DOC: Adding doxygen documentation for new functions

Modules/Core/ImageBase/include/otbNoDataHelper.h

@@ -53,6 +53,18 @@ std::vector<bool> & flags, const std::vector<double> & values) {
 }
 
 /**
+* Reads a pixel and change the no data value if it is found. No data
+* value is changed either if the pixel value is NaN or if the pixel
+* value equals the no data value and flag is true.
+* 
+* \param pixel The pixel to process \param flags A vector of size > 1
+* containing a flag per band to indicate if a no data value is
+* available for this band
+* \param values A vector of size > 1 corresponding to the current no data
+* value for each band. If flag is 0, the value will be ignored.
+* \param newValues A vector of size > 1 corresponding to the new no data
+* value for each band. If flag is 0, the value will be ignored. 
+*
 */
 template<typename T> T ChangeNoData(const T & pixel, const
                                     std::vector<bool> & flags,
@@ -99,6 +111,10 @@ template <typename T> bool IsNoData(const itk::VariableLengthVector<T> & pixel,
   return false;
 }
 
+
+/**
+ * Specialization of ChangeNoData function to handle itk::VariableLengthVector
+ */
 template <typename T> itk::VariableLengthVector<T> ChangeNoData(const itk::VariableLengthVector<T> & pixel,
                                                                 const std::vector<bool> & flags,
                                                                 const std::vector<double> & values,