# Copyright (c) Facebook, Inc. and its affiliates. # All rights reserved. # # This source code is licensed under the license found in the # LICENSE file in the root directory of this source tree. # # All contributions by Andy Brock: # Copyright (c) 2019 Andy Brock # # MIT License import numpy as np import math import functools import torch import torch.nn as nn from torch.nn import init import torch.optim as optim import torch.nn.functional as F from torch.nn import Parameter as P import layers from sync_batchnorm import SynchronizedBatchNorm2d as SyncBatchNorm2d # BigGAN-deep: uses a different resblock and pattern # Architectures for G # Attention is passed in in the format '32_64' to mean applying an attention # block at both resolution 32x32 and 64x64. Just '64' will apply at 64x64. # Channel ratio is the ratio of class GBlock(nn.Module): def __init__( self, in_channels, out_channels, which_conv=nn.Conv2d, which_bn=layers.bn, activation=None, upsample=None, channel_ratio=4, ): super(GBlock, self).__init__() self.in_channels, self.out_channels = in_channels, out_channels self.hidden_channels = self.in_channels // channel_ratio self.which_conv, self.which_bn = which_conv, which_bn self.activation = activation # Conv layers self.conv1 = self.which_conv( self.in_channels, self.hidden_channels, kernel_size=1, padding=0 ) self.conv2 = self.which_conv(self.hidden_channels, self.hidden_channels) self.conv3 = self.which_conv(self.hidden_channels, self.hidden_channels) self.conv4 = self.which_conv( self.hidden_channels, self.out_channels, kernel_size=1, padding=0 ) # Batchnorm layers self.bn1 = self.which_bn(self.in_channels) self.bn2 = self.which_bn(self.hidden_channels) self.bn3 = self.which_bn(self.hidden_channels) self.bn4 = self.which_bn(self.hidden_channels) # upsample layers self.upsample = upsample def forward(self, x, y): # Project down to channel ratio h = self.conv1(self.activation(self.bn1(x, y))) # Apply next BN-ReLU h = self.activation(self.bn2(h, y)) # Drop channels in x if necessary if self.in_channels != self.out_channels: x = x[:, : self.out_channels] # Upsample both h and x at this point if self.upsample: h = self.upsample(h) x = self.upsample(x) # 3x3 convs h = self.conv2(h) h = self.conv3(self.activation(self.bn3(h, y))) # Final 1x1 conv h = self.conv4(self.activation(self.bn4(h, y))) return h + x def G_arch(ch=64, attention="64", ksize="333333", dilation="111111"): arch = {} arch[256] = { "in_channels": [ch * item for item in [16, 16, 8, 8, 4, 2]], "out_channels": [ch * item for item in [16, 8, 8, 4, 2, 1]], "upsample": [True] * 6, "resolution": [8, 16, 32, 64, 128, 256], "attention": { 2 ** i: (2 ** i in [int(item) for item in attention.split("_")]) for i in range(3, 9) }, } arch[128] = { "in_channels": [ch * item for item in [16, 16, 8, 4, 2]], "out_channels": [ch * item for item in [16, 8, 4, 2, 1]], "upsample": [True] * 5, "resolution": [8, 16, 32, 64, 128], "attention": { 2 ** i: (2 ** i in [int(item) for item in attention.split("_")]) for i in range(3, 8) }, } arch[64] = { "in_channels": [ch * item for item in [16, 16, 8, 4]], "out_channels": [ch * item for item in [16, 8, 4, 2]], "upsample": [True] * 4, "resolution": [8, 16, 32, 64], "attention": { 2 ** i: (2 ** i in [int(item) for item in attention.split("_")]) for i in range(3, 7) }, } arch[32] = { "in_channels": [ch * item for item in [4, 4, 4]], "out_channels": [ch * item for item in [4, 4, 4]], "upsample": [True] * 3, "resolution": [8, 16, 32], "attention": { 2 ** i: (2 ** i in [int(item) for item in attention.split("_")]) for i in range(3, 6) }, } return arch class Generator(nn.Module): def __init__( self, G_ch=64, G_depth=2, dim_z=128, bottom_width=4, resolution=128, G_kernel_size=3, G_attn="64", n_classes=1000, num_G_SVs=1, num_G_SV_itrs=1, G_shared=True, shared_dim=0, hier=False, cross_replica=False, mybn=False, G_activation=nn.ReLU(inplace=False), G_lr=5e-5, G_B1=0.0, G_B2=0.999, adam_eps=1e-8, BN_eps=1e-5, SN_eps=1e-12, G_mixed_precision=False, G_fp16=False, G_init="ortho", skip_init=False, no_optim=False, G_param="SN", norm_style="bn", **kwargs ): super(Generator, self).__init__() # Channel width mulitplier self.ch = G_ch # Number of resblocks per stage self.G_depth = G_depth # Dimensionality of the latent space self.dim_z = dim_z # The initial spatial dimensions self.bottom_width = bottom_width # Resolution of the output self.resolution = resolution # Kernel size? self.kernel_size = G_kernel_size # Attention? self.attention = G_attn # number of classes, for use in categorical conditional generation self.n_classes = n_classes # Use shared embeddings? self.G_shared = G_shared # Dimensionality of the shared embedding? Unused if not using G_shared self.shared_dim = shared_dim if shared_dim > 0 else dim_z # Hierarchical latent space? self.hier = hier # Cross replica batchnorm? self.cross_replica = cross_replica # Use my batchnorm? self.mybn = mybn # nonlinearity for residual blocks self.activation = G_activation # Initialization style self.init = G_init # Parameterization style self.G_param = G_param # Normalization style self.norm_style = norm_style # Epsilon for BatchNorm? self.BN_eps = BN_eps # Epsilon for Spectral Norm? self.SN_eps = SN_eps # fp16? self.fp16 = G_fp16 # Architecture dict self.arch = G_arch(self.ch, self.attention)[resolution] # Which convs, batchnorms, and linear layers to use if self.G_param == "SN": self.which_conv = functools.partial( layers.SNConv2d, kernel_size=3, padding=1, num_svs=num_G_SVs, num_itrs=num_G_SV_itrs, eps=self.SN_eps, ) self.which_linear = functools.partial( layers.SNLinear, num_svs=num_G_SVs, num_itrs=num_G_SV_itrs, eps=self.SN_eps, ) else: self.which_conv = functools.partial(nn.Conv2d, kernel_size=3, padding=1) self.which_linear = nn.Linear # We use a non-spectral-normed embedding here regardless; # For some reason applying SN to G's embedding seems to randomly cripple G self.which_embedding = nn.Embedding bn_linear = ( functools.partial(self.which_linear, bias=False) if self.G_shared else self.which_embedding ) self.which_bn = functools.partial( layers.ccbn, which_linear=bn_linear, cross_replica=self.cross_replica, mybn=self.mybn, input_size=( self.shared_dim + self.dim_z if self.G_shared else self.n_classes ), norm_style=self.norm_style, eps=self.BN_eps, ) # Prepare model # If not using shared embeddings, self.shared is just a passthrough self.shared = ( self.which_embedding(n_classes, self.shared_dim) if G_shared else layers.identity() ) # First linear layer self.linear = self.which_linear( self.dim_z + self.shared_dim, self.arch["in_channels"][0] * (self.bottom_width ** 2), ) # self.blocks is a doubly-nested list of modules, the outer loop intended # to be over blocks at a given resolution (resblocks and/or self-attention) # while the inner loop is over a given block self.blocks = [] for index in range(len(self.arch["out_channels"])): self.blocks += [ [ GBlock( in_channels=self.arch["in_channels"][index], out_channels=self.arch["in_channels"][index] if g_index == 0 else self.arch["out_channels"][index], which_conv=self.which_conv, which_bn=self.which_bn, activation=self.activation, upsample=( functools.partial(F.interpolate, scale_factor=2) if self.arch["upsample"][index] and g_index == (self.G_depth - 1) else None ), ) ] for g_index in range(self.G_depth) ] # If attention on this block, attach it to the end if self.arch["attention"][self.arch["resolution"][index]]: print( "Adding attention layer in G at resolution %d" % self.arch["resolution"][index] ) self.blocks[-1] += [ layers.Attention(self.arch["out_channels"][index], self.which_conv) ] # Turn self.blocks into a ModuleList so that it's all properly registered. self.blocks = nn.ModuleList([nn.ModuleList(block) for block in self.blocks]) # output layer: batchnorm-relu-conv. # Consider using a non-spectral conv here self.output_layer = nn.Sequential( layers.bn( self.arch["out_channels"][-1], cross_replica=self.cross_replica, mybn=self.mybn, ), self.activation, self.which_conv(self.arch["out_channels"][-1], 3), ) # Initialize weights. Optionally skip init for testing. if not skip_init: self.init_weights() # Set up optimizer # If this is an EMA copy, no need for an optim, so just return now if no_optim: return self.lr, self.B1, self.B2, self.adam_eps = G_lr, G_B1, G_B2, adam_eps if G_mixed_precision: print("Using fp16 adam in G...") import utils self.optim = utils.Adam16( params=self.parameters(), lr=self.lr, betas=(self.B1, self.B2), weight_decay=0, eps=self.adam_eps, ) else: self.optim = optim.Adam( params=self.parameters(), lr=self.lr, betas=(self.B1, self.B2), weight_decay=0, eps=self.adam_eps, ) # LR scheduling, left here for forward compatibility # self.lr_sched = {'itr' : 0}# if self.progressive else {} # self.j = 0 # Initialize def init_weights(self): self.param_count = 0 for module in self.modules(): if ( isinstance(module, nn.Conv2d) or isinstance(module, nn.Linear) or isinstance(module, nn.Embedding) ): if self.init == "ortho": init.orthogonal_(module.weight) elif self.init == "N02": init.normal_(module.weight, 0, 0.02) elif self.init in ["glorot", "xavier"]: init.xavier_uniform_(module.weight) else: print("Init style not recognized...") self.param_count += sum( [p.data.nelement() for p in module.parameters()] ) print("Param count for G" "s initialized parameters: %d" % self.param_count) # Note on this forward function: we pass in a y vector which has # already been passed through G.shared to enable easy class-wise # interpolation later. If we passed in the one-hot and then ran it through # G.shared in this forward function, it would be harder to handle. # NOTE: The z vs y dichotomy here is for compatibility with not-y def forward(self, z, y): # If hierarchical, concatenate zs and ys if self.hier: z = torch.cat([y, z], 1) y = z # First linear layer h = self.linear(z) # Reshape h = h.view(h.size(0), -1, self.bottom_width, self.bottom_width) # Loop over blocks for index, blocklist in enumerate(self.blocks): # Second inner loop in case block has multiple layers for block in blocklist: h = block(h, y) # Apply batchnorm-relu-conv-tanh at output return torch.tanh(self.output_layer(h)) class DBlock(nn.Module): def __init__( self, in_channels, out_channels, which_conv=layers.SNConv2d, wide=True, preactivation=True, activation=None, downsample=None, channel_ratio=4, ): super(DBlock, self).__init__() self.in_channels, self.out_channels = in_channels, out_channels # If using wide D (as in SA-GAN and BigGAN), change the channel pattern self.hidden_channels = self.out_channels // channel_ratio self.which_conv = which_conv self.preactivation = preactivation self.activation = activation self.downsample = downsample # Conv layers self.conv1 = self.which_conv( self.in_channels, self.hidden_channels, kernel_size=1, padding=0 ) self.conv2 = self.which_conv(self.hidden_channels, self.hidden_channels) self.conv3 = self.which_conv(self.hidden_channels, self.hidden_channels) self.conv4 = self.which_conv( self.hidden_channels, self.out_channels, kernel_size=1, padding=0 ) self.learnable_sc = True if (in_channels != out_channels) else False if self.learnable_sc: self.conv_sc = self.which_conv( in_channels, out_channels - in_channels, kernel_size=1, padding=0 ) def shortcut(self, x): if self.downsample: x = self.downsample(x) if self.learnable_sc: x = torch.cat([x, self.conv_sc(x)], 1) return x def forward(self, x): # 1x1 bottleneck conv h = self.conv1(F.relu(x)) # 3x3 convs h = self.conv2(self.activation(h)) h = self.conv3(self.activation(h)) # relu before downsample h = self.activation(h) # downsample if self.downsample: h = self.downsample(h) # final 1x1 conv h = self.conv4(h) return h + self.shortcut(x) # Discriminator architecture, same paradigm as G's above def D_arch(ch=64, attention="64", ksize="333333", dilation="111111"): arch = {} arch[256] = { "in_channels": [item * ch for item in [1, 2, 4, 8, 8, 16]], "out_channels": [item * ch for item in [2, 4, 8, 8, 16, 16]], "downsample": [True] * 6 + [False], "resolution": [128, 64, 32, 16, 8, 4, 4], "attention": { 2 ** i: 2 ** i in [int(item) for item in attention.split("_")] for i in range(2, 8) }, } arch[128] = { "in_channels": [item * ch for item in [1, 2, 4, 8, 16]], "out_channels": [item * ch for item in [2, 4, 8, 16, 16]], "downsample": [True] * 5 + [False], "resolution": [64, 32, 16, 8, 4, 4], "attention": { 2 ** i: 2 ** i in [int(item) for item in attention.split("_")] for i in range(2, 8) }, } arch[64] = { "in_channels": [item * ch for item in [1, 2, 4, 8]], "out_channels": [item * ch for item in [2, 4, 8, 16]], "downsample": [True] * 4 + [False], "resolution": [32, 16, 8, 4, 4], "attention": { 2 ** i: 2 ** i in [int(item) for item in attention.split("_")] for i in range(2, 7) }, } arch[32] = { "in_channels": [item * ch for item in [4, 4, 4]], "out_channels": [item * ch for item in [4, 4, 4]], "downsample": [True, True, False, False], "resolution": [16, 16, 16, 16], "attention": { 2 ** i: 2 ** i in [int(item) for item in attention.split("_")] for i in range(2, 6) }, } return arch class Discriminator(nn.Module): def __init__( self, D_ch=64, D_wide=True, D_depth=2, resolution=128, D_kernel_size=3, D_attn="64", n_classes=1000, num_D_SVs=1, num_D_SV_itrs=1, D_activation=nn.ReLU(inplace=False), D_lr=2e-4, D_B1=0.0, D_B2=0.999, adam_eps=1e-8, SN_eps=1e-12, output_dim=1, D_mixed_precision=False, D_fp16=False, D_init="ortho", skip_init=False, D_param="SN", **kwargs ): super(Discriminator, self).__init__() # Width multiplier self.ch = D_ch # Use Wide D as in BigGAN and SA-GAN or skinny D as in SN-GAN? self.D_wide = D_wide # How many resblocks per stage? self.D_depth = D_depth # Resolution self.resolution = resolution # Kernel size self.kernel_size = D_kernel_size # Attention? self.attention = D_attn # Number of classes self.n_classes = n_classes # Activation self.activation = D_activation # Initialization style self.init = D_init # Parameterization style self.D_param = D_param # Epsilon for Spectral Norm? self.SN_eps = SN_eps # Fp16? self.fp16 = D_fp16 # Architecture self.arch = D_arch(self.ch, self.attention)[resolution] # Which convs, batchnorms, and linear layers to use # No option to turn off SN in D right now if self.D_param == "SN": self.which_conv = functools.partial( layers.SNConv2d, kernel_size=3, padding=1, num_svs=num_D_SVs, num_itrs=num_D_SV_itrs, eps=self.SN_eps, ) self.which_linear = functools.partial( layers.SNLinear, num_svs=num_D_SVs, num_itrs=num_D_SV_itrs, eps=self.SN_eps, ) self.which_embedding = functools.partial( layers.SNEmbedding, num_svs=num_D_SVs, num_itrs=num_D_SV_itrs, eps=self.SN_eps, ) # Prepare model # Stem convolution self.input_conv = self.which_conv(3, self.arch["in_channels"][0]) # self.blocks is a doubly-nested list of modules, the outer loop intended # to be over blocks at a given resolution (resblocks and/or self-attention) self.blocks = [] for index in range(len(self.arch["out_channels"])): self.blocks += [ [ DBlock( in_channels=self.arch["in_channels"][index] if d_index == 0 else self.arch["out_channels"][index], out_channels=self.arch["out_channels"][index], which_conv=self.which_conv, wide=self.D_wide, activation=self.activation, preactivation=True, downsample=( nn.AvgPool2d(2) if self.arch["downsample"][index] and d_index == 0 else None ), ) for d_index in range(self.D_depth) ] ] # If attention on this block, attach it to the end if self.arch["attention"][self.arch["resolution"][index]]: print( "Adding attention layer in D at resolution %d" % self.arch["resolution"][index] ) self.blocks[-1] += [ layers.Attention(self.arch["out_channels"][index], self.which_conv) ] # Turn self.blocks into a ModuleList so that it's all properly registered. self.blocks = nn.ModuleList([nn.ModuleList(block) for block in self.blocks]) # Linear output layer. The output dimension is typically 1, but may be # larger if we're e.g. turning this into a VAE with an inference output self.linear = self.which_linear(self.arch["out_channels"][-1], output_dim) # Embedding for projection discrimination self.embed = self.which_embedding(self.n_classes, self.arch["out_channels"][-1]) # Initialize weights if not skip_init: self.init_weights() # Set up optimizer self.lr, self.B1, self.B2, self.adam_eps = D_lr, D_B1, D_B2, adam_eps if D_mixed_precision: print("Using fp16 adam in D...") import utils self.optim = utils.Adam16( params=self.parameters(), lr=self.lr, betas=(self.B1, self.B2), weight_decay=0, eps=self.adam_eps, ) else: self.optim = optim.Adam( params=self.parameters(), lr=self.lr, betas=(self.B1, self.B2), weight_decay=0, eps=self.adam_eps, ) # LR scheduling, left here for forward compatibility # self.lr_sched = {'itr' : 0}# if self.progressive else {} # self.j = 0 # Initialize def init_weights(self): self.param_count = 0 for module in self.modules(): if ( isinstance(module, nn.Conv2d) or isinstance(module, nn.Linear) or isinstance(module, nn.Embedding) ): if self.init == "ortho": init.orthogonal_(module.weight) elif self.init == "N02": init.normal_(module.weight, 0, 0.02) elif self.init in ["glorot", "xavier"]: init.xavier_uniform_(module.weight) else: print("Init style not recognized...") self.param_count += sum( [p.data.nelement() for p in module.parameters()] ) print("Param count for D" "s initialized parameters: %d" % self.param_count) def forward(self, x, y=None): # Run input conv h = self.input_conv(x) # Loop over blocks for index, blocklist in enumerate(self.blocks): for block in blocklist: h = block(h) # Apply global sum pooling as in SN-GAN h = torch.sum(self.activation(h), [2, 3]) # Get initial class-unconditional output out = self.linear(h) # Get projection of final featureset onto class vectors and add to evidence out = out + torch.sum(self.embed(y) * h, 1, keepdim=True) return out # Parallelized G_D to minimize cross-gpu communication # Without this, Generator outputs would get all-gathered and then rebroadcast. class G_D(nn.Module): def __init__(self, G, D): super(G_D, self).__init__() self.G = G self.D = D def forward( self, z, gy, x=None, dy=None, train_G=False, return_G_z=False, split_D=False ): # If training G, enable grad tape with torch.set_grad_enabled(train_G): # Get Generator output given noise G_z = self.G(z, self.G.shared(gy)) # Cast as necessary if self.G.fp16 and not self.D.fp16: G_z = G_z.float() if self.D.fp16 and not self.G.fp16: G_z = G_z.half() # Split_D means to run D once with real data and once with fake, # rather than concatenating along the batch dimension. if split_D: D_fake = self.D(G_z, gy) if x is not None: D_real = self.D(x, dy) return D_fake, D_real else: if return_G_z: return D_fake, G_z else: return D_fake # If real data is provided, concatenate it with the Generator's output # along the batch dimension for improved efficiency. else: D_input = torch.cat([G_z, x], 0) if x is not None else G_z D_class = torch.cat([gy, dy], 0) if dy is not None else gy # Get Discriminator output D_out = self.D(D_input, D_class) if x is not None: return torch.split(D_out, [G_z.shape[0], x.shape[0]]) # D_fake, D_real else: if return_G_z: return D_out, G_z else: return D_out