About binary classification problem (a target class and background)

[fengxfeng0]

Hello, author! I'm very interested in your work.
Recently I was trying to do a binary weakly supervised segmentation task with your code (containing only one target class and the rest as background), but I ran into some problems, such as:
(1) num_class is set to 1 or 2;
(2) How to set the label
I experimented with num_class set to 2 (because setting to 1 seemed to give an error), but the results were poor (not as good as the original IRN method), so I wanted to ask if this work was appropriate for my task.
Thank you and look forward to your reply!