Many techniques of image processing have been developed to analyse more precisely geological information obtained from satellites. SPOT, which is a recent project in France, will furnish stereoscopic image, with good resolution of surfaces(20m $ imes$ 20m or 10m $ imes$ 10m), and give altitudes(DEM) which can be restored automatically. One of the researches for the exploitation of this data, intends to recognize and distinguish automatically the geomorphological forms, containing important geological information from DEM. Along which the information obtained obtained from image processing, it will play an important role in the understanding of the surface of the terrain. This study was carried out in collaboration with University of Paris-6 and Ecole National des Sciences G$'{e}$ographiques(Institute G$'{e}$ographique National of France: IGN).