seawolf2357's picture
Deploy from GitHub repository
3b58dfc verified
import hashlib
import os
from collections import namedtuple
import requests
import torch
import torch.nn as nn
from torchvision import models
from tqdm import tqdm
URL_MAP = {"vgg_lpips": "https://heibox.uni-heidelberg.de/f/607503859c864bc1b30b/?dl=1"}
CKPT_MAP = {"vgg_lpips": "vgg.pth"}
MD5_MAP = {"vgg_lpips": "d507d7349b931f0638a25a48a722f98a"}
def md5_hash(path):
with open(path, "rb") as f:
content = f.read()
return hashlib.md5(content).hexdigest()
def download(url, local_path, chunk_size=1024):
os.makedirs(os.path.split(local_path)[0], exist_ok=True)
with requests.get(url, stream=True) as r:
total_size = int(r.headers.get("content-length", 0))
with tqdm(total=total_size, unit="B", unit_scale=True) as pbar:
with open(local_path, "wb") as f:
for data in r.iter_content(chunk_size=chunk_size):
if data:
f.write(data)
pbar.update(chunk_size)
def get_ckpt_path(name, root, check=False):
assert name in URL_MAP
path = os.path.join(root, CKPT_MAP[name])
if not os.path.exists(path) or (check and not md5_hash(path) == MD5_MAP[name]):
print("Downloading {} model from {} to {}".format(name, URL_MAP[name], path))
download(URL_MAP[name], path)
md5 = md5_hash(path)
assert md5 == MD5_MAP[name], md5
return path
class LPIPS(nn.Module):
# Learned perceptual metric
def __init__(self, use_dropout=True):
super().__init__()
self.scaling_layer = ScalingLayer()
self.chns = [64, 128, 256, 512, 512] # vg16 features
self.net = vgg16(pretrained=True, requires_grad=False)
self.lin0 = NetLinLayer(self.chns[0], use_dropout=use_dropout)
self.lin1 = NetLinLayer(self.chns[1], use_dropout=use_dropout)
self.lin2 = NetLinLayer(self.chns[2], use_dropout=use_dropout)
self.lin3 = NetLinLayer(self.chns[3], use_dropout=use_dropout)
self.lin4 = NetLinLayer(self.chns[4], use_dropout=use_dropout)
self.load_from_pretrained()
for param in self.parameters():
param.requires_grad = False
def load_from_pretrained(self, name="vgg_lpips"):
ckpt = get_ckpt_path(name, "model_zoo/taming/modules/autoencoder/lpips")
self.load_state_dict(torch.load(ckpt, map_location=torch.device("cpu")), strict=False)
# print("loaded pretrained LPIPS loss from {}".format(ckpt))
@classmethod
def from_pretrained(cls, name="vgg_lpips"):
if name != "vgg_lpips":
raise NotImplementedError
model = cls()
ckpt = get_ckpt_path(name)
model.load_state_dict(torch.load(ckpt, map_location=torch.device("cpu")), strict=False)
return model
def forward(self, input, target):
in0_input, in1_input = (self.scaling_layer(input), self.scaling_layer(target))
outs0, outs1 = self.net(in0_input), self.net(in1_input)
feats0, feats1, diffs = {}, {}, {}
lins = [self.lin0, self.lin1, self.lin2, self.lin3, self.lin4]
for kk in range(len(self.chns)):
feats0[kk], feats1[kk] = normalize_tensor(outs0[kk]), normalize_tensor(outs1[kk])
diffs[kk] = (feats0[kk] - feats1[kk]) ** 2
res = [spatial_average(lins[kk].model(diffs[kk]), keepdim=True) for kk in range(len(self.chns))]
val = res[0]
for l in range(1, len(self.chns)):
val += res[l]
return val
class ScalingLayer(nn.Module):
def __init__(self):
super(ScalingLayer, self).__init__()
self.register_buffer("shift", torch.Tensor([-0.030, -0.088, -0.188])[None, :, None, None])
self.register_buffer("scale", torch.Tensor([0.458, 0.448, 0.450])[None, :, None, None])
def forward(self, inp):
return (inp - self.shift) / self.scale
class NetLinLayer(nn.Module):
"""A single linear layer which does a 1x1 conv"""
def __init__(self, chn_in, chn_out=1, use_dropout=False):
super(NetLinLayer, self).__init__()
layers = (
[
nn.Dropout(),
]
if (use_dropout)
else []
)
layers += [
nn.Conv2d(chn_in, chn_out, 1, stride=1, padding=0, bias=False),
]
self.model = nn.Sequential(*layers)
class vgg16(torch.nn.Module):
def __init__(self, requires_grad=False, pretrained=True):
super(vgg16, self).__init__()
vgg_pretrained_features = models.vgg16(pretrained=pretrained).features
self.slice1 = torch.nn.Sequential()
self.slice2 = torch.nn.Sequential()
self.slice3 = torch.nn.Sequential()
self.slice4 = torch.nn.Sequential()
self.slice5 = torch.nn.Sequential()
self.N_slices = 5
for x in range(4):
self.slice1.add_module(str(x), vgg_pretrained_features[x])
for x in range(4, 9):
self.slice2.add_module(str(x), vgg_pretrained_features[x])
for x in range(9, 16):
self.slice3.add_module(str(x), vgg_pretrained_features[x])
for x in range(16, 23):
self.slice4.add_module(str(x), vgg_pretrained_features[x])
for x in range(23, 30):
self.slice5.add_module(str(x), vgg_pretrained_features[x])
if not requires_grad:
for param in self.parameters():
param.requires_grad = False
def forward(self, X):
h = self.slice1(X)
h_relu1_2 = h
h = self.slice2(h)
h_relu2_2 = h
h = self.slice3(h)
h_relu3_3 = h
h = self.slice4(h)
h_relu4_3 = h
h = self.slice5(h)
h_relu5_3 = h
vgg_outputs = namedtuple("VggOutputs", ["relu1_2", "relu2_2", "relu3_3", "relu4_3", "relu5_3"])
out = vgg_outputs(h_relu1_2, h_relu2_2, h_relu3_3, h_relu4_3, h_relu5_3)
return out
def normalize_tensor(x, eps=1e-10):
norm_factor = torch.sqrt(torch.sum(x**2, dim=1, keepdim=True))
return x / (norm_factor + eps)
def spatial_average(x, keepdim=True):
return x.mean([2, 3], keepdim=keepdim)