ENH: Adding a method in medata interface base class to retrieve no data flags and values

Modules/Core/Metadata/include/otbImageMetadataInterfaceBase.h

@@ -107,6 +107,12 @@ public:
   double GetGCPZ(unsigned int GCPnum) const;
 //  otbMetadataGetGCPnumMacro(GCPZ, double, GCPnum, unsigned int);
 
+  /** 
+   * Get The no data flags if existing
+   * return False otherwise
+   */
+  bool GetNoDataFlags(std::vector<bool> & flags, std::vector<double> & values) const;
+
   /** Get the six coefficients of affine geoTtransform. */
 
   VectorType GetGeoTransform() const;

Modules/Core/Metadata/src/otbImageMetadataInterfaceBase.cxx

@@ -222,6 +222,17 @@ ImageMetadataInterfaceBase::GetGCPZ(unsigned int GCPnum) const
   else return (0);
 }
 
+bool
+ImageMetadataInterfaceBase::GetNoDataFlags(std::vector<bool> & flags, std::vector<double> & values) const
+{
+  bool ret = itk::ExposeMetaData<std::vector<bool> >(this->GetMetaDataDictionary(),MetaDataKey::NoDataValueAvailable,flags);
+
+  if (ret)
+    ret = itk::ExposeMetaData<std::vector<double> >(this->GetMetaDataDictionary(),MetaDataKey::NoDataValue,values);
+
+  return ret;
+}
+
 ImageMetadataInterfaceBase::VectorType
 ImageMetadataInterfaceBase::GetGeoTransform() const
 {