# pylint: skip-file
# type: ignore
import math
import random
import torch
from torch import nn
from .gfpganv1_arch import ResUpBlock
from .stylegan2_bilinear_arch import (
ConvLayer,
EqualConv2d,
EqualLinear,
ResBlock,
ScaledLeakyReLU,
StyleGAN2GeneratorBilinear,
)
class StyleGAN2GeneratorBilinearSFT(StyleGAN2GeneratorBilinear):
"""StyleGAN2 Generator with SFT modulation (Spatial Feature Transform).
It is the bilinear version. It does not use the complicated UpFirDnSmooth function that is not friendly for
deployment. It can be easily converted to the clean version: StyleGAN2GeneratorCSFT.
Args:
out_size (int): The spatial size of outputs.
num_style_feat (int): Channel number of style features. Default: 512.
num_mlp (int): Layer number of MLP style layers. Default: 8.
channel_multiplier (int): Channel multiplier for large networks of StyleGAN2. Default: 2.
lr_mlp (float): Learning rate multiplier for mlp layers. Default: 0.01.
narrow (float): The narrow ratio for channels. Default: 1.
sft_half (bool): Whether to apply SFT on half of the input channels. Default: False.
"""
def __init__(
self,
out_size,
num_style_feat=512,
num_mlp=8,
channel_multiplier=2,
lr_mlp=0.01,
narrow=1,
sft_half=False,
):
super(StyleGAN2GeneratorBilinearSFT, self).__init__(
out_size,
num_style_feat=num_style_feat,
num_mlp=num_mlp,
channel_multiplier=channel_multiplier,
lr_mlp=lr_mlp,
narrow=narrow,
)
self.sft_half = sft_half
def forward(
self,
styles,
conditions,
input_is_latent=False,
noise=None,
randomize_noise=True,
truncation=1,
truncation_latent=None,
inject_index=None,
return_latents=False,
):
"""Forward function for StyleGAN2GeneratorBilinearSFT.
Args:
styles (list[Tensor]): Sample codes of styles.
conditions (list[Tensor]): SFT conditions to generators.
input_is_latent (bool): Whether input is latent style. Default: False.
noise (Tensor | None): Input noise or None. Default: None.
randomize_noise (bool): Randomize noise, used when 'noise' is False. Default: True.
truncation (float): The truncation ratio. Default: 1.
truncation_latent (Tensor | None): The truncation latent tensor. Default: None.
inject_index (int | None): The injection index for mixing noise. Default: None.
return_latents (bool): Whether to return style latents. Default: False.
"""
# style codes -> latents with Style MLP layer
if not input_is_latent:
styles = [self.style_mlp(s) for s in styles]
# noises
if noise is None:
if randomize_noise:
noise = [None] * self.num_layers # for each style conv layer
else: # use the stored noise
noise = [
getattr(self.noises, f"noise{i}") for i in range(self.num_layers)
]
# style truncation
if truncation < 1:
style_truncation = []
for style in styles:
style_truncation.append(
truncation_latent + truncation * (style - truncation_latent)
)
styles = style_truncation
# get style latents with injection
if len(styles) == 1:
inject_index = self.num_latent
if styles[0].ndim < 3:
# repeat latent code for all the layers
latent = styles[0].unsqueeze(1).repeat(1, inject_index, 1)
else: # used for encoder with different latent code for each layer
latent = styles[0]
elif len(styles) == 2: # mixing noises
if inject_index is None:
inject_index = random.randint(1, self.num_latent - 1)
latent1 = styles[0].unsqueeze(1).repeat(1, inject_index, 1)
latent2 = (
styles[1].unsqueeze(1).repeat(1, self.num_latent - inject_index, 1)
)
latent = torch.cat([latent1, latent2], 1)
# main generation
out = self.constant_input(latent.shape[0])
out = self.style_conv1(out, latent[:, 0], noise=noise[0])
skip = self.to_rgb1(out, latent[:, 1])
i = 1
for conv1, conv2, noise1, noise2, to_rgb in zip(
self.style_convs[::2],
self.style_convs[1::2],
noise[1::2],
noise[2::2],
self.to_rgbs,
):
out = conv1(out, latent[:, i], noise=noise1)
# the conditions may have fewer levels
if i < len(conditions):
# SFT part to combine the conditions
if self.sft_half: # only apply SFT to half of the channels
out_same, out_sft = torch.split(out, int(out.size(1) // 2), dim=1)
out_sft = out_sft * conditions[i - 1] + conditions[i]
out = torch.cat([out_same, out_sft], dim=1)
else: # apply SFT to all the channels
out = out * conditions[i - 1] + conditions[i]
out = conv2(out, latent[:, i + 1], noise=noise2)
skip = to_rgb(out, latent[:, i + 2], skip) # feature back to the rgb space
i += 2
image = skip
if return_latents:
return image, latent
else:
return image, None
class GFPGANBilinear(nn.Module):
"""The GFPGAN architecture: Unet + StyleGAN2 decoder with SFT.
It is the bilinear version and it does not use the complicated UpFirDnSmooth function that is not friendly for
deployment. It can be easily converted to the clean version: GFPGANv1Clean.
Ref: GFP-GAN: Towards Real-World Blind Face Restoration with Generative Facial Prior.
Args:
out_size (int): The spatial size of outputs.
num_style_feat (int): Channel number of style features. Default: 512.
channel_multiplier (int): Channel multiplier for large networks of StyleGAN2. Default: 2.
decoder_load_path (str): The path to the pre-trained decoder model (usually, the StyleGAN2). Default: None.
fix_decoder (bool): Whether to fix the decoder. Default: True.
num_mlp (int): Layer number of MLP style layers. Default: 8.
lr_mlp (float): Learning rate multiplier for mlp layers. Default: 0.01.
input_is_latent (bool): Whether input is latent style. Default: False.
different_w (bool): Whether to use different latent w for different layers. Default: False.
narrow (float): The narrow ratio for channels. Default: 1.
sft_half (bool): Whether to apply SFT on half of the input channels. Default: False.
"""
def __init__(
self,
out_size,
num_style_feat=512,
channel_multiplier=1,
decoder_load_path=None,
fix_decoder=True,
# for stylegan decoder
num_mlp=8,
lr_mlp=0.01,
input_is_latent=False,
different_w=False,
narrow=1,
sft_half=False,
):
super(GFPGANBilinear, self).__init__()
self.input_is_latent = input_is_latent
self.different_w = different_w
self.num_style_feat = num_style_feat
self.min_size_restriction = 512
unet_narrow = narrow * 0.5 # by default, use a half of input channels
channels = {
"4": int(512 * unet_narrow),
"8": int(512 * unet_narrow),
"16": int(512 * unet_narrow),
"32": int(512 * unet_narrow),
"64": int(256 * channel_multiplier * unet_narrow),
"128": int(128 * channel_multiplier * unet_narrow),
"256": int(64 * channel_multiplier * unet_narrow),
"512": int(32 * channel_multiplier * unet_narrow),
"1024": int(16 * channel_multiplier * unet_narrow),
}
self.log_size = int(math.log(out_size, 2))
first_out_size = 2 ** (int(math.log(out_size, 2)))
self.conv_body_first = ConvLayer(
3, channels[f"{first_out_size}"], 1, bias=True, activate=True
)
# downsample
in_channels = channels[f"{first_out_size}"]
self.conv_body_down = nn.ModuleList()
for i in range(self.log_size, 2, -1):
out_channels = channels[f"{2**(i - 1)}"]
self.conv_body_down.append(ResBlock(in_channels, out_channels))
in_channels = out_channels
self.final_conv = ConvLayer(
in_channels, channels["4"], 3, bias=True, activate=True
)
# upsample
in_channels = channels["4"]
self.conv_body_up = nn.ModuleList()
for i in range(3, self.log_size + 1):
out_channels = channels[f"{2**i}"]
self.conv_body_up.append(ResUpBlock(in_channels, out_channels))
in_channels = out_channels
# to RGB
self.toRGB = nn.ModuleList()
for i in range(3, self.log_size + 1):
self.toRGB.append(
EqualConv2d(
channels[f"{2**i}"],
3,
1,
stride=1,
padding=0,
bias=True,
bias_init_val=0,
)
)
if different_w:
linear_out_channel = (int(math.log(out_size, 2)) * 2 - 2) * num_style_feat
else:
linear_out_channel = num_style_feat
self.final_linear = EqualLinear(
channels["4"] * 4 * 4,
linear_out_channel,
bias=True,
bias_init_val=0,
lr_mul=1,
activation=None,
)
# the decoder: stylegan2 generator with SFT modulations
self.stylegan_decoder = StyleGAN2GeneratorBilinearSFT(
out_size=out_size,
num_style_feat=num_style_feat,
num_mlp=num_mlp,
channel_multiplier=channel_multiplier,
lr_mlp=lr_mlp,
narrow=narrow,
sft_half=sft_half,
)
# load pre-trained stylegan2 model if necessary
if decoder_load_path:
self.stylegan_decoder.load_state_dict(
torch.load(
decoder_load_path, map_location=lambda storage, loc: storage
)["params_ema"]
)
# fix decoder without updating params
if fix_decoder:
for _, param in self.stylegan_decoder.named_parameters():
param.requires_grad = False
# for SFT modulations (scale and shift)
self.condition_scale = nn.ModuleList()
self.condition_shift = nn.ModuleList()
for i in range(3, self.log_size + 1):
out_channels = channels[f"{2**i}"]
if sft_half:
sft_out_channels = out_channels
else:
sft_out_channels = out_channels * 2
self.condition_scale.append(
nn.Sequential(
EqualConv2d(
out_channels,
out_channels,
3,
stride=1,
padding=1,
bias=True,
bias_init_val=0,
),
ScaledLeakyReLU(0.2),
EqualConv2d(
out_channels,
sft_out_channels,
3,
stride=1,
padding=1,
bias=True,
bias_init_val=1,
),
)
)
self.condition_shift.append(
nn.Sequential(
EqualConv2d(
out_channels,
out_channels,
3,
stride=1,
padding=1,
bias=True,
bias_init_val=0,
),
ScaledLeakyReLU(0.2),
EqualConv2d(
out_channels,
sft_out_channels,
3,
stride=1,
padding=1,
bias=True,
bias_init_val=0,
),
)
)
def forward(self, x, return_latents=False, return_rgb=True, randomize_noise=True):
"""Forward function for GFPGANBilinear.
Args:
x (Tensor): Input images.
return_latents (bool): Whether to return style latents. Default: False.
return_rgb (bool): Whether return intermediate rgb images. Default: True.
randomize_noise (bool): Randomize noise, used when 'noise' is False. Default: True.
"""
conditions = []
unet_skips = []
out_rgbs = []
# encoder
feat = self.conv_body_first(x)
for i in range(self.log_size - 2):
feat = self.conv_body_down[i](feat)
unet_skips.insert(0, feat)
feat = self.final_conv(feat)
# style code
style_code = self.final_linear(feat.view(feat.size(0), -1))
if self.different_w:
style_code = style_code.view(style_code.size(0), -1, self.num_style_feat)
# decode
for i in range(self.log_size - 2):
# add unet skip
feat = feat + unet_skips[i]
# ResUpLayer
feat = self.conv_body_up[i](feat)
# generate scale and shift for SFT layers
scale = self.condition_scale[i](feat)
conditions.append(scale.clone())
shift = self.condition_shift[i](feat)
conditions.append(shift.clone())
# generate rgb images
if return_rgb:
out_rgbs.append(self.toRGB[i](feat))
# decoder
image, _ = self.stylegan_decoder(
[style_code],
conditions,
return_latents=return_latents,
input_is_latent=self.input_is_latent,
randomize_noise=randomize_noise,
)
return image, out_rgbs