using map instead of multimap for motion estimation methods (only unique words were used)

utilite/include/rtabmap/utilite/UStl.h

@@ -470,6 +470,15 @@ inline std::list<V> uVectorToList(const std::vector<V> & v)
 	return std::list<V>(v.begin(), v.end());
 }
 
+/**
+ * Convert a std::multimap to a std::map
+ */
+template<class K, class V>
+inline std::map<K, V> uMultimapToMap(const std::multimap<K, V> & m)
+{
+	return std::map<K, V>(m.begin(), m.end());
+}
+
 /**
  * Append a list to another list.
  * @param list the list on which the other list will be appended