How to set different levels of the mask in y_train_dir as mask[..., 0], mask[..., 1] ... ?

[jtyytim]

Hello,

For the multi-class segmentation, I want to know how to set different levels of the mask in y_train_dir as mask[..., 0], mask[..., 1] ... like that? Can you explain how to realize it with my own data?

Thanks, Thiem