mirror of
https://github.com/ostris/ai-toolkit.git
synced 2026-01-26 16:39:47 +00:00
Sampling tests and added fixes for cleanups
This commit is contained in:
@@ -282,12 +282,34 @@ class BaseSDTrainProcess(BaseTrainProcess):
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items = glob.glob(os.path.join(self.save_root, pattern))
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# Separate files and directories
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safetensors_files = [f for f in items if f.endswith('.safetensors')]
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pt_files = [f for f in items if f.endswith('.pt')]
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directories = [d for d in items if os.path.isdir(d) and not d.endswith('.safetensors')]
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# Combine the list and sort by creation time
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combined_items = safetensors_files + directories
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# Sort the lists by creation time if they are not empty
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if safetensors_files:
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safetensors_files.sort(key=os.path.getctime)
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if pt_files:
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pt_files.sort(key=os.path.getctime)
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if directories:
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directories.sort(key=os.path.getctime)
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# Combine and sort the lists
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combined_items = safetensors_files + directories + pt_files
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combined_items.sort(key=os.path.getctime)
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# Use slicing with a check to avoid 'NoneType' error
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safetensors_to_remove = safetensors_files[
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:-self.save_config.max_step_saves_to_keep] if safetensors_files else []
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pt_files_to_remove = pt_files[:-self.save_config.max_step_saves_to_keep] if pt_files else []
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directories_to_remove = directories[:-self.save_config.max_step_saves_to_keep] if directories else []
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combined_items_to_remove = combined_items[
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:-self.save_config.max_step_saves_to_keep] if combined_items else []
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items_to_remove = safetensors_to_remove + pt_files_to_remove + directories_to_remove
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# remove all but the latest max_step_saves_to_keep
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items_to_remove = combined_items[:-self.save_config.max_step_saves_to_keep]
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# items_to_remove = combined_items[:-self.save_config.max_step_saves_to_keep]
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for item in items_to_remove:
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self.print(f"Removing old save: {item}")
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if os.path.isdir(item):
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@@ -655,14 +677,15 @@ class BaseSDTrainProcess(BaseTrainProcess):
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do_double = False
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with self.timer('prepare_noise'):
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num_train_timesteps = self.sd.noise_scheduler.config['num_train_timesteps']
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if self.train_config.noise_scheduler == 'lcm':
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self.sd.noise_scheduler.set_timesteps(
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1000, device=self.device_torch, original_inference_steps=1000
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num_train_timesteps, device=self.device_torch, original_inference_steps=num_train_timesteps
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)
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else:
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self.sd.noise_scheduler.set_timesteps(
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1000, device=self.device_torch
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num_train_timesteps, device=self.device_torch
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)
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# if self.train_config.timestep_sampling == 'style' or self.train_config.timestep_sampling == 'content':
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@@ -17,6 +17,8 @@ from diffusers import (
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from k_diffusion.external import CompVisDenoiser
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from toolkit.samplers.scheduling_ddpm import ADDPMScheduler
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# scheduler:
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SCHEDULER_LINEAR_START = 0.00085
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SCHEDULER_LINEAR_END = 0.0120
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@@ -76,6 +78,8 @@ def get_sampler(
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scheduler_cls = KDPM2AncestralDiscreteScheduler
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elif sampler == "lcm":
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scheduler_cls = LCMScheduler
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elif sampler == "addpm":
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scheduler_cls = ADDPMScheduler
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config = copy.deepcopy(sdxl_sampler_config)
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config.update(sched_init_args)
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460
toolkit/samplers/scheduling_ddpm.py
Normal file
460
toolkit/samplers/scheduling_ddpm.py
Normal file
@@ -0,0 +1,460 @@
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# Copyright 2023 UC Berkeley Team and The HuggingFace Team. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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# DISCLAIMER: This file is strongly influenced by https://github.com/ermongroup/ddim
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import math
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from dataclasses import dataclass
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from typing import List, Optional, Tuple, Union
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import numpy as np
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import torch
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from diffusers.configuration_utils import ConfigMixin, register_to_config
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from diffusers.utils import BaseOutput
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from diffusers.utils.torch_utils import randn_tensor
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from diffusers.schedulers.scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
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@dataclass
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class DDPMSchedulerOutput(BaseOutput):
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"""
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Output class for the scheduler's `step` function output.
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Args:
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prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
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Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
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denoising loop.
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pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
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The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
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`pred_original_sample` can be used to preview progress or for guidance.
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"""
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prev_sample: torch.FloatTensor
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pred_original_sample: Optional[torch.FloatTensor] = None
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def betas_for_alpha_bar(
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num_diffusion_timesteps,
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max_beta=0.999,
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alpha_transform_type="cosine",
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):
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"""
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Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
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(1-beta) over time from t = [0,1].
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Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
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to that part of the diffusion process.
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Args:
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num_diffusion_timesteps (`int`): the number of betas to produce.
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max_beta (`float`): the maximum beta to use; use values lower than 1 to
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prevent singularities.
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alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
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Choose from `cosine` or `exp`
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Returns:
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betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
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"""
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if alpha_transform_type == "cosine":
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def alpha_bar_fn(t):
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return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
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elif alpha_transform_type == "exp":
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def alpha_bar_fn(t):
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return math.exp(t * -12.0)
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else:
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raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
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betas = []
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for i in range(num_diffusion_timesteps):
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t1 = i / num_diffusion_timesteps
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t2 = (i + 1) / num_diffusion_timesteps
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betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
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return torch.tensor(betas, dtype=torch.float32)
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class ADDPMScheduler(SchedulerMixin, ConfigMixin):
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"""
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`DDPMScheduler` explores the connections between denoising score matching and Langevin dynamics sampling.
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This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
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methods the library implements for all schedulers such as loading and saving.
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Args:
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num_train_timesteps (`int`, defaults to 1000):
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The number of diffusion steps to train the model.
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beta_start (`float`, defaults to 0.0001):
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The starting `beta` value of inference.
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beta_end (`float`, defaults to 0.02):
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The final `beta` value.
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beta_schedule (`str`, defaults to `"linear"`):
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The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
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`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
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variance_type (`str`, defaults to `"fixed_small"`):
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Clip the variance when adding noise to the denoised sample. Choose from `fixed_small`, `fixed_small_log`,
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`fixed_large`, `fixed_large_log`, `learned` or `learned_range`.
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clip_sample (`bool`, defaults to `True`):
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Clip the predicted sample for numerical stability.
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clip_sample_range (`float`, defaults to 1.0):
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The maximum magnitude for sample clipping. Valid only when `clip_sample=True`.
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prediction_type (`str`, defaults to `epsilon`, *optional*):
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Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
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`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
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Video](https://imagen.research.google/video/paper.pdf) paper).
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thresholding (`bool`, defaults to `False`):
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Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
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as Stable Diffusion.
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dynamic_thresholding_ratio (`float`, defaults to 0.995):
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The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
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sample_max_value (`float`, defaults to 1.0):
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The threshold value for dynamic thresholding. Valid only when `thresholding=True`.
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timestep_spacing (`str`, defaults to `"leading"`):
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The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
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Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
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steps_offset (`int`, defaults to 0):
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An offset added to the inference steps. You can use a combination of `offset=1` and
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`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
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Diffusion.
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"""
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_compatibles = [e.name for e in KarrasDiffusionSchedulers]
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order = 1
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@register_to_config
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def __init__(
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self,
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num_train_timesteps: int = 1000,
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beta_start: float = 0.0001,
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beta_end: float = 0.02,
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beta_schedule: str = "linear",
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trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
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variance_type: str = "fixed_small",
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clip_sample: bool = True,
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prediction_type: str = "epsilon",
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thresholding: bool = False,
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dynamic_thresholding_ratio: float = 0.995,
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clip_sample_range: float = 1.0,
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sample_max_value: float = 1.0,
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timestep_spacing: str = "leading",
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steps_offset: int = 0,
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):
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if trained_betas is not None:
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self.betas = torch.tensor(trained_betas, dtype=torch.float32)
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elif beta_schedule == "linear":
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self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
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elif beta_schedule == "scaled_linear":
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# this schedule is very specific to the latent diffusion model.
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self.betas = (
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torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
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)
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elif beta_schedule == "squaredcos_cap_v2":
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# Glide cosine schedule
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self.betas = betas_for_alpha_bar(num_train_timesteps)
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elif beta_schedule == "sigmoid":
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# GeoDiff sigmoid schedule
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betas = torch.linspace(-6, 6, num_train_timesteps)
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self.betas = torch.sigmoid(betas) * (beta_end - beta_start) + beta_start
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else:
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raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
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self.alphas = 1.0 - self.betas
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self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
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self.one = torch.tensor(1.0)
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# standard deviation of the initial noise distribution
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self.init_noise_sigma = 1.0
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self.is_training = False
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# setable values
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self.custom_timesteps = False
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self.num_inference_steps = None
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self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy())
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self.variance_type = variance_type
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def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
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"""
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Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
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current timestep.
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Args:
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sample (`torch.FloatTensor`):
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The input sample.
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timestep (`int`, *optional*):
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The current timestep in the diffusion chain.
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Returns:
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`torch.FloatTensor`:
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A scaled input sample.
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"""
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return sample
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def set_timesteps(
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self,
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num_inference_steps: Optional[int] = None,
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device: Union[str, torch.device] = None,
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timesteps: Optional[List[int]] = None,
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):
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original_steps = 50 if num_inference_steps != 1000 else 1000
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train_timesteps = self.config['num_train_timesteps']
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strength = 1.0
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c = train_timesteps // original_steps
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# LCM Training Steps Schedule
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lcm_origin_timesteps = np.asarray(list(range(1, int(original_steps * strength) + 1))) * c - 1
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skipping_step = len(lcm_origin_timesteps) // num_inference_steps
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# LCM Inference Steps Schedule
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timesteps = lcm_origin_timesteps[::-skipping_step][:num_inference_steps]
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self._step_index = None
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self.timesteps = torch.from_numpy(timesteps.copy()).to(device)
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def _get_variance(self, t, predicted_variance=None, variance_type=None):
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prev_t = self.previous_timestep(t)
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alpha_prod_t = self.alphas_cumprod[t]
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alpha_prod_t_prev = self.alphas_cumprod[prev_t] if prev_t >= 0 else self.one
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current_beta_t = 1 - alpha_prod_t / alpha_prod_t_prev
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# For t > 0, compute predicted variance βt (see formula (6) and (7) from https://arxiv.org/pdf/2006.11239.pdf)
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# and sample from it to get previous sample
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# x_{t-1} ~ N(pred_prev_sample, variance) == add variance to pred_sample
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variance = (1 - alpha_prod_t_prev) / (1 - alpha_prod_t) * current_beta_t
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# we always take the log of variance, so clamp it to ensure it's not 0
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variance = torch.clamp(variance, min=1e-20)
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if variance_type is None:
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variance_type = self.config.variance_type
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# hacks - were probably added for training stability
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if variance_type == "fixed_small":
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variance = variance
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# for rl-diffuser https://arxiv.org/abs/2205.09991
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elif variance_type == "fixed_small_log":
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variance = torch.log(variance)
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variance = torch.exp(0.5 * variance)
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elif variance_type == "fixed_large":
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variance = current_beta_t
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elif variance_type == "fixed_large_log":
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# Glide max_log
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variance = torch.log(current_beta_t)
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elif variance_type == "learned":
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return predicted_variance
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elif variance_type == "learned_range":
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min_log = torch.log(variance)
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max_log = torch.log(current_beta_t)
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frac = (predicted_variance + 1) / 2
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variance = frac * max_log + (1 - frac) * min_log
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return variance
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def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
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"""
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"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
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prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
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s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
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pixels from saturation at each step. We find that dynamic thresholding results in significantly better
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photorealism as well as better image-text alignment, especially when using very large guidance weights."
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|
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https://arxiv.org/abs/2205.11487
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"""
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dtype = sample.dtype
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batch_size, channels, *remaining_dims = sample.shape
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if dtype not in (torch.float32, torch.float64):
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sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
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# Flatten sample for doing quantile calculation along each image
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sample = sample.reshape(batch_size, channels * np.prod(remaining_dims))
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abs_sample = sample.abs() # "a certain percentile absolute pixel value"
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s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
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s = torch.clamp(
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s, min=1, max=self.config.sample_max_value
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) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
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s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
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sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
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sample = sample.reshape(batch_size, channels, *remaining_dims)
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sample = sample.to(dtype)
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return sample
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def step(
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self,
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model_output: torch.FloatTensor,
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timestep: int,
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sample: torch.FloatTensor,
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generator=None,
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return_dict: bool = True,
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) -> Union[DDPMSchedulerOutput, Tuple]:
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"""
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Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
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process from the learned model outputs (most often the predicted noise).
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Args:
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model_output (`torch.FloatTensor`):
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The direct output from learned diffusion model.
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timestep (`float`):
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The current discrete timestep in the diffusion chain.
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sample (`torch.FloatTensor`):
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A current instance of a sample created by the diffusion process.
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generator (`torch.Generator`, *optional*):
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A random number generator.
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return_dict (`bool`, *optional*, defaults to `True`):
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Whether or not to return a [`~schedulers.scheduling_ddpm.DDPMSchedulerOutput`] or `tuple`.
|
||||
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||||
Returns:
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[`~schedulers.scheduling_ddpm.DDPMSchedulerOutput`] or `tuple`:
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||||
If return_dict is `True`, [`~schedulers.scheduling_ddpm.DDPMSchedulerOutput`] is returned, otherwise a
|
||||
tuple is returned where the first element is the sample tensor.
|
||||
|
||||
"""
|
||||
t = timestep
|
||||
|
||||
prev_t = self.previous_timestep(t)
|
||||
|
||||
if model_output.shape[1] == sample.shape[1] * 2 and self.variance_type in ["learned", "learned_range"]:
|
||||
model_output, predicted_variance = torch.split(model_output, sample.shape[1], dim=1)
|
||||
else:
|
||||
predicted_variance = None
|
||||
|
||||
# 1. compute alphas, betas
|
||||
alpha_prod_t = self.alphas_cumprod[t]
|
||||
alpha_prod_t_prev = self.alphas_cumprod[prev_t] if prev_t >= 0 else self.one
|
||||
beta_prod_t = 1 - alpha_prod_t
|
||||
beta_prod_t_prev = 1 - alpha_prod_t_prev
|
||||
current_alpha_t = alpha_prod_t / alpha_prod_t_prev
|
||||
current_beta_t = 1 - current_alpha_t
|
||||
|
||||
# 2. compute predicted original sample from predicted noise also called
|
||||
# "predicted x_0" of formula (15) from https://arxiv.org/pdf/2006.11239.pdf
|
||||
if self.config.prediction_type == "epsilon":
|
||||
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
|
||||
elif self.config.prediction_type == "sample":
|
||||
pred_original_sample = model_output
|
||||
elif self.config.prediction_type == "v_prediction":
|
||||
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
|
||||
else:
|
||||
raise ValueError(
|
||||
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample` or"
|
||||
" `v_prediction` for the DDPMScheduler."
|
||||
)
|
||||
|
||||
# 3. Clip or threshold "predicted x_0"
|
||||
if self.config.thresholding:
|
||||
pred_original_sample = self._threshold_sample(pred_original_sample)
|
||||
elif self.config.clip_sample:
|
||||
pred_original_sample = pred_original_sample.clamp(
|
||||
-self.config.clip_sample_range, self.config.clip_sample_range
|
||||
)
|
||||
|
||||
# 4. Compute coefficients for pred_original_sample x_0 and current sample x_t
|
||||
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
|
||||
pred_original_sample_coeff = (alpha_prod_t_prev ** (0.5) * current_beta_t) / beta_prod_t
|
||||
current_sample_coeff = current_alpha_t ** (0.5) * beta_prod_t_prev / beta_prod_t
|
||||
|
||||
# 5. Compute predicted previous sample µ_t
|
||||
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
|
||||
pred_prev_sample = pred_original_sample_coeff * pred_original_sample + current_sample_coeff * sample
|
||||
|
||||
# 6. Add noise
|
||||
variance = 0
|
||||
if t > 0:
|
||||
device = model_output.device
|
||||
variance_noise = randn_tensor(
|
||||
model_output.shape, generator=generator, device=device, dtype=model_output.dtype
|
||||
)
|
||||
if self.variance_type == "fixed_small_log":
|
||||
variance = self._get_variance(t, predicted_variance=predicted_variance) * variance_noise
|
||||
elif self.variance_type == "learned_range":
|
||||
variance = self._get_variance(t, predicted_variance=predicted_variance)
|
||||
variance = torch.exp(0.5 * variance) * variance_noise
|
||||
else:
|
||||
variance = (self._get_variance(t, predicted_variance=predicted_variance) ** 0.5) * variance_noise
|
||||
|
||||
pred_prev_sample = pred_prev_sample + variance
|
||||
|
||||
if not return_dict:
|
||||
return (pred_prev_sample,)
|
||||
|
||||
return DDPMSchedulerOutput(prev_sample=pred_prev_sample, pred_original_sample=pred_original_sample)
|
||||
|
||||
def add_noise(
|
||||
self,
|
||||
original_samples: torch.FloatTensor,
|
||||
noise: torch.FloatTensor,
|
||||
timesteps: torch.IntTensor,
|
||||
) -> torch.FloatTensor:
|
||||
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
|
||||
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
|
||||
timesteps = timesteps.to(original_samples.device)
|
||||
|
||||
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
|
||||
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
|
||||
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
|
||||
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
|
||||
|
||||
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
|
||||
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
|
||||
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
|
||||
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
|
||||
|
||||
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
|
||||
return noisy_samples
|
||||
|
||||
def get_velocity(
|
||||
self, sample: torch.FloatTensor, noise: torch.FloatTensor, timesteps: torch.IntTensor
|
||||
) -> torch.FloatTensor:
|
||||
# Make sure alphas_cumprod and timestep have same device and dtype as sample
|
||||
alphas_cumprod = self.alphas_cumprod.to(device=sample.device, dtype=sample.dtype)
|
||||
timesteps = timesteps.to(sample.device)
|
||||
|
||||
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
|
||||
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
|
||||
while len(sqrt_alpha_prod.shape) < len(sample.shape):
|
||||
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
|
||||
|
||||
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
|
||||
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
|
||||
while len(sqrt_one_minus_alpha_prod.shape) < len(sample.shape):
|
||||
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
|
||||
|
||||
velocity = sqrt_alpha_prod * noise - sqrt_one_minus_alpha_prod * sample
|
||||
return velocity
|
||||
|
||||
def __len__(self):
|
||||
return self.config.num_train_timesteps
|
||||
|
||||
def previous_timestep(self, timestep):
|
||||
if self.custom_timesteps:
|
||||
index = (self.timesteps == timestep).nonzero(as_tuple=True)[0][0]
|
||||
if index == self.timesteps.shape[0] - 1:
|
||||
prev_t = torch.tensor(-1)
|
||||
else:
|
||||
prev_t = self.timesteps[index + 1]
|
||||
else:
|
||||
num_inference_steps = (
|
||||
self.num_inference_steps if self.num_inference_steps else self.config.num_train_timesteps
|
||||
)
|
||||
prev_t = timestep - self.config.num_train_timesteps // num_inference_steps
|
||||
|
||||
return prev_t
|
||||
@@ -675,6 +675,9 @@ class StableDiffusion:
|
||||
do_classifier_free_guidance = False
|
||||
elif latents.shape[0] * 2 != text_embeddings.text_embeds.shape[0]:
|
||||
raise ValueError("Batch size of latents must be the same or half the batch size of text embeddings")
|
||||
latents = latents.to(self.device_torch)
|
||||
text_embeddings = text_embeddings.to(self.device_torch)
|
||||
timestep = timestep.to(self.device_torch)
|
||||
|
||||
if self.is_xl:
|
||||
with torch.no_grad():
|
||||
|
||||
Reference in New Issue
Block a user