diff --git a/rtengine/curves.h b/rtengine/curves.h
index ff579fe79..2983a98ba 100644
--- a/rtengine/curves.h
+++ b/rtengine/curves.h
@@ -191,6 +191,18 @@ class CurveFactory {
 	//static inline float    gamma_srgb       (double x) { return gammatab_srgb[x]; }
 	//static inline float    gamma            (double x) { return gammatab[x]; }
 	//static inline float    igamma_srgb      (double x) { return igammatab_srgb[x]; }
+	
+	static inline float hlcurve (const float exp_scale, const float comp, const float hlrange, float level) 
+	{
+		if (comp>0.0) {
+			float val = level+(hlrange-65536.0);
+			float Y = val*exp_scale/hlrange;
+			float R = hlrange/(val*comp);
+			return log(1.0+Y*comp)*R;
+		} else {
+			return exp_scale;
+		}
+	}
 
   public:
     static void complexCurve (double ecomp, double black, double hlcompr, double hlcomprthresh, double shcompr, double br, double contr, double gamma_, bool igamma_, const std::vector<double>& curvePoints, LUTu & histogram,LUTf & hlCurve, LUTf & shCurve,LUTf & outCurve, LUTu & outBeforeCCurveHistogram, int skip=1);
diff --git a/rtengine/improccoordinator.cc b/rtengine/improccoordinator.cc
index aa8529fff..331fcb751 100644
--- a/rtengine/improccoordinator.cc
+++ b/rtengine/improccoordinator.cc
@@ -246,7 +246,7 @@ void ImProcCoordinator::updatePreviewImage (int todo, Crop* cropCall) {
         try
         {
             ipf.lab2rgb (nprevl, previmg);
-        }
+			workimg = ipf.lab2rgb (nprevl, 0,0,pW,pH, params.icm.working);        }
         catch(char * str)
         {
            progress ("Error converting file...",0);
@@ -298,6 +298,7 @@ void ImProcCoordinator::freeAll () {
         }
         else
             delete previmg;
+		delete workimg;
         delete shmap;
         for (int i=0; i<pH; i++)
             delete [] buffer[i];
@@ -337,6 +338,7 @@ if (settings->verbose) printf ("setscale before lock\n");
         oprevl = new LabImage (pW, pH);    
         nprevl = new LabImage (pW, pH);    
         previmg = new Image8 (pW, pH);
+		workimg = new Image8 (pW, pH);
         shmap = new SHMap (pW, pH, true);
         
         buffer = new int*[pH];
@@ -368,9 +370,9 @@ void ImProcCoordinator::updateHistograms (int x1, int y1, int x2, int y2) {
     for (int i=y1; i<y2; i++) {
         int ofs = (i*pW + x1)*3;
         for (int j=x1; j<x2; j++) {
-			int r=previmg->data[ofs++];
-			int g=previmg->data[ofs++];
-			int b=previmg->data[ofs++];
+			int r=workimg->data[ofs++];
+			int g=workimg->data[ofs++];
+			int b=workimg->data[ofs++];
 
 			//bcrgbhist[(int)(0.299*r + 0.587*g + 0.114*b)]++;
             rhist[r]++;
diff --git a/rtengine/improccoordinator.h b/rtengine/improccoordinator.h
index 77a7efab4..855492272 100644
--- a/rtengine/improccoordinator.h
+++ b/rtengine/improccoordinator.h
@@ -46,6 +46,8 @@ class ImProcCoordinator : public StagedImageProcessor {
         LabImage *oprevl;    
         LabImage *nprevl;    
         Image8 *previmg;
+		Image8 *workimg;
+
         ImageSource* imgsrc;
         
         int** buffer;
diff --git a/rtengine/improcfun.cc b/rtengine/improcfun.cc
index e8bf98697..1e86ae8bb 100644
--- a/rtengine/improcfun.cc
+++ b/rtengine/improcfun.cc
@@ -278,6 +278,11 @@ void ImProcFunctions::rgbProc (Imagefloat* working, LabImage* lab, LUTf & hltone
 	if (sCurveEnabled) sCurve = new FlatCurve(params->hsvequalizer.scurve);
 	if (vCurveEnabled) vCurve = new FlatCurve(params->hsvequalizer.vcurve);
 	
+	const float exp_scale = pow (2.0, params->toneCurve.expcomp);
+	const float comp = (params->toneCurve.expcomp + 1.0)*params->toneCurve.hlcompr/100.0;
+	const float shoulder = ((65536.0/exp_scale)*(params->toneCurve.hlcomprthresh/200.0))+0.1;
+	const float hlrange = 65536.0-shoulder;
+	
 	
 #pragma omp parallel for if (multiThread)
     for (int i=0; i<tH; i++) {
@@ -322,8 +327,10 @@ void ImProcFunctions::rgbProc (Imagefloat* working, LabImage* lab, LUTf & hltone
 
 			//TODO: proper treatment of out-of-gamut colors
 			//float tonefactor = hltonecurve[(0.299f*r+0.587f*g+0.114f*b)];
-			float tonefactor=(hltonecurve[r] + hltonecurve[g] + hltonecurve[b])/3;
-
+			float tonefactor=((r<MAXVAL ? hltonecurve[r] : CurveFactory::hlcurve (exp_scale, comp, hlrange, r) ) + \
+							  (g<MAXVAL ? hltonecurve[g] : CurveFactory::hlcurve (exp_scale, comp, hlrange, g) ) + \
+							  (r<MAXVAL ? hltonecurve[b] : CurveFactory::hlcurve (exp_scale, comp, hlrange, b) ) )/3.0;
+			
 			r = (r*tonefactor);
 			g = (g*tonefactor);
 			b = (b*tonefactor);
diff --git a/rtengine/rawimagesource.cc b/rtengine/rawimagesource.cc
index ce25fe15e..bf99fc390 100644
--- a/rtengine/rawimagesource.cc
+++ b/rtengine/rawimagesource.cc
@@ -229,12 +229,12 @@ void RawImageSource::getImage (ColorTemp ctemp, int tran, Imagefloat* image, Pre
     gm = camwb_green / gm;
     bm = camwb_blue / bm;
 
-    float mul_lum = 0.299*rm + 0.587*gm + 0.114*bm;
+    /*float mul_lum = 0.299*rm + 0.587*gm + 0.114*bm;
     rm /= mul_lum;
     gm /= mul_lum;
-    bm /= mul_lum;    
-/*
-    //initialGain=1.0;
+    bm /= mul_lum;*/    
+
+    /*//initialGain=1.0;
 	// in floating point, should keep white point fixed and recover higher values with exposure slider
     //if (hrp.enabled) */
     float min = rm;
diff --git a/rtgui/crophandler.cc b/rtgui/crophandler.cc
index 9cc176289..3d391bd9b 100644
--- a/rtgui/crophandler.cc
+++ b/rtgui/crophandler.cc
@@ -245,7 +245,7 @@ void CropHandler::setDetailedCrop (IImage8* im, IImage8* imtrue, rtengine::procp
     if (ax==cropX && ay==cropY && aw==cropW && ah==cropH && askip==(zoom>=1000?1:zoom)) {
         cropimg_width = im->getWidth ();
         cropimg_height = im->getHeight ();
-        cropimg = new unsigned char [6*cropimg_width*cropimg_height];
+        cropimg = new unsigned char [3*cropimg_width*cropimg_height];
 		cropimgtrue = new unsigned char [3*cropimg_width*cropimg_height];
         memcpy (cropimg, im->getData(), 3*cropimg_width*cropimg_height);
 		memcpy (cropimgtrue, imtrue->getData(), 3*cropimg_width*cropimg_height);