| import numpy as np |
| import torch |
| import torch.utils.data |
| import torch.utils.data.distributed |
| from torch import nn |
|
|
|
|
| class ResNet_G(nn.Module): |
|
|
| def __init__(self, data_dim, z_dim, size, nfilter=64, nfilter_max=512, bn=True, res_ratio=0.1, **kwargs): |
| super().__init__() |
| self.input_dim = z_dim |
| self.output_dim = z_dim |
| self.dropout_rate = 0 |
|
|
| s0 = self.s0 = 4 |
| nf = self.nf = nfilter |
| nf_max = self.nf_max = nfilter_max |
| self.bn = bn |
| self.z_dim = z_dim |
|
|
| |
| nlayers = int(np.log2(size / s0)) |
| self.nf0 = min(nf_max, nf * 2 ** (nlayers + 1)) |
|
|
| self.fc = nn.Linear(z_dim, self.nf0 * s0 * s0) |
| if self.bn: |
| self.bn1d = nn.BatchNorm1d(self.nf0 * s0 * s0) |
| self.relu = nn.LeakyReLU(0.2, inplace=True) |
|
|
| blocks = [] |
| for i in range(nlayers, 0, -1): |
| nf0 = min(nf * 2 ** (i + 1), nf_max) |
| nf1 = min(nf * 2 ** i, nf_max) |
| blocks += [ |
| ResNetBlock(nf0, nf1, bn=self.bn, res_ratio=res_ratio), |
| nn.Upsample(scale_factor=2) |
| ] |
|
|
| nf0 = min(nf * 2, nf_max) |
| nf1 = min(nf, nf_max) |
| blocks += [ |
| ResNetBlock(nf0, nf1, bn=self.bn, res_ratio=res_ratio), |
| ResNetBlock(nf1, nf1, bn=self.bn, res_ratio=res_ratio) |
| ] |
|
|
| self.resnet = nn.Sequential(*blocks) |
| self.conv_img = nn.Conv2d(nf, 3, 3, padding=1) |
|
|
| self.fc_out = nn.Linear(3 * size * size, data_dim) |
|
|
| def forward(self, z, return_intermediate=False): |
| |
| batch_size = z.size(0) |
| |
| out = self.fc(z) |
| if self.bn: |
| out = self.bn1d(out) |
| out = self.relu(out) |
| if return_intermediate: |
| l_1 = out.detach().clone() |
| out = out.view(batch_size, self.nf0, self.s0, self.s0) |
| |
|
|
| out = self.resnet(out) |
|
|
| |
| |
|
|
| out = self.conv_img(out) |
| out = self.relu(out) |
| out.flatten(1) |
| out = self.fc_out(out.flatten(1)) |
|
|
| if return_intermediate: |
| return out, l_1 |
| return out |
|
|
| def sample_latent(self, n_samples, z_size, temperature): |
| return torch.randn((n_samples, z_size)) * temperature |
|
|
|
|
| class ResNet_D(nn.Module): |
|
|
| def __init__(self, data_dim, size, nfilter=64, nfilter_max=512, res_ratio=0.1): |
| super().__init__() |
| s0 = self.s0 = 4 |
| nf = self.nf = nfilter |
| nf_max = self.nf_max = nfilter_max |
| self.size = size |
|
|
| |
| nlayers = int(np.log2(size / s0)) |
| self.nf0 = min(nf_max, nf * 2 ** nlayers) |
|
|
| nf0 = min(nf, nf_max) |
| nf1 = min(nf * 2, nf_max) |
| blocks = [ |
| ResNetBlock(nf0, nf0, bn=False, res_ratio=res_ratio), |
| ResNetBlock(nf0, nf1, bn=False, res_ratio=res_ratio) |
| ] |
|
|
| self.fc_input = nn.Linear(data_dim, 3 * size * size) |
|
|
| for i in range(1, nlayers + 1): |
| nf0 = min(nf * 2 ** i, nf_max) |
| nf1 = min(nf * 2 ** (i + 1), nf_max) |
| blocks += [ |
| nn.AvgPool2d(3, stride=2, padding=1), |
| ResNetBlock(nf0, nf1, bn=False, res_ratio=res_ratio), |
| ] |
|
|
| self.conv_img = nn.Conv2d(3, 1 * nf, 3, padding=1) |
| self.relu = nn.LeakyReLU(0.2, inplace=True) |
| self.resnet = nn.Sequential(*blocks) |
|
|
| self.fc = nn.Linear(self.nf0 * s0 * s0, 1) |
|
|
| def forward(self, x): |
| batch_size = x.size(0) |
|
|
| out = self.fc_input(x) |
| out = self.relu(out).view(batch_size, 3, self.size, self.size) |
|
|
| out = self.relu((self.conv_img(out))) |
| out = self.resnet(out) |
| out = out.view(batch_size, self.nf0 * self.s0 * self.s0) |
| out = self.fc(out) |
|
|
| return out |
|
|
|
|
| class ResNetBlock(nn.Module): |
|
|
| def __init__(self, fin, fout, fhidden=None, bn=True, res_ratio=0.1): |
| super().__init__() |
| |
| self.bn = bn |
| self.is_bias = not bn |
| self.learned_shortcut = (fin != fout) |
| self.fin = fin |
| self.fout = fout |
| if fhidden is None: |
| self.fhidden = min(fin, fout) |
| else: |
| self.fhidden = fhidden |
| self.res_ratio = res_ratio |
|
|
| |
| self.conv_0 = nn.Conv2d(self.fin, self.fhidden, 3, stride=1, padding=1, bias=self.is_bias) |
| if self.bn: |
| self.bn2d_0 = nn.BatchNorm2d(self.fhidden) |
| self.conv_1 = nn.Conv2d(self.fhidden, self.fout, 3, stride=1, padding=1, bias=self.is_bias) |
| if self.bn: |
| self.bn2d_1 = nn.BatchNorm2d(self.fout) |
| if self.learned_shortcut: |
| self.conv_s = nn.Conv2d(self.fin, self.fout, 1, stride=1, padding=0, bias=False) |
| if self.bn: |
| self.bn2d_s = nn.BatchNorm2d(self.fout) |
| self.relu = nn.LeakyReLU(0.2, inplace=True) |
|
|
| def forward(self, x): |
| x_s = self._shortcut(x) |
| dx = self.conv_0(x) |
| if self.bn: |
| dx = self.bn2d_0(dx) |
| dx = self.relu(dx) |
| dx = self.conv_1(dx) |
| if self.bn: |
| dx = self.bn2d_1(dx) |
| out = self.relu(x_s + self.res_ratio * dx) |
| return out |
|
|
| def _shortcut(self, x): |
| if self.learned_shortcut: |
| x_s = self.conv_s(x) |
| if self.bn: |
| x_s = self.bn2d_s(x_s) |
| else: |
| x_s = x |
| return x_s |
|
|