ashawkey/zero123-xl-diffusers
659k
1# Copyright 2023 The HuggingFace Team. All rights reserved.2#3# Licensed under the Apache License, Version 2.0 (the "License");4# you may not use this file except in compliance with the License.5# You may obtain a copy of the License at6#7# http://www.apache.org/licenses/LICENSE-2.08#9# Unless required by applicable law or agreed to in writing, software10# distributed under the License is distributed on an "AS IS" BASIS,11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.12# See the License for the specific language governing permissions and13# limitations under the License.14 15import inspect16import math17import warnings18from typing import Any, Callable, Dict, List, Optional, Union19 20import PIL21import torch22import torchvision.transforms.functional as TF23from diffusers.configuration_utils import ConfigMixin, FrozenDict, register_to_config24from diffusers.image_processor import VaeImageProcessor25from diffusers.models import AutoencoderKL, UNet2DConditionModel26from diffusers.models.modeling_utils import ModelMixin27from diffusers.pipelines.pipeline_utils import DiffusionPipeline28from diffusers.pipelines.stable_diffusion import StableDiffusionPipelineOutput29from diffusers.pipelines.stable_diffusion.safety_checker import (30 StableDiffusionSafetyChecker,31)32from diffusers.schedulers import KarrasDiffusionSchedulers33from diffusers.utils import deprecate, is_accelerate_available, logging34from diffusers.utils.torch_utils import randn_tensor35from packaging import version36from transformers import CLIPImageProcessor, CLIPVisionModelWithProjection37 38logger = logging.get_logger(__name__) # pylint: disable=invalid-name39 40 41class CLIPCameraProjection(ModelMixin, ConfigMixin):42 """43 A Projection layer for CLIP embedding and camera embedding.44 45 Parameters:46 embedding_dim (`int`, *optional*, defaults to 768): The dimension of the model input `clip_embed`47 additional_embeddings (`int`, *optional*, defaults to 4): The number of additional tokens appended to the48 projected `hidden_states`. The actual length of the used `hidden_states` is `num_embeddings +49 additional_embeddings`.50 """51 52 @register_to_config53 def __init__(self, embedding_dim: int = 768, additional_embeddings: int = 4):54 super().__init__()55 self.embedding_dim = embedding_dim56 self.additional_embeddings = additional_embeddings57 58 self.input_dim = self.embedding_dim + self.additional_embeddings59 self.output_dim = self.embedding_dim60 61 self.proj = torch.nn.Linear(self.input_dim, self.output_dim)62 63 def forward(64 self,65 embedding: torch.FloatTensor,66 ):67 """68 The [`PriorTransformer`] forward method.69 70 Args:71 hidden_states (`torch.FloatTensor` of shape `(batch_size, input_dim)`):72 The currently input embeddings.73 74 Returns:75 The output embedding projection (`torch.FloatTensor` of shape `(batch_size, output_dim)`).76 """77 proj_embedding = self.proj(embedding)78 return proj_embedding79 80 81class Zero123Pipeline(DiffusionPipeline):82 r"""83 Pipeline to generate variations from an input image using Stable Diffusion.84 85 This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods the86 library implements for all the pipelines (such as downloading or saving, running on a particular device, etc.)87 88 Args:89 vae ([`AutoencoderKL`]):90 Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations.91 image_encoder ([`CLIPVisionModelWithProjection`]):92 Frozen CLIP image-encoder. Stable Diffusion Image Variation uses the vision portion of93 [CLIP](https://huggingface.co/docs/transformers/model_doc/clip#transformers.CLIPVisionModelWithProjection),94 specifically the [clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14) variant.95 unet ([`UNet2DConditionModel`]): Conditional U-Net architecture to denoise the encoded image latents.96 scheduler ([`SchedulerMixin`]):97 A scheduler to be used in combination with `unet` to denoise the encoded image latents. Can be one of98 [`DDIMScheduler`], [`LMSDiscreteScheduler`], or [`PNDMScheduler`].99 safety_checker ([`StableDiffusionSafetyChecker`]):100 Classification module that estimates whether generated images could be considered offensive or harmful.101 Please, refer to the [model card](https://huggingface.co/runwayml/stable-diffusion-v1-5) for details.102 feature_extractor ([`CLIPImageProcessor`]):103 Model that extracts features from generated images to be used as inputs for the `safety_checker`.104 """105 # TODO: feature_extractor is required to encode images (if they are in PIL format),106 # we should give a descriptive message if the pipeline doesn't have one.107 _optional_components = ["safety_checker"]108 109 def __init__(110 self,111 vae: AutoencoderKL,112 image_encoder: CLIPVisionModelWithProjection,113 unet: UNet2DConditionModel,114 scheduler: KarrasDiffusionSchedulers,115 safety_checker: StableDiffusionSafetyChecker,116 feature_extractor: CLIPImageProcessor,117 clip_camera_projection: CLIPCameraProjection,118 requires_safety_checker: bool = True,119 ):120 super().__init__()121 122 if safety_checker is None and requires_safety_checker:123 logger.warn(124 f"You have disabled the safety checker for {self.__class__} by passing `safety_checker=None`. Ensure"125 " that you abide to the conditions of the Stable Diffusion license and do not expose unfiltered"126 " results in services or applications open to the public. Both the diffusers team and Hugging Face"127 " strongly recommend to keep the safety filter enabled in all public facing circumstances, disabling"128 " it only for use-cases that involve analyzing network behavior or auditing its results. For more"129 " information, please have a look at https://github.com/huggingface/diffusers/pull/254 ."130 )131 132 if safety_checker is not None and feature_extractor is None:133 raise ValueError(134 "Make sure to define a feature extractor when loading {self.__class__} if you want to use the safety"135 " checker. If you do not want to use the safety checker, you can pass `'safety_checker=None'` instead."136 )137 138 is_unet_version_less_0_9_0 = hasattr(139 unet.config, "_diffusers_version"140 ) and version.parse(141 version.parse(unet.config._diffusers_version).base_version142 ) < version.parse(143 "0.9.0.dev0"144 )145 is_unet_sample_size_less_64 = (146 hasattr(unet.config, "sample_size") and unet.config.sample_size < 64147 )148 if is_unet_version_less_0_9_0 and is_unet_sample_size_less_64:149 deprecation_message = (150 "The configuration file of the unet has set the default `sample_size` to smaller than"151 " 64 which seems highly unlikely .If you're checkpoint is a fine-tuned version of any of the"152 " following: \n- CompVis/stable-diffusion-v1-4 \n- CompVis/stable-diffusion-v1-3 \n-"153 " CompVis/stable-diffusion-v1-2 \n- CompVis/stable-diffusion-v1-1 \n- runwayml/stable-diffusion-v1-5"154 " \n- runwayml/stable-diffusion-inpainting \n you should change 'sample_size' to 64 in the"155 " configuration file. Please make sure to update the config accordingly as leaving `sample_size=32`"156 " in the config might lead to incorrect results in future versions. If you have downloaded this"157 " checkpoint from the Hugging Face Hub, it would be very nice if you could open a Pull request for"158 " the `unet/config.json` file"159 )160 deprecate(161 "sample_size<64", "1.0.0", deprecation_message, standard_warn=False162 )163 new_config = dict(unet.config)164 new_config["sample_size"] = 64165 unet._internal_dict = FrozenDict(new_config)166 167 self.register_modules(168 vae=vae,169 image_encoder=image_encoder,170 unet=unet,171 scheduler=scheduler,172 safety_checker=safety_checker,173 feature_extractor=feature_extractor,174 clip_camera_projection=clip_camera_projection,175 )176 self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1)177 self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)178 self.register_to_config(requires_safety_checker=requires_safety_checker)179 180 def enable_sequential_cpu_offload(self, gpu_id=0):181 r"""182 Offloads all models to CPU using accelerate, significantly reducing memory usage. When called, unet,183 text_encoder, vae and safety checker have their state dicts saved to CPU and then are moved to a184 `torch.device('meta') and loaded to GPU only when their specific submodule has its `forward` method called.185 """186 if is_accelerate_available():187 from accelerate import cpu_offload188 else:189 raise ImportError("Please install accelerate via `pip install accelerate`")190 191 device = torch.device(f"cuda:{gpu_id}")192 193 for cpu_offloaded_model in [194 self.unet,195 self.image_encoder,196 self.vae,197 self.safety_checker,198 ]:199 if cpu_offloaded_model is not None:200 cpu_offload(cpu_offloaded_model, device)201 202 @property203 # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline._execution_device204 def _execution_device(self):205 r"""206 Returns the device on which the pipeline's models will be executed. After calling207 `pipeline.enable_sequential_cpu_offload()` the execution device can only be inferred from Accelerate's module208 hooks.209 """210 if not hasattr(self.unet, "_hf_hook"):211 return self.device212 for module in self.unet.modules():213 if (214 hasattr(module, "_hf_hook")215 and hasattr(module._hf_hook, "execution_device")216 and module._hf_hook.execution_device is not None217 ):218 return torch.device(module._hf_hook.execution_device)219 return self.device220 221 def _encode_image(222 self,223 image,224 elevation,225 azimuth,226 distance,227 device,228 num_images_per_prompt,229 do_classifier_free_guidance,230 clip_image_embeddings=None,231 image_camera_embeddings=None,232 ):233 dtype = next(self.image_encoder.parameters()).dtype234 235 if image_camera_embeddings is None:236 if image is None:237 assert clip_image_embeddings is not None238 image_embeddings = clip_image_embeddings.to(device=device, dtype=dtype)239 else:240 if not isinstance(image, torch.Tensor):241 image = self.feature_extractor(242 images=image, return_tensors="pt"243 ).pixel_values244 245 image = image.to(device=device, dtype=dtype)246 image_embeddings = self.image_encoder(image).image_embeds247 image_embeddings = image_embeddings.unsqueeze(1)248 249 bs_embed, seq_len, _ = image_embeddings.shape250 251 if isinstance(elevation, float):252 elevation = torch.as_tensor(253 [elevation] * bs_embed, dtype=dtype, device=device254 )255 if isinstance(azimuth, float):256 azimuth = torch.as_tensor(257 [azimuth] * bs_embed, dtype=dtype, device=device258 )259 if isinstance(distance, float):260 distance = torch.as_tensor(261 [distance] * bs_embed, dtype=dtype, device=device262 )263 264 camera_embeddings = torch.stack(265 [266 torch.deg2rad(elevation),267 torch.sin(torch.deg2rad(azimuth)),268 torch.cos(torch.deg2rad(azimuth)),269 distance,270 ],271 dim=-1,272 )[:, None, :]273 274 image_embeddings = torch.cat([image_embeddings, camera_embeddings], dim=-1)275 276 # project (image, camera) embeddings to the same dimension as clip embeddings277 image_embeddings = self.clip_camera_projection(image_embeddings)278 else:279 image_embeddings = image_camera_embeddings.to(device=device, dtype=dtype)280 bs_embed, seq_len, _ = image_embeddings.shape281 282 # duplicate image embeddings for each generation per prompt, using mps friendly method283 image_embeddings = image_embeddings.repeat(1, num_images_per_prompt, 1)284 image_embeddings = image_embeddings.view(285 bs_embed * num_images_per_prompt, seq_len, -1286 )287 288 if do_classifier_free_guidance:289 negative_prompt_embeds = torch.zeros_like(image_embeddings)290 291 # For classifier free guidance, we need to do two forward passes.292 # Here we concatenate the unconditional and text embeddings into a single batch293 # to avoid doing two forward passes294 image_embeddings = torch.cat([negative_prompt_embeds, image_embeddings])295 296 return image_embeddings297 298 # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.run_safety_checker299 def run_safety_checker(self, image, device, dtype):300 if self.safety_checker is None:301 has_nsfw_concept = None302 else:303 if torch.is_tensor(image):304 feature_extractor_input = self.image_processor.postprocess(305 image, output_type="pil"306 )307 else:308 feature_extractor_input = self.image_processor.numpy_to_pil(image)309 safety_checker_input = self.feature_extractor(310 feature_extractor_input, return_tensors="pt"311 ).to(device)312 image, has_nsfw_concept = self.safety_checker(313 images=image, clip_input=safety_checker_input.pixel_values.to(dtype)314 )315 return image, has_nsfw_concept316 317 # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.decode_latents318 def decode_latents(self, latents):319 warnings.warn(320 "The decode_latents method is deprecated and will be removed in a future version. Please"321 " use VaeImageProcessor instead",322 FutureWarning,323 )324 latents = 1 / self.vae.config.scaling_factor * latents325 image = self.vae.decode(latents, return_dict=False)[0]326 image = (image / 2 + 0.5).clamp(0, 1)327 # we always cast to float32 as this does not cause significant overhead and is compatible with bfloat16328 image = image.cpu().permute(0, 2, 3, 1).float().numpy()329 return image330 331 # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.prepare_extra_step_kwargs332 def prepare_extra_step_kwargs(self, generator, eta):333 # prepare extra kwargs for the scheduler step, since not all schedulers have the same signature334 # eta (η) is only used with the DDIMScheduler, it will be ignored for other schedulers.335 # eta corresponds to η in DDIM paper: https://arxiv.org/abs/2010.02502336 # and should be between [0, 1]337 338 accepts_eta = "eta" in set(339 inspect.signature(self.scheduler.step).parameters.keys()340 )341 extra_step_kwargs = {}342 if accepts_eta:343 extra_step_kwargs["eta"] = eta344 345 # check if the scheduler accepts generator346 accepts_generator = "generator" in set(347 inspect.signature(self.scheduler.step).parameters.keys()348 )349 if accepts_generator:350 extra_step_kwargs["generator"] = generator351 return extra_step_kwargs352 353 def check_inputs(self, image, height, width, callback_steps):354 # TODO: check image size or adjust image size to (height, width)355 356 if height % 8 != 0 or width % 8 != 0:357 raise ValueError(358 f"`height` and `width` have to be divisible by 8 but are {height} and {width}."359 )360 361 if (callback_steps is None) or (362 callback_steps is not None363 and (not isinstance(callback_steps, int) or callback_steps <= 0)364 ):365 raise ValueError(366 f"`callback_steps` has to be a positive integer but is {callback_steps} of type"367 f" {type(callback_steps)}."368 )369 370 # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.prepare_latents371 def prepare_latents(372 self,373 batch_size,374 num_channels_latents,375 height,376 width,377 dtype,378 device,379 generator,380 latents=None,381 ):382 shape = (383 batch_size,384 num_channels_latents,385 height // self.vae_scale_factor,386 width // self.vae_scale_factor,387 )388 if isinstance(generator, list) and len(generator) != batch_size:389 raise ValueError(390 f"You have passed a list of generators of length {len(generator)}, but requested an effective batch"391 f" size of {batch_size}. Make sure the batch size matches the length of the generators."392 )393 394 if latents is None:395 latents = randn_tensor(396 shape, generator=generator, device=device, dtype=dtype397 )398 else:399 latents = latents.to(device)400 401 # scale the initial noise by the standard deviation required by the scheduler402 latents = latents * self.scheduler.init_noise_sigma403 return latents404 405 def _get_latent_model_input(406 self,407 latents: torch.FloatTensor,408 image: Optional[409 Union[PIL.Image.Image, List[PIL.Image.Image], torch.FloatTensor]410 ],411 num_images_per_prompt: int,412 do_classifier_free_guidance: bool,413 image_latents: Optional[torch.FloatTensor] = None,414 ):415 if isinstance(image, PIL.Image.Image):416 image_pt = TF.to_tensor(image).unsqueeze(0).to(latents)417 elif isinstance(image, list):418 image_pt = torch.stack([TF.to_tensor(img) for img in image], dim=0).to(419 latents420 )421 elif isinstance(image, torch.Tensor):422 image_pt = image423 else:424 image_pt = None425 426 if image_pt is None:427 assert image_latents is not None428 image_pt = image_latents.repeat_interleave(num_images_per_prompt, dim=0)429 else:430 image_pt = image_pt * 2.0 - 1.0 # scale to [-1, 1]431 # FIXME: encoded latents should be multiplied with self.vae.config.scaling_factor432 # but zero123 was not trained this way433 image_pt = self.vae.encode(image_pt).latent_dist.mode()434 image_pt = image_pt.repeat_interleave(num_images_per_prompt, dim=0)435 if do_classifier_free_guidance:436 latent_model_input = torch.cat(437 [438 torch.cat([latents, latents], dim=0),439 torch.cat([torch.zeros_like(image_pt), image_pt], dim=0),440 ],441 dim=1,442 )443 else:444 latent_model_input = torch.cat([latents, image_pt], dim=1)445 446 return latent_model_input447 448 @torch.no_grad()449 def __call__(450 self,451 image: Optional[452 Union[PIL.Image.Image, List[PIL.Image.Image], torch.FloatTensor]453 ] = None,454 elevation: Optional[Union[float, torch.FloatTensor]] = None,455 azimuth: Optional[Union[float, torch.FloatTensor]] = None,456 distance: Optional[Union[float, torch.FloatTensor]] = None,457 height: Optional[int] = None,458 width: Optional[int] = None,459 num_inference_steps: int = 50,460 guidance_scale: float = 3.0,461 num_images_per_prompt: int = 1,462 eta: float = 0.0,463 generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,464 latents: Optional[torch.FloatTensor] = None,465 clip_image_embeddings: Optional[torch.FloatTensor] = None,466 image_camera_embeddings: Optional[torch.FloatTensor] = None,467 image_latents: Optional[torch.FloatTensor] = None,468 output_type: Optional[str] = "pil",469 return_dict: bool = True,470 callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None,471 callback_steps: int = 1,472 cross_attention_kwargs: Optional[Dict[str, Any]] = None,473 ):474 r"""475 Function invoked when calling the pipeline for generation.476 477 Args:478 image (`PIL.Image.Image` or `List[PIL.Image.Image]` or `torch.FloatTensor`):479 The image or images to guide the image generation. If you provide a tensor, it needs to comply with the480 configuration of481 [this](https://huggingface.co/lambdalabs/sd-image-variations-diffusers/blob/main/feature_extractor/preprocessor_config.json)482 `CLIPImageProcessor`483 height (`int`, *optional*, defaults to self.unet.config.sample_size * self.vae_scale_factor):484 The height in pixels of the generated image.485 width (`int`, *optional*, defaults to self.unet.config.sample_size * self.vae_scale_factor):486 The width in pixels of the generated image.487 num_inference_steps (`int`, *optional*, defaults to 50):488 The number of denoising steps. More denoising steps usually lead to a higher quality image at the489 expense of slower inference.490 guidance_scale (`float`, *optional*, defaults to 7.5):491 Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).492 `guidance_scale` is defined as `w` of equation 2. of [Imagen493 Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting `guidance_scale >494 1`. Higher guidance scale encourages to generate images that are closely linked to the text `prompt`,495 usually at the expense of lower image quality.496 num_images_per_prompt (`int`, *optional*, defaults to 1):497 The number of images to generate per prompt.498 eta (`float`, *optional*, defaults to 0.0):499 Corresponds to parameter eta (η) in the DDIM paper: https://arxiv.org/abs/2010.02502. Only applies to500 [`schedulers.DDIMScheduler`], will be ignored for others.501 generator (`torch.Generator`, *optional*):502 One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html)503 to make generation deterministic.504 latents (`torch.FloatTensor`, *optional*):505 Pre-generated noisy latents, sampled from a Gaussian distribution, to be used as inputs for image506 generation. Can be used to tweak the same generation with different prompts. If not provided, a latents507 tensor will ge generated by sampling using the supplied random `generator`.508 output_type (`str`, *optional*, defaults to `"pil"`):509 The output format of the generate image. Choose between510 [PIL](https://pillow.readthedocs.io/en/stable/): `PIL.Image.Image` or `np.array`.511 return_dict (`bool`, *optional*, defaults to `True`):512 Whether or not to return a [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] instead of a513 plain tuple.514 callback (`Callable`, *optional*):515 A function that will be called every `callback_steps` steps during inference. The function will be516 called with the following arguments: `callback(step: int, timestep: int, latents: torch.FloatTensor)`.517 callback_steps (`int`, *optional*, defaults to 1):518 The frequency at which the `callback` function will be called. If not specified, the callback will be519 called at every step.520 521 Returns:522 [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] or `tuple`:523 [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] if `return_dict` is True, otherwise a `tuple.524 When returning a tuple, the first element is a list with the generated images, and the second element is a525 list of `bool`s denoting whether the corresponding generated image likely represents "not-safe-for-work"526 (nsfw) content, according to the `safety_checker`.527 """528 # 0. Default height and width to unet529 height = height or self.unet.config.sample_size * self.vae_scale_factor530 width = width or self.unet.config.sample_size * self.vae_scale_factor531 532 # 1. Check inputs. Raise error if not correct533 # TODO: check input elevation, azimuth, and distance534 # TODO: check image, clip_image_embeddings, image_latents535 self.check_inputs(image, height, width, callback_steps)536 537 # 2. Define call parameters538 if isinstance(image, PIL.Image.Image):539 batch_size = 1540 elif isinstance(image, list):541 batch_size = len(image)542 elif isinstance(image, torch.Tensor):543 batch_size = image.shape[0]544 else:545 assert image_latents is not None546 assert (547 clip_image_embeddings is not None or image_camera_embeddings is not None548 )549 batch_size = image_latents.shape[0]550 551 device = self._execution_device552 # here `guidance_scale` is defined analog to the guidance weight `w` of equation (2)553 # of the Imagen paper: https://arxiv.org/pdf/2205.11487.pdf . `guidance_scale = 1`554 # corresponds to doing no classifier free guidance.555 do_classifier_free_guidance = guidance_scale > 1.0556 557 # 3. Encode input image558 if isinstance(image, PIL.Image.Image) or isinstance(image, list):559 pil_image = image560 elif isinstance(image, torch.Tensor):561 pil_image = [TF.to_pil_image(image[i]) for i in range(image.shape[0])]562 else:563 pil_image = None564 image_embeddings = self._encode_image(565 pil_image,566 elevation,567 azimuth,568 distance,569 device,570 num_images_per_prompt,571 do_classifier_free_guidance,572 clip_image_embeddings,573 image_camera_embeddings,574 )575 576 # 4. Prepare timesteps577 self.scheduler.set_timesteps(num_inference_steps, device=device)578 timesteps = self.scheduler.timesteps579 580 # 5. Prepare latent variables581 # num_channels_latents = self.unet.config.in_channels582 num_channels_latents = 4 # FIXME: hard-coded583 latents = self.prepare_latents(584 batch_size * num_images_per_prompt,585 num_channels_latents,586 height,587 width,588 image_embeddings.dtype,589 device,590 generator,591 latents,592 )593 594 # 6. Prepare extra step kwargs. TODO: Logic should ideally just be moved out of the pipeline595 extra_step_kwargs = self.prepare_extra_step_kwargs(generator, eta)596 597 # 7. Denoising loop598 num_warmup_steps = len(timesteps) - num_inference_steps * self.scheduler.order599 with self.progress_bar(total=num_inference_steps) as progress_bar:600 for i, t in enumerate(timesteps):601 # expand the latents if we are doing classifier free guidance602 latent_model_input = self._get_latent_model_input(603 latents,604 image,605 num_images_per_prompt,606 do_classifier_free_guidance,607 image_latents,608 )609 latent_model_input = self.scheduler.scale_model_input(610 latent_model_input, t611 )612 613 # predict the noise residual614 noise_pred = self.unet(615 latent_model_input,616 t,617 encoder_hidden_states=image_embeddings,618 cross_attention_kwargs=cross_attention_kwargs,619 ).sample620 621 # perform guidance622 if do_classifier_free_guidance:623 noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)624 noise_pred = noise_pred_uncond + guidance_scale * (625 noise_pred_text - noise_pred_uncond626 )627 628 # compute the previous noisy sample x_t -> x_t-1629 latents = self.scheduler.step(630 noise_pred, t, latents, **extra_step_kwargs631 ).prev_sample632 633 # call the callback, if provided634 if i == len(timesteps) - 1 or (635 (i + 1) > num_warmup_steps and (i + 1) % self.scheduler.order == 0636 ):637 progress_bar.update()638 if callback is not None and i % callback_steps == 0:639 callback(i, t, latents)640 641 if not output_type == "latent":642 image = self.vae.decode(643 latents / self.vae.config.scaling_factor, return_dict=False644 )[0]645 image, has_nsfw_concept = self.run_safety_checker(646 image, device, image_embeddings.dtype647 )648 else:649 image = latents650 has_nsfw_concept = None651 652 if has_nsfw_concept is None:653 do_denormalize = [True] * image.shape[0]654 else:655 do_denormalize = [not has_nsfw for has_nsfw in has_nsfw_concept]656 657 image = self.image_processor.postprocess(658 image, output_type=output_type, do_denormalize=do_denormalize659 )660 661 if not return_dict:662 return (image, has_nsfw_concept)663 664 return StableDiffusionPipelineOutput(665 images=image, nsfw_content_detected=has_nsfw_concept666 )