Definiens Developer 7 - PCI Geomatics

Definiens Developer 7 - Reference Book3 Algorithms Reference3.3 Basic Classification AlgorithmsClassification algorithms analyze image objects according defined criteria and assignthem each to a class that best meets the defined criteria.3.3.1 Assign ClassAssign all objects of the image object domain to the class specified by the Use classparameter. The membership value for the assigned class is set to 1 for all objectsindependent of the class description. The second and third best classification results areset to 0 .assign classUse classSelect the class for the assignment from the drop-down list box. You can also create anew class for the assignment within the drop-down list.3.3.2 ClassificationEvaluates the membership value of an image object to a list of selected classes. Theclassification result of the image object is updated according to the class evaluationresult. The three best classes are stored in the image object classification result. Classeswithout a class description are assumed to have a membership value of 1.classificationActive classesChoose the list of active classes for the classification.Erase old classification, if there is no new classificationValueYesNoDescriptionIf the membership value of the image object is below the acceptance threshold(see classification settings) for all classes, the current classification of the imageobject is deleted.If the membership value of the image object is below the acceptance threshold(see classification settings) for all classes, the current classification of the imageobject is kept.Use Class DescriptionValueYesNoDescriptionClass descriptions are evaluated for all classes. The image object is assigned to theclass with the highest membership value.Class descriptions are ignored. This option delivers valuable results only if Activeclasses contains exactly one class.If you do not use the class description, it is recommended to use the algorithm assignclass algorithm instead. Assign Class on page 2828