135 lines
5.3 KiB
Python
135 lines
5.3 KiB
Python
import math
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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import numpy as np
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from models.archs.srflow.FlowUpsamplerNet import FlowUpsamplerNet
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import models.archs.srflow.thops as thops
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import models.archs.srflow.flow as flow
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from models.archs.srflow.RRDBNet_arch import RRDBNet
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class SRFlowNet(nn.Module):
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def __init__(self, in_nc, out_nc, nf, nb, quant, flow_block_maps, noise_quant,
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hidden_channels=64, gc=32, scale=4, K=16, L=3, train_rrdb_at_step=0,
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hr_img_shape=(128,128,3), coupling='CondAffineSeparatedAndCond'):
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super(SRFlowNet, self).__init__()
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self.scale = scale
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self.noise_quant = noise_quant
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self.quant = quant
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self.flow_block_maps = flow_block_maps
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self.RRDB = RRDBNet(in_nc, out_nc, nf, nb, gc, scale, flow_block_maps)
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self.train_rrdb_step = train_rrdb_at_step
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self.RRDB_training = True
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self.flowUpsamplerNet = FlowUpsamplerNet(image_shape=hr_img_shape,
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hidden_channels=hidden_channels,
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scale=scale, rrdb_blocks=flow_block_maps,
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K=K, L=L, flow_coupling=coupling)
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self.i = 0
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def forward(self, gt=None, lr=None, reverse=False, z=None, eps_std=None, epses=None, reverse_with_grad=False,
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lr_enc=None,
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add_gt_noise=False, step=None, y_label=None):
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if not reverse:
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return self.normal_flow(gt, lr, epses=epses, lr_enc=lr_enc, add_gt_noise=add_gt_noise, step=step,
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y_onehot=y_label)
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else:
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assert lr.shape[1] == 3
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if reverse_with_grad:
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return self.reverse_flow(lr, z, y_onehot=y_label, eps_std=eps_std, epses=epses, lr_enc=lr_enc,
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add_gt_noise=add_gt_noise)
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else:
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with torch.no_grad():
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return self.reverse_flow(lr, z, y_onehot=y_label, eps_std=eps_std, epses=epses, lr_enc=lr_enc,
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add_gt_noise=add_gt_noise)
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def normal_flow(self, gt, lr, y_onehot=None, epses=None, lr_enc=None, add_gt_noise=True, step=None):
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if lr_enc is None:
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lr_enc = self.rrdbPreprocessing(lr)
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logdet = torch.zeros_like(gt[:, 0, 0, 0])
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pixels = thops.pixels(gt)
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z = gt
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if add_gt_noise:
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# Setup
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if self.noise_quant:
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z = z + ((torch.rand(z.shape, device=z.device) - 0.5) / self.quant)
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logdet = logdet + float(-np.log(self.quant) * pixels)
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# Encode
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epses, logdet = self.flowUpsamplerNet(rrdbResults=lr_enc, gt=z, logdet=logdet, reverse=False, epses=epses,
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y_onehot=y_onehot)
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objective = logdet.clone()
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if isinstance(epses, (list, tuple)):
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z = epses[-1]
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else:
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z = epses
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objective = objective + flow.GaussianDiag.logp(None, None, z)
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nll = (-objective) / float(np.log(2.) * pixels)
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if isinstance(epses, list):
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return epses, nll, logdet
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return z, nll, logdet
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def rrdbPreprocessing(self, lr):
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rrdbResults = self.RRDB(lr, get_steps=True)
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block_idxs = self.flow_block_maps
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if len(block_idxs) > 0:
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concat = torch.cat([rrdbResults["block_{}".format(idx)] for idx in block_idxs], dim=1)
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keys = ['last_lr_fea', 'fea_up1', 'fea_up2', 'fea_up4']
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if 'fea_up0' in rrdbResults.keys():
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keys.append('fea_up0')
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if 'fea_up-1' in rrdbResults.keys():
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keys.append('fea_up-1')
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if self.scale >= 8:
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keys.append('fea_up8')
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if self.scale == 16:
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keys.append('fea_up16')
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for k in keys:
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h = rrdbResults[k].shape[2]
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w = rrdbResults[k].shape[3]
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rrdbResults[k] = torch.cat([rrdbResults[k], F.interpolate(concat, (h, w))], dim=1)
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return rrdbResults
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def get_score(self, disc_loss_sigma, z):
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score_real = 0.5 * (1 - 1 / (disc_loss_sigma ** 2)) * thops.sum(z ** 2, dim=[1, 2, 3]) - \
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z.shape[1] * z.shape[2] * z.shape[3] * math.log(disc_loss_sigma)
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return -score_real
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def reverse_flow(self, lr, z, y_onehot, eps_std, epses=None, lr_enc=None, add_gt_noise=True):
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logdet = torch.zeros_like(lr[:, 0, 0, 0])
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pixels = thops.pixels(lr) * self.scale ** 2
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if add_gt_noise:
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logdet = logdet - float(-np.log(self.quant) * pixels)
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if lr_enc is None:
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lr_enc = self.rrdbPreprocessing(lr)
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x, logdet = self.flowUpsamplerNet(rrdbResults=lr_enc, z=z, eps_std=eps_std, reverse=True, epses=epses,
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logdet=logdet)
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return x, logdet
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def set_rrdb_training(self, trainable):
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if self.RRDB_training != trainable:
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for p in self.RRDB.parameters():
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if not trainable:
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p.DO_NOT_TRAIN = True
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elif hasattr(p, "DO_NOT_TRAIN"):
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del p.DO_NOT_TRAIN
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self.RRDB_training = trainable
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def update_for_step(self, step, experiments_path='.'):
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self.set_rrdb_training(step > self.train_rrdb_step) |