Lugi OP t1_iqodhe1 wrote on October 1, 2022 at 10:05 PM

Reply to comment by VenerableSpace_ in [D] Focal loss - why it scales down the loss of minority class? by Lugi

Yes, but the problem here is while they mention that in the paper, finally they use alpha of 0.25, which weighs down the minority (foreground) - while the background (majority) class has scaling of 0.75. This is what I'm concerned about.

VenerableSpace_ t1_iqorbnu wrote on October 1, 2022 at 11:53 PM

Ahh I see now, its been a while since I read that paper. So they chalk it down to the interaction between alpha and the focal term. You can see how they need to use a non-intuitive value for alpha when they introduce the focal loss term in tab. 1b. especially when gamma > 0.5