DL-Art-School/codes/models/archs/arch_util.py
2020-11-11 13:56:45 -07:00

569 lines
22 KiB
Python

import torch
import torch.nn as nn
import torch.nn.init as init
import torch.nn.functional as F
import torch.nn.utils.spectral_norm as SpectralNorm
from math import sqrt
def kaiming_init(module,
a=0,
mode='fan_out',
nonlinearity='relu',
bias=0,
distribution='normal'):
assert distribution in ['uniform', 'normal']
if distribution == 'uniform':
nn.init.kaiming_uniform_(
module.weight, a=a, mode=mode, nonlinearity=nonlinearity)
else:
nn.init.kaiming_normal_(
module.weight, a=a, mode=mode, nonlinearity=nonlinearity)
if hasattr(module, 'bias') and module.bias is not None:
nn.init.constant_(module.bias, bias)
def pixel_norm(x, epsilon=1e-8):
return x * torch.rsqrt(torch.mean(torch.pow(x, 2), dim=1, keepdims=True) + epsilon)
def initialize_weights(net_l, scale=1):
if not isinstance(net_l, list):
net_l = [net_l]
for net in net_l:
for m in net.modules():
if isinstance(m, nn.Conv2d) or isinstance(m, nn.Conv3d):
init.kaiming_normal_(m.weight, a=0, mode='fan_in')
m.weight.data *= scale # for residual block
if m.bias is not None:
m.bias.data.zero_()
elif isinstance(m, nn.Linear):
init.kaiming_normal_(m.weight, a=0, mode='fan_in')
m.weight.data *= scale
if m.bias is not None:
m.bias.data.zero_()
elif isinstance(m, nn.BatchNorm2d):
init.constant_(m.weight, 1)
init.constant_(m.bias.data, 0.0)
def make_layer(block, num_blocks, **kwarg):
"""Make layers by stacking the same blocks.
Args:
block (nn.module): nn.module class for basic block.
num_blocks (int): number of blocks.
Returns:
nn.Sequential: Stacked blocks in nn.Sequential.
"""
layers = []
for _ in range(num_blocks):
layers.append(block(**kwarg))
return nn.Sequential(*layers)
def default_init_weights(module, scale=1):
"""Initialize network weights.
Args:
modules (nn.Module): Modules to be initialized.
scale (float): Scale initialized weights, especially for residual
blocks.
"""
for m in module.modules():
if isinstance(m, nn.Conv2d):
kaiming_init(m, a=0, mode='fan_in', bias=0)
m.weight.data *= scale
elif isinstance(m, nn.Linear):
kaiming_init(m, a=0, mode='fan_in', bias=0)
m.weight.data *= scale
class ResidualBlock(nn.Module):
'''Residual block with BN
---Conv-BN-ReLU-Conv-+-
|________________|
'''
def __init__(self, nf=64):
super(ResidualBlock, self).__init__()
self.lrelu = nn.LeakyReLU(negative_slope=0.1, inplace=True)
self.conv1 = nn.Conv2d(nf, nf, 3, 1, 1, bias=True)
self.BN1 = nn.BatchNorm2d(nf)
self.conv2 = nn.Conv2d(nf, nf, 3, 1, 1, bias=True)
self.BN2 = nn.BatchNorm2d(nf)
# initialization
initialize_weights([self.conv1, self.conv2], 0.1)
def forward(self, x):
identity = x
out = self.lrelu(self.BN1(self.conv1(x)))
out = self.BN2(self.conv2(out))
return identity + out
class ResidualBlockSpectralNorm(nn.Module):
'''Residual block with Spectral Normalization.
---SpecConv-ReLU-SpecConv-+-
|________________|
'''
def __init__(self, nf, total_residual_blocks):
super(ResidualBlockSpectralNorm, self).__init__()
self.lrelu = nn.LeakyReLU(negative_slope=0.1, inplace=True)
self.conv1 = SpectralNorm(nn.Conv2d(nf, nf, 3, 1, 1, bias=True))
self.conv2 = SpectralNorm(nn.Conv2d(nf, nf, 3, 1, 1, bias=True))
initialize_weights([self.conv1, self.conv2], 1)
def forward(self, x):
identity = x
out = self.lrelu(self.conv1(x))
out = self.conv2(out)
return identity + out
class ResidualBlock_noBN(nn.Module):
'''Residual block w/o BN
---Conv-ReLU-Conv-+-
|________________|
'''
def __init__(self, nf=64):
super(ResidualBlock_noBN, self).__init__()
self.lrelu = nn.LeakyReLU(negative_slope=0.1, inplace=True)
self.conv1 = nn.Conv2d(nf, nf, 3, 1, 1, bias=True)
self.conv2 = nn.Conv2d(nf, nf, 3, 1, 1, bias=True)
# initialization
initialize_weights([self.conv1, self.conv2], 0.1)
def forward(self, x):
identity = x
out = self.lrelu(self.conv1(x))
out = self.conv2(out)
return identity + out
class ResidualBlockGN(nn.Module):
'''Residual block with GroupNorm
---Conv-GN-ReLU-Conv-+-
|________________|
'''
def __init__(self, nf=64):
super(ResidualBlockGN, self).__init__()
self.lrelu = nn.LeakyReLU(negative_slope=0.1, inplace=True)
self.conv1 = nn.Conv2d(nf, nf, 3, 1, 1, bias=True)
self.BN1 = nn.GroupNorm(8, nf)
self.conv2 = nn.Conv2d(nf, nf, 3, 1, 1, bias=True)
self.BN2 = nn.GroupNorm(8, nf)
# initialization
initialize_weights([self.conv1, self.conv2], 0.1)
def forward(self, x):
identity = x
out = self.lrelu(self.BN1(self.conv1(x)))
out = self.BN2(self.conv2(out))
return identity + out
def flow_warp(x, flow, interp_mode='bilinear', padding_mode='zeros'):
"""Warp an image or feature map with optical flow
Args:
x (Tensor): size (N, C, H, W)
flow (Tensor): size (N, H, W, 2), normal value
interp_mode (str): 'nearest' or 'bilinear'
padding_mode (str): 'zeros' or 'border' or 'reflection'
Returns:
Tensor: warped image or feature map
"""
assert x.size()[-2:] == flow.size()[1:3]
B, C, H, W = x.size()
# mesh grid
grid_y, grid_x = torch.meshgrid(torch.arange(0, H), torch.arange(0, W))
grid = torch.stack((grid_x, grid_y), 2).float() # W(x), H(y), 2
grid.requires_grad = False
grid = grid.type_as(x)
vgrid = grid + flow
# scale grid to [-1,1]
vgrid_x = 2.0 * vgrid[:, :, :, 0] / max(W - 1, 1) - 1.0
vgrid_y = 2.0 * vgrid[:, :, :, 1] / max(H - 1, 1) - 1.0
vgrid_scaled = torch.stack((vgrid_x, vgrid_y), dim=3)
output = F.grid_sample(x, vgrid_scaled, mode=interp_mode, padding_mode=padding_mode)
return output
class PixelUnshuffle(nn.Module):
def __init__(self, reduction_factor):
super(PixelUnshuffle, self).__init__()
self.r = reduction_factor
def forward(self, x):
(b, f, w, h) = x.shape
x = x.contiguous().view(b, f, w // self.r, self.r, h // self.r, self.r)
x = x.permute(0, 1, 3, 5, 2, 4).contiguous().view(b, f * (self.r ** 2), w // self.r, h // self.r)
return x
# simply define a silu function
def silu(input):
'''
Applies the Sigmoid Linear Unit (SiLU) function element-wise:
SiLU(x) = x * sigmoid(x)
'''
return input * torch.sigmoid(input)
# create a class wrapper from PyTorch nn.Module, so
# the function now can be easily used in models
class SiLU(nn.Module):
'''
Applies the Sigmoid Linear Unit (SiLU) function element-wise:
SiLU(x) = x * sigmoid(x)
Shape:
- Input: (N, *) where * means, any number of additional
dimensions
- Output: (N, *), same shape as the input
References:
- Related paper:
https://arxiv.org/pdf/1606.08415.pdf
Examples:
>>> m = silu()
>>> input = torch.randn(2)
>>> output = m(input)
'''
def __init__(self):
'''
Init method.
'''
super().__init__() # init the base class
def forward(self, input):
'''
Forward pass of the function.
'''
return silu(input)
''' Convenience class with Conv->BN->ReLU. Includes weight initialization and auto-padding for standard
kernel sizes. '''
class ConvBnRelu(nn.Module):
def __init__(self, filters_in, filters_out, kernel_size=3, stride=1, activation=True, norm=True, bias=True):
super(ConvBnRelu, self).__init__()
padding_map = {1: 0, 3: 1, 5: 2, 7: 3}
assert kernel_size in padding_map.keys()
self.conv = nn.Conv2d(filters_in, filters_out, kernel_size, stride, padding_map[kernel_size], bias=bias)
if norm:
self.bn = nn.BatchNorm2d(filters_out)
else:
self.bn = None
if activation:
self.relu = nn.ReLU()
else:
self.relu = None
# Init params.
for m in self.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu' if self.relu else 'linear')
elif isinstance(m, (nn.BatchNorm2d, nn.GroupNorm)):
nn.init.constant_(m.weight, 1)
nn.init.constant_(m.bias, 0)
def forward(self, x):
x = self.conv(x)
if self.bn:
x = self.bn(x)
if self.relu:
return self.relu(x)
else:
return x
''' Convenience class with Conv->BN->SiLU. Includes weight initialization and auto-padding for standard
kernel sizes. '''
class ConvBnSilu(nn.Module):
def __init__(self, filters_in, filters_out, kernel_size=3, stride=1, activation=True, norm=True, bias=True, weight_init_factor=1):
super(ConvBnSilu, self).__init__()
padding_map = {1: 0, 3: 1, 5: 2, 7: 3}
assert kernel_size in padding_map.keys()
self.conv = nn.Conv2d(filters_in, filters_out, kernel_size, stride, padding_map[kernel_size], bias=bias)
if norm:
self.bn = nn.BatchNorm2d(filters_out)
else:
self.bn = None
if activation:
self.silu = SiLU()
else:
self.silu = None
# Init params.
for m in self.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu' if self.silu else 'linear')
m.weight.data *= weight_init_factor
if m.bias is not None:
m.bias.data.zero_()
elif isinstance(m, (nn.BatchNorm2d, nn.GroupNorm)):
nn.init.constant_(m.weight, 1)
nn.init.constant_(m.bias, 0)
def forward(self, x):
x = self.conv(x)
if self.bn:
x = self.bn(x)
if self.silu:
return self.silu(x)
else:
return x
''' Convenience class with Conv->BN->LeakyReLU. Includes weight initialization and auto-padding for standard
kernel sizes. '''
class ConvBnLelu(nn.Module):
def __init__(self, filters_in, filters_out, kernel_size=3, stride=1, activation=True, norm=True, bias=True, weight_init_factor=1):
super(ConvBnLelu, self).__init__()
padding_map = {1: 0, 3: 1, 5: 2, 7: 3}
assert kernel_size in padding_map.keys()
self.conv = nn.Conv2d(filters_in, filters_out, kernel_size, stride, padding_map[kernel_size], bias=bias)
if norm:
self.bn = nn.BatchNorm2d(filters_out)
else:
self.bn = None
if activation:
self.lelu = nn.LeakyReLU(negative_slope=.1)
else:
self.lelu = None
# Init params.
for m in self.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_normal_(m.weight, a=.1, mode='fan_out',
nonlinearity='leaky_relu' if self.lelu else 'linear')
m.weight.data *= weight_init_factor
if m.bias is not None:
m.bias.data.zero_()
elif isinstance(m, (nn.BatchNorm2d, nn.GroupNorm)):
nn.init.constant_(m.weight, 1)
nn.init.constant_(m.bias, 0)
def forward(self, x):
x = self.conv(x)
if self.bn:
x = self.bn(x)
if self.lelu:
return self.lelu(x)
else:
return x
''' Convenience class with Conv->GroupNorm->LeakyReLU. Includes weight initialization and auto-padding for standard
kernel sizes. '''
class ConvGnLelu(nn.Module):
def __init__(self, filters_in, filters_out, kernel_size=3, stride=1, activation=True, norm=True, bias=True, num_groups=8, weight_init_factor=1):
super(ConvGnLelu, self).__init__()
padding_map = {1: 0, 3: 1, 5: 2, 7: 3}
assert kernel_size in padding_map.keys()
self.conv = nn.Conv2d(filters_in, filters_out, kernel_size, stride, padding_map[kernel_size], bias=bias)
if norm:
self.gn = nn.GroupNorm(num_groups, filters_out)
else:
self.gn = None
if activation:
self.lelu = nn.LeakyReLU(negative_slope=.1)
else:
self.lelu = None
# Init params.
for m in self.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_normal_(m.weight, a=.1, mode='fan_out',
nonlinearity='leaky_relu' if self.lelu else 'linear')
m.weight.data *= weight_init_factor
if m.bias is not None:
m.bias.data.zero_()
elif isinstance(m, (nn.BatchNorm2d, nn.GroupNorm)):
nn.init.constant_(m.weight, 1)
nn.init.constant_(m.bias, 0)
def forward(self, x):
x = self.conv(x)
if self.gn:
x = self.gn(x)
if self.lelu:
return self.lelu(x)
else:
return x
''' Convenience class with Conv->BN->SiLU. Includes weight initialization and auto-padding for standard
kernel sizes. '''
class ConvGnSilu(nn.Module):
def __init__(self, filters_in, filters_out, kernel_size=3, stride=1, activation=True, norm=True, bias=True, num_groups=8, weight_init_factor=1):
super(ConvGnSilu, self).__init__()
padding_map = {1: 0, 3: 1, 5: 2, 7: 3}
assert kernel_size in padding_map.keys()
self.conv = nn.Conv2d(filters_in, filters_out, kernel_size, stride, padding_map[kernel_size], bias=bias)
if norm:
self.gn = nn.GroupNorm(num_groups, filters_out)
else:
self.gn = None
if activation:
self.silu = SiLU()
else:
self.silu = None
# Init params.
for m in self.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu' if self.silu else 'linear')
m.weight.data *= weight_init_factor
if m.bias is not None:
m.bias.data.zero_()
elif isinstance(m, (nn.BatchNorm2d, nn.GroupNorm)):
nn.init.constant_(m.weight, 1)
nn.init.constant_(m.bias, 0)
def forward(self, x):
x = self.conv(x)
if self.gn:
x = self.gn(x)
if self.silu:
return self.silu(x)
else:
return x
# Simple way to chain multiple conv->act->norms together in an intuitive way.
class MultiConvBlock(nn.Module):
def __init__(self, filters_in, filters_mid, filters_out, kernel_size, depth, scale_init=1, norm=False, weight_init_factor=1):
assert depth >= 2
super(MultiConvBlock, self).__init__()
self.noise_scale = nn.Parameter(torch.full((1,), fill_value=.01))
self.bnconvs = nn.ModuleList([ConvBnLelu(filters_in, filters_mid, kernel_size, norm=norm, bias=False, weight_init_factor=weight_init_factor)] +
[ConvBnLelu(filters_mid, filters_mid, kernel_size, norm=norm, bias=False, weight_init_factor=weight_init_factor) for i in range(depth - 2)] +
[ConvBnLelu(filters_mid, filters_out, kernel_size, activation=False, norm=False, bias=False, weight_init_factor=weight_init_factor)])
self.scale = nn.Parameter(torch.full((1,), fill_value=scale_init, dtype=torch.float))
self.bias = nn.Parameter(torch.zeros(1))
def forward(self, x, noise=None):
if noise is not None:
noise = noise * self.noise_scale
x = x + noise
for m in self.bnconvs:
x = m.forward(x)
return x * self.scale + self.bias
# Block that upsamples 2x and reduces incoming filters by 2x. It preserves structure by taking a passthrough feed
# along with the feature representation.
class ExpansionBlock(nn.Module):
def __init__(self, filters_in, filters_out=None, block=ConvGnSilu):
super(ExpansionBlock, self).__init__()
if filters_out is None:
filters_out = filters_in // 2
self.decimate = block(filters_in, filters_out, kernel_size=1, bias=False, activation=False, norm=True)
self.process_passthrough = block(filters_out, filters_out, kernel_size=3, bias=True, activation=False, norm=True)
self.conjoin = block(filters_out*2, filters_out, kernel_size=3, bias=False, activation=True, norm=False)
self.process = block(filters_out, filters_out, kernel_size=3, bias=False, activation=True, norm=True)
# input is the feature signal with shape (b, f, w, h)
# passthrough is the structure signal with shape (b, f/2, w*2, h*2)
# output is conjoined upsample with shape (b, f/2, w*2, h*2)
def forward(self, input, passthrough):
x = F.interpolate(input, scale_factor=2, mode="nearest")
x = self.decimate(x)
p = self.process_passthrough(passthrough)
x = self.conjoin(torch.cat([x, p], dim=1))
return self.process(x)
# Block that upsamples 2x and reduces incoming filters by 2x. It preserves structure by taking a passthrough feed
# along with the feature representation.
# Differs from ExpansionBlock because it performs all processing in 2xfilter space and decimates at the last step.
class ExpansionBlock2(nn.Module):
def __init__(self, filters_in, filters_out=None, block=ConvGnSilu):
super(ExpansionBlock2, self).__init__()
if filters_out is None:
filters_out = filters_in // 2
self.decimate = block(filters_in, filters_out, kernel_size=1, bias=False, activation=False, norm=True)
self.process_passthrough = block(filters_out, filters_out, kernel_size=3, bias=True, activation=False, norm=True)
self.conjoin = block(filters_out*2, filters_out*2, kernel_size=3, bias=False, activation=True, norm=False)
self.reduce = block(filters_out*2, filters_out, kernel_size=3, bias=False, activation=True, norm=True)
# input is the feature signal with shape (b, f, w, h)
# passthrough is the structure signal with shape (b, f/2, w*2, h*2)
# output is conjoined upsample with shape (b, f/2, w*2, h*2)
def forward(self, input, passthrough):
x = F.interpolate(input, scale_factor=2, mode="nearest")
x = self.decimate(x)
p = self.process_passthrough(passthrough)
x = self.conjoin(torch.cat([x, p], dim=1))
return self.reduce(x)
# Similar to ExpansionBlock2 but does not upsample.
class ConjoinBlock(nn.Module):
def __init__(self, filters_in, filters_out=None, filters_pt=None, block=ConvGnSilu, norm=True):
super(ConjoinBlock, self).__init__()
if filters_out is None:
filters_out = filters_in
if filters_pt is None:
filters_pt = filters_in
self.process = block(filters_in + filters_pt, filters_in + filters_pt, kernel_size=3, bias=False, activation=True, norm=norm)
self.decimate = block(filters_in + filters_pt, filters_out, kernel_size=1, bias=False, activation=False, norm=norm)
def forward(self, input, passthrough):
x = torch.cat([input, passthrough], dim=1)
x = self.process(x)
return self.decimate(x)
# Designed explicitly to join a mainline trunk with reference data. Implemented as a residual branch.
class ReferenceJoinBlock(nn.Module):
def __init__(self, nf, residual_weight_init_factor=1, block=ConvGnLelu, final_norm=False, kernel_size=3, depth=3, join=True):
super(ReferenceJoinBlock, self).__init__()
self.branch = MultiConvBlock(nf * 2, nf + nf // 2, nf, kernel_size=kernel_size, depth=depth,
scale_init=residual_weight_init_factor, norm=False,
weight_init_factor=residual_weight_init_factor)
if join:
self.join_conv = block(nf, nf, kernel_size=kernel_size, norm=final_norm, bias=False, activation=True)
else:
self.join_conv = None
def forward(self, x, ref):
joined = torch.cat([x, ref], dim=1)
branch = self.branch(joined)
if self.join_conv is not None:
return self.join_conv(x + branch), torch.std(branch)
else:
return x + branch, torch.std(branch)
# Basic convolutional upsampling block that uses interpolate.
class UpconvBlock(nn.Module):
def __init__(self, filters_in, filters_out=None, block=ConvGnSilu, norm=True, activation=True, bias=False):
super(UpconvBlock, self).__init__()
self.process = block(filters_in, filters_out, kernel_size=3, bias=bias, activation=activation, norm=norm)
def forward(self, x):
x = F.interpolate(x, scale_factor=2, mode="nearest")
return self.process(x)
# Scales an image up 2x and performs intermediary processing. Designed to be the final block in an SR network.
class FinalUpsampleBlock2x(nn.Module):
def __init__(self, nf, block=ConvGnLelu, out_nc=3, scale=2):
super(FinalUpsampleBlock2x, self).__init__()
if scale == 2:
self.chain = nn.Sequential(block(nf, nf, kernel_size=3, norm=False, activation=True, bias=True),
UpconvBlock(nf, nf // 2, block=block, norm=False, activation=True, bias=True),
block(nf // 2, nf // 2, kernel_size=3, norm=False, activation=False, bias=True),
block(nf // 2, out_nc, kernel_size=3, norm=False, activation=False, bias=False))
else:
self.chain = nn.Sequential(block(nf, nf, kernel_size=3, norm=False, activation=True, bias=True),
UpconvBlock(nf, nf, block=block, norm=False, activation=True, bias=True),
block(nf, nf, kernel_size=3, norm=False, activation=False, bias=True),
UpconvBlock(nf, nf // 2, block=block, norm=False, activation=True, bias=True),
block(nf // 2, nf // 2, kernel_size=3, norm=False, activation=False, bias=True),
block(nf // 2, out_nc, kernel_size=3, norm=False, activation=False, bias=False))
def forward(self, x):
return self.chain(x)