ETUDE COMPARATIVE DE METHODES DE CLASSIFICATION 
POUR LES SOLS ET LES VEGETAUX 
C. Morzier, P. Meylan, A. Musy 
Institut de Génie Rural 
Ecole Polytechnique Fédérale de Lausanne (Suisse) 
Abstract 
Presentation of the complete data processing system of numerical 
pictures for soils and crops classification. Three different data sets are 
used for these studies: ground truth data for soil and vegetation, remote 
sensing data collected by an areoplane multispectral scanner, and areal 
photographies. The multispectral data are controlled by different statis- 
tical methods and with a visual examination of a computer print-out. The 
conventional photographies are digitized with an electro-optical camera 
  
connected to a mini-computer. 
The software package of the AEI includes several classification 
programs using supervised and unsupervised technics. For a supervised 
classification, the sample processing is done with ground truth data, 
visualisation and areal photographies. The quality of the sample technic 
is increased by using a descriptive discrimination based on a hierarchical 
clustering and a decisional discrimination of the samples. Three supervi- 
sed classifications schemas are used: Sebestyen's classification, rectan- 
gular and barycentric methods. The results of these classifications are 
compared to the ground truth data of several verifications test field. So, 
it is possible to compare the performances of the algorithms used.