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import torch | |
import torch.nn as nn | |
import torch.nn.functional as F | |
import torchvision | |
from models.ade20k import ModelBuilder | |
from saicinpainting.utils import check_and_warn_input_range | |
IMAGENET_MEAN = torch.FloatTensor([0.485, 0.456, 0.406])[None, :, None, None] | |
IMAGENET_STD = torch.FloatTensor([0.229, 0.224, 0.225])[None, :, None, None] | |
class PerceptualLoss(nn.Module): | |
def __init__(self, normalize_inputs=True): | |
super(PerceptualLoss, self).__init__() | |
self.normalize_inputs = normalize_inputs | |
self.mean_ = IMAGENET_MEAN | |
self.std_ = IMAGENET_STD | |
vgg = torchvision.models.vgg19(pretrained=True).features | |
vgg_avg_pooling = [] | |
for weights in vgg.parameters(): | |
weights.requires_grad = False | |
for module in vgg.modules(): | |
if module.__class__.__name__ == 'Sequential': | |
continue | |
elif module.__class__.__name__ == 'MaxPool2d': | |
vgg_avg_pooling.append(nn.AvgPool2d(kernel_size=2, stride=2, padding=0)) | |
else: | |
vgg_avg_pooling.append(module) | |
self.vgg = nn.Sequential(*vgg_avg_pooling) | |
def do_normalize_inputs(self, x): | |
return (x - self.mean_.to(x.device)) / self.std_.to(x.device) | |
def partial_losses(self, input, target, mask=None): | |
check_and_warn_input_range(target, 0, 1, 'PerceptualLoss target in partial_losses') | |
# we expect input and target to be in [0, 1] range | |
losses = [] | |
if self.normalize_inputs: | |
features_input = self.do_normalize_inputs(input) | |
features_target = self.do_normalize_inputs(target) | |
else: | |
features_input = input | |
features_target = target | |
for layer in self.vgg[:30]: | |
features_input = layer(features_input) | |
features_target = layer(features_target) | |
if layer.__class__.__name__ == 'ReLU': | |
loss = F.mse_loss(features_input, features_target, reduction='none') | |
if mask is not None: | |
cur_mask = F.interpolate(mask, size=features_input.shape[-2:], | |
mode='bilinear', align_corners=False) | |
loss = loss * (1 - cur_mask) | |
loss = loss.mean(dim=tuple(range(1, len(loss.shape)))) | |
losses.append(loss) | |
return losses | |
def forward(self, input, target, mask=None): | |
losses = self.partial_losses(input, target, mask=mask) | |
return torch.stack(losses).sum(dim=0) | |
def get_global_features(self, input): | |
check_and_warn_input_range(input, 0, 1, 'PerceptualLoss input in get_global_features') | |
if self.normalize_inputs: | |
features_input = self.do_normalize_inputs(input) | |
else: | |
features_input = input | |
features_input = self.vgg(features_input) | |
return features_input | |
class ResNetPL(nn.Module): | |
def __init__(self, weight=1, | |
weights_path=None, arch_encoder='resnet50dilated', segmentation=True): | |
super().__init__() | |
self.impl = ModelBuilder.get_encoder(weights_path=weights_path, | |
arch_encoder=arch_encoder, | |
arch_decoder='ppm_deepsup', | |
fc_dim=2048, | |
segmentation=segmentation) | |
self.impl.eval() | |
for w in self.impl.parameters(): | |
w.requires_grad_(False) | |
self.weight = weight | |
def forward(self, pred, target): | |
pred = (pred - IMAGENET_MEAN.to(pred)) / IMAGENET_STD.to(pred) | |
target = (target - IMAGENET_MEAN.to(target)) / IMAGENET_STD.to(target) | |
pred_feats = self.impl(pred, return_feature_maps=True) | |
target_feats = self.impl(target, return_feature_maps=True) | |
result = torch.stack([F.mse_loss(cur_pred, cur_target) | |
for cur_pred, cur_target | |
in zip(pred_feats, target_feats)]).sum() * self.weight | |
return result | |