DOC: added reference to the algorithm

Modules/Filtering/DimensionalityReduction/include/otbFastICAImageFilter.h

@@ -28,11 +28,16 @@
 namespace otb
 {
 /** \class FastICAImageFilter
- * \brief Performs a Independent Component Analysis
- *
- * The internal structure of this filter is a filter-to-filter like structure.
- * The estimation of the covariance matrix has persistent capabilities...
+ * \brief Performs a Independent Component Analysis (ICA)
  *
+ * This filter is an implementation of the stabilized fixed-point FastICA
+ * algorithm described in [1] with a symetric decorrelation at each step.
+ * 
+ * The contrast function and its derivative can be supplied to the filter as 
+ * lambda functions.
+ * 
+ * [1] Fast and robust fixed-point algorithms for independent component analysis
+ * 
  * \sa PCAImageFilter
  *
  * \ingroup OTBDimensionalityReduction
@@ -195,7 +200,7 @@ protected:
   unsigned int m_NumberOfIterations; // def is 50
   double m_ConvergenceThreshold; // def is 1e-4
   ContrastFunctionType m_ContrastFunction; // see g() function in the biblio. Def is tanh
-  ContrastFunctionType m_ContrastFunctionDerivative; 
+  ContrastFunctionType m_ContrastFunctionDerivative; // derivative of g().
   double m_Mu; // def is 1. in [0, 1]
 
   PCAFilterPointerType m_PCAFilter;