event);
 		void setActiveParam (int ac);
 		void reset ();
-		void updateBackgroundHistogram (unsigned int* hist);
+		void updateBackgroundHistogram (LUTu & hist);
 };
 
 #endif
diff --git a/rtgui/tonecurve.cc b/rtgui/tonecurve.cc
index 8bebb3a9b..9cd678a49 100644
--- a/rtgui/tonecurve.cc
+++ b/rtgui/tonecurve.cc
@@ -393,7 +393,7 @@ void ToneCurve::setAdjusterBehavior (bool expadd, bool hlcompadd, bool hlcompthr
 	satAdd = satadd;
 }
 
-void ToneCurve::updateCurveBackgroundHistogram (unsigned* hist) {
+void ToneCurve::updateCurveBackgroundHistogram (LUTu & hist) {
 
     shape->updateBackgroundHistogram (hist);
 }
diff --git a/rtgui/tonecurve.h b/rtgui/tonecurve.h
index 5c79b295c..2b5303f81 100644
--- a/rtgui/tonecurve.h
+++ b/rtgui/tonecurve.h
@@ -69,7 +69,7 @@ class ToneCurve : public Gtk::VBox, public AdjusterListener, public FoldableTool
     void curveChanged ();
     void expandCurve (bool isExpanded);
     bool isCurveExpanded ();
-    void updateCurveBackgroundHistogram (unsigned* hist);
+    void updateCurveBackgroundHistogram (LUTu & hist);
 };
 
 #endif
diff --git a/rtgui/toolpanelcoord.cc b/rtgui/toolpanelcoord.cc
index b017bb4aa..57ad8fd61 100644
--- a/rtgui/toolpanelcoord.cc
+++ b/rtgui/toolpanelcoord.cc
@@ -470,7 +470,7 @@ int ToolPanelCoordinator::getSpotWBRectSize () {
     return whitebalance->getSize ();
 }
 
-void ToolPanelCoordinator::updateCurveBackgroundHistogram (unsigned* histrgb, unsigned* histl) {
+void ToolPanelCoordinator::updateCurveBackgroundHistogram (LUTu &histrgb, LUTu &histl) {
 
     curve->updateCurveBackgroundHistogram (histrgb);
     lcurve->updateCurveBackgroundHistogram (histl);
diff --git a/rtgui/toolpanelcoord.h b/rtgui/toolpanelcoord.h
index 694f3ea7b..aa269b959 100644
--- a/rtgui/toolpanelcoord.h
+++ b/rtgui/toolpanelcoord.h
@@ -149,7 +149,7 @@ class ToolPanelCoordinator :    public ToolPanelListener,
         ~ToolPanelCoordinator ();
 
         bool getChangedState                ()                                      { return hasChanged; }
-        void updateCurveBackgroundHistogram (unsigned* histrgb, unsigned* histl);
+		void updateCurveBackgroundHistogram (LUTu & histrgb, LUTu & histl);
         void foldAllButOne (Gtk::Box* parent, FoldableToolPanel* openedSection);
 
         // multiple listeners can be added that are notified on changes (typical: profile panel and the history)