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Running
on
Zero
Running
on
Zero
File size: 1,137 Bytes
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import torch
from torch import nn
def get_loss(name):
if name == "cosface":
return CosFace()
elif name == "arcface":
return ArcFace()
else:
raise ValueError()
class CosFace(nn.Module):
def __init__(self, s=64.0, m=0.40):
super(CosFace, self).__init__()
self.s = s
self.m = m
def forward(self, cosine, label):
index = torch.where(label != -1)[0]
m_hot = torch.zeros(index.size()[0], cosine.size()[1], device=cosine.device)
m_hot.scatter_(1, label[index, None], self.m)
cosine[index] -= m_hot
ret = cosine * self.s
return ret
class ArcFace(nn.Module):
def __init__(self, s=64.0, m=0.5):
super(ArcFace, self).__init__()
self.s = s
self.m = m
def forward(self, cosine: torch.Tensor, label):
index = torch.where(label != -1)[0]
m_hot = torch.zeros(index.size()[0], cosine.size()[1], device=cosine.device)
m_hot.scatter_(1, label[index, None], self.m)
cosine.acos_()
cosine[index] += m_hot
cosine.cos_().mul_(self.s)
return cosine
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