hey, i have a serious prob wish is the combination of 6 layers that represent a classification results for each class. So the goal is to have one image that combine the overall classes for the Accuracy assessment procedure. the same process will be applied to other group of layer for label two (12 layers) and label 3 (18 layers). i tray to use arcgis for that procedure using the mosaic tool, and it doesn't work. Map algebra also doesn't give result (using merge and mosaic function). So please help me up to figure out a solution for that issues.