diff --git a/TODO b/TODO
index 434c9f2..e3a360e 100644
--- a/TODO
+++ b/TODO
@@ -1,4 +1,5 @@
 Technology Preview 2 :
+- Implement High Dynamic Range (with OpenEXR or Radiance file format support ?).
 - Fully move layer management from BaseForm to BaseFormLayer.
 - Replace terrain canvas editor by full sculpting editor.
    => Add a generation dialog, with fixed resolution.
@@ -43,7 +44,6 @@ Technlogy Preview 3 :
 Technology Preview 4 :
 - Restore render progress.
 - Store the terrain canvases in a tree to allow "multi-res" edition.
-- Implement High Dynamic Range.
 - Implement Sub Surface Scattering for water.
 - Use bicubic interpolation for antialiasing.
 - Allow for larger renders/antialias (will need several two-pass chunks).
diff --git a/gui_qt/dialogrender.cpp b/gui_qt/dialogrender.cpp
index c17bfbe..b809f54 100644
--- a/gui_qt/dialogrender.cpp
+++ b/gui_qt/dialogrender.cpp
@@ -26,6 +26,7 @@ static void _renderStart(int width, int height, Color background)
 
 static void _renderDraw(int x, int y, Color col)
 {
+    col = colorProfileApply(_current_dialog->_hdr_profile, col);
     _current_dialog->pixbuf->setPixel(x, _current_dialog->pixbuf->height() - 1 - y, colorToQColor(col).rgb());
 }
 
@@ -79,6 +80,8 @@ DialogRender::DialogRender(QWidget *parent, Renderer* renderer):
     _render_thread = NULL;
     _renderer = renderer;
 
+    _hdr_profile = colorProfileCreate();
+
     setModal(true);
     setWindowTitle(tr("Paysages 3D - Render"));
     setLayout(new QVBoxLayout());
@@ -116,6 +119,7 @@ DialogRender::~DialogRender()
 
         delete _render_thread;
     }
+    colorProfileDelete(_hdr_profile);
     delete pixbuf;
     delete pixbuf_lock;
 }
diff --git a/gui_qt/dialogrender.h b/gui_qt/dialogrender.h
index ad0d49b..f33edf6 100644
--- a/gui_qt/dialogrender.h
+++ b/gui_qt/dialogrender.h
@@ -9,6 +9,7 @@
 #include <QLabel>
 #include <QMutex>
 #include "../lib_paysages/renderer.h"
+#include "../lib_paysages/color.h"
 
 class DialogRender : public QDialog
 {
@@ -25,6 +26,7 @@ public:
     QImage* pixbuf;
     QMutex* pixbuf_lock;
     QWidget* area;
+    ColorProfile* _hdr_profile;
 
 private slots:
     void applyRenderSize(int width, int height);
diff --git a/lib_paysages/atmosphere/bruneton.c b/lib_paysages/atmosphere/bruneton.c
index 885992d..074f900 100644
--- a/lib_paysages/atmosphere/bruneton.c
+++ b/lib_paysages/atmosphere/bruneton.c
@@ -302,22 +302,6 @@ static Color _transmittanceWithShadow(double r, double mu)
     return mu < -sqrt(1.0 - (Rg / r) * (Rg / r)) ? COLOR_BLACK : _transmittance(r, mu);
 }
 
-static Color _hdr(Color c1, Color c2, Color c3)
-{
-    Color L = {c1.r + c2.r + c3.r, c1.g + c2.g + c3.g, c1.b + c2.b + c3.b, 1.0};
-
-    L.r *= exposure;
-    L.g *= exposure;
-    L.b *= exposure;
-    L.a = 1.0;
-
-    L.r = L.r < 1.413 ? pow(L.r * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.r);
-    L.g = L.g < 1.413 ? pow(L.g * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.g);
-    L.b = L.b < 1.413 ? pow(L.b * 0.38317, 1.0 / 2.2) : 1.0 - exp(-L.b);
-
-    return L;
-}
-
 static void _getMuMuSNu(double x, double y, double r, Color dhdH, double* mu, double* muS, double* nu)
 {
     double d;
@@ -1252,9 +1236,12 @@ Color brunetonGetSkyColor(AtmosphereDefinition* definition, Vector3 eye, Vector3
 
     Vector3 attenuation;
     Color inscatterColor = _getInscatterColor(&x, &t, v, s, &r, &mu, &attenuation); /* S[L]-T(x,xs)S[l]|xs */
-    Color groundColor = COLOR_BLACK;
     Color sunColor = _sunColor(x, 0.0, v, s, r, mu); /* L0 */
-    return _hdr(sunColor, groundColor, inscatterColor); /* Eq (16) */
+
+    inscatterColor.r += sunColor.r;
+    inscatterColor.g += sunColor.g;
+    inscatterColor.b += sunColor.b;
+    return inscatterColor; /* Eq (16) */
 }
 
 Color brunetonApplyAerialPerspective(Renderer* renderer, Vector3 location, Color base)
@@ -1297,6 +1284,9 @@ Color brunetonApplyAerialPerspective(Renderer* renderer, Vector3 location, Color
     Vector3 attenuation;
     Color inscatterColor = _getInscatterColor(&x, &t, v, s, &r, &mu, &attenuation); /* S[L]-T(x,xs)S[l]|xs */
     Color groundColor = _groundColor(base, x, t, v, s, r, mu, attenuation); //R[L0]+R[L*]*/
-    Color sunColor = COLOR_BLACK;
-    return _hdr(sunColor, groundColor, inscatterColor); /* Eq (16) */
+
+    groundColor.r += inscatterColor.r;
+    groundColor.g += inscatterColor.g;
+    groundColor.b += inscatterColor.b;
+    return groundColor; /* Eq (16) */
 }
diff --git a/lib_paysages/atmosphere/presets.c b/lib_paysages/atmosphere/presets.c
index eccdb04..4a5e81c 100644
--- a/lib_paysages/atmosphere/presets.c
+++ b/lib_paysages/atmosphere/presets.c
@@ -24,34 +24,34 @@ void atmosphereAutoPreset(AtmosphereDefinition* definition, AtmospherePreset pre
             definition->model = ATMOSPHERE_MODEL_BRUNETON;
             definition->hour = 15;
             definition->minute = 0;
-            definition->dome_lighting = 0.6;
+            definition->dome_lighting = 0.2;
             break;
         case ATMOSPHERE_PRESET_CLEAR_SUNSET:
             definition->model = ATMOSPHERE_MODEL_BRUNETON;
             definition->hour = 17;
             definition->minute = 45;
-            definition->dome_lighting = 0.8;
+            definition->dome_lighting = 0.3;
             definition->sun_radius = 0.03;
             break;
         case ATMOSPHERE_PRESET_HAZY_MORNING:
             definition->model = ATMOSPHERE_MODEL_PREETHAM;
             definition->hour = 8;
             definition->minute = 30;
-            definition->dome_lighting = 0.5;
+            definition->dome_lighting = 0.25;
             definition->humidity = 0.3;
             break;
         case ATMOSPHERE_PRESET_FOGGY:
             definition->model = ATMOSPHERE_MODEL_PREETHAM;
             definition->hour = 15;
             definition->minute = 0;
-            definition->dome_lighting = 0.7;
+            definition->dome_lighting = 0.1;
             definition->humidity = 0.6;
             break;
         case ATMOSPHERE_PRESET_STORMY:
             definition->model = ATMOSPHERE_MODEL_PREETHAM;
             definition->hour = 15;
             definition->minute = 0;
-            definition->dome_lighting = 0.3;
+            definition->dome_lighting = 0.05;
             definition->humidity = 0.9;
             break;
         default:
diff --git a/lib_paysages/color.c b/lib_paysages/color.c
index 227907c..553f12b 100644
--- a/lib_paysages/color.c
+++ b/lib_paysages/color.c
@@ -3,9 +3,12 @@
 #include <stdlib.h>
 #include <assert.h>
 #include <string.h>
+#include <math.h>
 #include "tools.h"
 #include "curve.h"
 
+/******************************** Color ********************************/
+
 Color COLOR_TRANSPARENT = {0.0, 0.0, 0.0, 0.0};
 Color COLOR_BLACK = {0.0, 0.0, 0.0, 1.0};
 Color COLOR_RED = {1.0, 0.0, 0.0, 1.0};
@@ -14,13 +17,6 @@ Color COLOR_BLUE = {0.0, 0.0, 1.0, 1.0};
 Color COLOR_WHITE = {1.0, 1.0, 1.0, 1.0};
 Color COLOR_GREY = {0.5, 0.5, 0.5, 1.0};
 
-struct ColorGradation
-{
-    Curve* red;
-    Curve* green;
-    Curve* blue;
-};
-
 void colorSave(PackStream* stream, Color* col)
 {
     packWriteDouble(stream, &col->r);
@@ -60,48 +56,48 @@ unsigned int colorTo32BitABGR(Color* col)
 Color colorFrom32BitRGBA(unsigned int col)
 {
     Color result;
-    
+
     result.r = ((double)(col & 0x000000FF)) / 255.0;
     result.g = ((double)((col & 0x0000FF00) >> 8)) / 255.0;
     result.b = ((double)((col & 0x00FF0000) >> 16)) / 255.0;
     result.a = ((double)((col & 0xFF000000) >> 24)) / 255.0;
-    
+
     return result;
 }
 
 Color colorFrom32BitBGRA(unsigned int col)
 {
     Color result;
-    
+
     result.b = ((double)(col & 0x000000FF)) / 255.0;
     result.g = ((double)((col & 0x0000FF00) >> 8)) / 255.0;
     result.r = ((double)((col & 0x00FF0000) >> 16)) / 255.0;
     result.a = ((double)((col & 0xFF000000) >> 24)) / 255.0;
-    
+
     return result;
 }
 
 Color colorFrom32BitARGB(unsigned int col)
 {
     Color result;
-    
+
     result.a = ((double)(col & 0x000000FF)) / 255.0;
     result.r = ((double)((col & 0x0000FF00) >> 8)) / 255.0;
     result.g = ((double)((col & 0x00FF0000) >> 16)) / 255.0;
     result.b = ((double)((col & 0xFF000000) >> 24)) / 255.0;
-    
+
     return result;
 }
 
 Color colorFrom32BitABGR(unsigned int col)
 {
     Color result;
-    
+
     result.a = ((double)(col & 0x000000FF)) / 255.0;
     result.b = ((double)((col & 0x0000FF00) >> 8)) / 255.0;
     result.g = ((double)((col & 0x00FF0000) >> 16)) / 255.0;
     result.r = ((double)((col & 0xFF000000) >> 24)) / 255.0;
-    
+
     return result;
 }
 
@@ -125,7 +121,20 @@ void colorMask(Color* base, Color* mask)
 
 double colorNormalize(Color* col)
 {
-    double max = colorGetValue(col);
+    if (col->r > 1.0)
+    {
+        col->r = 1.0;
+    }
+    if (col->g > 1.0)
+    {
+        col->g = 1.0;
+    }
+    if (col->b > 1.0)
+    {
+        col->b = 1.0;
+    }
+    return 1.0;
+    /*double max = colorGetValue(col);
 
     assert(max >= 0.0);
     assert(col->r >= 0.0);
@@ -139,7 +148,7 @@ double colorNormalize(Color* col)
         col->g /= max;
         col->b /= max;
     }
-    return max;
+    return max;*/
 }
 
 double colorGetValue(Color* col)
@@ -158,6 +167,96 @@ double colorGetValue(Color* col)
     return max;
 }
 
+/******************************** ColorProfile ********************************/
+struct ColorProfile
+{
+    double minvalue;
+    double maxvalue;
+};
+
+ColorProfile* colorProfileCreate()
+{
+    ColorProfile* profile;
+
+    profile = malloc(sizeof(ColorProfile));
+
+    colorProfileClear(profile);
+
+    return profile;
+}
+
+void colorProfileDelete(ColorProfile* profile)
+{
+    free(profile);
+}
+
+void colorProfileSave(PackStream* stream, ColorProfile* profile)
+{
+    /* TODO */
+}
+
+void colorProfileLoad(PackStream* stream, ColorProfile* profile)
+{
+    /* TODO */
+}
+
+void colorProfileClear(ColorProfile* profile)
+{
+    profile->minvalue = 0.0;
+    profile->maxvalue = 3.0;
+}
+
+int colorProfileCollect(ColorProfile* profile, Color pixel)
+{
+    int changed = 0;
+    double value = pixel.r + pixel.g + pixel.b;
+
+    if (value < profile->minvalue)
+    {
+        profile->minvalue = value;
+        changed = 1;
+    }
+    if (value > profile->maxvalue)
+    {
+        profile->maxvalue = value;
+        changed = 1;
+    }
+    return changed;
+}
+
+float A = 0.15;
+float B = 0.50;
+float C = 0.10;
+float D = 0.20;
+float E = 0.02;
+float F = 0.30;
+float W = 11.2;
+
+static double _uncharted2Tonemap(double x)
+{
+   return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F;
+}
+
+Color colorProfileApply(ColorProfile* profile, Color pixel)
+{
+    double exposure_bias = 2.0;
+    double white_scale = 1.0 / _uncharted2Tonemap(W);
+
+    pixel.r = pow(_uncharted2Tonemap(pixel.r * exposure_bias) * white_scale, 1.0 / 2.2);
+    pixel.g = pow(_uncharted2Tonemap(pixel.g * exposure_bias) * white_scale, 1.0 / 2.2);
+    pixel.b = pow(_uncharted2Tonemap(pixel.b * exposure_bias) * white_scale, 1.0 / 2.2);
+
+    return pixel;
+}
+
+/******************************** ColorGradation ********************************/
+struct ColorGradation
+{
+    Curve* red;
+    Curve* green;
+    Curve* blue;
+};
+
 ColorGradation* colorGradationCreate()
 {
     ColorGradation* result;
@@ -166,7 +265,7 @@ ColorGradation* colorGradationCreate()
     result->red = curveCreate();
     result->green = curveCreate();
     result->blue = curveCreate();
-    
+
     return result;
 }
 
@@ -264,7 +363,7 @@ Color colorGradationGet(ColorGradation* gradation, double value)
     result.g = curveGetValue(gradation->green, value);
     result.b = curveGetValue(gradation->blue, value);
     result.a = 1.0;
-    
+
     return result;
 }
 
diff --git a/lib_paysages/color.h b/lib_paysages/color.h
index efda8b9..2b87d3b 100644
--- a/lib_paysages/color.h
+++ b/lib_paysages/color.h
@@ -2,6 +2,7 @@
 #define _PAYSAGES_COLOR_H_
 
 #include "curve.h"
+#include "pack.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -41,6 +42,19 @@ void colorMask(Color* base, Color* mask);
 double colorNormalize(Color* col);
 double colorGetValue(Color* col);
 
+/* HDR profile for tone-mapping */
+typedef struct ColorProfile ColorProfile;
+
+ColorProfile* colorProfileCreate();
+void colorProfileDelete(ColorProfile* profile);
+
+void colorProfileSave(PackStream* stream, ColorProfile* profile);
+void colorProfileLoad(PackStream* stream, ColorProfile* profile);
+
+void colorProfileClear(ColorProfile* profile);
+int colorProfileCollect(ColorProfile* profile, Color pixel);
+Color colorProfileApply(ColorProfile* profile, Color pixel);
+
 /* ColorGradation */
 typedef struct ColorGradation ColorGradation;
 
diff --git a/lib_paysages/render.c b/lib_paysages/render.c
index b1d3414..29e36de 100644
--- a/lib_paysages/render.c
+++ b/lib_paysages/render.c
@@ -6,6 +6,7 @@
 
 #include "shared/types.h"
 #include "color.h"
+#include "renderer.h"
 #include "system.h"
 
 typedef struct
@@ -95,7 +96,7 @@ void renderQuit()
 RenderArea* renderCreateArea()
 {
     RenderArea* result;
-    
+
     result = malloc(sizeof(RenderArea));
     result->params.width = 1;
     result->params.height = 1;
@@ -118,7 +119,7 @@ RenderArea* renderCreateArea()
     result->callback_start = _callbackStart;
     result->callback_draw = _callbackDraw;
     result->callback_update = _callbackUpdate;
-    
+
     return result;
 }
 
@@ -134,7 +135,7 @@ void renderDeleteArea(RenderArea* area)
 void renderSetParams(RenderArea* area, RenderParams params)
 {
     int width, height;
-    
+
     width = params.width * params.antialias;
     height = params.height * params.antialias;
 
@@ -178,7 +179,7 @@ void renderClear(RenderArea* area)
     RenderFragment* pixel;
     int x;
     int y;
-    
+
     area->fragment_callbacks_count = 1;
     area->fragment_callbacks[0].function = NULL;
     area->fragment_callbacks[0].data = NULL;
@@ -237,7 +238,7 @@ static inline Color _getFinalPixel(RenderArea* area, int x, int y)
     Color result, col;
     int sx, sy;
     RenderFragment* pixel_data;
-    
+
     result.r = result.g = result.b = 0.0;
     result.a = 1.0;
     for (sx = 0; sx < area->params.antialias; sx++)
@@ -267,7 +268,7 @@ static inline Color _getFinalPixel(RenderArea* area, int x, int y)
             result.b += col.b / (double)(area->params.antialias * area->params.antialias);
         }
     }
-    
+
     return result;
 }
 
@@ -275,7 +276,7 @@ static void _processDirtyPixels(RenderArea* area)
 {
     int x, y;
     int down, up, left, right;
-    
+
     down = area->dirty_down / area->params.antialias;
     up = area->dirty_up / area->params.antialias;
     left = area->dirty_left / area->params.antialias;
@@ -323,7 +324,7 @@ static inline unsigned int _pushCallback(RenderArea* area, FragmentCallback call
             return i;
         }
     }
-    
+
     if (area->fragment_callbacks_count >= 64)
     {
         return 0;
@@ -339,7 +340,7 @@ static inline unsigned int _pushCallback(RenderArea* area, FragmentCallback call
 static void _pushFragment(RenderArea* area, int x, int y, double z, int edge, Vector3 location, int callback)
 {
     RenderFragment* pixel_data;
-    
+
     if (x >= 0 && x < area->params.width * area->params.antialias && y >= 0 && y < area->params.height * area->params.antialias && z > 1.0)
     {
         pixel_data = area->pixels + (y * area->params.width * area->params.antialias + x);
@@ -382,7 +383,7 @@ static void _pushScanPoint(RenderArea* area, ScanPoint* point)
 {
     point->x = (int)floor(point->pixel.x);
     point->y = (int)floor(point->pixel.y);
-    
+
     if (point->x < 0 || point->x >= area->params.width * area->params.antialias)
     {
         return;
@@ -466,7 +467,7 @@ static void _pushScanLineEdge(RenderArea* area, ScanPoint* point1, ScanPoint* po
             _scanInterpolate(point1, &diff, fx / dx, &point);
 
             /*point.pixel.x = (double)curx;*/
-            
+
             _pushScanPoint(area, &point);
         }
     }
@@ -541,7 +542,7 @@ void renderPushTriangle(RenderArea* area, Vector3 pixel1, Vector3 pixel2, Vector
     {
         return;
     }
-    
+
     point1.pixel = pixel1;
     point1.location = location1;
     point1.callback = _pushCallback(area, fragment_callback);
@@ -553,13 +554,13 @@ void renderPushTriangle(RenderArea* area, Vector3 pixel1, Vector3 pixel2, Vector
     point3.pixel = pixel3;
     point3.location = location3;
     point3.callback = _pushCallback(area, fragment_callback);
-    
+
     _clearScanLines(area);
-    
+
     _pushScanLineEdge(area, &point1, &point2);
     _pushScanLineEdge(area, &point2, &point3);
     _pushScanLineEdge(area, &point3, &point1);
-    
+
     mutexAcquire(area->lock);
     _renderScanLines(area);
     mutexRelease(area->lock);
@@ -584,18 +585,18 @@ void* _renderPostProcessChunk(void* data)
             {
                 FragmentCallback callback;
                 Color col;
-                
+
                 callback = chunk->area->fragment_callbacks[fragment->flags.callback];
                 if (callback.function)
                 {
                     col = callback.function(chunk->renderer, fragment->data.location, callback.data);
-                    colorNormalize(&col);
+                    /*colorNormalize(&col);*/
                 }
                 else
                 {
                     col = COLOR_BLACK;
                 }
-                
+
                 fragment->data.color.r = col.r;
                 fragment->data.color.g = col.g;
                 fragment->data.color.b = col.b;
diff --git a/lib_paysages/render.h b/lib_paysages/render.h
index 82cdc8b..647e897 100644
--- a/lib_paysages/render.h
+++ b/lib_paysages/render.h
@@ -3,12 +3,25 @@
 
 #include <stdio.h>
 #include "shared/types.h"
-#include "renderer.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
-    
+
+typedef void (*RenderCallbackStart)(int width, int height, Color background);
+typedef void (*RenderCallbackDraw)(int x, int y, Color col);
+typedef void (*RenderCallbackUpdate)(double progress);
+
+typedef struct RenderArea RenderArea;
+
+typedef struct
+{
+    int width;
+    int height;
+    int antialias;
+    int quality;
+} RenderParams;
+
 void renderInit();
 void renderQuit();
 
diff --git a/lib_paysages/renderer.h b/lib_paysages/renderer.h
index 3a3b26e..0c60e89 100644
--- a/lib_paysages/renderer.h
+++ b/lib_paysages/renderer.h
@@ -4,6 +4,7 @@
 #include "shared/types.h"
 #include "atmosphere/public.h"
 #include "terrain/public.h"
+#include "render.h"
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/lib_paysages/shared/types.h b/lib_paysages/shared/types.h
index 65bc42b..cea7668 100644
--- a/lib_paysages/shared/types.h
+++ b/lib_paysages/shared/types.h
@@ -15,14 +15,6 @@ typedef struct LightStatus LightStatus;
 
 typedef Color (*f_RenderFragmentCallback)(struct Renderer* renderer, Vector3 location, void* data);
 
-typedef struct
-{
-    int width;
-    int height;
-    int antialias;
-    int quality;
-} RenderParams;
-
 typedef struct
 {
     int length;
@@ -39,12 +31,6 @@ typedef struct
     double shininess;
 } SurfaceMaterial;
 
-typedef void (*RenderCallbackStart)(int width, int height, Color background);
-typedef void (*RenderCallbackDraw)(int x, int y, Color col);
-typedef void (*RenderCallbackUpdate)(double progress);
-
-typedef struct RenderArea RenderArea;
-
 typedef struct
 {
     int hit;