import torch
import torch.nn as nn
from torchvision import models
import torch.nn.functional as F
from functools import partial
class DecoderBlock(nn.Module):
def __init__(self, in_channels, n_filters):
super(DecoderBlock, self).__init__()
self.conv1 = nn.Conv2d(in_channels, in_channels // 4, 1)
self.norm1 = nn.BatchNorm2d(in_channels // 4)
self.relu1 = nonlinearity
self.deconv2 = nn.ConvTranspose2d(in_channels // 4, in_channels // 4, 3, stride=2, padding=1, output_padding=1)
self.norm2 = nn.BatchNorm2d(in_channels // 4)
self.relu2 = nonlinearity
self.conv3 = nn.Conv2d(in_channels // 4, n_filters, 1)
self.norm3 = nn.BatchNorm2d(n_filters)
self.relu3 = nonlinearity
def forward(self, x):
x = self.conv1(x)
x = self.norm1(x)
x = self.relu1(x)
x = self.deconv2(x)
x = self.norm2(x)
x = self.relu2(x)
x = self.conv3(x)
x = self.norm3(x)
x = self.relu3(x)
return x
class CE_Net_(nn.Module):
def __init__(self, num_classes=Constants.BINARY_CLASS, num_channels=3):
super(CE_Net_, self).__init__()
filters = [64, 128, 256, 512]
resnet = models.resnet34(pretrained=True)
self.firstconv = resnet.conv1
self.firstbn = resnet.bn1
self.firstrelu = resnet.relu
self.firstmaxpool = resnet.maxpool
self.encoder1 = resnet.layer1
self.encoder2 = resnet.layer2
self.encoder3 = resnet.layer3
self.encoder4 = resnet.layer4
self.dblock = DACblock(512)
self.spp = SPPblock(512)
self.decoder4 = DecoderBlock(516, filters[2])
self.decoder3 = DecoderBlock(filters[2], filters[1])
self.decoder2 = DecoderBlock(filters[1], filters[0])
self.decoder1 = DecoderBlock(filters[0], filters[0])
self.finaldeconv1 = nn.ConvTranspose2d(filters[0], 32, 4, 2, 1)
self.finalrelu1 = nonlinearity
self.finalconv2 = nn.Conv2d(32, 32, 3, padding=1)
self.finalrelu2 = nonlinearity
self.finalconv3 = nn.Conv2d(32, num_classes, 3, padding=1)
def forward(self, x):
# Encoder
x = self.firstconv(x)
x = self.firstbn(x)
x = self.firstrelu(x)
x = self.firstmaxpool(x)
e1 = self.encoder1(x)
e2 = self.encoder2(e1)
e3 = self.encoder3(e2)
e4 = self.encoder4(e3)
# Center
e4 = self.dblock(e4)
e4 = self.spp(e4)
# Decoder
d4 = self.decoder4(e4) + e3
d3 = self.decoder3(d4) + e2
d2 = self.decoder2(d3) + e1
d1 = self.decoder1(d2)
out = self.finaldeconv1(d1)
out = self.finalrelu1(out)
out = self.finalconv2(out)
out = self.finalrelu2(out)
out = self.finalconv3(out)
return out
UNet
class double_conv(nn.Module):
def __init__(self, in_ch, out_ch):
super(double_conv, self).__init__()
self.conv = nn.Sequential(
nn.Conv2d(in_ch, out_ch, kernel_size=3, padding=1),
nn.BatchNorm2d(out_ch),
nn.ReLU(inplace=True),
nn.Conv2d(out_ch, out_ch, kernel_size=3, padding=1),
nn.BatchNorm2d(out_ch),
nn.ReLU(inplace=True)
)
def forward(self, x):
x = self.conv(x)
return x
class inconv(nn.Module):
def __init__(self, in_ch, out_ch):
super(inconv, self).__init__()
self.conv = double_conv(in_ch, out_ch)
def forward(self, x):
x = self.conv(x)
return x
class down(nn.Module):
def __init__(self, in_ch, out_ch):
super(down, self).__init__()
self.max_pool_conv = nn.Sequential(
nn.MaxPool2d(2),
double_conv(in_ch, out_ch)
)
def forward(self, x):
x = self.max_pool_conv(x)
return x
class up(nn.Module):
def __init__(self, in_ch, out_ch, bilinear=True):
super(up, self).__init__()
if bilinear:
self.up = nn.Upsample(scale_factor=2, mode='bilinear', align_corners=True)
else:
self.up = nn.ConvTranspose2d(in_ch // 2, in_ch // 2, 2, stride=2)
self.conv = double_conv(in_ch, out_ch)
def forward(self, x1, x2):
x1 = self.up(x1)
x = torch.cat([x2, x1], dim=1)
x = self.conv(x)
return x
class outconv(nn.Module):
def __init__(self, in_ch, out_ch):
super(outconv, self).__init__()
self.conv = nn.Conv2d(in_ch, out_ch, kernel_size=1)
def forward(self, x):
x = self.conv(x)
return x
class UNet(nn.Module):
def __init__(self, n_channels=3, n_classes=1):
super(UNet, self).__init__()
self.inc = inconv(n_channels, 64)
self.down1 = down(64, 128)
self.down2 = down(128, 256)
self.down3 = down(256, 512)
self.down4 = down(512, 512)
self.up1 = up(1024, 256)
self.up2 = up(512, 128)
self.up3 = up(256, 64)
self.up4 = up(128, 64)
self.outc = outconv(64, n_classes)
def forward(self, x):
x1 = self.inc(x)
x2 = self.down1(x1)
x3 = self.down2(x2)
x4 = self.down3(x3)
x5 = self.down4(x4)
x = self.up1(x5, x4)
x = self.up2(x, x3)
x = self.up3(x, x2)
x = self.up4(x, x1)
x = self.outc(x)
return x