Spaces:
Sleeping
Sleeping
File size: 2,326 Bytes
68c537d |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 |
import torch.nn as nn
import torch
from torchvision import models
class Vgg19(torch.nn.Module):
def __init__(self, requires_grad=False):
super(Vgg19, self).__init__()
vgg_pretrained_features = models.vgg19(pretrained=True).features
self.slice1 = torch.nn.Sequential()
self.slice2 = torch.nn.Sequential()
self.slice3 = torch.nn.Sequential()
self.slice4 = torch.nn.Sequential()
self.slice5 = torch.nn.Sequential()
for x in range(2):
self.slice1.add_module(str(x), vgg_pretrained_features[x])
for x in range(2, 7):
self.slice2.add_module(str(x), vgg_pretrained_features[x])
for x in range(7, 12):
self.slice3.add_module(str(x), vgg_pretrained_features[x])
for x in range(12, 21):
self.slice4.add_module(str(x), vgg_pretrained_features[x])
for x in range(21, 30):
self.slice5.add_module(str(x), vgg_pretrained_features[x])
if not requires_grad:
for param in self.parameters():
param.requires_grad = False
def forward(self, X):
h_relu1 = self.slice1(X)
h_relu2 = self.slice2(h_relu1)
h_relu3 = self.slice3(h_relu2)
h_relu4 = self.slice4(h_relu3)
h_relu5 = self.slice5(h_relu4)
return [h_relu1, h_relu2, h_relu3, h_relu4, h_relu5]
class ContrastLoss(nn.Module):
def __init__(self, ablation=False):
super(ContrastLoss, self).__init__()
self.vgg = Vgg19().cuda()
self.l1 = nn.L1Loss()
self.weights = [1.0/32, 1.0/16, 1.0/8, 1.0/4, 1.0]
self.ab = ablation
def forward(self, a, p, n):
a_re = a.repeat(1, 3, 1, 1)
p_re = p.repeat(1, 3, 1, 1)
n_re = n.repeat(1, 3, 1, 1)
a_vgg, p_vgg, n_vgg = self.vgg(a_re), self.vgg(p_re), self.vgg(n_re)
loss = 0
d_ap, d_an = 0, 0
for i in range(len(a_vgg)):
d_ap = self.l1(a_vgg[i], p_vgg[i].detach())
if not self.ab:
d_an = self.l1(a_vgg[i], n_vgg[i].detach())
contrastive = d_ap / (d_an + 1e-7)
else:
contrastive = d_ap
loss += self.weights[i] * contrastive
return loss
|