158 lines
6.1 KiB
Python
158 lines
6.1 KiB
Python
import functools
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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import models.archs.arch_util as arch_util
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import torchvision
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class ResidualDenseBlock_5C(nn.Module):
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def __init__(self, nf=64, gc=32, bias=True):
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super(ResidualDenseBlock_5C, self).__init__()
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# gc: growth channel, i.e. intermediate channels
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self.conv1 = nn.Conv2d(nf, gc, 3, 1, 1, bias=bias)
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self.conv2 = nn.Conv2d(nf + gc, gc, 3, 1, 1, bias=bias)
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self.conv3 = nn.Conv2d(nf + 2 * gc, gc, 3, 1, 1, bias=bias)
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self.conv4 = nn.Conv2d(nf + 3 * gc, gc, 3, 1, 1, bias=bias)
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self.conv5 = nn.Conv2d(nf + 4 * gc, nf, 3, 1, 1, bias=bias)
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self.lrelu = nn.LeakyReLU(negative_slope=0.2, inplace=True)
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# initialization
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arch_util.initialize_weights([self.conv1, self.conv2, self.conv3, self.conv4, self.conv5],
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0.1)
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def forward(self, x):
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x1 = self.lrelu(self.conv1(x))
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x2 = self.lrelu(self.conv2(torch.cat((x, x1), 1)))
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x3 = self.lrelu(self.conv3(torch.cat((x, x1, x2), 1)))
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x4 = self.lrelu(self.conv4(torch.cat((x, x1, x2, x3), 1)))
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x5 = self.conv5(torch.cat((x, x1, x2, x3, x4), 1))
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return x5 * 0.2 + x
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class RRDB(nn.Module):
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'''Residual in Residual Dense Block'''
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def __init__(self, nf, gc=32):
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super(RRDB, self).__init__()
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self.RDB1 = ResidualDenseBlock_5C(nf, gc)
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self.RDB2 = ResidualDenseBlock_5C(nf, gc)
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self.RDB3 = ResidualDenseBlock_5C(nf, gc)
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def forward(self, x):
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out = self.RDB1(x)
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out = self.RDB2(out)
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out = self.RDB3(out)
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return out * 0.2 + x
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class RRDBNet(nn.Module):
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def __init__(self, in_nc, out_nc, nf, nb, gc=32, scale=2):
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super(RRDBNet, self).__init__()
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RRDB_block_f = functools.partial(RRDB, nf=nf, gc=gc)
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self.scale = scale
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self.conv_first = nn.Conv2d(in_nc, nf, 7, 1, padding=3, bias=True)
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self.RRDB_trunk = arch_util.make_layer(RRDB_block_f, nb)
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self.trunk_conv = nn.Conv2d(nf, nf, 3, 1, 1, bias=True)
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#### upsampling
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self.upconv1 = nn.Conv2d(nf, nf, 5, 1, padding=2, bias=True)
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self.upconv2 = nn.Conv2d(nf, nf, 5, 1, padding=2, bias=True)
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self.HRconv = nn.Conv2d(nf, nf, 5, 1, padding=2, bias=True)
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self.conv_last = nn.Conv2d(nf, out_nc, 3, 1, 1, bias=True)
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self.lrelu = nn.LeakyReLU(negative_slope=0.2, inplace=True)
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def forward(self, x):
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fea = self.conv_first(x)
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trunk = self.trunk_conv(self.RRDB_trunk(fea))
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fea = fea + trunk
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if self.scale >= 2:
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fea = F.interpolate(fea, scale_factor=2, mode='nearest')
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fea = self.lrelu(self.upconv1(fea))
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if self.scale >= 4:
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fea = F.interpolate(fea, scale_factor=2, mode='nearest')
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fea = self.lrelu(self.upconv2(fea))
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out = self.conv_last(self.lrelu(self.HRconv(fea)))
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return (out,)
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# Variant of RRDBNet that is "assisted" by an external pretrained image classifier whose
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# intermediate layers have been splayed out, pixel-shuffled, and fed back in.
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class AssistedRRDBNet(nn.Module):
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# in_nc=number of input channels.
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# out_nc=number of output channels.
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# nf=internal filter count
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# nb=number of additional blocks after the assistance layers.
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# gc=growth channel inside of residual blocks
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# scale=the number of times the output is doubled in size.
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def __init__(self, in_nc, out_nc, nf, nb, gc=32, scale=2):
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super(AssistedRRDBNet, self).__init__()
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self.scale = scale
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self.conv_first = nn.Conv2d(in_nc, nf, 7, 1, padding=3, bias=True)
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# Set-up the assist-net, which should do feature extraction for us.
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self.assistnet = torchvision.models.wide_resnet50_2(pretrained=True)
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self.set_enable_assistnet_training(False)
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assist_nf = [2, 4, 8, 16] # Fixed for resnet. Re-evaluate if using other networks.
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self.assist1 = RRDB(nf + assist_nf[0], gc)
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self.assist2 = RRDB(nf + sum(assist_nf[:2]), gc)
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self.assist3 = RRDB(nf + sum(assist_nf[:3]), gc)
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self.assist4 = RRDB(nf + sum(assist_nf), gc)
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nf = nf + sum(assist_nf)
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# After this, it's just a "standard" RRDB net.
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RRDB_block_f = functools.partial(RRDB, nf=nf, gc=gc)
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self.RRDB_trunk = arch_util.make_layer(RRDB_block_f, nb)
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self.trunk_conv = nn.Conv2d(nf, nf, 3, 1, 1, bias=True)
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#### upsampling
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self.upconv1 = nn.Conv2d(nf, nf, 5, 1, padding=2, bias=True)
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self.upconv2 = nn.Conv2d(nf, nf, 5, 1, padding=2, bias=True)
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self.HRconv = nn.Conv2d(nf, nf, 5, 1, padding=2, bias=True)
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self.conv_last = nn.Conv2d(nf, out_nc, 3, 1, 1, bias=True)
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self.lrelu = nn.LeakyReLU(negative_slope=0.2, inplace=True)
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def set_enable_assistnet_training(self, en):
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for p in self.assistnet.parameters():
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p.requires_grad = en
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def res_extract(self, x):
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x = self.assistnet.conv1(x)
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x = self.assistnet.bn1(x)
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x = self.assistnet.relu(x)
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x = self.assistnet.maxpool(x)
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x = self.assistnet.layer1(x)
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l1 = F.pixel_shuffle(x, 4)
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x = self.assistnet.layer2(x)
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l2 = F.pixel_shuffle(x, 8)
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x = self.assistnet.layer3(x)
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l3 = F.pixel_shuffle(x, 16)
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x = self.assistnet.layer4(x)
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l4 = F.pixel_shuffle(x, 32)
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return l1, l2, l3, l4
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def forward(self, x):
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# Invoke the assistant net first.
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l1, l2, l3, l4 = self.res_extract(x)
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fea = self.conv_first(x)
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fea = self.assist1(torch.cat([fea, l4], dim=1))
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fea = self.assist2(torch.cat([fea, l3], dim=1))
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fea = self.assist3(torch.cat([fea, l2], dim=1))
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fea = self.assist4(torch.cat([fea, l1], dim=1))
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trunk = self.trunk_conv(self.RRDB_trunk(fea))
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fea = fea + trunk
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if self.scale >= 2:
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fea = F.interpolate(fea, scale_factor=2, mode='nearest')
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fea = self.lrelu(self.upconv1(fea))
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if self.scale >= 4:
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fea = F.interpolate(fea, scale_factor=2, mode='nearest')
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fea = self.lrelu(self.upconv2(fea))
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out = self.conv_last(self.lrelu(self.HRconv(fea)))
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return (out,) |