diff --git a/corelib/include/rtabmap/core/clams/discrete_depth_distortion_model.h b/corelib/include/rtabmap/core/clams/discrete_depth_distortion_model.h
index bfc974f1..ade192b1 100644
--- a/corelib/include/rtabmap/core/clams/discrete_depth_distortion_model.h
+++ b/corelib/include/rtabmap/core/clams/discrete_depth_distortion_model.h
@@ -66,6 +66,16 @@ namespace clams
 
   class RTABMAP_EXP DiscreteDepthDistortionModel
   {
+  public:
+    // returns all divisors of num
+    static std::set<size_t> getDivisors(const size_t &num);
+
+    // returns divisor from divisors closest to ref
+    static size_t getClosestToRef(const std::set<size_t> &divisors, const double &ref);
+
+    // sets bin_width and bin_height to appropriate values
+    static void getBinSize(const size_t &width, const size_t &height, size_t &bin_width, size_t &bin_height);
+
   public:
     DiscreteDepthDistortionModel() :
     	width_(0),
diff --git a/corelib/include/rtabmap/core/util3d.h b/corelib/include/rtabmap/core/util3d.h
index e88cadb3..65745d41 100644
--- a/corelib/include/rtabmap/core/util3d.h
+++ b/corelib/include/rtabmap/core/util3d.h
@@ -319,15 +319,6 @@ pcl::PointCloud<pcl::PointXYZ>::Ptr RTABMAP_EXP loadCloud(
 		int downsampleStep = 1,
 		float voxelSize = 0.0f);
 
-// returns all divisors of num
-std::set<size_t> get_divisors(const size_t &num);
-
-// returns divisor from divisors closest to ref
-size_t GetClosestToRef(const std::set<size_t> &divisors, const double &ref);
-
-// sets bin_width and bin_height to appropriate values
-void GetBinSize(const size_t &width, const size_t &height, size_t &bin_width, size_t &bin_height);
-
 } // namespace util3d
 } // namespace rtabmap
 
diff --git a/corelib/src/clams/discrete_depth_distortion_model.cpp b/corelib/src/clams/discrete_depth_distortion_model.cpp
index 777ad803..21d25af8 100644
--- a/corelib/src/clams/discrete_depth_distortion_model.cpp
+++ b/corelib/src/clams/discrete_depth_distortion_model.cpp
@@ -153,6 +153,57 @@ namespace clams
       UDEBUG("Frustum: multipliers=%d", multipliers_.rows());
     }
 
+  std::set<size_t> DiscreteDepthDistortionModel::getDivisors(const size_t &num)
+  {
+    std::set<size_t> divisors;
+    for(size_t i = 1; i <= num; i++)
+    {
+      if(num % i == 0)
+      {
+        divisors.insert(i);
+      }
+    }
+    return divisors;
+  }
+
+  size_t DiscreteDepthDistortionModel::getClosestToRef(const std::set<size_t> &divisors, const double &ref)
+  {
+    std::set<size_t>::iterator low, prev;
+    low = divisors.lower_bound(ref);
+    if(low == divisors.end())
+    {
+      return *(--divisors.end());
+    }
+    else if(low == divisors.begin())
+    {
+      return *low;
+    }
+    else
+    {
+      prev = low;
+      --prev;
+      if((ref - *prev) <= (*low - ref))
+      {
+        return *prev;
+      }
+      else
+      {
+        return *low;
+      }
+    }
+  }
+
+  void DiscreteDepthDistortionModel::getBinSize(const size_t &width, const size_t &height, size_t &bin_width, size_t &bin_height) {
+    double ratio = width / static_cast<double>(height);
+    std::set<size_t> divisors = getDivisors(width);
+    double ref_bin_width = 8;
+    bin_width = getClosestToRef(divisors, ref_bin_width);
+    divisors = getDivisors(height);
+    double ref_bin_height = ref_bin_width / ratio;
+    bin_height = getClosestToRef(divisors, ref_bin_height);
+  }
+
+
   DiscreteDepthDistortionModel::DiscreteDepthDistortionModel(const DiscreteDepthDistortionModel& other)
   {
     *this = other;
diff --git a/corelib/src/util3d.cpp b/corelib/src/util3d.cpp
index 688e78fe..dceef1bf 100644
--- a/corelib/src/util3d.cpp
+++ b/corelib/src/util3d.cpp
@@ -2275,56 +2275,6 @@ pcl::PointCloud<pcl::PointXYZ>::Ptr loadCloud(
 	return util3d::transformPointCloud(cloud, transform);
 }
 
-std::set<size_t> get_divisors(const size_t &num)
-{
-	std::set<size_t> divisors;
-		for(size_t i = 1; i <= num; i++)
-		{
-			if(num % i == 0)
-			{
-				divisors.insert(i);
-			}
-		}
-	return divisors;
-}
-
-size_t GetClosestToRef(const std::set<size_t> &divisors, const double &ref)
-{
-	std::set<size_t>::iterator low, prev;
-	low = divisors.lower_bound(ref);
-	if(low == divisors.end())
-	{
-		return *(--divisors.end());
-	}
-	else if(low == divisors.begin())
-	{
-		return *low;
-	}
-	else
-	{
-		prev = low;
-		--prev;
-		if((ref - *prev) <= (*low - ref))
-		{
-			return *prev;
-		}
-		else
-		{
-			return *low;
-		}
-	}
-}
-
-void GetBinSize(const size_t &width, const size_t &height, size_t &bin_width, size_t &bin_height) {
-	double ratio = width / static_cast<double>(height);
-	std::set<size_t> divisors = get_divisors(width);
-	double ref_bin_width = 8;
-	bin_width = GetClosestToRef(divisors, ref_bin_width);
-	divisors = get_divisors(height);
-	double ref_bin_height = ref_bin_width / ratio;
-	bin_height = GetClosestToRef(divisors, ref_bin_height);
-}
-
 }
 
 }
diff --git a/guilib/src/DepthCalibrationDialog.cpp b/guilib/src/DepthCalibrationDialog.cpp
index 57bfc726..53faec50 100644
--- a/guilib/src/DepthCalibrationDialog.cpp
+++ b/guilib/src/DepthCalibrationDialog.cpp
@@ -392,7 +392,7 @@ void DepthCalibrationDialog::calibrate(
 			if(_model == 0)
 			{
 				size_t bin_width, bin_height;
-				util3d::GetBinSize(imageSize.width, imageSize.height, bin_width, bin_height);
+                                clams::DiscreteDepthDistortionModel::getBinSize(imageSize.width, imageSize.height, bin_width, bin_height);
 				_model = new clams::DiscreteDepthDistortionModel(imageSize.width, imageSize.height, bin_width, bin_height);
 			}
 			UASSERT(_model->getWidth() == imageSize.width && _model->getHeight() == imageSize.height);