About num_classes

[Oktai15]

Hello, @ternaus!
Thanks for your code, it's really cool, but meaning of num_classes, for instance, in Unet16, isn't clear.

If I have car and background then I consider that image has 2 num_classes: 0 - background and 1 - car. But according to your code, in my example, you suppose that image has only one class. Why?

Thanks in advance.