The implemented architecture is taken from the work in . The number of classes used in this specific model is 2. It can be modified by changing the number of filters in the last convolutional layer based on your needs.
 Vijay Badrinarayanan, Alex Kendall, and Roberto Cipolla. SegNet: A deep convolutional encoderdecoder architecture for image segmentation. arxiv:1511.00561, 2015.