sgm/modules/autoencoding/lpips/vqperceptual.py

import torch
import torch.nn.functional as F


def hinge_d_loss(logits_real, logits_fake):
    loss_real = torch.mean(F.relu(1.0 - logits_real))
    loss_fake = torch.mean(F.relu(1.0 + logits_fake))
    d_loss = 0.5 * (loss_real + loss_fake)
    return d_loss


def vanilla_d_loss(logits_real, logits_fake):
    d_loss = 0.5 * (
        torch.mean(torch.nn.functional.softplus(-logits_real))
        + torch.mean(torch.nn.functional.softplus(logits_fake))
    )
    return d_loss