"""
Copyright (C) 2019 NVIDIA Corporation. All rights reserved.
Licensed under the CC BY-NC-SA 4.0 license (https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode).
"""
import torch
import torch.nn as nn
import torch.nn.functional as F
import torchvision
import torch.nn.utils.spectral_norm as spectral_norm
from models.networks.normalization import SPADE
class SPADEResnetBlock(nn.Module):
def __init__(self, fin, fout, opt, semantic_nc=None):
super().__init__()
self.learned_shortcut = (fin != fout)
fmiddle = min(fin, fout)
if semantic_nc is None:
semantic_nc = opt.semantic_nc
self.conv_0 = nn.Conv2d(fin, fmiddle, kernel_size=3, padding=1)
self.conv_1 = nn.Conv2d(fmiddle, fout, kernel_size=3, padding=1)
if self.learned_shortcut:
self.conv_s = nn.Conv2d(fin, fout, kernel_size=1, bias=False)
if 'spectral' in opt.norm_G:
self.conv_0 = spectral_norm(self.conv_0)
self.conv_1 = spectral_norm(self.conv_1)
if self.learned_shortcut:
self.conv_s = spectral_norm(self.conv_s)
spade_config_str = opt.norm_G.replace('spectral', '')
self.norm_0 = SPADE(spade_config_str, fin, semantic_nc)
self.norm_1 = SPADE(spade_config_str, fmiddle, semantic_nc)
if self.learned_shortcut:
self.norm_s = SPADE(spade_config_str, fin, semantic_nc)
def forward(self, x, seg):
x_s = self.shortcut(x, seg)
dx = self.conv_0(self.actvn(self.norm_0(x, seg)))
dx = self.conv_1(self.actvn(self.norm_1(dx, seg)))
out = x_s + dx
return out
def shortcut(self, x, seg):
if self.learned_shortcut:
x_s = self.conv_s(self.norm_s(x, seg))
else:
x_s = x
return x_s
def actvn(self, x):
return F.leaky_relu(x, 2e-1)
class ResnetBlock(nn.Module):
def __init__(self, dim, norm_layer, activation=nn.ReLU(False), kernel_size=3):
super().__init__()
pw = (kernel_size - 1) // 2
self.conv_block = nn.Sequential(
nn.ReflectionPad2d(pw),
norm_layer(nn.Conv2d(dim, dim, kernel_size=kernel_size)),
activation,
nn.ReflectionPad2d(pw),
norm_layer(nn.Conv2d(dim, dim, kernel_size=kernel_size))
)
def forward(self, x):
y = self.conv_block(x)
out = x + y
return out
class VGG19(torch.nn.Module):
def __init__(self, requires_grad=False):
super().__init__()
vgg_pretrained_features = torchvision.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)
out = [h_relu1, h_relu2, h_relu3, h_relu4, h_relu5]
return out