forked from mrq/DL-Art-School
372 lines
18 KiB
Python
372 lines
18 KiB
Python
import torch
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import torch.nn as nn
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from models.networks import define_F
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from models.loss import GANLoss
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import random
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import functools
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import torchvision
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def create_loss(opt_loss, env):
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type = opt_loss['type']
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if type == 'pix':
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return PixLoss(opt_loss, env)
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elif type == 'feature':
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return FeatureLoss(opt_loss, env)
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elif type == 'interpreted_feature':
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return InterpretedFeatureLoss(opt_loss, env)
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elif type == 'generator_gan':
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return GeneratorGanLoss(opt_loss, env)
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elif type == 'discriminator_gan':
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return DiscriminatorGanLoss(opt_loss, env)
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elif type == 'geometric':
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return GeometricSimilarityGeneratorLoss(opt_loss, env)
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elif type == 'translational':
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return TranslationInvarianceLoss(opt_loss, env)
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elif type == 'recursive':
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return RecursiveInvarianceLoss(opt_loss, env)
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else:
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raise NotImplementedError
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# Converts params to a list of tensors extracted from state. Works with list/tuple params as well as scalars.
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def extract_params_from_state(params, state, root=True):
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if isinstance(params, list) or isinstance(params, tuple):
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p = [extract_params_from_state(r, state, False) for r in params]
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elif isinstance(params, str):
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p = state[params]
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else:
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p = params
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# The root return must always be a list.
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if root and not isinstance(p, list):
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p = [p]
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return p
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class ConfigurableLoss(nn.Module):
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def __init__(self, opt, env):
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super(ConfigurableLoss, self).__init__()
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self.opt = opt
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self.env = env
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self.metrics = []
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# net is either a scalar network being trained or a list of networks being trained, depending on the configuration.
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def forward(self, net, state):
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raise NotImplementedError
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def extra_metrics(self):
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return self.metrics
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def get_basic_criterion_for_name(name, device):
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if name == 'l1':
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return nn.L1Loss().to(device)
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elif name == 'l2':
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return nn.MSELoss().to(device)
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elif name == 'cosine':
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return nn.CosineEmbeddingLoss().to(device)
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else:
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raise NotImplementedError
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class PixLoss(ConfigurableLoss):
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def __init__(self, opt, env):
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super(PixLoss, self).__init__(opt, env)
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self.opt = opt
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self.criterion = get_basic_criterion_for_name(opt['criterion'], env['device'])
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def forward(self, _, state):
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return self.criterion(state[self.opt['fake']], state[self.opt['real']])
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class FeatureLoss(ConfigurableLoss):
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def __init__(self, opt, env):
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super(FeatureLoss, self).__init__(opt, env)
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self.opt = opt
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self.criterion = get_basic_criterion_for_name(opt['criterion'], env['device'])
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self.netF = define_F(which_model=opt['which_model_F'],
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load_path=opt['load_path'] if 'load_path' in opt.keys() else None).to(self.env['device'])
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if not env['opt']['dist']:
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self.netF = torch.nn.parallel.DataParallel(self.netF)
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def forward(self, _, state):
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with torch.no_grad():
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logits_real = self.netF(state[self.opt['real']])
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logits_fake = self.netF(state[self.opt['fake']])
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if self.opt['criterion'] == 'cosine':
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return self.criterion(logits_fake, logits_real, torch.ones(1, device=logits_fake.device))
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else:
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return self.criterion(logits_fake, logits_real)
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# Special form of feature loss which first computes the feature embedding for the truth space, then uses a second
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# network which was trained to replicate that embedding on an altered input space (for example, LR or greyscale) to
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# compute the embedding in the generated space. Useful for weakening the influence of the feature network in controlled
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# ways.
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class InterpretedFeatureLoss(ConfigurableLoss):
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def __init__(self, opt, env):
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super(InterpretedFeatureLoss, self).__init__(opt, env)
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self.opt = opt
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self.criterion = get_basic_criterion_for_name(opt['criterion'], env['device'])
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self.netF_real = define_F(which_model=opt['which_model_F']).to(self.env['device'])
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self.netF_gen = define_F(which_model=opt['which_model_F'], load_path=opt['load_path']).to(self.env['device'])
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if not env['opt']['dist']:
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self.netF_real = torch.nn.parallel.DataParallel(self.netF_real)
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self.netF_gen = torch.nn.parallel.DataParallel(self.netF_gen)
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def forward(self, _, state):
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logits_real = self.netF_real(state[self.opt['real']])
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logits_fake = self.netF_gen(state[self.opt['fake']])
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return self.criterion(logits_fake, logits_real)
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class GeneratorGanLoss(ConfigurableLoss):
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def __init__(self, opt, env):
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super(GeneratorGanLoss, self).__init__(opt, env)
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self.opt = opt
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self.criterion = GANLoss(opt['gan_type'], 1.0, 0.0).to(env['device'])
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self.noise = None if 'noise' not in opt.keys() else opt['noise']
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self.detach_real = opt['detach_real'] if 'detach_real' in opt.keys() else True
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# This is a mechanism to prevent backpropagation for a GAN loss if it goes too low. This can be used to balance
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# generators and discriminators by essentially having them skip steps while their counterparts "catch up".
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self.min_loss = opt['min_loss'] if 'min_loss' in opt.keys() else 0
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self.loss_rotating_buffer = torch.zeros(10, requires_grad=False)
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self.rb_ptr = 0
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self.losses_computed = 0
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def forward(self, _, state):
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netD = self.env['discriminators'][self.opt['discriminator']]
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real = extract_params_from_state(self.opt['real'], state)
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fake = extract_params_from_state(self.opt['fake'], state)
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if self.noise:
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nreal = []
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nfake = []
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for i, t in enumerate(real):
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if isinstance(t, torch.Tensor):
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nreal.append(t + torch.randn_like(t) * self.noise)
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nfake.append(fake[i] + torch.randn_like(t) * self.noise)
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else:
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nreal.append(t)
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nfake.append(fake[i])
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real = nreal
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fake = nfake
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if self.opt['gan_type'] in ['gan', 'pixgan', 'pixgan_fea']:
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pred_g_fake = netD(*fake)
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loss = self.criterion(pred_g_fake, True)
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elif self.opt['gan_type'] == 'ragan':
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pred_d_real = netD(*real)
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if self.detach_real:
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pred_d_real = pred_d_real.detach()
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pred_g_fake = netD(*fake)
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loss = (self.criterion(pred_d_real - torch.mean(pred_g_fake), False) +
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self.criterion(pred_g_fake - torch.mean(pred_d_real), True)) / 2
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else:
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raise NotImplementedError
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self.loss_rotating_buffer[self.rb_ptr] = loss.item()
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self.rb_ptr = (self.rb_ptr + 1) % self.loss_rotating_buffer.shape[0]
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if torch.mean(self.loss_rotating_buffer) < self.min_loss:
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return 0
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self.losses_computed += 1
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self.metrics.append(("loss_counter", self.losses_computed))
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return loss
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class DiscriminatorGanLoss(ConfigurableLoss):
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def __init__(self, opt, env):
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super(DiscriminatorGanLoss, self).__init__(opt, env)
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self.opt = opt
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self.criterion = GANLoss(opt['gan_type'], 1.0, 0.0).to(env['device'])
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self.noise = None if 'noise' not in opt.keys() else opt['noise']
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# This is a mechanism to prevent backpropagation for a GAN loss if it goes too low. This can be used to balance
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# generators and discriminators by essentially having them skip steps while their counterparts "catch up".
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self.min_loss = opt['min_loss'] if 'min_loss' in opt.keys() else 0
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self.loss_rotating_buffer = torch.zeros(10, requires_grad=False)
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self.rb_ptr = 0
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self.losses_computed = 0
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def forward(self, net, state):
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self.metrics = []
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real = extract_params_from_state(self.opt['real'], state)
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real = [r.detach() for r in real]
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fake = extract_params_from_state(self.opt['fake'], state)
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fake = [f.detach() for f in fake]
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if self.noise:
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nreal = []
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nfake = []
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for i, t in enumerate(real):
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if isinstance(t, torch.Tensor):
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nreal.append(t + torch.randn_like(t) * self.noise)
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nfake.append(fake[i] + torch.randn_like(t) * self.noise)
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else:
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nreal.append(t)
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nfake.append(fake[i])
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real = nreal
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fake = nfake
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d_real = net(*real)
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d_fake = net(*fake)
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if self.opt['gan_type'] in ['gan', 'pixgan']:
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self.metrics.append(("d_fake", torch.mean(d_fake)))
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self.metrics.append(("d_real", torch.mean(d_real)))
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l_real = self.criterion(d_real, True)
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l_fake = self.criterion(d_fake, False)
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l_total = l_real + l_fake
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loss = l_total
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elif self.opt['gan_type'] == 'ragan':
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d_fake_diff = d_fake - torch.mean(d_real)
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self.metrics.append(("d_fake_diff", torch.mean(d_fake_diff)))
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loss = (self.criterion(d_real - torch.mean(d_fake), True) +
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self.criterion(d_fake_diff, False))
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else:
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raise NotImplementedError
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self.loss_rotating_buffer[self.rb_ptr] = loss.item()
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self.rb_ptr = (self.rb_ptr + 1) % self.loss_rotating_buffer.shape[0]
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if torch.mean(self.loss_rotating_buffer) < self.min_loss:
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return 0
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self.losses_computed += 1
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self.metrics.append(("loss_counter", self.losses_computed))
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return loss
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# Computes a loss created by comparing the output of a generator to the output from the same generator when fed an
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# input that has been altered randomly by rotation or flip.
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# The "real" parameter to this loss is the actual output of the generator (from an injection point)
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# The "fake" parameter is the LR input that produced the "real" parameter when fed through the generator.
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class GeometricSimilarityGeneratorLoss(ConfigurableLoss):
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def __init__(self, opt, env):
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super(GeometricSimilarityGeneratorLoss, self).__init__(opt, env)
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self.opt = opt
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self.generator = opt['generator']
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self.criterion = get_basic_criterion_for_name(opt['criterion'], env['device'])
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self.gen_input_for_alteration = opt['input_alteration_index'] if 'input_alteration_index' in opt.keys() else 0
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self.gen_output_to_use = opt['generator_output_index'] if 'generator_output_index' in opt.keys() else None
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self.detach_fake = opt['detach_fake'] if 'detach_fake' in opt.keys() else False
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# Returns a random alteration and its counterpart (that undoes the alteration)
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def random_alteration(self):
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return random.choice([(functools.partial(torch.flip, dims=(2,)), functools.partial(torch.flip, dims=(2,))),
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(functools.partial(torch.flip, dims=(3,)), functools.partial(torch.flip, dims=(3,))),
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(functools.partial(torch.rot90, k=1, dims=[2,3]), functools.partial(torch.rot90, k=3, dims=[2,3])),
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(functools.partial(torch.rot90, k=2, dims=[2,3]), functools.partial(torch.rot90, k=2, dims=[2,3])),
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(functools.partial(torch.rot90, k=3, dims=[2,3]), functools.partial(torch.rot90, k=1, dims=[2,3]))])
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def forward(self, net, state):
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self.metrics = []
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net = self.env['generators'][self.generator] # Get the network from an explicit parameter.
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# The <net> parameter is not reliable for generator losses since often they are combined with many networks.
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fake = extract_params_from_state(self.opt['fake'], state)
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alteration, undo_fn = self.random_alteration()
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altered = []
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for i, t in enumerate(fake):
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if i == self.gen_input_for_alteration:
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altered.append(alteration(t))
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else:
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altered.append(t)
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if self.detach_fake:
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with torch.no_grad():
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upsampled_altered = net(*altered)
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else:
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upsampled_altered = net(*altered)
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if self.gen_output_to_use:
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upsampled_altered = upsampled_altered[self.gen_output_to_use]
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# Undo alteration on HR image
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upsampled_altered = undo_fn(upsampled_altered)
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if self.opt['criterion'] == 'cosine':
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return self.criterion(state[self.opt['real']], upsampled_altered, torch.ones(1, device=upsampled_altered.device))
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else:
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return self.criterion(state[self.opt['real']], upsampled_altered)
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# Computes a loss created by comparing the output of a generator to the output from the same generator when fed an
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# input that has been translated in a random direction.
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# The "real" parameter to this loss is the actual output of the generator on the top left image patch.
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# The "fake" parameter is the output base fed into a ImagePatchInjector.
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class TranslationInvarianceLoss(ConfigurableLoss):
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def __init__(self, opt, env):
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super(TranslationInvarianceLoss, self).__init__(opt, env)
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self.opt = opt
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self.generator = opt['generator']
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self.criterion = get_basic_criterion_for_name(opt['criterion'], env['device'])
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self.gen_input_for_alteration = opt['input_alteration_index'] if 'input_alteration_index' in opt.keys() else 0
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self.gen_output_to_use = opt['generator_output_index'] if 'generator_output_index' in opt.keys() else None
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self.patch_size = opt['patch_size']
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self.overlap = opt['overlap'] # For maximum overlap, can be calculated as 2*patch_size-image_size
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self.detach_fake = opt['detach_fake']
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assert(self.patch_size > self.overlap)
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def forward(self, net, state):
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self.metrics = []
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net = self.env['generators'][self.generator] # Get the network from an explicit parameter.
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# The <net> parameter is not reliable for generator losses since often they are combined with many networks.
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border_sz = self.patch_size - self.overlap
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translation = random.choice([("top_right", border_sz, border_sz+self.overlap, 0, self.overlap),
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("bottom_left", 0, self.overlap, border_sz, border_sz+self.overlap),
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("bottom_right", 0, self.overlap, 0, self.overlap)])
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trans_name, hl, hh, wl, wh = translation
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# Change the "fake" input name that we are translating to one that specifies the random translation.
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fake = self.opt['fake'].copy()
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fake[self.gen_input_for_alteration] = "%s_%s" % (fake[self.gen_input_for_alteration], trans_name)
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input = extract_params_from_state(fake, state)
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if self.detach_fake:
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with torch.no_grad():
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trans_output = net(*input)
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else:
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trans_output = net(*input)
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if self.gen_output_to_use is not None:
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fake_shared_output = trans_output[self.gen_output_to_use][:, :, hl:hh, wl:wh]
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else:
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fake_shared_output = trans_output[:, :, hl:hh, wl:wh]
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# The "real" input is assumed to always come from the top left tile.
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gen_output = state[self.opt['real']]
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real_shared_output = gen_output[:, :, border_sz:border_sz+self.overlap, border_sz:border_sz+self.overlap]
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if self.opt['criterion'] == 'cosine':
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return self.criterion(fake_shared_output, real_shared_output, torch.ones(1, device=real_shared_output.device))
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else:
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return self.criterion(fake_shared_output, real_shared_output)
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# Computes a loss repeatedly feeding the generator downsampled inputs created from its outputs. The expectation is
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# that the generator's outputs do not change on repeated forward passes.
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# The "real" parameter to this loss is the actual output of the generator.
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# The "fake" parameter is the expected inputs that should be fed into the generator. 'input_alteration_index' is changed
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# so that it feeds the recursive input.
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class RecursiveInvarianceLoss(ConfigurableLoss):
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def __init__(self, opt, env):
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super(RecursiveInvarianceLoss, self).__init__(opt, env)
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self.opt = opt
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self.generator = opt['generator']
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self.criterion = get_basic_criterion_for_name(opt['criterion'], env['device'])
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self.gen_input_for_alteration = opt['input_alteration_index'] if 'input_alteration_index' in opt.keys() else 0
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self.gen_output_to_use = opt['generator_output_index'] if 'generator_output_index' in opt.keys() else None
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self.recursive_depth = opt['recursive_depth'] # How many times to recursively feed the output of the generator back into itself
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self.downsample_factor = opt['downsample_factor'] # Just 1/opt['scale']. Necessary since this loss doesnt have access to opt['scale'].
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assert(self.recursive_depth > 0)
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def forward(self, net, state):
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self.metrics = []
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net = self.env['generators'][self.generator] # Get the network from an explicit parameter.
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# The <net> parameter is not reliable for generator losses since they can be combined with many networks.
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gen_output = state[self.opt['real']]
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recurrent_gen_output = gen_output
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fake = self.opt['fake'].copy()
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input = extract_params_from_state(fake, state)
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for i in range(self.recursive_depth):
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input[self.gen_input_for_alteration] = torch.nn.functional.interpolate(recurrent_gen_output, scale_factor=self.downsample_factor, mode="nearest")
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recurrent_gen_output = net(*input)[self.gen_output_to_use]
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compare_real = gen_output
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compare_fake = recurrent_gen_output
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if self.opt['criterion'] == 'cosine':
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return self.criterion(compare_real, compare_fake, torch.ones(1, device=compare_real.device))
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else:
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return self.criterion(compare_real, compare_fake)
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