mirror of
https://github.com/graphdeco-inria/gaussian-splatting
synced 2024-11-24 04:53:57 +00:00
92 lines
2.9 KiB
Python
92 lines
2.9 KiB
Python
#
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# Copyright (C) 2023, Inria
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# GRAPHDECO research group, https://team.inria.fr/graphdeco
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# All rights reserved.
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#
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# This software is free for non-commercial, research and evaluation use
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# under the terms of the LICENSE.md file.
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#
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# For inquiries contact george.drettakis@inria.fr
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#
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import torch
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import torch.nn.functional as F
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from torch.autograd import Variable
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from math import exp
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try:
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from diff_gaussian_rasterization._C import fusedssim, fusedssim_backward
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except:
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pass
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C1 = 0.01 ** 2
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C2 = 0.03 ** 2
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class FusedSSIMMap(torch.autograd.Function):
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@staticmethod
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def forward(ctx, C1, C2, img1, img2):
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ssim_map = fusedssim(C1, C2, img1, img2)
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ctx.save_for_backward(img1.detach(), img2)
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ctx.C1 = C1
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ctx.C2 = C2
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return ssim_map
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@staticmethod
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def backward(ctx, opt_grad):
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img1, img2 = ctx.saved_tensors
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C1, C2 = ctx.C1, ctx.C2
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grad = fusedssim_backward(C1, C2, img1, img2, opt_grad)
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return None, None, grad, None
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def l1_loss(network_output, gt):
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return torch.abs((network_output - gt)).mean()
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def l2_loss(network_output, gt):
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return ((network_output - gt) ** 2).mean()
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def gaussian(window_size, sigma):
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gauss = torch.Tensor([exp(-(x - window_size // 2) ** 2 / float(2 * sigma ** 2)) for x in range(window_size)])
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return gauss / gauss.sum()
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def create_window(window_size, channel):
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_1D_window = gaussian(window_size, 1.5).unsqueeze(1)
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_2D_window = _1D_window.mm(_1D_window.t()).float().unsqueeze(0).unsqueeze(0)
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window = Variable(_2D_window.expand(channel, 1, window_size, window_size).contiguous())
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return window
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def ssim(img1, img2, window_size=11, size_average=True):
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channel = img1.size(-3)
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window = create_window(window_size, channel)
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if img1.is_cuda:
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window = window.cuda(img1.get_device())
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window = window.type_as(img1)
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return _ssim(img1, img2, window, window_size, channel, size_average)
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def _ssim(img1, img2, window, window_size, channel, size_average=True):
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mu1 = F.conv2d(img1, window, padding=window_size // 2, groups=channel)
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mu2 = F.conv2d(img2, window, padding=window_size // 2, groups=channel)
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mu1_sq = mu1.pow(2)
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mu2_sq = mu2.pow(2)
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mu1_mu2 = mu1 * mu2
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sigma1_sq = F.conv2d(img1 * img1, window, padding=window_size // 2, groups=channel) - mu1_sq
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sigma2_sq = F.conv2d(img2 * img2, window, padding=window_size // 2, groups=channel) - mu2_sq
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sigma12 = F.conv2d(img1 * img2, window, padding=window_size // 2, groups=channel) - mu1_mu2
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C1 = 0.01 ** 2
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C2 = 0.03 ** 2
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ssim_map = ((2 * mu1_mu2 + C1) * (2 * sigma12 + C2)) / ((mu1_sq + mu2_sq + C1) * (sigma1_sq + sigma2_sq + C2))
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if size_average:
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return ssim_map.mean()
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else:
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return ssim_map.mean(1).mean(1).mean(1)
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def fast_ssim(img1, img2):
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ssim_map = FusedSSIMMap.apply(C1, C2, img1, img2)
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return ssim_map.mean()
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