ABSTRACT
For a processing technique to be applicable to any investigation, the best possible images should be chosen according to the objectives, environment and theme. An image processing not suited to the objective pursued does not provide correct answers. The processing techniques employed are often those given in available software’s. Hence, it is particularly important when purchasing the software to check that it is compatible with the problems to be solved. The image processing results ought to be evaluated from the semantic as well as graphic point of view. It is important to interpret the shape of the map zones obtained for each landscape unit and thematic group. This is carried out by analysis of shape criteria (perimeter and surface area), readily obtained, especially when a geographic information system is available. Collection of such information is often a long process but must be entirely reliable since the type of classification, method and procedure recommended are based on it.
