diff --git a/src/colorred.c b/src/colorred.c
index 4eaacc44..bdebd672 100644
--- a/src/colorred.c
+++ b/src/colorred.c
@@ -34,23 +34,24 @@ but :
   * No loss of precision
 */
 
-CT_Node* CT_new() {return NULL;}
+CT_Tree* CT_new() {return calloc(1, sizeof(CT_Tree));}
 
 // debug helper
+/*
 void CT_Print(CT_Node* node)
 {
 	printf("R %d %d\tG %d %d\tB %d %d\ti %d\n",
 		node->Rmin, node->Rmax, node->Gmin, node->Gmax,
 		node->Bmin, node->Bmax, node->index);
 }
+*/
 
-void CT_set(CT_Node** colorTree, byte Rmin, byte Gmin, byte Bmin,
+void CT_set(CT_Tree* colorTree, byte Rmin, byte Gmin, byte Bmin,
 	byte Rmax, byte Gmax, byte Bmax, byte index)
 {
-	int i;
 	CT_Node* parent;
 	// Create and setup node
-	CT_Node* node = malloc(sizeof(CT_Node));
+	CT_Node* node = &colorTree->nodes[++colorTree->nodecount];
 	
 	node->Rmin = Rmin;
 	node->Gmin = Gmin;
@@ -58,20 +59,11 @@ void CT_set(CT_Node** colorTree, byte Rmin, byte Gmin, byte Bmin,
 	node->Rmax = Rmax;
 	node->Gmax = Gmax;
 	node->Bmax = Bmax;
-	node->index = index;
-	
-	printf("Add node:");
-	CT_Print(node);
-	
-	for(i = 0; i < 2; i++)
-		node->children[i] = NULL;
+	node->children[1] = index;
 	
 	// Now insert it in tree
-	parent = *colorTree;
-	if (parent == NULL) {
-		// This is our first node.
-		*colorTree = node;
-	} else for(;;) {
+	parent = &colorTree->nodes[0];
+	if (parent != NULL) for(;;) {
 		// Find where to insert ourselves
 		
 		// pre-condition: the parent we're looking at is a superset of the node we're inserting
@@ -81,12 +73,12 @@ void CT_set(CT_Node** colorTree, byte Rmin, byte Gmin, byte Bmin,
 		// 1 child: either we're included in the child, and recurse, or we''re not, and insert at child 1
 		// 2 child: one of them has to be a superset of the node.
 		
-		if (parent->children[0] == NULL)
+		if (parent->children[0] == 0)
 		{
-			parent->children[0] = node;	
+			parent->children[0] = colorTree->nodecount;	
 			break;
 		} else {
-			CT_Node* child0 = parent->children[0];
+			CT_Node* child0 = &colorTree->nodes[parent->children[0]];
 			if (child0->Rmin <= node->Rmin
 				&& child0->Gmin <= node->Gmin
 				&& child0->Bmin <= node->Bmin
@@ -95,28 +87,31 @@ void CT_set(CT_Node** colorTree, byte Rmin, byte Gmin, byte Bmin,
 				&& child0->Bmax >= node->Bmax
 			) {
 				parent = child0;
-			} else if(parent->children[1] == NULL)
+			} else if(parent->children[1] == 0)
 			{
-				parent->children[1] = node;	
+				parent->children[1] = colorTree->nodecount;	
 				break;
 			} else {
-				parent = parent->children[1];
+				parent = &colorTree->nodes[parent->children[1]];
 			}
 		}
 	}
 }
 
-byte CT_get(CT_Node* node, byte r, byte g, byte b)
+byte CT_get(CT_Tree* tree, byte r, byte g, byte b)
 {	
 	// pre condition: node contains (rgb)
 	// find the leaf that also contains (rgb)
 	
+	CT_Node* node = &tree->nodes[0];
+	
 	for(;;) {
-		if(node->children[0] == NULL)
-			return node->index;
+		if(node->children[0] == 0)
+			// return the palette index
+			return node->children[1];
 		else {
 			// Left or right ?
-			CT_Node* child0 = node->children[0];
+			CT_Node* child0 = &tree->nodes[node->children[0]];
 			if (child0->Rmin <= r
 				&& child0->Gmin <= g
 				&& child0->Bmin <= b
@@ -128,20 +123,13 @@ byte CT_get(CT_Node* node, byte r, byte g, byte b)
 				node = child0;
 			} else {
 				// right
-				node = node->children[1];
+				node = &tree->nodes[node->children[1]];
 			}
 		}
 	}
 }
 
-void CT_delete(CT_Node* tree)
+void CT_delete(CT_Tree* tree)
 {
-	int i;
-	if (tree == NULL)
-		return;
-	for	(i = 0; i < 2; i++)
-	{
-		CT_delete(tree->children[i]);
-	}
 	free(tree);
 }
diff --git a/src/colorred.h b/src/colorred.h
index 62d1ea12..b1927c1f 100644
--- a/src/colorred.h
+++ b/src/colorred.h
@@ -55,17 +55,22 @@ typedef struct CT_Node_s
 	// * makes them smaller
 	// * helps with cache locality
 	
-	// palette index (valid iff any child is NULL)
-	byte index;
-	
-	// child nodes
-	struct CT_Node_s* children[2];
+	// Child nodes :
+	// Either two indices in the colorTree array, or
+	// 0 and a palette index
+	// 0 is not a valid array index, because no node points to the root !
+	word children[2];
 } CT_Node;
 
-CT_Node* CT_new();
-void CT_delete(CT_Node* t);
-byte CT_get(CT_Node* t,byte r,byte g,byte b);
-void CT_set(CT_Node** colorTree, byte Rmin, byte Gmin, byte Bmin,
+typedef struct ColorTree_S {
+	short nodecount;
+	CT_Node nodes[511];
+} CT_Tree;
+
+CT_Tree* CT_new();
+void CT_delete(CT_Tree* t);
+byte CT_get(CT_Tree* t,byte r,byte g,byte b);
+void CT_set(CT_Tree* colorTree, byte Rmin, byte Gmin, byte Bmin,
 	byte Rmax, byte Gmax, byte Bmax, byte index);
 
 #endif
diff --git a/src/op_c.c b/src/op_c.c
index 7f6ce582..f8744f51 100644
--- a/src/op_c.c
+++ b/src/op_c.c
@@ -435,11 +435,9 @@ ENDCRUSH:
   c->bmin=bmin;     c->bmax=bmax;
   
   // Find the longest axis to know which way to split the cluster
-  // This multiplications are supposed to improve the result, but may or may not
-  // work, actually.
-  r=(c->rmax-c->rmin)*299;
-  g=(c->vmax-c->vmin)*587;
-  b=(c->bmax-c->bmin)*114;
+  r=(c->rmax-c->rmin);
+  g=(c->vmax-c->vmin);
+  b=(c->bmax-c->bmin);
 
   if (g>=r)
   {
@@ -796,7 +794,7 @@ void CS_Set(T_Cluster_set * cs,T_Cluster * c)
 // 5) We take the box with the biggest number of pixels inside and we split it again
 // 6) Iterate until there are 256 boxes. Associate each of them to its middle color
 // At the same time, put the split clusters in the color tree for later palette lookup
-void CS_Generate(T_Cluster_set * cs, T_Occurrence_table * to, CT_Node** colorTree)
+void CS_Generate(T_Cluster_set * cs, T_Occurrence_table * to, CT_Tree* colorTree)
 {
   T_Cluster current;
   T_Cluster Nouveau1;
@@ -911,7 +909,7 @@ void CS_Sort_by_luminance(T_Cluster_set * cs)
 
 
 /// Generates the palette from the clusters, then the conversion table to map (RGB) to a palette index
-void CS_Generate_color_table_and_palette(T_Cluster_set * cs,CT_Node** tc,T_Components * palette)
+void CS_Generate_color_table_and_palette(T_Cluster_set * cs,CT_Tree* tc,T_Components * palette)
 {
   int index;
   T_Cluster* current = cs->clusters;
@@ -1034,11 +1032,11 @@ void GS_Generate(T_Gradient_set * ds,T_Cluster_set * cs)
 
 
 /// Compute best palette for given picture.
-CT_Node* Optimize_palette(T_Bitmap24B image, int size,
+CT_Tree* Optimize_palette(T_Bitmap24B image, int size,
   T_Components * palette, int r, int g, int b)
 {	
   T_Occurrence_table * to;
-  CT_Node* tc;
+  CT_Tree* tc;
   T_Cluster_set * cs;
   T_Gradient_set * ds;
 
@@ -1050,13 +1048,13 @@ CT_Node* Optimize_palette(T_Bitmap24B image, int size,
     return 0;
 
   tc = CT_new();
-  /*
+  
   if (tc == NULL)
   {
   	OT_delete(to);
   	return NULL;
   }
-*/
+
   // Count pixels for each color
   OT_count_occurrences(to, image, size);
 
@@ -1071,7 +1069,7 @@ CT_Node* Optimize_palette(T_Bitmap24B image, int size,
   // Ok, everything was allocated
 
   // Generate the cluster set with median cut algorithm
-  CS_Generate(cs, to, &tc);
+  CS_Generate(cs, to, tc);
   //CS_Check(cs);
 
   // Compute the color data for each cluster (palette entry + HL)
@@ -1091,7 +1089,7 @@ CT_Node* Optimize_palette(T_Bitmap24B image, int size,
   //CS_Check(cs);
   
   // And finally generate the conversion table to map RGB > pal. index
-  CS_Generate_color_table_and_palette(cs, &tc, palette);
+  CS_Generate_color_table_and_palette(cs, tc, palette);
   //CS_Check(cs);
   
   CS_Delete(cs);
@@ -1119,7 +1117,7 @@ int Modified_value(int value,int modif)
 /// Convert a 24b image to 256 colors (with a given palette and conversion table)
 /// This destroys the 24b picture !
 /// Uses floyd steinberg dithering.
-void Convert_24b_bitmap_to_256_Floyd_Steinberg(T_Bitmap256 dest,T_Bitmap24B source,int width,int height,T_Components * palette,CT_Node* tc)
+void Convert_24b_bitmap_to_256_Floyd_Steinberg(T_Bitmap256 dest,T_Bitmap24B source,int width,int height,T_Components * palette,CT_Tree* tc)
 {
   T_Bitmap24B current;
   T_Bitmap24B c_plus1;
@@ -1215,7 +1213,7 @@ void Convert_24b_bitmap_to_256_Floyd_Steinberg(T_Bitmap256 dest,T_Bitmap24B sour
 /// Converts from 24b to 256c without dithering, using given conversion table
 void Convert_24b_bitmap_to_256_nearest_neighbor(T_Bitmap256 dest,
   T_Bitmap24B source, int width, int height, __attribute__((unused)) T_Components * palette,
-  CT_Node* tc)
+  CT_Tree* tc)
 {
   T_Bitmap24B current;
   T_Bitmap256 d;
@@ -1274,7 +1272,7 @@ int Convert_24b_bitmap_to_256(T_Bitmap256 dest,T_Bitmap24B source,int width,int
   return Convert_24b_bitmap_to_256_fast(dest, source, width, height, palette);  
 
   #else
-  CT_Node* table; // table de conversion
+  CT_Tree* table; // table de conversion
   int                ip;    // index de précision pour la conversion
 
   // On essaye d'obtenir une table de conversion qui loge en mémoire, avec la
diff --git a/src/op_c.h b/src/op_c.h
index 161e77c5..de7d4d6b 100644
--- a/src/op_c.h
+++ b/src/op_c.h
@@ -158,9 +158,9 @@ T_Cluster_set * CS_New(int nbmax,T_Occurrence_table * to);
 void CS_Delete(T_Cluster_set * cs);
 void CS_Get(T_Cluster_set * cs,T_Cluster * c);
 void CS_Set(T_Cluster_set * cs,T_Cluster * c);
-void CS_Generate(T_Cluster_set * cs,T_Occurrence_table * to, CT_Node** colorTree);
+void CS_Generate(T_Cluster_set * cs,T_Occurrence_table * to, CT_Tree* colorTree);
 void CS_Compute_colors(T_Cluster_set * cs,T_Occurrence_table * to);
-void CS_Generate_color_table_and_palette(T_Cluster_set * cs,CT_Node** tc,T_Components * palette);
+void CS_Generate_color_table_and_palette(T_Cluster_set * cs,CT_Tree* tc,T_Components * palette);
 
 /////////////////////////////////////////////////////////////////////////////
 //////////////////////////// Méthodes de gestion des ensembles de dégradés //