Depth calibration: move GetBinSize to clams namespace

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),