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#
# Copyright (C) 2023, Inria
# GRAPHDECO research group, https://team.inria.fr/graphdeco
# All rights reserved.
#
# This software is free for non-commercial, research and evaluation use
# under the terms of the LICENSE.md file.
#
# For inquiries contact george.drettakis@inria.fr
#
import torch
import torch.nn.functional as F
from torch.autograd import Variable
from math import exp
def l1_loss(network_output, gt):
return torch.abs((network_output - gt)).mean()
def l2_loss(network_output, gt):
return ((network_output - gt) ** 2).mean()
def gaussian(window_size, sigma):
gauss = torch.Tensor([exp(-(x - window_size // 2) ** 2 / float(2 * sigma ** 2)) for x in range(window_size)])
return gauss / gauss.sum()
def create_window(window_size, channel):
_1D_window = gaussian(window_size, 1.5).unsqueeze(1)
_2D_window = _1D_window.mm(_1D_window.t()).float().unsqueeze(0).unsqueeze(0)
window = Variable(_2D_window.expand(channel, 1, window_size, window_size).contiguous())
return window
def ssim(img1, img2, window_size=11, size_average=True):
channel = img1.size(-3)
window = create_window(window_size, channel)
if img1.is_cuda:
window = window.cuda(img1.get_device())
window = window.type_as(img1)
return _ssim(img1, img2, window, window_size, channel, size_average)
def _ssim(img1, img2, window, window_size, channel, size_average=True):
mu1 = F.conv2d(img1, window, padding=window_size // 2, groups=channel)
mu2 = F.conv2d(img2, window, padding=window_size // 2, groups=channel)
mu1_sq = mu1.pow(2)
mu2_sq = mu2.pow(2)
mu1_mu2 = mu1 * mu2
sigma1_sq = F.conv2d(img1 * img1, window, padding=window_size // 2, groups=channel) - mu1_sq
sigma2_sq = F.conv2d(img2 * img2, window, padding=window_size // 2, groups=channel) - mu2_sq
sigma12 = F.conv2d(img1 * img2, window, padding=window_size // 2, groups=channel) - mu1_mu2
C1 = 0.01 ** 2
C2 = 0.03 ** 2
ssim_map = ((2 * mu1_mu2 + C1) * (2 * sigma12 + C2)) / ((mu1_sq + mu2_sq + C1) * (sigma1_sq + sigma2_sq + C2))
if size_average:
return ssim_map.mean()
else:
return ssim_map.mean(1).mean(1).mean(1)
import torch
import torch.nn as nn
from taming.modules.losses.vqperceptual import * # TODO: taming dependency yes/no?
class LPIPSWithDiscriminator(nn.Module):
def __init__(self, disc_start, logvar_init=0.0, kl_weight=1.0, pixelloss_weight=1.0,
disc_num_layers=3, disc_in_channels=3, disc_factor=1.0, disc_weight=1.0,
perceptual_weight=1.0, use_actnorm=False, disc_conditional=False,
disc_loss="hinge"):
super().__init__()
assert disc_loss in ["hinge", "vanilla"]
self.kl_weight = kl_weight
self.pixel_weight = pixelloss_weight
self.perceptual_loss = LPIPS().eval()
self.perceptual_weight = perceptual_weight
# output log variance
self.logvar = nn.Parameter(torch.ones(size=()) * logvar_init)
self.discriminator = NLayerDiscriminator(input_nc=disc_in_channels,
n_layers=disc_num_layers,
use_actnorm=use_actnorm
).apply(weights_init)
self.discriminator_iter_start = disc_start
self.disc_loss = hinge_d_loss if disc_loss == "hinge" else vanilla_d_loss
self.disc_factor = disc_factor
self.discriminator_weight = disc_weight
self.disc_conditional = disc_conditional
def calculate_adaptive_weight(self, nll_loss, g_loss, last_layer=None):
if last_layer is not None:
nll_grads = torch.autograd.grad(nll_loss, last_layer, retain_graph=True)[0]
g_grads = torch.autograd.grad(g_loss, last_layer, retain_graph=True)[0]
else:
nll_grads = torch.autograd.grad(nll_loss, self.last_layer[0], retain_graph=True)[0]
g_grads = torch.autograd.grad(g_loss, self.last_layer[0], retain_graph=True)[0]
d_weight = torch.norm(nll_grads) / (torch.norm(g_grads) + 1e-4)
d_weight = torch.clamp(d_weight, 0.0, 1e4).detach()
d_weight = d_weight * self.discriminator_weight
return d_weight
def forward(self, inputs, reconstructions, optimizer_idx,
global_step, last_layer=None, cond=None, split="train"):
rec_loss = torch.abs(inputs.contiguous() - reconstructions.contiguous())
if self.perceptual_weight > 0:
p_loss = self.perceptual_loss(inputs.contiguous(), reconstructions.contiguous())
rec_loss = rec_loss + self.perceptual_weight * p_loss
# nll_loss = rec_loss / torch.exp(self.logvar) + self.logvar
# now the GAN part
if optimizer_idx == 0:
# generator update
logits_fake = self.discriminator(reconstructions.contiguous())
# g_loss = -torch.mean(logits_fake)
g_loss = F.relu(1 - logits_fake).mean()
# if self.disc_factor > 0.0:
# try:
# d_weight = self.calculate_adaptive_weight(nll_loss, g_loss, last_layer=last_layer)
# except RuntimeError:
# assert not self.training
# d_weight = torch.tensor(0.0)
# else:
# d_weight = torch.tensor(0.0)
# disc_factor = adopt_weight(self.disc_factor, global_step, threshold=self.discriminator_iter_start)
# loss = d_weight * disc_factor * g_loss
# return loss, log
return g_loss
if optimizer_idx == 1:
# second pass for discriminator update
logits_real = self.discriminator(inputs.contiguous().detach())
logits_fake = self.discriminator(reconstructions.contiguous().detach())
# disc_factor = adopt_weight(self.disc_factor, global_step, threshold=self.discriminator_iter_start)
# d_loss = disc_factor * self.disc_loss(logits_real, logits_fake)
# log = {"{}/disc_loss".format(split): d_loss.clone().detach().mean(),
# "{}/logits_real".format(split): logits_real.detach().mean(),
# "{}/logits_fake".format(split): logits_fake.detach().mean()
# }
# return d_loss, log
d_loss = self.disc_loss(logits_real, logits_fake)
return d_loss
import torch
from chamfer_distance import ChamferDistance
# 初始化 Chamfer Distance 模块
chamfer_dist_module = ChamferDistance()
def calculate_chamfer_loss(pred, gt):
"""
计算 Chamfer Distance 损失
Args:
pred (torch.Tensor): 预测点云,维度为 (batch_size, num_points, 3)
gt (torch.Tensor): 真实点云,维度为 (batch_size, num_points, 3)
chamfer_dist_module (ChamferDistance): 预先初始化的 Chamfer Distance 模块
Returns:
torch.Tensor: Chamfer Distance 损失
"""
# 计算 Chamfer Distance
dist1, dist2, idx1, idx2 = chamfer_dist_module(pred, gt)
loss = (torch.mean(dist1) + torch.mean(dist2)) / 2
return loss
if __name__ == "__main__":
discriminator = LPIPSWithDiscriminator(disc_start=0, disc_weight=0.5)
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