Exercice 3 : Détection des changements multi-temporels et surveillance - suite   Classification result showing lava (white) and non-lava (black) for the Landsat images of 11 December 2001 (left) and 15 January 2003 (right). Arithmétique de bandes     Classification result showing lava (white) and non-lava (black) for the Landsat images of 11 December 2001 (left) and 15 January 2003 (right), filtered with a 5x5 median filter.