import html import inspect import re import urllib.parse as ul from typing import Any, Callable, Dict, List, Optional, Union import numpy as np import PIL.Image import torch from transformers import CLIPImageProcessor, T5EncoderModel, T5Tokenizer from ...loaders import LoraLoaderMixin from ...models import UNet2DConditionModel from ...schedulers import DDPMScheduler from ...utils import ( BACKENDS_MAPPING, PIL_INTERPOLATION, is_bs4_available, is_ftfy_available, logging, replace_example_docstring, ) from ...utils.torch_utils import randn_tensor from ..pipeline_utils import DiffusionPipeline from .pipeline_output import IFPipelineOutput from .safety_checker import IFSafetyChecker from .watermark import IFWatermarker logger = logging.get_logger(__name__) # pylint: disable=invalid-name if is_bs4_available(): from bs4 import BeautifulSoup if is_ftfy_available(): import ftfy def resize(images: PIL.Image.Image, img_size: int) -> PIL.Image.Image: w, h = images.size coef = w / h w, h = img_size, img_size if coef >= 1: w = int(round(img_size / 8 * coef) * 8) else: h = int(round(img_size / 8 / coef) * 8) images = images.resize((w, h), resample=PIL_INTERPOLATION["bicubic"], reducing_gap=None) return images EXAMPLE_DOC_STRING = """ Examples: ```py >>> from diffusers import IFImg2ImgPipeline, IFImg2ImgSuperResolutionPipeline, DiffusionPipeline >>> from diffusers.utils import pt_to_pil >>> import torch >>> from PIL import Image >>> import requests >>> from io import BytesIO >>> url = "https://raw.githubusercontent.com/CompVis/stable-diffusion/main/assets/stable-samples/img2img/sketch-mountains-input.jpg" >>> response = requests.get(url) >>> original_image = Image.open(BytesIO(response.content)).convert("RGB") >>> original_image = original_image.resize((768, 512)) >>> pipe = IFImg2ImgPipeline.from_pretrained( ... "DeepFloyd/IF-I-XL-v1.0", ... variant="fp16", ... torch_dtype=torch.float16, ... ) >>> pipe.enable_model_cpu_offload() >>> prompt = "A fantasy landscape in style minecraft" >>> prompt_embeds, negative_embeds = pipe.encode_prompt(prompt) >>> image = pipe( ... image=original_image, ... prompt_embeds=prompt_embeds, ... negative_prompt_embeds=negative_embeds, ... output_type="pt", ... ).images >>> # save intermediate image >>> pil_image = pt_to_pil(image) >>> pil_image[0].save("./if_stage_I.png") >>> super_res_1_pipe = IFImg2ImgSuperResolutionPipeline.from_pretrained( ... "DeepFloyd/IF-II-L-v1.0", ... text_encoder=None, ... variant="fp16", ... torch_dtype=torch.float16, ... ) >>> super_res_1_pipe.enable_model_cpu_offload() >>> image = super_res_1_pipe( ... image=image, ... original_image=original_image, ... prompt_embeds=prompt_embeds, ... negative_prompt_embeds=negative_embeds, ... ).images >>> image[0].save("./if_stage_II.png") ``` """ class IFImg2ImgPipeline(DiffusionPipeline, LoraLoaderMixin): tokenizer: T5Tokenizer text_encoder: T5EncoderModel unet: UNet2DConditionModel scheduler: DDPMScheduler feature_extractor: Optional[CLIPImageProcessor] safety_checker: Optional[IFSafetyChecker] watermarker: Optional[IFWatermarker] bad_punct_regex = re.compile( r"[" + "#®•©™&@·º½¾¿¡§~" + r"\)" + r"\(" + r"\]" + r"\[" + r"\}" + r"\{" + r"\|" + "\\" + r"\/" + r"\*" + r"]{1,}" ) # noqa _optional_components = ["tokenizer", "text_encoder", "safety_checker", "feature_extractor", "watermarker"] model_cpu_offload_seq = "text_encoder->unet" _exclude_from_cpu_offload = ["watermarker"] def __init__( self, tokenizer: T5Tokenizer, text_encoder: T5EncoderModel, unet: UNet2DConditionModel, scheduler: DDPMScheduler, safety_checker: Optional[IFSafetyChecker], feature_extractor: Optional[CLIPImageProcessor], watermarker: Optional[IFWatermarker], requires_safety_checker: bool = True, ): super().__init__() if safety_checker is None and requires_safety_checker: logger.warning( f"You have disabled the safety checker for {self.__class__} by passing `safety_checker=None`. Ensure" " that you abide to the conditions of the IF license and do not expose unfiltered" " results in services or applications open to the public. Both the diffusers team and Hugging Face" " strongly recommend to keep the safety filter enabled in all public facing circumstances, disabling" " it only for use-cases that involve analyzing network behavior or auditing its results. For more" " information, please have a look at https://github.com/huggingface/diffusers/pull/254 ." ) if safety_checker is not None and feature_extractor is None: raise ValueError( "Make sure to define a feature extractor when loading {self.__class__} if you want to use the safety" " checker. If you do not want to use the safety checker, you can pass `'safety_checker=None'` instead." ) self.register_modules( tokenizer=tokenizer, text_encoder=text_encoder, unet=unet, scheduler=scheduler, safety_checker=safety_checker, feature_extractor=feature_extractor, watermarker=watermarker, ) self.register_to_config(requires_safety_checker=requires_safety_checker) @torch.no_grad() def encode_prompt( self, prompt: Union[str, List[str]], do_classifier_free_guidance: bool = True, num_images_per_prompt: int = 1, device: Optional[torch.device] = None, negative_prompt: Optional[Union[str, List[str]]] = None, prompt_embeds: Optional[torch.FloatTensor] = None, negative_prompt_embeds: Optional[torch.FloatTensor] = None, clean_caption: bool = False, ): r""" Encodes the prompt into text encoder hidden states. Args: prompt (`str` or `List[str]`, *optional*): prompt to be encoded do_classifier_free_guidance (`bool`, *optional*, defaults to `True`): whether to use classifier free guidance or not num_images_per_prompt (`int`, *optional*, defaults to 1): number of images that should be generated per prompt device: (`torch.device`, *optional*): torch device to place the resulting embeddings on negative_prompt (`str` or `List[str]`, *optional*): The prompt or prompts not to guide the image generation. If not defined, one has to pass `negative_prompt_embeds`. instead. If not defined, one has to pass `negative_prompt_embeds`. instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is less than `1`). prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not provided, text embeddings will be generated from `prompt` input argument. negative_prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated negative text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not provided, negative_prompt_embeds will be generated from `negative_prompt` input argument. clean_caption (bool, defaults to `False`): If `True`, the function will preprocess and clean the provided caption before encoding. """ if prompt is not None and negative_prompt is not None: if type(prompt) is not type(negative_prompt): raise TypeError( f"`negative_prompt` should be the same type to `prompt`, but got {type(negative_prompt)} !=" f" {type(prompt)}." ) if device is None: device = self._execution_device if prompt is not None and isinstance(prompt, str): batch_size = 1 elif prompt is not None and isinstance(prompt, list): batch_size = len(prompt) else: batch_size = prompt_embeds.shape[0] # while T5 can handle much longer input sequences than 77, the text encoder was trained with a max length of 77 for IF max_length = 77 if prompt_embeds is None: prompt = self._text_preprocessing(prompt, clean_caption=clean_caption) text_inputs = self.tokenizer( prompt, padding="max_length", max_length=max_length, truncation=True, add_special_tokens=True, return_tensors="pt", ) text_input_ids = text_inputs.input_ids untruncated_ids = self.tokenizer(prompt, padding="longest", return_tensors="pt").input_ids if untruncated_ids.shape[-1] >= text_input_ids.shape[-1] and not torch.equal( text_input_ids, untruncated_ids ): removed_text = self.tokenizer.batch_decode(untruncated_ids[:, max_length - 1 : -1]) logger.warning( "The following part of your input was truncated because CLIP can only handle sequences up to" f" {max_length} tokens: {removed_text}" ) attention_mask = text_inputs.attention_mask.to(device) prompt_embeds = self.text_encoder( text_input_ids.to(device), attention_mask=attention_mask, ) prompt_embeds = prompt_embeds[0] if self.text_encoder is not None: dtype = self.text_encoder.dtype elif self.unet is not None: dtype = self.unet.dtype else: dtype = None prompt_embeds = prompt_embeds.to(dtype=dtype, device=device) bs_embed, seq_len, _ = prompt_embeds.shape # duplicate text embeddings for each generation per prompt, using mps friendly method prompt_embeds = prompt_embeds.repeat(1, num_images_per_prompt, 1) prompt_embeds = prompt_embeds.view(bs_embed * num_images_per_prompt, seq_len, -1) # get unconditional embeddings for classifier free guidance if do_classifier_free_guidance and negative_prompt_embeds is None: uncond_tokens: List[str] if negative_prompt is None: uncond_tokens = [""] * batch_size elif isinstance(negative_prompt, str): uncond_tokens = [negative_prompt] elif batch_size != len(negative_prompt): raise ValueError( f"`negative_prompt`: {negative_prompt} has batch size {len(negative_prompt)}, but `prompt`:" f" {prompt} has batch size {batch_size}. Please make sure that passed `negative_prompt` matches" " the batch size of `prompt`." ) else: uncond_tokens = negative_prompt uncond_tokens = self._text_preprocessing(uncond_tokens, clean_caption=clean_caption) max_length = prompt_embeds.shape[1] uncond_input = self.tokenizer( uncond_tokens, padding="max_length", max_length=max_length, truncation=True, return_attention_mask=True, add_special_tokens=True, return_tensors="pt", ) attention_mask = uncond_input.attention_mask.to(device) negative_prompt_embeds = self.text_encoder( uncond_input.input_ids.to(device), attention_mask=attention_mask, ) negative_prompt_embeds = negative_prompt_embeds[0] if do_classifier_free_guidance: # duplicate unconditional embeddings for each generation per prompt, using mps friendly method seq_len = negative_prompt_embeds.shape[1] negative_prompt_embeds = negative_prompt_embeds.to(dtype=dtype, device=device) negative_prompt_embeds = negative_prompt_embeds.repeat(1, num_images_per_prompt, 1) negative_prompt_embeds = negative_prompt_embeds.view(batch_size * num_images_per_prompt, seq_len, -1) # For classifier free guidance, we need to do two forward passes. # Here we concatenate the unconditional and text embeddings into a single batch # to avoid doing two forward passes else: negative_prompt_embeds = None return prompt_embeds, negative_prompt_embeds # Copied from diffusers.pipelines.deepfloyd_if.pipeline_if.IFPipeline.run_safety_checker def run_safety_checker(self, image, device, dtype): if self.safety_checker is not None: safety_checker_input = self.feature_extractor(self.numpy_to_pil(image), return_tensors="pt").to(device) image, nsfw_detected, watermark_detected = self.safety_checker( images=image, clip_input=safety_checker_input.pixel_values.to(dtype=dtype), ) else: nsfw_detected = None watermark_detected = None return image, nsfw_detected, watermark_detected # Copied from diffusers.pipelines.deepfloyd_if.pipeline_if.IFPipeline.prepare_extra_step_kwargs def prepare_extra_step_kwargs(self, generator, eta): # prepare extra kwargs for the scheduler step, since not all schedulers have the same signature # eta (η) is only used with the DDIMScheduler, it will be ignored for other schedulers. # eta corresponds to η in DDIM paper: https://arxiv.org/abs/2010.02502 # and should be between [0, 1] accepts_eta = "eta" in set(inspect.signature(self.scheduler.step).parameters.keys()) extra_step_kwargs = {} if accepts_eta: extra_step_kwargs["eta"] = eta # check if the scheduler accepts generator accepts_generator = "generator" in set(inspect.signature(self.scheduler.step).parameters.keys()) if accepts_generator: extra_step_kwargs["generator"] = generator return extra_step_kwargs def check_inputs( self, prompt, image, batch_size, callback_steps, negative_prompt=None, prompt_embeds=None, negative_prompt_embeds=None, ): if (callback_steps is None) or ( callback_steps is not None and (not isinstance(callback_steps, int) or callback_steps <= 0) ): raise ValueError( f"`callback_steps` has to be a positive integer but is {callback_steps} of type" f" {type(callback_steps)}." ) if prompt is not None and prompt_embeds is not None: raise ValueError( f"Cannot forward both `prompt`: {prompt} and `prompt_embeds`: {prompt_embeds}. Please make sure to" " only forward one of the two." ) elif prompt is None and prompt_embeds is None: raise ValueError( "Provide either `prompt` or `prompt_embeds`. Cannot leave both `prompt` and `prompt_embeds` undefined." ) elif prompt is not None and (not isinstance(prompt, str) and not isinstance(prompt, list)): raise ValueError(f"`prompt` has to be of type `str` or `list` but is {type(prompt)}") if negative_prompt is not None and negative_prompt_embeds is not None: raise ValueError( f"Cannot forward both `negative_prompt`: {negative_prompt} and `negative_prompt_embeds`:" f" {negative_prompt_embeds}. Please make sure to only forward one of the two." ) if prompt_embeds is not None and negative_prompt_embeds is not None: if prompt_embeds.shape != negative_prompt_embeds.shape: raise ValueError( "`prompt_embeds` and `negative_prompt_embeds` must have the same shape when passed directly, but" f" got: `prompt_embeds` {prompt_embeds.shape} != `negative_prompt_embeds`" f" {negative_prompt_embeds.shape}." ) if isinstance(image, list): check_image_type = image[0] else: check_image_type = image if ( not isinstance(check_image_type, torch.Tensor) and not isinstance(check_image_type, PIL.Image.Image) and not isinstance(check_image_type, np.ndarray) ): raise ValueError( "`image` has to be of type `torch.FloatTensor`, `PIL.Image.Image`, `np.ndarray`, or List[...] but is" f" {type(check_image_type)}" ) if isinstance(image, list): image_batch_size = len(image) elif isinstance(image, torch.Tensor): image_batch_size = image.shape[0] elif isinstance(image, PIL.Image.Image): image_batch_size = 1 elif isinstance(image, np.ndarray): image_batch_size = image.shape[0] else: assert False if batch_size != image_batch_size: raise ValueError(f"image batch size: {image_batch_size} must be same as prompt batch size {batch_size}") # Copied from diffusers.pipelines.deepfloyd_if.pipeline_if.IFPipeline._text_preprocessing def _text_preprocessing(self, text, clean_caption=False): if clean_caption and not is_bs4_available(): logger.warning(BACKENDS_MAPPING["bs4"][-1].format("Setting `clean_caption=True`")) logger.warning("Setting `clean_caption` to False...") clean_caption = False if clean_caption and not is_ftfy_available(): logger.warning(BACKENDS_MAPPING["ftfy"][-1].format("Setting `clean_caption=True`")) logger.warning("Setting `clean_caption` to False...") clean_caption = False if not isinstance(text, (tuple, list)): text = [text] def process(text: str): if clean_caption: text = self._clean_caption(text) text = self._clean_caption(text) else: text = text.lower().strip() return text return [process(t) for t in text] # Copied from diffusers.pipelines.deepfloyd_if.pipeline_if.IFPipeline._clean_caption def _clean_caption(self, caption): caption = str(caption) caption = ul.unquote_plus(caption) caption = caption.strip().lower() caption = re.sub("", "person", caption) # urls: caption = re.sub( r"\b((?:https?:(?:\/{1,3}|[a-zA-Z0-9%])|[a-zA-Z0-9.\-]+[.](?:com|co|ru|net|org|edu|gov|it)[\w/-]*\b\/?(?!@)))", # noqa "", caption, ) # regex for urls caption = re.sub( r"\b((?:www:(?:\/{1,3}|[a-zA-Z0-9%])|[a-zA-Z0-9.\-]+[.](?:com|co|ru|net|org|edu|gov|it)[\w/-]*\b\/?(?!@)))", # noqa "", caption, ) # regex for urls # html: caption = BeautifulSoup(caption, features="html.parser").text # @ caption = re.sub(r"@[\w\d]+\b", "", caption) # 31C0—31EF CJK Strokes # 31F0—31FF Katakana Phonetic Extensions # 3200—32FF Enclosed CJK Letters and Months # 3300—33FF CJK Compatibility # 3400—4DBF CJK Unified Ideographs Extension A # 4DC0—4DFF Yijing Hexagram Symbols # 4E00—9FFF CJK Unified Ideographs caption = re.sub(r"[\u31c0-\u31ef]+", "", caption) caption = re.sub(r"[\u31f0-\u31ff]+", "", caption) caption = re.sub(r"[\u3200-\u32ff]+", "", caption) caption = re.sub(r"[\u3300-\u33ff]+", "", caption) caption = re.sub(r"[\u3400-\u4dbf]+", "", caption) caption = re.sub(r"[\u4dc0-\u4dff]+", "", caption) caption = re.sub(r"[\u4e00-\u9fff]+", "", caption) ####################################################### # все виды тире / all types of dash --> "-" caption = re.sub( r"[\u002D\u058A\u05BE\u1400\u1806\u2010-\u2015\u2E17\u2E1A\u2E3A\u2E3B\u2E40\u301C\u3030\u30A0\uFE31\uFE32\uFE58\uFE63\uFF0D]+", # noqa "-", caption, ) # кавычки к одному стандарту caption = re.sub(r"[`´«»“”¨]", '"', caption) caption = re.sub(r"[‘’]", "'", caption) # " caption = re.sub(r""?", "", caption) # & caption = re.sub(r"&", "", caption) # ip adresses: caption = re.sub(r"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}", " ", caption) # article ids: caption = re.sub(r"\d:\d\d\s+$", "", caption) # \n caption = re.sub(r"\\n", " ", caption) # "#123" caption = re.sub(r"#\d{1,3}\b", "", caption) # "#12345.." caption = re.sub(r"#\d{5,}\b", "", caption) # "123456.." caption = re.sub(r"\b\d{6,}\b", "", caption) # filenames: caption = re.sub(r"[\S]+\.(?:png|jpg|jpeg|bmp|webp|eps|pdf|apk|mp4)", "", caption) # caption = re.sub(r"[\"\']{2,}", r'"', caption) # """AUSVERKAUFT""" caption = re.sub(r"[\.]{2,}", r" ", caption) # """AUSVERKAUFT""" caption = re.sub(self.bad_punct_regex, r" ", caption) # ***AUSVERKAUFT***, #AUSVERKAUFT caption = re.sub(r"\s+\.\s+", r" ", caption) # " . " # this-is-my-cute-cat / this_is_my_cute_cat regex2 = re.compile(r"(?:\-|\_)") if len(re.findall(regex2, caption)) > 3: caption = re.sub(regex2, " ", caption) caption = ftfy.fix_text(caption) caption = html.unescape(html.unescape(caption)) caption = re.sub(r"\b[a-zA-Z]{1,3}\d{3,15}\b", "", caption) # jc6640 caption = re.sub(r"\b[a-zA-Z]+\d+[a-zA-Z]+\b", "", caption) # jc6640vc caption = re.sub(r"\b\d+[a-zA-Z]+\d+\b", "", caption) # 6640vc231 caption = re.sub(r"(worldwide\s+)?(free\s+)?shipping", "", caption) caption = re.sub(r"(free\s)?download(\sfree)?", "", caption) caption = re.sub(r"\bclick\b\s(?:for|on)\s\w+", "", caption) caption = re.sub(r"\b(?:png|jpg|jpeg|bmp|webp|eps|pdf|apk|mp4)(\simage[s]?)?", "", caption) caption = re.sub(r"\bpage\s+\d+\b", "", caption) caption = re.sub(r"\b\d*[a-zA-Z]+\d+[a-zA-Z]+\d+[a-zA-Z\d]*\b", r" ", caption) # j2d1a2a... caption = re.sub(r"\b\d+\.?\d*[xх×]\d+\.?\d*\b", "", caption) caption = re.sub(r"\b\s+\:\s+", r": ", caption) caption = re.sub(r"(\D[,\./])\b", r"\1 ", caption) caption = re.sub(r"\s+", " ", caption) caption.strip() caption = re.sub(r"^[\"\']([\w\W]+)[\"\']$", r"\1", caption) caption = re.sub(r"^[\'\_,\-\:;]", r"", caption) caption = re.sub(r"[\'\_,\-\:\-\+]$", r"", caption) caption = re.sub(r"^\.\S+$", "", caption) return caption.strip() def preprocess_image(self, image: PIL.Image.Image) -> torch.Tensor: if not isinstance(image, list): image = [image] def numpy_to_pt(images): if images.ndim == 3: images = images[..., None] images = torch.from_numpy(images.transpose(0, 3, 1, 2)) return images if isinstance(image[0], PIL.Image.Image): new_image = [] for image_ in image: image_ = image_.convert("RGB") image_ = resize(image_, self.unet.config.sample_size) image_ = np.array(image_) image_ = image_.astype(np.float32) image_ = image_ / 127.5 - 1 new_image.append(image_) image = new_image image = np.stack(image, axis=0) # to np image = numpy_to_pt(image) # to pt elif isinstance(image[0], np.ndarray): image = np.concatenate(image, axis=0) if image[0].ndim == 4 else np.stack(image, axis=0) image = numpy_to_pt(image) elif isinstance(image[0], torch.Tensor): image = torch.cat(image, axis=0) if image[0].ndim == 4 else torch.stack(image, axis=0) return image # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion_img2img.StableDiffusionImg2ImgPipeline.get_timesteps def get_timesteps(self, num_inference_steps, strength): # get the original timestep using init_timestep init_timestep = min(int(num_inference_steps * strength), num_inference_steps) t_start = max(num_inference_steps - init_timestep, 0) timesteps = self.scheduler.timesteps[t_start * self.scheduler.order :] if hasattr(self.scheduler, "set_begin_index"): self.scheduler.set_begin_index(t_start * self.scheduler.order) return timesteps, num_inference_steps - t_start def prepare_intermediate_images( self, image, timestep, batch_size, num_images_per_prompt, dtype, device, generator=None ): _, channels, height, width = image.shape batch_size = batch_size * num_images_per_prompt shape = (batch_size, channels, height, width) if isinstance(generator, list) and len(generator) != batch_size: raise ValueError( f"You have passed a list of generators of length {len(generator)}, but requested an effective batch" f" size of {batch_size}. Make sure the batch size matches the length of the generators." ) noise = randn_tensor(shape, generator=generator, device=device, dtype=dtype) image = image.repeat_interleave(num_images_per_prompt, dim=0) image = self.scheduler.add_noise(image, noise, timestep) return image @torch.no_grad() @replace_example_docstring(EXAMPLE_DOC_STRING) def __call__( self, prompt: Union[str, List[str]] = None, image: Union[ PIL.Image.Image, torch.Tensor, np.ndarray, List[PIL.Image.Image], List[torch.Tensor], List[np.ndarray] ] = None, strength: float = 0.7, num_inference_steps: int = 80, timesteps: List[int] = None, guidance_scale: float = 10.0, negative_prompt: Optional[Union[str, List[str]]] = None, num_images_per_prompt: Optional[int] = 1, eta: float = 0.0, generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None, prompt_embeds: Optional[torch.FloatTensor] = None, negative_prompt_embeds: Optional[torch.FloatTensor] = None, output_type: Optional[str] = "pil", return_dict: bool = True, callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None, callback_steps: int = 1, clean_caption: bool = True, cross_attention_kwargs: Optional[Dict[str, Any]] = None, ): """ Function invoked when calling the pipeline for generation. Args: prompt (`str` or `List[str]`, *optional*): The prompt or prompts to guide the image generation. If not defined, one has to pass `prompt_embeds`. instead. image (`torch.FloatTensor` or `PIL.Image.Image`): `Image`, or tensor representing an image batch, that will be used as the starting point for the process. strength (`float`, *optional*, defaults to 0.7): Conceptually, indicates how much to transform the reference `image`. Must be between 0 and 1. `image` will be used as a starting point, adding more noise to it the larger the `strength`. The number of denoising steps depends on the amount of noise initially added. When `strength` is 1, added noise will be maximum and the denoising process will run for the full number of iterations specified in `num_inference_steps`. A value of 1, therefore, essentially ignores `image`. num_inference_steps (`int`, *optional*, defaults to 80): The number of denoising steps. More denoising steps usually lead to a higher quality image at the expense of slower inference. timesteps (`List[int]`, *optional*): Custom timesteps to use for the denoising process. If not defined, equal spaced `num_inference_steps` timesteps are used. Must be in descending order. guidance_scale (`float`, *optional*, defaults to 10.0): Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598). `guidance_scale` is defined as `w` of equation 2. of [Imagen Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting `guidance_scale > 1`. Higher guidance scale encourages to generate images that are closely linked to the text `prompt`, usually at the expense of lower image quality. negative_prompt (`str` or `List[str]`, *optional*): The prompt or prompts not to guide the image generation. If not defined, one has to pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is less than `1`). num_images_per_prompt (`int`, *optional*, defaults to 1): The number of images to generate per prompt. eta (`float`, *optional*, defaults to 0.0): Corresponds to parameter eta (η) in the DDIM paper: https://arxiv.org/abs/2010.02502. Only applies to [`schedulers.DDIMScheduler`], will be ignored for others. generator (`torch.Generator` or `List[torch.Generator]`, *optional*): One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make generation deterministic. prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not provided, text embeddings will be generated from `prompt` input argument. negative_prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated negative text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not provided, negative_prompt_embeds will be generated from `negative_prompt` input argument. output_type (`str`, *optional*, defaults to `"pil"`): The output format of the generate image. Choose between [PIL](https://pillow.readthedocs.io/en/stable/): `PIL.Image.Image` or `np.array`. return_dict (`bool`, *optional*, defaults to `True`): Whether or not to return a [`~pipelines.stable_diffusion.IFPipelineOutput`] instead of a plain tuple. callback (`Callable`, *optional*): A function that will be called every `callback_steps` steps during inference. The function will be called with the following arguments: `callback(step: int, timestep: int, latents: torch.FloatTensor)`. callback_steps (`int`, *optional*, defaults to 1): The frequency at which the `callback` function will be called. If not specified, the callback will be called at every step. clean_caption (`bool`, *optional*, defaults to `True`): Whether or not to clean the caption before creating embeddings. Requires `beautifulsoup4` and `ftfy` to be installed. If the dependencies are not installed, the embeddings will be created from the raw prompt. cross_attention_kwargs (`dict`, *optional*): A kwargs dictionary that if specified is passed along to the `AttentionProcessor` as defined under `self.processor` in [diffusers.models.attention_processor](https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention_processor.py). Examples: Returns: [`~pipelines.stable_diffusion.IFPipelineOutput`] or `tuple`: [`~pipelines.stable_diffusion.IFPipelineOutput`] if `return_dict` is True, otherwise a `tuple. When returning a tuple, the first element is a list with the generated images, and the second element is a list of `bool`s denoting whether the corresponding generated image likely represents "not-safe-for-work" (nsfw) or watermarked content, according to the `safety_checker`. """ # 1. Check inputs. Raise error if not correct if prompt is not None and isinstance(prompt, str): batch_size = 1 elif prompt is not None and isinstance(prompt, list): batch_size = len(prompt) else: batch_size = prompt_embeds.shape[0] self.check_inputs( prompt, image, batch_size, callback_steps, negative_prompt, prompt_embeds, negative_prompt_embeds ) # 2. Define call parameters device = self._execution_device # here `guidance_scale` is defined analog to the guidance weight `w` of equation (2) # of the Imagen paper: https://arxiv.org/pdf/2205.11487.pdf . `guidance_scale = 1` # corresponds to doing no classifier free guidance. do_classifier_free_guidance = guidance_scale > 1.0 # 3. Encode input prompt prompt_embeds, negative_prompt_embeds = self.encode_prompt( prompt, do_classifier_free_guidance, num_images_per_prompt=num_images_per_prompt, device=device, negative_prompt=negative_prompt, prompt_embeds=prompt_embeds, negative_prompt_embeds=negative_prompt_embeds, clean_caption=clean_caption, ) if do_classifier_free_guidance: prompt_embeds = torch.cat([negative_prompt_embeds, prompt_embeds]) dtype = prompt_embeds.dtype # 4. Prepare timesteps if timesteps is not None: self.scheduler.set_timesteps(timesteps=timesteps, device=device) timesteps = self.scheduler.timesteps num_inference_steps = len(timesteps) else: self.scheduler.set_timesteps(num_inference_steps, device=device) timesteps = self.scheduler.timesteps timesteps, num_inference_steps = self.get_timesteps(num_inference_steps, strength) # 5. Prepare intermediate images image = self.preprocess_image(image) image = image.to(device=device, dtype=dtype) noise_timestep = timesteps[0:1] noise_timestep = noise_timestep.repeat(batch_size * num_images_per_prompt) intermediate_images = self.prepare_intermediate_images( image, noise_timestep, batch_size, num_images_per_prompt, dtype, device, generator ) # 6. Prepare extra step kwargs. TODO: Logic should ideally just be moved out of the pipeline extra_step_kwargs = self.prepare_extra_step_kwargs(generator, eta) # HACK: see comment in `enable_model_cpu_offload` if hasattr(self, "text_encoder_offload_hook") and self.text_encoder_offload_hook is not None: self.text_encoder_offload_hook.offload() # 7. Denoising loop num_warmup_steps = len(timesteps) - num_inference_steps * self.scheduler.order with self.progress_bar(total=num_inference_steps) as progress_bar: for i, t in enumerate(timesteps): model_input = ( torch.cat([intermediate_images] * 2) if do_classifier_free_guidance else intermediate_images ) model_input = self.scheduler.scale_model_input(model_input, t) # predict the noise residual noise_pred = self.unet( model_input, t, encoder_hidden_states=prompt_embeds, cross_attention_kwargs=cross_attention_kwargs, return_dict=False, )[0] # perform guidance if do_classifier_free_guidance: noise_pred_uncond, noise_pred_text = noise_pred.chunk(2) noise_pred_uncond, _ = noise_pred_uncond.split(model_input.shape[1], dim=1) noise_pred_text, predicted_variance = noise_pred_text.split(model_input.shape[1], dim=1) noise_pred = noise_pred_uncond + guidance_scale * (noise_pred_text - noise_pred_uncond) noise_pred = torch.cat([noise_pred, predicted_variance], dim=1) if self.scheduler.config.variance_type not in ["learned", "learned_range"]: noise_pred, _ = noise_pred.split(model_input.shape[1], dim=1) # compute the previous noisy sample x_t -> x_t-1 intermediate_images = self.scheduler.step( noise_pred, t, intermediate_images, **extra_step_kwargs, return_dict=False )[0] # call the callback, if provided if i == len(timesteps) - 1 or ((i + 1) > num_warmup_steps and (i + 1) % self.scheduler.order == 0): progress_bar.update() if callback is not None and i % callback_steps == 0: callback(i, t, intermediate_images) image = intermediate_images if output_type == "pil": # 8. Post-processing image = (image / 2 + 0.5).clamp(0, 1) image = image.cpu().permute(0, 2, 3, 1).float().numpy() # 9. Run safety checker image, nsfw_detected, watermark_detected = self.run_safety_checker(image, device, prompt_embeds.dtype) # 10. Convert to PIL image = self.numpy_to_pil(image) # 11. Apply watermark if self.watermarker is not None: self.watermarker.apply_watermark(image, self.unet.config.sample_size) elif output_type == "pt": nsfw_detected = None watermark_detected = None if hasattr(self, "unet_offload_hook") and self.unet_offload_hook is not None: self.unet_offload_hook.offload() else: # 8. Post-processing image = (image / 2 + 0.5).clamp(0, 1) image = image.cpu().permute(0, 2, 3, 1).float().numpy() # 9. Run safety checker image, nsfw_detected, watermark_detected = self.run_safety_checker(image, device, prompt_embeds.dtype) # Offload all models self.maybe_free_model_hooks() if not return_dict: return (image, nsfw_detected, watermark_detected) return IFPipelineOutput(images=image, nsfw_detected=nsfw_detected, watermark_detected=watermark_detected)