import inspect import re from typing import Callable, List, Optional, Union import numpy as np import torch import PIL from diffusers import SchedulerMixin, StableDiffusionPipeline from diffusers.models import AutoencoderKL, UNet2DConditionModel from diffusers.pipelines.stable_diffusion import StableDiffusionPipelineOutput, StableDiffusionSafetyChecker from diffusers.utils import PIL_INTERPOLATION, deprecate, logging from transformers import CLIPFeatureExtractor, CLIPTextModel, CLIPTokenizer logger = logging.get_logger(__name__) # pylint: disable=invalid-name re_attention = re.compile( r""" \\\(| \\\)| \\\[| \\]| \\\\| \\| \(| \[| :([+-]?[.\d]+)\)| \)| ]| [^\\()\[\]:]+| : """, re.X, ) def parse_prompt_attention(text): """ Parses a string with attention tokens and returns a list of pairs: text and its associated weight. Accepted tokens are: (abc) - increases attention to abc by a multiplier of 1.1 (abc:3.12) - increases attention to abc by a multiplier of 3.12 [abc] - decreases attention to abc by a multiplier of 1.1 \( - literal character '(' \[ - literal character '[' \) - literal character ')' \] - literal character ']' \\ - literal character '\' anything else - just text >>> parse_prompt_attention('normal text') [['normal text', 1.0]] >>> parse_prompt_attention('an (important) word') [['an ', 1.0], ['important', 1.1], [' word', 1.0]] >>> parse_prompt_attention('(unbalanced') [['unbalanced', 1.1]] >>> parse_prompt_attention('\(literal\]') [['(literal]', 1.0]] >>> parse_prompt_attention('(unnecessary)(parens)') [['unnecessaryparens', 1.1]] >>> parse_prompt_attention('a (((house:1.3)) [on] a (hill:0.5), sun, (((sky))).') [['a ', 1.0], ['house', 1.5730000000000004], [' ', 1.1], ['on', 1.0], [' a ', 1.1], ['hill', 0.55], [', sun, ', 1.1], ['sky', 1.4641000000000006], ['.', 1.1]] """ res = [] round_brackets = [] square_brackets = [] round_bracket_multiplier = 1.1 square_bracket_multiplier = 1 / 1.1 def multiply_range(start_position, multiplier): for p in range(start_position, len(res)): res[p][1] *= multiplier for m in re_attention.finditer(text): text = m.group(0) weight = m.group(1) if text.startswith("\\"): res.append([text[1:], 1.0]) elif text == "(": round_brackets.append(len(res)) elif text == "[": square_brackets.append(len(res)) elif weight is not None and len(round_brackets) > 0: multiply_range(round_brackets.pop(), float(weight)) elif text == ")" and len(round_brackets) > 0: multiply_range(round_brackets.pop(), round_bracket_multiplier) elif text == "]" and len(square_brackets) > 0: multiply_range(square_brackets.pop(), square_bracket_multiplier) else: res.append([text, 1.0]) for pos in round_brackets: multiply_range(pos, round_bracket_multiplier) for pos in square_brackets: multiply_range(pos, square_bracket_multiplier) if len(res) == 0: res = [["", 1.0]] # merge runs of identical weights i = 0 while i + 1 < len(res): if res[i][1] == res[i + 1][1]: res[i][0] += res[i + 1][0] res.pop(i + 1) else: i += 1 return res def get_prompts_with_weights(pipe: StableDiffusionPipeline, prompt: List[str], max_length: int): r""" Tokenize a list of prompts and return its tokens with weights of each token. No padding, starting or ending token is included. """ tokens = [] weights = [] truncated = False for text in prompt: texts_and_weights = parse_prompt_attention(text) text_token = [] text_weight = [] for word, weight in texts_and_weights: # tokenize and discard the starting and the ending token token = pipe.tokenizer(word).input_ids[1:-1] text_token += token # copy the weight by length of token text_weight += [weight] * len(token) # stop if the text is too long (longer than truncation limit) if len(text_token) > max_length: truncated = True break # truncate if len(text_token) > max_length: truncated = True text_token = text_token[:max_length] text_weight = text_weight[:max_length] tokens.append(text_token) weights.append(text_weight) if truncated: logger.warning("Prompt was truncated. Try to shorten the prompt or increase max_embeddings_multiples") return tokens, weights def pad_tokens_and_weights(tokens, weights, max_length, bos, eos, no_boseos_middle=True, chunk_length=77): r""" Pad the tokens (with starting and ending tokens) and weights (with 1.0) to max_length. """ max_embeddings_multiples = (max_length - 2) // (chunk_length - 2) weights_length = max_length if no_boseos_middle else max_embeddings_multiples * chunk_length for i in range(len(tokens)): tokens[i] = [bos] + tokens[i] + [eos] * (max_length - 1 - len(tokens[i])) if no_boseos_middle: weights[i] = [1.0] + weights[i] + [1.0] * (max_length - 1 - len(weights[i])) else: w = [] if len(weights[i]) == 0: w = [1.0] * weights_length else: for j in range(max_embeddings_multiples): w.append(1.0) # weight for starting token in this chunk w += weights[i][j * (chunk_length - 2) : min(len(weights[i]), (j + 1) * (chunk_length - 2))] w.append(1.0) # weight for ending token in this chunk w += [1.0] * (weights_length - len(w)) weights[i] = w[:] return tokens, weights def get_unweighted_text_embeddings( pipe: StableDiffusionPipeline, text_input: torch.Tensor, chunk_length: int, no_boseos_middle: Optional[bool] = True, ): """ When the length of tokens is a multiple of the capacity of the text encoder, it should be split into chunks and sent to the text encoder individually. """ max_embeddings_multiples = (text_input.shape[1] - 2) // (chunk_length - 2) if max_embeddings_multiples > 1: text_embeddings = [] for i in range(max_embeddings_multiples): # extract the i-th chunk text_input_chunk = text_input[:, i * (chunk_length - 2) : (i + 1) * (chunk_length - 2) + 2].clone() # cover the head and the tail by the starting and the ending tokens text_input_chunk[:, 0] = text_input[0, 0] text_input_chunk[:, -1] = text_input[0, -1] text_embedding = pipe.text_encoder(text_input_chunk)[0] if no_boseos_middle: if i == 0: # discard the ending token text_embedding = text_embedding[:, :-1] elif i == max_embeddings_multiples - 1: # discard the starting token text_embedding = text_embedding[:, 1:] else: # discard both starting and ending tokens text_embedding = text_embedding[:, 1:-1] text_embeddings.append(text_embedding) text_embeddings = torch.concat(text_embeddings, axis=1) else: text_embeddings = pipe.text_encoder(text_input)[0] return text_embeddings def get_weighted_text_embeddings( pipe: StableDiffusionPipeline, prompt: Union[str, List[str]], uncond_prompt: Optional[Union[str, List[str]]] = None, max_embeddings_multiples: Optional[int] = 3, no_boseos_middle: Optional[bool] = False, skip_parsing: Optional[bool] = False, skip_weighting: Optional[bool] = False, **kwargs, ): r""" Prompts can be assigned with local weights using brackets. For example, prompt 'A (very beautiful) masterpiece' highlights the words 'very beautiful', and the embedding tokens corresponding to the words get multiplied by a constant, 1.1. Also, to regularize of the embedding, the weighted embedding would be scaled to preserve the original mean. Args: pipe (`StableDiffusionPipeline`): Pipe to provide access to the tokenizer and the text encoder. prompt (`str` or `List[str]`): The prompt or prompts to guide the image generation. uncond_prompt (`str` or `List[str]`): The unconditional prompt or prompts for guide the image generation. If unconditional prompt is provided, the embeddings of prompt and uncond_prompt are concatenated. max_embeddings_multiples (`int`, *optional*, defaults to `3`): The max multiple length of prompt embeddings compared to the max output length of text encoder. no_boseos_middle (`bool`, *optional*, defaults to `False`): If the length of text token is multiples of the capacity of text encoder, whether reserve the starting and ending token in each of the chunk in the middle. skip_parsing (`bool`, *optional*, defaults to `False`): Skip the parsing of brackets. skip_weighting (`bool`, *optional*, defaults to `False`): Skip the weighting. When the parsing is skipped, it is forced True. """ max_length = (pipe.tokenizer.model_max_length - 2) * max_embeddings_multiples + 2 if isinstance(prompt, str): prompt = [prompt] if not skip_parsing: prompt_tokens, prompt_weights = get_prompts_with_weights(pipe, prompt, max_length - 2) if uncond_prompt is not None: if isinstance(uncond_prompt, str): uncond_prompt = [uncond_prompt] uncond_tokens, uncond_weights = get_prompts_with_weights(pipe, uncond_prompt, max_length - 2) else: prompt_tokens = [ token[1:-1] for token in pipe.tokenizer(prompt, max_length=max_length, truncation=True).input_ids ] prompt_weights = [[1.0] * len(token) for token in prompt_tokens] if uncond_prompt is not None: if isinstance(uncond_prompt, str): uncond_prompt = [uncond_prompt] uncond_tokens = [ token[1:-1] for token in pipe.tokenizer(uncond_prompt, max_length=max_length, truncation=True).input_ids ] uncond_weights = [[1.0] * len(token) for token in uncond_tokens] # round up the longest length of tokens to a multiple of (model_max_length - 2) max_length = max([len(token) for token in prompt_tokens]) if uncond_prompt is not None: max_length = max(max_length, max([len(token) for token in uncond_tokens])) max_embeddings_multiples = min( max_embeddings_multiples, (max_length - 1) // (pipe.tokenizer.model_max_length - 2) + 1, ) max_embeddings_multiples = max(1, max_embeddings_multiples) max_length = (pipe.tokenizer.model_max_length - 2) * max_embeddings_multiples + 2 # pad the length of tokens and weights bos = pipe.tokenizer.bos_token_id eos = pipe.tokenizer.eos_token_id prompt_tokens, prompt_weights = pad_tokens_and_weights( prompt_tokens, prompt_weights, max_length, bos, eos, no_boseos_middle=no_boseos_middle, chunk_length=pipe.tokenizer.model_max_length, ) prompt_tokens = torch.tensor(prompt_tokens, dtype=torch.long, device=pipe.device) if uncond_prompt is not None: uncond_tokens, uncond_weights = pad_tokens_and_weights( uncond_tokens, uncond_weights, max_length, bos, eos, no_boseos_middle=no_boseos_middle, chunk_length=pipe.tokenizer.model_max_length, ) uncond_tokens = torch.tensor(uncond_tokens, dtype=torch.long, device=pipe.device) # get the embeddings text_embeddings = get_unweighted_text_embeddings( pipe, prompt_tokens, pipe.tokenizer.model_max_length, no_boseos_middle=no_boseos_middle, ) prompt_weights = torch.tensor(prompt_weights, dtype=text_embeddings.dtype, device=pipe.device) if uncond_prompt is not None: uncond_embeddings = get_unweighted_text_embeddings( pipe, uncond_tokens, pipe.tokenizer.model_max_length, no_boseos_middle=no_boseos_middle, ) uncond_weights = torch.tensor(uncond_weights, dtype=uncond_embeddings.dtype, device=pipe.device) # assign weights to the prompts and normalize in the sense of mean # TODO: should we normalize by chunk or in a whole (current implementation)? if (not skip_parsing) and (not skip_weighting): previous_mean = text_embeddings.float().mean(axis=[-2, -1]).to(text_embeddings.dtype) text_embeddings *= prompt_weights.unsqueeze(-1) current_mean = text_embeddings.float().mean(axis=[-2, -1]).to(text_embeddings.dtype) text_embeddings *= (previous_mean / current_mean).unsqueeze(-1).unsqueeze(-1) if uncond_prompt is not None: previous_mean = uncond_embeddings.float().mean(axis=[-2, -1]).to(uncond_embeddings.dtype) uncond_embeddings *= uncond_weights.unsqueeze(-1) current_mean = uncond_embeddings.float().mean(axis=[-2, -1]).to(uncond_embeddings.dtype) uncond_embeddings *= (previous_mean / current_mean).unsqueeze(-1).unsqueeze(-1) if uncond_prompt is not None: return text_embeddings, uncond_embeddings return text_embeddings, None def preprocess_image(image): w, h = image.size w, h = map(lambda x: x - x % 32, (w, h)) # resize to integer multiple of 32 image = image.resize((w, h), resample=PIL_INTERPOLATION["lanczos"]) image = np.array(image).astype(np.float32) / 255.0 image = image[None].transpose(0, 3, 1, 2) image = torch.from_numpy(image) return 2.0 * image - 1.0 def preprocess_mask(mask, scale_factor=8): mask = mask.convert("L") w, h = mask.size w, h = map(lambda x: x - x % 32, (w, h)) # resize to integer multiple of 32 mask = mask.resize((w // scale_factor, h // scale_factor), resample=PIL_INTERPOLATION["nearest"]) mask = np.array(mask).astype(np.float32) / 255.0 mask = np.tile(mask, (4, 1, 1)) mask = mask[None].transpose(0, 1, 2, 3) # what does this step do? mask = 1 - mask # repaint white, keep black mask = torch.from_numpy(mask) return mask class StableDiffusionLongPromptWeightingPipeline(StableDiffusionPipeline): r""" Pipeline for text-to-image generation using Stable Diffusion without tokens length limit, and support parsing weighting in prompt. This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods the library implements for all the pipelines (such as downloading or saving, running on a particular device, etc.) Args: vae ([`AutoencoderKL`]): Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations. text_encoder ([`CLIPTextModel`]): Frozen text-encoder. Stable Diffusion uses the text portion of [CLIP](https://huggingface.co/docs/transformers/model_doc/clip#transformers.CLIPTextModel), specifically the [clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14) variant. tokenizer (`CLIPTokenizer`): Tokenizer of class [CLIPTokenizer](https://huggingface.co/docs/transformers/v4.21.0/en/model_doc/clip#transformers.CLIPTokenizer). unet ([`UNet2DConditionModel`]): Conditional U-Net architecture to denoise the encoded image latents. scheduler ([`SchedulerMixin`]): A scheduler to be used in combination with `unet` to denoise the encoded image latents. Can be one of [`DDIMScheduler`], [`LMSDiscreteScheduler`], or [`PNDMScheduler`]. safety_checker ([`StableDiffusionSafetyChecker`]): Classification module that estimates whether generated images could be considered offensive or harmful. Please, refer to the [model card](https://huggingface.co/CompVis/stable-diffusion-v1-4) for details. feature_extractor ([`CLIPFeatureExtractor`]): Model that extracts features from generated images to be used as inputs for the `safety_checker`. """ def __init__( self, vae: AutoencoderKL, text_encoder: CLIPTextModel, tokenizer: CLIPTokenizer, unet: UNet2DConditionModel, scheduler: SchedulerMixin, safety_checker: StableDiffusionSafetyChecker, feature_extractor: CLIPFeatureExtractor, requires_safety_checker: bool = True, ): super().__init__( vae=vae, text_encoder=text_encoder, tokenizer=tokenizer, unet=unet, scheduler=scheduler, safety_checker=safety_checker, feature_extractor=feature_extractor, requires_safety_checker=requires_safety_checker, ) def _encode_prompt( self, prompt, device, num_images_per_prompt, do_classifier_free_guidance, negative_prompt, max_embeddings_multiples, ): r""" Encodes the prompt into text encoder hidden states. Args: prompt (`str` or `list(int)`): prompt to be encoded device: (`torch.device`): torch device num_images_per_prompt (`int`): number of images that should be generated per prompt do_classifier_free_guidance (`bool`): whether to use classifier free guidance or not negative_prompt (`str` or `List[str]`): The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored if `guidance_scale` is less than `1`). max_embeddings_multiples (`int`, *optional*, defaults to `3`): The max multiple length of prompt embeddings compared to the max output length of text encoder. """ batch_size = len(prompt) if isinstance(prompt, list) else 1 if negative_prompt is None: negative_prompt = [""] * batch_size elif isinstance(negative_prompt, str): negative_prompt = [negative_prompt] * batch_size if 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`." ) text_embeddings, uncond_embeddings = get_weighted_text_embeddings( pipe=self, prompt=prompt, uncond_prompt=negative_prompt if do_classifier_free_guidance else None, max_embeddings_multiples=max_embeddings_multiples, ) bs_embed, seq_len, _ = text_embeddings.shape text_embeddings = text_embeddings.repeat(1, num_images_per_prompt, 1) text_embeddings = text_embeddings.view(bs_embed * num_images_per_prompt, seq_len, -1) if do_classifier_free_guidance: bs_embed, seq_len, _ = uncond_embeddings.shape uncond_embeddings = uncond_embeddings.repeat(1, num_images_per_prompt, 1) uncond_embeddings = uncond_embeddings.view(bs_embed * num_images_per_prompt, seq_len, -1) text_embeddings = torch.cat([uncond_embeddings, text_embeddings]) return text_embeddings def check_inputs(self, prompt, height, width, strength, callback_steps): if 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 strength < 0 or strength > 1: raise ValueError(f"The value of strength should in [0.0, 1.0] but is {strength}") if height % 8 != 0 or width % 8 != 0: raise ValueError(f"`height` and `width` have to be divisible by 8 but are {height} and {width}.") 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)}." ) def get_timesteps(self, num_inference_steps, strength, device, is_text2img): if is_text2img: return self.scheduler.timesteps.to(device), num_inference_steps else: # get the original timestep using init_timestep offset = self.scheduler.config.get("steps_offset", 0) init_timestep = int(num_inference_steps * strength) + offset init_timestep = min(init_timestep, num_inference_steps) t_start = max(num_inference_steps - init_timestep + offset, 0) timesteps = self.scheduler.timesteps[t_start:].to(device) return timesteps, num_inference_steps - t_start 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, has_nsfw_concept = self.safety_checker( images=image, clip_input=safety_checker_input.pixel_values.to(dtype) ) else: has_nsfw_concept = None return image, has_nsfw_concept def decode_latents(self, latents): latents = 1 / 0.18215 * latents image = self.vae.decode(latents).sample image = (image / 2 + 0.5).clamp(0, 1) # we always cast to float32 as this does not cause significant overhead and is compatible with bfloa16 image = image.cpu().permute(0, 2, 3, 1).float().numpy() return image 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 prepare_latents(self, image, timestep, batch_size, height, width, dtype, device, generator, latents=None): if image is None: shape = ( batch_size, self.unet.in_channels, height // self.vae_scale_factor, width // self.vae_scale_factor, ) if latents is None: if device.type == "mps": # randn does not work reproducibly on mps latents = torch.randn(shape, generator=generator, device="cpu", dtype=dtype).to(device) else: latents = torch.randn(shape, generator=generator, device=device, dtype=dtype) else: if latents.shape != shape: raise ValueError(f"Unexpected latents shape, got {latents.shape}, expected {shape}") latents = latents.to(device) # scale the initial noise by the standard deviation required by the scheduler latents = latents * self.scheduler.init_noise_sigma return latents, None, None else: init_latent_dist = self.vae.encode(image).latent_dist init_latents = init_latent_dist.sample(generator=generator) init_latents = 0.18215 * init_latents init_latents = torch.cat([init_latents] * batch_size, dim=0) init_latents_orig = init_latents shape = init_latents.shape # add noise to latents using the timesteps if device.type == "mps": noise = torch.randn(shape, generator=generator, device="cpu", dtype=dtype).to(device) else: noise = torch.randn(shape, generator=generator, device=device, dtype=dtype) latents = self.scheduler.add_noise(init_latents, noise, timestep) return latents, init_latents_orig, noise @torch.no_grad() def __call__( self, prompt: Union[str, List[str]], negative_prompt: Optional[Union[str, List[str]]] = None, image: Union[torch.FloatTensor, PIL.Image.Image] = None, mask_image: Union[torch.FloatTensor, PIL.Image.Image] = None, height: int = 512, width: int = 512, num_inference_steps: int = 50, guidance_scale: float = 7.5, strength: float = 0.8, num_images_per_prompt: Optional[int] = 1, eta: float = 0.0, generator: Optional[torch.Generator] = None, latents: Optional[torch.FloatTensor] = None, max_embeddings_multiples: Optional[int] = 3, output_type: Optional[str] = "pil", return_dict: bool = True, callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None, is_cancelled_callback: Optional[Callable[[], bool]] = None, callback_steps: Optional[int] = 1, **kwargs, ): r""" Function invoked when calling the pipeline for generation. Args: prompt (`str` or `List[str]`): The prompt or prompts to guide the image generation. negative_prompt (`str` or `List[str]`, *optional*): The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored if `guidance_scale` is less than `1`). 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. mask_image (`torch.FloatTensor` or `PIL.Image.Image`): `Image`, or tensor representing an image batch, to mask `image`. White pixels in the mask will be replaced by noise and therefore repainted, while black pixels will be preserved. If `mask_image` is a PIL image, it will be converted to a single channel (luminance) before use. If it's a tensor, it should contain one color channel (L) instead of 3, so the expected shape would be `(B, H, W, 1)`. height (`int`, *optional*, defaults to 512): The height in pixels of the generated image. width (`int`, *optional*, defaults to 512): The width in pixels of the generated image. num_inference_steps (`int`, *optional*, defaults to 50): The number of denoising steps. More denoising steps usually lead to a higher quality image at the expense of slower inference. guidance_scale (`float`, *optional*, defaults to 7.5): 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. strength (`float`, *optional*, defaults to 0.8): 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_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`, *optional*): A [torch generator](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make generation deterministic. latents (`torch.FloatTensor`, *optional*): Pre-generated noisy latents, sampled from a Gaussian distribution, to be used as inputs for image generation. Can be used to tweak the same generation with different prompts. If not provided, a latents tensor will ge generated by sampling using the supplied random `generator`. max_embeddings_multiples (`int`, *optional*, defaults to `3`): The max multiple length of prompt embeddings compared to the max output length of text encoder. 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.StableDiffusionPipelineOutput`] 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)`. is_cancelled_callback (`Callable`, *optional*): A function that will be called every `callback_steps` steps during inference. If the function returns `True`, the inference will be cancelled. 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. Returns: `None` if cancelled by `is_cancelled_callback`, [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] or `tuple`: [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] 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) content, according to the `safety_checker`. """ message = "Please use `image` instead of `init_image`." init_image = deprecate("init_image", "0.12.0", message, take_from=kwargs) image = init_image or image # 0. Default height and width to unet height = height or self.unet.config.sample_size * self.vae_scale_factor width = width or self.unet.config.sample_size * self.vae_scale_factor # 1. Check inputs. Raise error if not correct self.check_inputs(prompt, height, width, strength, callback_steps) # 2. Define call parameters batch_size = 1 if isinstance(prompt, str) else len(prompt) 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 text_embeddings = self._encode_prompt( prompt, device, num_images_per_prompt, do_classifier_free_guidance, negative_prompt, max_embeddings_multiples, ) dtype = text_embeddings.dtype # 4. Preprocess image and mask if isinstance(image, PIL.Image.Image): image = preprocess_image(image) if image is not None: image = image.to(device=self.device, dtype=dtype) if isinstance(mask_image, PIL.Image.Image): mask_image = preprocess_mask(mask_image, self.vae_scale_factor) if mask_image is not None: mask = mask_image.to(device=self.device, dtype=dtype) mask = torch.cat([mask] * batch_size * num_images_per_prompt) else: mask = None # 5. set timesteps self.scheduler.set_timesteps(num_inference_steps, device=device) timesteps, num_inference_steps = self.get_timesteps(num_inference_steps, strength, device, image is None) latent_timestep = timesteps[:1].repeat(batch_size * num_images_per_prompt) # 6. Prepare latent variables latents, init_latents_orig, noise = self.prepare_latents( image, latent_timestep, batch_size * num_images_per_prompt, height, width, dtype, device, generator, latents, ) # 7. 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) # 8. 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): # expand the latents if we are doing classifier free guidance latent_model_input = torch.cat([latents] * 2) if do_classifier_free_guidance else latents latent_model_input = self.scheduler.scale_model_input(latent_model_input, t) # predict the noise residual noise_pred = self.unet(latent_model_input, t, encoder_hidden_states=text_embeddings).sample # perform guidance if do_classifier_free_guidance: noise_pred_uncond, noise_pred_text = noise_pred.chunk(2) noise_pred = noise_pred_uncond + guidance_scale * (noise_pred_text - noise_pred_uncond) # compute the previous noisy sample x_t -> x_t-1 latents = self.scheduler.step(noise_pred, t, latents, **extra_step_kwargs).prev_sample if mask is not None: # masking init_latents_proper = self.scheduler.add_noise(init_latents_orig, noise, torch.tensor([t])) latents = (init_latents_proper * mask) + (latents * (1 - mask)) # 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 i % callback_steps == 0: if callback is not None: callback(i, t, latents) if is_cancelled_callback is not None and is_cancelled_callback(): return None # 9. Post-processing image = self.decode_latents(latents) # 10. Run safety checker image, has_nsfw_concept = self.run_safety_checker(image, device, text_embeddings.dtype) # 11. Convert to PIL if output_type == "pil": image = self.numpy_to_pil(image) if not return_dict: return image, has_nsfw_concept return StableDiffusionPipelineOutput(images=image, nsfw_content_detected=has_nsfw_concept) def text2img( self, prompt: Union[str, List[str]], negative_prompt: Optional[Union[str, List[str]]] = None, height: int = 512, width: int = 512, num_inference_steps: int = 50, guidance_scale: float = 7.5, num_images_per_prompt: Optional[int] = 1, eta: float = 0.0, generator: Optional[torch.Generator] = None, latents: Optional[torch.FloatTensor] = None, max_embeddings_multiples: Optional[int] = 3, output_type: Optional[str] = "pil", return_dict: bool = True, callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None, is_cancelled_callback: Optional[Callable[[], bool]] = None, callback_steps: Optional[int] = 1, **kwargs, ): r""" Function for text-to-image generation. Args: prompt (`str` or `List[str]`): The prompt or prompts to guide the image generation. negative_prompt (`str` or `List[str]`, *optional*): The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored if `guidance_scale` is less than `1`). height (`int`, *optional*, defaults to 512): The height in pixels of the generated image. width (`int`, *optional*, defaults to 512): The width in pixels of the generated image. num_inference_steps (`int`, *optional*, defaults to 50): The number of denoising steps. More denoising steps usually lead to a higher quality image at the expense of slower inference. guidance_scale (`float`, *optional*, defaults to 7.5): 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. 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`, *optional*): A [torch generator](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make generation deterministic. latents (`torch.FloatTensor`, *optional*): Pre-generated noisy latents, sampled from a Gaussian distribution, to be used as inputs for image generation. Can be used to tweak the same generation with different prompts. If not provided, a latents tensor will ge generated by sampling using the supplied random `generator`. max_embeddings_multiples (`int`, *optional*, defaults to `3`): The max multiple length of prompt embeddings compared to the max output length of text encoder. 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.StableDiffusionPipelineOutput`] 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)`. is_cancelled_callback (`Callable`, *optional*): A function that will be called every `callback_steps` steps during inference. If the function returns `True`, the inference will be cancelled. 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. Returns: [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] or `tuple`: [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] 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) content, according to the `safety_checker`. """ return self.__call__( prompt=prompt, negative_prompt=negative_prompt, height=height, width=width, num_inference_steps=num_inference_steps, guidance_scale=guidance_scale, num_images_per_prompt=num_images_per_prompt, eta=eta, generator=generator, latents=latents, max_embeddings_multiples=max_embeddings_multiples, output_type=output_type, return_dict=return_dict, callback=callback, is_cancelled_callback=is_cancelled_callback, callback_steps=callback_steps, **kwargs, ) def img2img( self, image: Union[torch.FloatTensor, PIL.Image.Image], prompt: Union[str, List[str]], negative_prompt: Optional[Union[str, List[str]]] = None, strength: float = 0.8, num_inference_steps: Optional[int] = 50, guidance_scale: Optional[float] = 7.5, num_images_per_prompt: Optional[int] = 1, eta: Optional[float] = 0.0, generator: Optional[torch.Generator] = None, max_embeddings_multiples: Optional[int] = 3, output_type: Optional[str] = "pil", return_dict: bool = True, callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None, is_cancelled_callback: Optional[Callable[[], bool]] = None, callback_steps: Optional[int] = 1, **kwargs, ): r""" Function for image-to-image generation. Args: 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. prompt (`str` or `List[str]`): The prompt or prompts to guide the image generation. negative_prompt (`str` or `List[str]`, *optional*): The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored if `guidance_scale` is less than `1`). strength (`float`, *optional*, defaults to 0.8): 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 50): The number of denoising steps. More denoising steps usually lead to a higher quality image at the expense of slower inference. This parameter will be modulated by `strength`. guidance_scale (`float`, *optional*, defaults to 7.5): 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. 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`, *optional*): A [torch generator](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make generation deterministic. max_embeddings_multiples (`int`, *optional*, defaults to `3`): The max multiple length of prompt embeddings compared to the max output length of text encoder. 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.StableDiffusionPipelineOutput`] 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)`. is_cancelled_callback (`Callable`, *optional*): A function that will be called every `callback_steps` steps during inference. If the function returns `True`, the inference will be cancelled. 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. Returns: [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] or `tuple`: [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] 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) content, according to the `safety_checker`. """ return self.__call__( prompt=prompt, negative_prompt=negative_prompt, image=image, num_inference_steps=num_inference_steps, guidance_scale=guidance_scale, strength=strength, num_images_per_prompt=num_images_per_prompt, eta=eta, generator=generator, max_embeddings_multiples=max_embeddings_multiples, output_type=output_type, return_dict=return_dict, callback=callback, is_cancelled_callback=is_cancelled_callback, callback_steps=callback_steps, **kwargs, ) def inpaint( self, image: Union[torch.FloatTensor, PIL.Image.Image], mask_image: Union[torch.FloatTensor, PIL.Image.Image], prompt: Union[str, List[str]], negative_prompt: Optional[Union[str, List[str]]] = None, strength: float = 0.8, num_inference_steps: Optional[int] = 50, guidance_scale: Optional[float] = 7.5, num_images_per_prompt: Optional[int] = 1, eta: Optional[float] = 0.0, generator: Optional[torch.Generator] = None, max_embeddings_multiples: Optional[int] = 3, output_type: Optional[str] = "pil", return_dict: bool = True, callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None, is_cancelled_callback: Optional[Callable[[], bool]] = None, callback_steps: Optional[int] = 1, **kwargs, ): r""" Function for inpaint. Args: 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. This is the image whose masked region will be inpainted. mask_image (`torch.FloatTensor` or `PIL.Image.Image`): `Image`, or tensor representing an image batch, to mask `image`. White pixels in the mask will be replaced by noise and therefore repainted, while black pixels will be preserved. If `mask_image` is a PIL image, it will be converted to a single channel (luminance) before use. If it's a tensor, it should contain one color channel (L) instead of 3, so the expected shape would be `(B, H, W, 1)`. prompt (`str` or `List[str]`): The prompt or prompts to guide the image generation. negative_prompt (`str` or `List[str]`, *optional*): The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored if `guidance_scale` is less than `1`). strength (`float`, *optional*, defaults to 0.8): Conceptually, indicates how much to inpaint the masked area. Must be between 0 and 1. When `strength` is 1, the denoising process will be run on the masked area for the full number of iterations specified in `num_inference_steps`. `image` will be used as a reference for the masked area, adding more noise to that region the larger the `strength`. If `strength` is 0, no inpainting will occur. num_inference_steps (`int`, *optional*, defaults to 50): The reference number of denoising steps. More denoising steps usually lead to a higher quality image at the expense of slower inference. This parameter will be modulated by `strength`, as explained above. guidance_scale (`float`, *optional*, defaults to 7.5): 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. 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`, *optional*): A [torch generator](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make generation deterministic. max_embeddings_multiples (`int`, *optional*, defaults to `3`): The max multiple length of prompt embeddings compared to the max output length of text encoder. 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.StableDiffusionPipelineOutput`] 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)`. is_cancelled_callback (`Callable`, *optional*): A function that will be called every `callback_steps` steps during inference. If the function returns `True`, the inference will be cancelled. 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. Returns: [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] or `tuple`: [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] 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) content, according to the `safety_checker`. """ return self.__call__( prompt=prompt, negative_prompt=negative_prompt, image=image, mask_image=mask_image, num_inference_steps=num_inference_steps, guidance_scale=guidance_scale, strength=strength, num_images_per_prompt=num_images_per_prompt, eta=eta, generator=generator, max_embeddings_multiples=max_embeddings_multiples, output_type=output_type, return_dict=return_dict, callback=callback, is_cancelled_callback=is_cancelled_callback, callback_steps=callback_steps, **kwargs, )