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32da3e8 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 | from collections import namedtuple
import numpy as np
import torch
import math
import torch.nn as nn
from torchvision import models
from torch.utils.data import Dataset
import os
import sys
from pathlib import Path
# insert ../ as a module path
current_dir = Path(__file__).resolve().parent
parent_dir = current_dir.parent
if str(parent_dir) not in sys.path:
sys.path.insert(0, str(parent_dir))
from disc.lpips_utils import get_ckpt_path
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)
class ScalingLayer(nn.Module):
def __init__(self):
super(ScalingLayer, self).__init__()
self.register_buffer('shift', torch.Tensor([-.030, -.088, -.188])[None, :, None, None])
self.register_buffer('scale', torch.Tensor([.458, .448, .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):
super(VGG16, self).__init__()
vgg_pretrained_features = models.vgg16(weights='DEFAULT').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
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(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)
self.load_state_dict(
torch.load(
ckpt,
map_location=torch.device("cpu")),
strict=False
)
print("loaded pretrained LPIPS loss from {}".format(ckpt))
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 ImgArrDataset(Dataset):
"""
Serve as the wrapper purpose for `torch-fidelity` to calculate the metrics (FID),
which expects [B, C, H, W] tensor in uint8. We are returning a [C, H, W] tensor.
"""
def __init__(self, arr):
self.arr = arr
def __len__(self):
return len(self.arr)
def __getitem__(self, idx):
return torch.from_numpy(self.arr[idx]).permute(2, 0, 1)
######################################################
# 1. Convert NumPy arrays to Torch tensors, if needed
######################################################
def to_torch_tensor(np_array):
"""
Converts a NumPy array of shape (B, H, W, C) to a (B, C, H, W) float32 Torch tensor.
Expects image to be in [0, 1] or [0, 255].
Adjust if necessary.
"""
tensor = torch.from_numpy(np_array).permute(0, 3, 1, 2)
# If your data is in [0, 255], convert to [0, 1].
if tensor.max() > 1.0:
tensor = tensor.float() / 255.0
else:
tensor = tensor.float()
return tensor
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