2. IMAGE CLASSIFICATION
Image classification is an integral part of image processing. in remote sensing, supervised and non-supervised classifications are all based on spectral information. ENVI in this regard has better parameter setting, choices of classification and more diverse methods. For example, Isodata algorithm in ERDAS software needs six parameters, while ENVI needs 10 parameters. It is crystal clear that ENVI is better in classification. ENVI also shows better controls in non-supervised classification. ERDAS only provides one Isodata algorithm while ENVI provides two; in supervised classification ERDAS provides three algorithms while ENVI provides six.