237 lines
9.1 KiB
Python
237 lines
9.1 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright (c) Alibaba, Inc. and its affiliates.
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import numbers
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import random
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import torch
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import torch.nn.functional as F
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from scepter.modules.model.network.diffusion.diffusion import \
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GaussianDiffusionRF
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from scepter.modules.model.network.diffusion.schedules import noise_schedule
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from scepter.modules.model.network.ldm import LatentDiffusion
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from scepter.modules.model.registry import MODELS
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from scepter.modules.utils.config import dict_to_yaml
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from scepter.modules.utils.distribute import we
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@MODELS.register_class()
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class LatentDiffusionSD3(LatentDiffusion):
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para_dict = LatentDiffusion.para_dict
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def __init__(self, cfg, logger=None):
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super().__init__(cfg, logger=logger)
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self.shift_factor = cfg.get('SHIFT_FACTOR', 0)
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self.t_weight_type = cfg.get('T_WEIGHT', 'logit_normal')
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self.logit_mean = cfg.get('LOGIT_MEAN', 0.0)
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self.logit_std = cfg.get('LOGIT_STD', 1.0)
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def init_params(self):
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self.parameterization = self.cfg.get('PARAMETERIZATION', 'rf')
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assert self.parameterization in [
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'eps', 'x0', 'v', 'rf'
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], 'currently only supporting "eps" and "x0" and "v" and "rf"'
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self.num_timesteps = self.cfg.get('TIMESTEPS', 1000)
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self.schedule_args = {
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k.lower(): v
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for k, v in self.cfg.get('SCHEDULE_ARGS', {
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'NAME': 'logsnr_cosine_interp',
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'SCALE_MIN': 2.0,
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'SCALE_MAX': 4.0
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}).items()
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}
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self.min_snr_gamma = self.cfg.get('MIN_SNR_GAMMA', None)
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self.zero_terminal_snr = self.cfg.get('ZERO_TERMINAL_SNR', False)
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if self.zero_terminal_snr:
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assert self.parameterization == 'v', 'Now zero_terminal_snr only support v-prediction mode.'
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self.sigmas = noise_schedule(schedule=self.schedule_args.pop('name'),
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n=self.num_timesteps,
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zero_terminal_snr=self.zero_terminal_snr,
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**self.schedule_args)
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self.diffusion = GaussianDiffusionRF(
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sigmas=self.sigmas, prediction_type=self.parameterization)
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self.pretrained_model = self.cfg.get('PRETRAINED_MODEL', None)
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self.ignore_keys = self.cfg.get('IGNORE_KEYS', [])
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self.model_config = self.cfg.DIFFUSION_MODEL
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self.first_stage_config = self.cfg.FIRST_STAGE_MODEL
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self.cond_stage_config = self.cfg.COND_STAGE_MODEL
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self.tokenizer_config = self.cfg.get('TOKENIZER', None)
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self.loss_config = self.cfg.get('LOSS', None)
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self.scale_factor = self.cfg.get('SCALE_FACTOR', 0.18215)
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self.size_factor = self.cfg.get('SIZE_FACTOR', 8)
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self.default_n_prompt = self.cfg.get('DEFAULT_N_PROMPT', '')
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self.default_n_prompt = '' if self.default_n_prompt is None else self.default_n_prompt
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self.p_zero = self.cfg.get('P_ZERO', 0.0)
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self.train_n_prompt = self.cfg.get('TRAIN_N_PROMPT', '')
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if self.default_n_prompt is None:
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self.default_n_prompt = ''
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if self.train_n_prompt is None:
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self.train_n_prompt = ''
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self.use_ema = self.cfg.get('USE_EMA', False)
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self.model_ema_config = self.cfg.get('DIFFUSION_MODEL_EMA', None)
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def noise_sample(self, batch_size, h, w, g, c=4):
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noise = torch.empty(batch_size, c, h, w,
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device=we.device_id).normal_(generator=g)
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return noise
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def forward_train(self, image=None, noise=None, prompt=None, **kwargs):
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n, c, h, w = image.shape
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x_start = self.encode_first_stage(image, **kwargs)
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if self.t_weight_type == 'uniform':
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t = torch.randint(0,
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self.num_timesteps, (n, ),
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device=x_start.device).long()
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elif self.t_weight_type == 'logit_normal':
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density = F.sigmoid(
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torch.normal(mean=self.logit_mean,
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std=self.logit_std,
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size=(n, ),
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device=x_start.device))
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t = (density * (self.num_timesteps - 1)).round().long()
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sigma = (t + 1) / self.num_timesteps
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shift = self.schedule_args['shift']
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if shift > 1.:
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sigma = shift * sigma / (1 + (shift - 1) * sigma)
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t = sigma * self.num_timesteps
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context = {}
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if prompt and self.cond_stage_model:
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ctx, pooled = getattr(self.cond_stage_model, 'encode')(prompt)
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context['crossattn'] = ctx.float()
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context['y'] = pooled
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else:
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assert False
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if self.min_snr_gamma is not None:
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alphas = self.diffusion.alphas.to(we.device_id)[t]
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sigmas = self.diffusion.sigmas.pow(2).to(we.device_id)[t]
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snrs = (alphas / sigmas).clamp(min=1e-20)
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min_snrs = snrs.clamp(max=self.min_snr_gamma)
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weights = min_snrs / snrs
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else:
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weights = 1
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self.register_probe({'snrs_weights': weights})
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loss = self.diffusion.loss(x0=x_start,
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t=t,
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model=self.model,
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model_kwargs={
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'cond': context,
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},
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noise=noise,
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**kwargs)
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loss = loss * weights
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loss = loss.mean()
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ret = {'loss': loss, 'probe_data': {'prompt': prompt}}
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return ret
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@torch.no_grad()
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def forward_test(self,
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prompt=None,
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sampler='ddim',
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sample_steps=20,
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seed=2023,
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guide_scale=4.5,
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guide_rescale=0.0,
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**kwargs):
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g = torch.Generator(device=we.device_id)
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seed = seed if seed >= 0 else random.randint(0, 2**32 - 1)
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g.manual_seed(seed)
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num_samples = len(prompt)
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context = {}
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null_context = {}
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if prompt and self.cond_stage_model:
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ctx, pooled = getattr(self.cond_stage_model, 'encode')(prompt)
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null_ctx, null_pooled = getattr(self.cond_stage_model,
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'encode')([''] * len(prompt))
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context['crossattn'] = ctx.float()
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context['y'] = pooled.float()
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null_context['crossattn'] = null_ctx.float()
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null_context['y'] = null_pooled.float()
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else:
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assert False
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if 'index' in kwargs:
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kwargs.pop('index')
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image_size = None
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if 'meta' in kwargs:
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meta = kwargs.pop('meta')
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if 'image_size' in meta:
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h = int(meta['image_size'][0][0])
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w = int(meta['image_size'][1][0])
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image_size = [h, w]
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if 'image_size' in kwargs:
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image_size = kwargs.pop('image_size')
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if isinstance(image_size, numbers.Number):
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image_size = [image_size, image_size]
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if image_size is None:
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image_size = [1024, 1024]
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height, width = image_size
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noise = self.noise_sample(num_samples,
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height // self.size_factor,
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width // self.size_factor,
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g,
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c=16)
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# UNet use input n_prompt
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samples = self.diffusion.sample(
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solver=sampler,
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noise=noise,
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model=self.model,
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model_kwargs=[{
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'cond': context
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}, {
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'cond': null_context
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}] if guide_scale is not None and guide_scale > 0 else {
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'cond': context,
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},
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cat_uc=False,
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steps=sample_steps,
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guide_scale=guide_scale,
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guide_rescale=guide_rescale,
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show_progress=True,
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seed=seed,
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condition_fn=None,
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clamp=None,
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percentile=None,
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t_max=None,
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t_min=None,
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discard_penultimate_step=None,
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return_intermediate=None,
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**kwargs)
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x_samples = self.decode_first_stage(samples).float()
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x_samples = torch.clamp((x_samples + 1.0) / 2.0, min=0.0, max=1.0)
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outputs = list()
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for i, (p, img) in enumerate(zip(prompt, x_samples)):
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one_tup = {'prompt': str(p), 'n_prompt': '', 'image': img}
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outputs.append(one_tup)
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return outputs
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@staticmethod
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def get_config_template():
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return dict_to_yaml('MODEL',
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__class__.__name__,
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LatentDiffusionSD3.para_dict,
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set_name=True)
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@torch.no_grad()
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def encode_first_stage(self, x, **kwargs):
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z = self.first_stage_model.encode(x)
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return self.scale_factor * (z - self.shift_factor)
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@torch.no_grad()
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def decode_first_stage(self, z):
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z = 1. / self.scale_factor * z + self.shift_factor
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return self.first_stage_model.decode(z)
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