Efesasa0's picture
b6b6742
from src.model_parts import ResidualDoubleConv, UpSample, DownSample, EmbedFC
import torch.nn as nn
import torch
class ContextUnet(nn.Module):
def __init__(self, in_channels, features=256, context_features=10, image_size=(16, 16)):
super(ContextUnet, self).__init__()
self.in_channels = in_channels
self.features = features
self.context_features = context_features
self.height, self.width = image_size
self.init_conv = ResidualDoubleConv(in_channels, features, is_residual=True)
self.down1 = DownSample(features, features)
self.down2 = DownSample(features, 2*features)
self.to_vec = nn.Sequential(
nn.AvgPool2d((4)),
nn.GELU(),
)
self.timeembed1 = EmbedFC(1, 2*features)
self.timeembed2 = EmbedFC(1, 1*features)
self.contextembed1 = EmbedFC(context_features, 2*features)
self.contextembed2 = EmbedFC(context_features, 1*features)
self.up0 = nn.Sequential(
nn.ConvTranspose2d(2*features, 2*features, self.height//4, self.height//4),
nn.GroupNorm(8, 2*features),
nn.ReLU(),
)
self.up1 = UpSample(4*features, features)
self.up2 = UpSample(2*features, features)
self.out = nn.Sequential(
nn.Conv2d(2*features, features, 3, 1, 1),
nn.GroupNorm(8, features),
nn.ReLU(),
nn.Conv2d(features, self.in_channels, 3, 1, 1),
)
def forward(self, x, t, c=None):
x = self.init_conv(x)
down1 = self.down1(x)
down2 = self.down2(down1)
hiddenvec = self.to_vec(down2)
if c is None:
c = torch.zeros(x.shape[0], self.context_features).to(x)
cemb1 = self.contextembed1(c).view(-1, self.features*2, 1, 1)
temb1 = self.timeembed1(t).view(-1, self.features*2, 1, 1)
cemb2 = self.contextembed2(c).view(-1, self.features, 1, 1)
temb2 = self.timeembed2(t).view(-1, self.features, 1, 1)
up1 = self.up0(hiddenvec)
up2 = self.up1(cemb1*up1 + temb1, down2)
up3 = self.up2(cemb2*up2 + temb2, down1)
out = self.out(torch.cat((up3, x), 1))
return out