In this first approach,

• the initial classification is a maximum likelihood classification, including textural features,
  
  
• followed by a second step consisting in updating the initial classification by means of
• expert knowledge for best localization of the classes searched and
• out image information (for example height, soils, proximity of roads, rivers, ...).

The technique used is an expert system approach, with rules of production for knowledge representation. This expert system is called ICARE (Image CARtography Expert) [Des91].