From ed2a6ce2f8a52724149dfc59e08d00db9b2bd498 Mon Sep 17 00:00:00 2001
From: cnr-isti-vclab <paolo.cignoni@isti.cnr.it>
Date: Thu, 17 Jul 2008 10:07:19 +0000
Subject: [PATCH] Added Desaturation filter and relative functions. An ENUM for
 Desaturation methods has been added too. Added EQ filter and relative
 functions. It works just on lighness right now. Comments still to be written.
 work in progress.

---
 vcg/complex/trimesh/update/color.h | 95 +++++++++++++++++++++++++++++-
 1 file changed, 93 insertions(+), 2 deletions(-)

diff --git a/vcg/complex/trimesh/update/color.h b/vcg/complex/trimesh/update/color.h
index 9cc32158..8b3d1bef 100644
--- a/vcg/complex/trimesh/update/color.h
+++ b/vcg/complex/trimesh/update/color.h
@@ -64,7 +64,8 @@ Changed name from plural to singular (normals->normal)
 #define __VCG_TRI_UPDATE_COLOR
 #include <limits>
 #include <math.h>
-#include <vcg/space/color4.h>
+#include <vcg/space/color4.h>
+#include <vcg/math/histogram.h>
 
 namespace vcg {
 namespace tri {
@@ -574,13 +575,103 @@ static int Colourisation(UpdateMeshType &m, Color4b c, float intensity, const bo
 
 static Color4b ColorApplyDiff(Color4b old_color, Color4b new_color, float intensity)
 {
-  return Color4b( ValueApplyDiff(old_color[0],new_color[0],intensity), ValueApplyDiff(old_color[1],new_color[1],intensity), ValueApplyDiff(old_color[2], new_color[2],intensity), 1);
+  return Color4b( ValueApplyDiff(old_color[0],new_color[0],intensity), ValueApplyDiff(old_color[1],new_color[1],intensity), ValueApplyDiff(old_color[2], new_color[2],intensity), 255);
 }
 
 static int ValueApplyDiff(int old_value, int new_value, float intensity)
 {
   return  math::Clamp<int>((int)(old_value + intensity * (new_value - old_value)), 0, 255);
+}
+
+static int Desaturation(UpdateMeshType &m, int method, const bool ProcessSelected=false)
+{
+  int counter=0;
+  VertexIterator vi;
+  for(vi=m.vert.begin();vi!=m.vert.end();++vi) //scan all the vertex...
+  {
+    if(!(*vi).IsD()) //if it has not been deleted...
+    {
+      if(!ProcessSelected || (*vi).IsS()) //if this vertex has been selected, do transormation
+      {
+        (*vi).C() = ColorDesaturate((*vi).C(), method);
+        ++counter;
+      }
+    }
+  }
+  return counter;
+}
+
+enum DesaturationMethods {M_LIGHTNESS = 0, M_MEAN = 1};
+
+static Color4b ColorDesaturate(Color4b c, int method)
+{
+  switch(method){
+    case M_LIGHTNESS:{
+      int val = (int)ComputeLightness(c);
+      return Color4b( val, val, val, 255);
+    }
+    case M_MEAN:{
+      int val = (int)ComputeMeanLightness(c);
+      return Color4b( val, val, val, 255);
+    }
+    default: assert(0);
+  }
+}
+
+static float ComputeMeanLightness(Color4b c)
+{
+    return float(c[0]+c[1]+c[2])/3.0f;
 }
+
+static int Equalize(UpdateMeshType &m, const bool ProcessSelected=false)
+{
+  int counter=0;
+  VertexIterator vi;
+  //FILE *fp;
+	//fp=fopen("added.txt","a+");
+  Histogramf H;
+  H.Clear();
+	H.SetRange(0, 255, 255);
+
+  for(vi=m.vert.begin();vi!=m.vert.end();++vi) //scan all the vertex...
+  {
+    if(!(*vi).IsD()) //if it has not been deleted...
+    {
+      if(!ProcessSelected || (*vi).IsS()) //if this vertex has been selected, do transormation
+      {
+        int v = (int)(ComputeLightness((*vi).C())+0.5);
+        H.Add(v);
+      }
+    }
+  }
+
+	int cdf[256];
+	cdf[0] = H.BinCount(0);
+	for(int i=1; i<256; i++){
+    cdf[i] = H.BinCount(float(i)) + cdf[i-1];
+  }
+
+  for(vi=m.vert.begin();vi!=m.vert.end();++vi) //scan all the vertex...
+  {
+    if(!(*vi).IsD()) //if it has not been deleted...
+    {
+      if(!ProcessSelected || (*vi).IsS()) //if this vertex has been selected, do transormation
+      {
+        (*vi).C()=ColorEqualize((*vi).C(), cdf[(int)(ComputeLightness((*vi).C())+0.5)], cdf[0], cdf[255]);
+        ++counter;
+      }
+    }
+  }
+  return counter;
+}
+
+static Color4b ColorEqualize(Color4b c, int cdfValue, int cdfMin, int cdfMax)
+{
+  //int v = (int)ComputeLightness(c);
+  float v = float((cdfValue - cdfMin)/float(cdfMax - cdfMin)) * 255.0f;
+
+  return Color4b( (int)v, (int)v, (int)v, 255);
+}
 
 };