import math import torch import torch.nn as nn import torch.nn.functional as F import numpy as np from models.srflow.RRDBNet_arch import RRDBNet from models.srflow.FlowUpsamplerNet import FlowUpsamplerNet import models.srflow.thops as thops import models.srflow.flow as flow from utils.util import opt_get class SRFlowNet(nn.Module): def __init__(self, in_nc, out_nc, nf, nb, gc=32, scale=4, K=None, opt=None, step=None): super(SRFlowNet, self).__init__() self.opt = opt self.quant = 255 if opt_get(opt, ['datasets', 'train', 'quant']) is \ None else opt_get(opt, ['datasets', 'train', 'quant']) initial_stride = opt_get(opt, ['networks', 'generator', 'initial_stride'], 1) self.RRDB = RRDBNet(in_nc, out_nc, nf=nf, nb=nb, gc=gc, scale=scale, opt=opt, initial_conv_stride=initial_stride) if 'pretrain_rrdb' in opt['networks']['generator'].keys(): rrdb_state_dict = torch.load(opt['networks']['generator']['pretrain_rrdb']) self.RRDB.load_state_dict(rrdb_state_dict, strict=True) hidden_channels = opt_get(opt, ['networks', 'generator','flow', 'hidden_channels']) hidden_channels = hidden_channels or 64 self.RRDB_training = opt_get(self.opt, ['networks', 'generator','train_RRDB'], default=False) self.flow_scale = opt_get(self.opt, ['networks', 'generator', 'flow_scale'], default=opt['scale']) self.patch_sz = opt_get(self.opt, ['networks', 'generator', 'flow', 'patch_size'], 160) self.flowUpsamplerNet = \ FlowUpsamplerNet((self.patch_sz, self.patch_sz, 3), hidden_channels, K, flow_coupling=opt['networks']['generator']['flow']['coupling'], opt=opt) self.i = 0 self.dbg_logp = 0 self.dbg_logdet = 0 def get_random_z(self, heat, seed=None, batch_size=1, lr_shape=None, device='cuda'): if seed: torch.manual_seed(seed) if opt_get(self.opt, ['networks', 'generator', 'flow', 'split', 'enable']): C = self.flowUpsamplerNet.C H = int(self.flow_scale * lr_shape[0] // (self.flowUpsamplerNet.scaleH * self.flow_scale / self.RRDB.scale)) W = int(self.flow_scale * lr_shape[1] // (self.flowUpsamplerNet.scaleW * self.flow_scale / self.RRDB.scale)) size = (batch_size, C, H, W) if heat == 0: z = torch.zeros(size) else: z = torch.normal(mean=0, std=heat, size=size) else: L = opt_get(self.opt, ['networks', 'generator', 'flow', 'L']) or 3 fac = 2 ** (L - 3) z_size = int(self.lr_size // (2 ** (L - 3))) z = torch.normal(mean=0, std=heat, size=(batch_size, 3 * 8 * 8 * fac * fac, z_size, z_size)) return z.to(device) def forward(self, gt=None, lr=None, z=None, eps_std=None, reverse=False, epses=None, reverse_with_grad=False, lr_enc=None, add_gt_noise=True, step=None, y_label=None): if not reverse: return self.normal_flow(gt, lr, epses=epses, lr_enc=lr_enc, add_gt_noise=add_gt_noise, step=step, y_onehot=y_label) else: assert lr.shape[1] == 3 if z is None: # Synthesize it. Accommodate mismatches in LR scale and flow_scale, which are normally handled by the RRDB subnet. lr_shape = [d * self.opt['scale'] / self.flow_scale for d in lr.shape[2:]] z = self.get_random_z(eps_std, batch_size=lr.shape[0], lr_shape=lr_shape, device=lr.device) if reverse_with_grad: return self.reverse_flow(lr, z, y_onehot=y_label, eps_std=eps_std, epses=epses, lr_enc=lr_enc, add_gt_noise=add_gt_noise) else: with torch.no_grad(): return self.reverse_flow(lr, z, y_onehot=y_label, eps_std=eps_std, epses=epses, lr_enc=lr_enc, add_gt_noise=add_gt_noise) def normal_flow(self, gt, lr, y_onehot=None, epses=None, lr_enc=None, add_gt_noise=True, step=None): if lr_enc is None: if self.RRDB_training: lr_enc = self.rrdbPreprocessing(lr) else: with torch.no_grad(): lr_enc = self.rrdbPreprocessing(lr) logdet = torch.zeros_like(gt[:, 0, 0, 0]) pixels = thops.pixels(gt) z = gt if add_gt_noise: # Setup noiseQuant = opt_get(self.opt, ['networks', 'generator','flow', 'augmentation', 'noiseQuant'], True) if noiseQuant: z = z + ((torch.rand(z.shape, device=z.device) - 0.5) / self.quant) logdet = logdet + float(-np.log(self.quant) * pixels) # Encode epses, logdet = self.flowUpsamplerNet(rrdbResults=lr_enc, gt=z, logdet=logdet, reverse=False, epses=[], y_onehot=y_onehot) objective = logdet.clone() if isinstance(epses, (list, tuple)): z = epses[-1] else: z = epses logp = flow.GaussianDiag.logp(None, None, z) objective = objective + logp nll = (-objective) / float(np.log(2.) * pixels) self.dbg_logp = -logp.mean().item() / float(np.log(2.) * pixels) self.dbg_logdet = -logdet.mean().item() / float(np.log(2.) * pixels) if isinstance(epses, list): return epses, nll, logdet return z, nll, logdet def get_debug_values(self, s, n): return {"logp": self.dbg_logp, "logdet": self.dbg_logdet} def rrdbPreprocessing(self, lr): rrdbResults = self.RRDB(lr, get_steps=True) block_idxs = opt_get(self.opt, ['networks', 'generator', 'flow', 'stackRRDB', 'blocks']) or [] if len(block_idxs) > 0: concat = torch.cat([rrdbResults["block_{}".format(idx)] for idx in block_idxs], dim=1) if opt_get(self.opt, ['networks', 'generator','flow', 'stackRRDB', 'concat']) or False: keys = ['last_lr_fea', 'fea_up1', 'fea_up2', 'fea_up4'] if 'fea_up0' in rrdbResults.keys(): keys.append('fea_up0') if 'fea_up-1' in rrdbResults.keys(): keys.append('fea_up-1') if self.flow_scale >= 8: keys.append('fea_up8') if self.flow_scale == 16: keys.append('fea_up16') for k in keys: h = rrdbResults[k].shape[2] w = rrdbResults[k].shape[3] rrdbResults[k] = torch.cat([rrdbResults[k], F.interpolate(concat, (h, w))], dim=1) return rrdbResults def get_score(self, disc_loss_sigma, z): score_real = 0.5 * (1 - 1 / (disc_loss_sigma ** 2)) * thops.sum(z ** 2, dim=[1, 2, 3]) - \ z.shape[1] * z.shape[2] * z.shape[3] * math.log(disc_loss_sigma) return -score_real def reverse_flow(self, lr, z, y_onehot, eps_std, epses=None, lr_enc=None, add_gt_noise=True): logdet = torch.zeros_like(lr[:, 0, 0, 0]) pixels = thops.pixels(lr) * self.opt['scale'] ** 2 if add_gt_noise: logdet = logdet - float(-np.log(self.quant) * pixels) if lr_enc is None: if self.RRDB_training: lr_enc = self.rrdbPreprocessing(lr) else: with torch.no_grad(): lr_enc = self.rrdbPreprocessing(lr) x, logdet = self.flowUpsamplerNet(rrdbResults=lr_enc, z=z, eps_std=eps_std, reverse=True, epses=epses, logdet=logdet) return x, logdet, lr_enc['out']