# Copyright 2024 The HuggingFace Team. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. from __future__ import annotations import abc import inspect from typing import Any, Callable, Dict, List, Optional, Tuple, Union import numpy as np import torch import torch.nn.functional as F from packaging import version from transformers import ( CLIPImageProcessor, CLIPTextModel, CLIPTokenizer, CLIPVisionModelWithProjection, ) from diffusers import AutoencoderKL, DiffusionPipeline, UNet2DConditionModel from diffusers.configuration_utils import FrozenDict, deprecate from diffusers.image_processor import VaeImageProcessor from diffusers.loaders import ( FromSingleFileMixin, IPAdapterMixin, StableDiffusionLoraLoaderMixin, TextualInversionLoaderMixin, ) from diffusers.models.attention import Attention from diffusers.models.lora import adjust_lora_scale_text_encoder from diffusers.pipelines.stable_diffusion import StableDiffusionPipelineOutput from diffusers.pipelines.stable_diffusion.safety_checker import ( StableDiffusionSafetyChecker, ) from diffusers.schedulers import KarrasDiffusionSchedulers from diffusers.utils import ( USE_PEFT_BACKEND, logging, scale_lora_layers, unscale_lora_layers, ) from diffusers.utils.torch_utils import randn_tensor logger = logging.get_logger(__name__) # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.rescale_noise_cfg def rescale_noise_cfg(noise_cfg, noise_pred_text, guidance_rescale=0.0): """ Rescale `noise_cfg` according to `guidance_rescale`. Based on findings of [Common Diffusion Noise Schedules and Sample Steps are Flawed](https://arxiv.org/pdf/2305.08891.pdf). See Section 3.4 """ std_text = noise_pred_text.std(dim=list(range(1, noise_pred_text.ndim)), keepdim=True) std_cfg = noise_cfg.std(dim=list(range(1, noise_cfg.ndim)), keepdim=True) # rescale the results from guidance (fixes overexposure) noise_pred_rescaled = noise_cfg * (std_text / std_cfg) # mix with the original results from guidance by factor guidance_rescale to avoid "plain looking" images noise_cfg = guidance_rescale * noise_pred_rescaled + (1 - guidance_rescale) * noise_cfg return noise_cfg class Prompt2PromptPipeline( DiffusionPipeline, TextualInversionLoaderMixin, StableDiffusionLoraLoaderMixin, IPAdapterMixin, FromSingleFileMixin, ): r""" Pipeline for text-to-image generation using Stable Diffusion. This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods implemented for all pipelines (downloading, saving, running on a particular device, etc.). The pipeline also inherits the following loading methods: - [`~loaders.TextualInversionLoaderMixin.load_textual_inversion`] for loading textual inversion embeddings - [`~loaders.StableDiffusionLoraLoaderMixin.load_lora_weights`] for loading LoRA weights - [`~loaders.StableDiffusionLoraLoaderMixin.save_lora_weights`] for saving LoRA weights - [`~loaders.FromSingleFileMixin.from_single_file`] for loading `.ckpt` files - [`~loaders.IPAdapterMixin.load_ip_adapter`] for loading IP Adapters Args: vae ([`AutoencoderKL`]): Variational Auto-Encoder (VAE) model to encode and decode images to and from latent representations. text_encoder ([`~transformers.CLIPTextModel`]): Frozen text-encoder ([clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14)). tokenizer ([`~transformers.CLIPTokenizer`]): A `CLIPTokenizer` to tokenize text. unet ([`UNet2DConditionModel`]): A `UNet2DConditionModel` 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/runwayml/stable-diffusion-v1-5) for more details about a model's potential harms. feature_extractor ([`~transformers.CLIPImageProcessor`]): A `CLIPImageProcessor` to extract features from generated images; used as inputs to the `safety_checker`. """ model_cpu_offload_seq = "text_encoder->image_encoder->unet->vae" _exclude_from_cpu_offload = ["safety_checker"] _callback_tensor_inputs = ["latents", "prompt_embeds", "negative_prompt_embeds"] _optional_components = ["safety_checker", "feature_extractor"] def __init__( self, vae: AutoencoderKL, text_encoder: CLIPTextModel, tokenizer: CLIPTokenizer, unet: UNet2DConditionModel, scheduler: KarrasDiffusionSchedulers, safety_checker: StableDiffusionSafetyChecker, feature_extractor: CLIPImageProcessor, image_encoder: CLIPVisionModelWithProjection = None, requires_safety_checker: bool = True, ): super().__init__() if hasattr(scheduler.config, "steps_offset") and scheduler.config.steps_offset != 1: deprecation_message = ( f"The configuration file of this scheduler: {scheduler} is outdated. `steps_offset`" f" should be set to 1 instead of {scheduler.config.steps_offset}. Please make sure " "to update the config accordingly as leaving `steps_offset` might led to incorrect results" " in future versions. If you have downloaded this checkpoint from the Hugging Face Hub," " it would be very nice if you could open a Pull request for the `scheduler/scheduler_config.json`" " file" ) deprecate("steps_offset!=1", "1.0.0", deprecation_message, standard_warn=False) new_config = dict(scheduler.config) new_config["steps_offset"] = 1 scheduler._internal_dict = FrozenDict(new_config) if hasattr(scheduler.config, "clip_sample") and scheduler.config.clip_sample is True: deprecation_message = ( f"The configuration file of this scheduler: {scheduler} has not set the configuration `clip_sample`." " `clip_sample` should be set to False in the configuration file. Please make sure to update the" " config accordingly as not setting `clip_sample` in the config might lead to incorrect results in" " future versions. If you have downloaded this checkpoint from the Hugging Face Hub, it would be very" " nice if you could open a Pull request for the `scheduler/scheduler_config.json` file" ) deprecate("clip_sample not set", "1.0.0", deprecation_message, standard_warn=False) new_config = dict(scheduler.config) new_config["clip_sample"] = False scheduler._internal_dict = FrozenDict(new_config) 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 Stable Diffusion 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." ) is_unet_version_less_0_9_0 = hasattr(unet.config, "_diffusers_version") and version.parse( version.parse(unet.config._diffusers_version).base_version ) < version.parse("0.9.0.dev0") is_unet_sample_size_less_64 = hasattr(unet.config, "sample_size") and unet.config.sample_size < 64 if is_unet_version_less_0_9_0 and is_unet_sample_size_less_64: deprecation_message = ( "The configuration file of the unet has set the default `sample_size` to smaller than" " 64 which seems highly unlikely. If your checkpoint is a fine-tuned version of any of the" " following: \n- CompVis/stable-diffusion-v1-4 \n- CompVis/stable-diffusion-v1-3 \n-" " CompVis/stable-diffusion-v1-2 \n- CompVis/stable-diffusion-v1-1 \n- runwayml/stable-diffusion-v1-5" " \n- runwayml/stable-diffusion-inpainting \n you should change 'sample_size' to 64 in the" " configuration file. Please make sure to update the config accordingly as leaving `sample_size=32`" " in the config might lead to incorrect results in future versions. If you have downloaded this" " checkpoint from the Hugging Face Hub, it would be very nice if you could open a Pull request for" " the `unet/config.json` file" ) deprecate("sample_size<64", "1.0.0", deprecation_message, standard_warn=False) new_config = dict(unet.config) new_config["sample_size"] = 64 unet._internal_dict = FrozenDict(new_config) self.register_modules( vae=vae, text_encoder=text_encoder, tokenizer=tokenizer, unet=unet, scheduler=scheduler, safety_checker=safety_checker, feature_extractor=feature_extractor, image_encoder=image_encoder, ) self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1) self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor) self.register_to_config(requires_safety_checker=requires_safety_checker) # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline._encode_prompt def _encode_prompt( self, prompt, device, num_images_per_prompt, do_classifier_free_guidance, negative_prompt=None, prompt_embeds: Optional[torch.Tensor] = None, negative_prompt_embeds: Optional[torch.Tensor] = None, lora_scale: Optional[float] = None, **kwargs, ): deprecation_message = "`_encode_prompt()` is deprecated and it will be removed in a future version. Use `encode_prompt()` instead. Also, be aware that the output format changed from a concatenated tensor to a tuple." deprecate("_encode_prompt()", "1.0.0", deprecation_message, standard_warn=False) prompt_embeds_tuple = self.encode_prompt( prompt=prompt, device=device, num_images_per_prompt=num_images_per_prompt, do_classifier_free_guidance=do_classifier_free_guidance, negative_prompt=negative_prompt, prompt_embeds=prompt_embeds, negative_prompt_embeds=negative_prompt_embeds, lora_scale=lora_scale, **kwargs, ) # concatenate for backwards comp prompt_embeds = torch.cat([prompt_embeds_tuple[1], prompt_embeds_tuple[0]]) return prompt_embeds # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.encode_prompt def encode_prompt( self, prompt, device, num_images_per_prompt, do_classifier_free_guidance, negative_prompt=None, prompt_embeds: Optional[torch.Tensor] = None, negative_prompt_embeds: Optional[torch.Tensor] = None, lora_scale: Optional[float] = None, clip_skip: Optional[int] = None, ): r""" Encodes the prompt into text encoder hidden states. Args: prompt (`str` or `List[str]`, *optional*): 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]`, *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`). prompt_embeds (`torch.Tensor`, *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.Tensor`, *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. lora_scale (`float`, *optional*): A LoRA scale that will be applied to all LoRA layers of the text encoder if LoRA layers are loaded. clip_skip (`int`, *optional*): Number of layers to be skipped from CLIP while computing the prompt embeddings. A value of 1 means that the output of the pre-final layer will be used for computing the prompt embeddings. """ # set lora scale so that monkey patched LoRA # function of text encoder can correctly access it if lora_scale is not None and isinstance(self, StableDiffusionLoraLoaderMixin): self._lora_scale = lora_scale # dynamically adjust the LoRA scale if not USE_PEFT_BACKEND: adjust_lora_scale_text_encoder(self.text_encoder, lora_scale) else: scale_lora_layers(self.text_encoder, lora_scale) 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] if prompt_embeds is None: # textual inversion: process multi-vector tokens if necessary if isinstance(self, TextualInversionLoaderMixin): prompt = self.maybe_convert_prompt(prompt, self.tokenizer) text_inputs = self.tokenizer( prompt, padding="max_length", max_length=self.tokenizer.model_max_length, truncation=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[:, self.tokenizer.model_max_length - 1 : -1] ) logger.warning( "The following part of your input was truncated because CLIP can only handle sequences up to" f" {self.tokenizer.model_max_length} tokens: {removed_text}" ) if hasattr(self.text_encoder.config, "use_attention_mask") and self.text_encoder.config.use_attention_mask: attention_mask = text_inputs.attention_mask.to(device) else: attention_mask = None if clip_skip is None: prompt_embeds = self.text_encoder(text_input_ids.to(device), attention_mask=attention_mask) prompt_embeds = prompt_embeds[0] else: prompt_embeds = self.text_encoder( text_input_ids.to(device), attention_mask=attention_mask, output_hidden_states=True, ) # Access the `hidden_states` first, that contains a tuple of # all the hidden states from the encoder layers. Then index into # the tuple to access the hidden states from the desired layer. prompt_embeds = prompt_embeds[-1][-(clip_skip + 1)] # We also need to apply the final LayerNorm here to not mess with the # representations. The `last_hidden_states` that we typically use for # obtaining the final prompt representations passes through the LayerNorm # layer. prompt_embeds = self.text_encoder.text_model.final_layer_norm(prompt_embeds) if self.text_encoder is not None: prompt_embeds_dtype = self.text_encoder.dtype elif self.unet is not None: prompt_embeds_dtype = self.unet.dtype else: prompt_embeds_dtype = prompt_embeds.dtype prompt_embeds = prompt_embeds.to(dtype=prompt_embeds_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 prompt is not None and 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)}." ) 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 # textual inversion: process multi-vector tokens if necessary if isinstance(self, TextualInversionLoaderMixin): uncond_tokens = self.maybe_convert_prompt(uncond_tokens, self.tokenizer) max_length = prompt_embeds.shape[1] uncond_input = self.tokenizer( uncond_tokens, padding="max_length", max_length=max_length, truncation=True, return_tensors="pt", ) if hasattr(self.text_encoder.config, "use_attention_mask") and self.text_encoder.config.use_attention_mask: attention_mask = uncond_input.attention_mask.to(device) else: attention_mask = None 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=prompt_embeds_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) if isinstance(self, StableDiffusionLoraLoaderMixin) and USE_PEFT_BACKEND: # Retrieve the original scale by scaling back the LoRA layers unscale_lora_layers(self.text_encoder, lora_scale) return prompt_embeds, negative_prompt_embeds # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.run_safety_checker def run_safety_checker(self, image, device, dtype): if self.safety_checker is None: has_nsfw_concept = None else: if torch.is_tensor(image): feature_extractor_input = self.image_processor.postprocess(image, output_type="pil") else: feature_extractor_input = self.image_processor.numpy_to_pil(image) safety_checker_input = self.feature_extractor(feature_extractor_input, return_tensors="pt").to(device) image, has_nsfw_concept = self.safety_checker( images=image, clip_input=safety_checker_input.pixel_values.to(dtype) ) return image, has_nsfw_concept # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.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 # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.check_inputs def check_inputs( self, prompt, height, width, callback_steps, negative_prompt=None, prompt_embeds=None, negative_prompt_embeds=None, ip_adapter_image=None, ip_adapter_image_embeds=None, callback_on_step_end_tensor_inputs=None, ): 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 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 callback_on_step_end_tensor_inputs is not None and not all( k in self._callback_tensor_inputs for k in callback_on_step_end_tensor_inputs ): raise ValueError( f"`callback_on_step_end_tensor_inputs` has to be in {self._callback_tensor_inputs}, but found {[k for k in callback_on_step_end_tensor_inputs if k not in self._callback_tensor_inputs]}" ) 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 ip_adapter_image is not None and ip_adapter_image_embeds is not None: raise ValueError( "Provide either `ip_adapter_image` or `ip_adapter_image_embeds`. Cannot leave both `ip_adapter_image` and `ip_adapter_image_embeds` defined." ) # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.prepare_latents def prepare_latents( self, batch_size, num_channels_latents, height, width, dtype, device, generator, latents=None, ): shape = ( batch_size, num_channels_latents, height // self.vae_scale_factor, width // self.vae_scale_factor, ) 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." ) if latents is None: latents = randn_tensor(shape, generator=generator, device=device, dtype=dtype) else: 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 @torch.no_grad() def __call__( self, prompt: Union[str, List[str]], height: Optional[int] = None, width: Optional[int] = None, num_inference_steps: int = 50, guidance_scale: float = 7.5, 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, latents: Optional[torch.Tensor] = None, prompt_embeds: Optional[torch.Tensor] = None, negative_prompt_embeds: Optional[torch.Tensor] = None, output_type: Optional[str] = "pil", return_dict: bool = True, callback: Optional[Callable[[int, int, torch.Tensor], None]] = None, callback_steps: Optional[int] = 1, cross_attention_kwargs: Optional[Dict[str, Any]] = None, guidance_rescale: float = 0.0, ): r""" Function invoked when calling the pipeline for generation. Args: prompt (`str` or `List[str]`): The prompt or prompts to guide the image generation. height (`int`, *optional*, defaults to self.unet.config.sample_size * self.vae_scale_factor): The height in pixels of the generated image. width (`int`, *optional*, defaults to self.unet.config.sample_size * self.vae_scale_factor): 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. 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`). 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*): One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make generation deterministic. latents (`torch.Tensor`, *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`. 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.Tensor)`. 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. cross_attention_kwargs (`dict`, *optional*): A kwargs dictionary that if specified is passed along to the [`AttentionProcessor`] as defined in [`self.processor`](https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention_processor.py). The keyword arguments to configure the edit are: - edit_type (`str`). The edit type to apply. Can be either of `replace`, `refine`, `reweight`. - n_cross_replace (`int`): Number of diffusion steps in which cross attention should be replaced - n_self_replace (`int`): Number of diffusion steps in which self attention should be replaced - local_blend_words(`List[str]`, *optional*, default to `None`): Determines which area should be changed. If None, then the whole image can be changed. - equalizer_words(`List[str]`, *optional*, default to `None`): Required for edit type `reweight`. Determines which words should be enhanced. - equalizer_strengths (`List[float]`, *optional*, default to `None`) Required for edit type `reweight`. Determines which how much the words in `equalizer_words` should be enhanced. guidance_rescale (`float`, *optional*, defaults to 0.0): Guidance rescale factor from [Common Diffusion Noise Schedules and Sample Steps are Flawed](https://arxiv.org/pdf/2305.08891.pdf). Guidance rescale factor should fix overexposure when using zero terminal SNR. 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`. """ self.controller = create_controller( prompt, cross_attention_kwargs, num_inference_steps, tokenizer=self.tokenizer, device=self.device, ) self.register_attention_control(self.controller) # add attention controller # 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, callback_steps) # 2. Define call parameters 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] 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_encoder_lora_scale = ( cross_attention_kwargs.get("scale", None) if cross_attention_kwargs is not None else None ) prompt_embeds = self._encode_prompt( prompt, device, num_images_per_prompt, do_classifier_free_guidance, negative_prompt, prompt_embeds=prompt_embeds, negative_prompt_embeds=negative_prompt_embeds, lora_scale=text_encoder_lora_scale, ) # 4. Prepare timesteps self.scheduler.set_timesteps(num_inference_steps, device=device) timesteps = self.scheduler.timesteps # 5. Prepare latent variables num_channels_latents = self.unet.config.in_channels latents = self.prepare_latents( batch_size * num_images_per_prompt, num_channels_latents, height, width, prompt_embeds.dtype, device, generator, latents, ) # 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) # 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): # 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=prompt_embeds).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) if do_classifier_free_guidance and guidance_rescale > 0.0: # Based on 3.4. in https://arxiv.org/pdf/2305.08891.pdf noise_pred = rescale_noise_cfg(noise_pred, noise_pred_text, guidance_rescale=guidance_rescale) # compute the previous noisy sample x_t -> x_t-1 latents = self.scheduler.step(noise_pred, t, latents, **extra_step_kwargs).prev_sample # step callback latents = self.controller.step_callback(latents) # 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: step_idx = i // getattr(self.scheduler, "order", 1) callback(step_idx, t, latents) # 8. Post-processing if not output_type == "latent": image = self.vae.decode(latents / self.vae.config.scaling_factor, return_dict=False)[0] image, has_nsfw_concept = self.run_safety_checker(image, device, prompt_embeds.dtype) else: image = latents has_nsfw_concept = None # 9. Run safety checker if has_nsfw_concept is None: do_denormalize = [True] * image.shape[0] else: do_denormalize = [not has_nsfw for has_nsfw in has_nsfw_concept] image = self.image_processor.postprocess(image, output_type=output_type, do_denormalize=do_denormalize) # Offload last model to CPU if hasattr(self, "final_offload_hook") and self.final_offload_hook is not None: self.final_offload_hook.offload() if not return_dict: return (image, has_nsfw_concept) return StableDiffusionPipelineOutput(images=image, nsfw_content_detected=has_nsfw_concept) def register_attention_control(self, controller): attn_procs = {} cross_att_count = 0 for name in self.unet.attn_processors.keys(): (None if name.endswith("attn1.processor") else self.unet.config.cross_attention_dim) if name.startswith("mid_block"): self.unet.config.block_out_channels[-1] place_in_unet = "mid" elif name.startswith("up_blocks"): block_id = int(name[len("up_blocks.")]) list(reversed(self.unet.config.block_out_channels))[block_id] place_in_unet = "up" elif name.startswith("down_blocks"): block_id = int(name[len("down_blocks.")]) self.unet.config.block_out_channels[block_id] place_in_unet = "down" else: continue cross_att_count += 1 attn_procs[name] = P2PCrossAttnProcessor(controller=controller, place_in_unet=place_in_unet) self.unet.set_attn_processor(attn_procs) controller.num_att_layers = cross_att_count class P2PCrossAttnProcessor: def __init__(self, controller, place_in_unet): super().__init__() self.controller = controller self.place_in_unet = place_in_unet def __call__( self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None, ): batch_size, sequence_length, _ = hidden_states.shape attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) query = attn.to_q(hidden_states) is_cross = encoder_hidden_states is not None encoder_hidden_states = encoder_hidden_states if encoder_hidden_states is not None else hidden_states key = attn.to_k(encoder_hidden_states) value = attn.to_v(encoder_hidden_states) query = attn.head_to_batch_dim(query) key = attn.head_to_batch_dim(key) value = attn.head_to_batch_dim(value) attention_probs = attn.get_attention_scores(query, key, attention_mask) # one line change self.controller(attention_probs, is_cross, self.place_in_unet) hidden_states = torch.bmm(attention_probs, value) hidden_states = attn.batch_to_head_dim(hidden_states) # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) return hidden_states def create_controller( prompts: List[str], cross_attention_kwargs: Dict, num_inference_steps: int, tokenizer, device, ) -> AttentionControl: edit_type = cross_attention_kwargs.get("edit_type", None) local_blend_words = cross_attention_kwargs.get("local_blend_words", None) equalizer_words = cross_attention_kwargs.get("equalizer_words", None) equalizer_strengths = cross_attention_kwargs.get("equalizer_strengths", None) n_cross_replace = cross_attention_kwargs.get("n_cross_replace", 0.4) n_self_replace = cross_attention_kwargs.get("n_self_replace", 0.4) # only replace if edit_type == "replace" and local_blend_words is None: return AttentionReplace( prompts, num_inference_steps, n_cross_replace, n_self_replace, tokenizer=tokenizer, device=device, ) # replace + localblend if edit_type == "replace" and local_blend_words is not None: lb = LocalBlend(prompts, local_blend_words, tokenizer=tokenizer, device=device) return AttentionReplace( prompts, num_inference_steps, n_cross_replace, n_self_replace, lb, tokenizer=tokenizer, device=device, ) # only refine if edit_type == "refine" and local_blend_words is None: return AttentionRefine( prompts, num_inference_steps, n_cross_replace, n_self_replace, tokenizer=tokenizer, device=device, ) # refine + localblend if edit_type == "refine" and local_blend_words is not None: lb = LocalBlend(prompts, local_blend_words, tokenizer=tokenizer, device=device) return AttentionRefine( prompts, num_inference_steps, n_cross_replace, n_self_replace, lb, tokenizer=tokenizer, device=device, ) # reweight if edit_type == "reweight": assert ( equalizer_words is not None and equalizer_strengths is not None ), "To use reweight edit, please specify equalizer_words and equalizer_strengths." assert len(equalizer_words) == len( equalizer_strengths ), "equalizer_words and equalizer_strengths must be of same length." equalizer = get_equalizer(prompts[1], equalizer_words, equalizer_strengths, tokenizer=tokenizer) return AttentionReweight( prompts, num_inference_steps, n_cross_replace, n_self_replace, tokenizer=tokenizer, device=device, equalizer=equalizer, ) raise ValueError(f"Edit type {edit_type} not recognized. Use one of: replace, refine, reweight.") class AttentionControl(abc.ABC): def step_callback(self, x_t): return x_t def between_steps(self): return @property def num_uncond_att_layers(self): return 0 @abc.abstractmethod def forward(self, attn, is_cross: bool, place_in_unet: str): raise NotImplementedError def __call__(self, attn, is_cross: bool, place_in_unet: str): if self.cur_att_layer >= self.num_uncond_att_layers: h = attn.shape[0] attn[h // 2 :] = self.forward(attn[h // 2 :], is_cross, place_in_unet) self.cur_att_layer += 1 if self.cur_att_layer == self.num_att_layers + self.num_uncond_att_layers: self.cur_att_layer = 0 self.cur_step += 1 self.between_steps() return attn def reset(self): self.cur_step = 0 self.cur_att_layer = 0 def __init__(self): self.cur_step = 0 self.num_att_layers = -1 self.cur_att_layer = 0 class EmptyControl(AttentionControl): def forward(self, attn, is_cross: bool, place_in_unet: str): return attn class AttentionStore(AttentionControl): @staticmethod def get_empty_store(): return { "down_cross": [], "mid_cross": [], "up_cross": [], "down_self": [], "mid_self": [], "up_self": [], } def forward(self, attn, is_cross: bool, place_in_unet: str): key = f"{place_in_unet}_{'cross' if is_cross else 'self'}" if attn.shape[1] <= 32**2: # avoid memory overhead self.step_store[key].append(attn) return attn def between_steps(self): if len(self.attention_store) == 0: self.attention_store = self.step_store else: for key in self.attention_store: for i in range(len(self.attention_store[key])): self.attention_store[key][i] += self.step_store[key][i] self.step_store = self.get_empty_store() def get_average_attention(self): average_attention = { key: [item / self.cur_step for item in self.attention_store[key]] for key in self.attention_store } return average_attention def reset(self): super(AttentionStore, self).reset() self.step_store = self.get_empty_store() self.attention_store = {} def __init__(self): super(AttentionStore, self).__init__() self.step_store = self.get_empty_store() self.attention_store = {} class LocalBlend: def __call__(self, x_t, attention_store): k = 1 maps = attention_store["down_cross"][2:4] + attention_store["up_cross"][:3] maps = [item.reshape(self.alpha_layers.shape[0], -1, 1, 16, 16, self.max_num_words) for item in maps] maps = torch.cat(maps, dim=1) maps = (maps * self.alpha_layers).sum(-1).mean(1) mask = F.max_pool2d(maps, (k * 2 + 1, k * 2 + 1), (1, 1), padding=(k, k)) mask = F.interpolate(mask, size=(x_t.shape[2:])) mask = mask / mask.max(2, keepdims=True)[0].max(3, keepdims=True)[0] mask = mask.gt(self.threshold) mask = (mask[:1] + mask[1:]).float() x_t = x_t[:1] + mask * (x_t - x_t[:1]) return x_t def __init__( self, prompts: List[str], words: [List[List[str]]], tokenizer, device, threshold=0.3, max_num_words=77, ): self.max_num_words = 77 alpha_layers = torch.zeros(len(prompts), 1, 1, 1, 1, self.max_num_words) for i, (prompt, words_) in enumerate(zip(prompts, words)): if isinstance(words_, str): words_ = [words_] for word in words_: ind = get_word_inds(prompt, word, tokenizer) alpha_layers[i, :, :, :, :, ind] = 1 self.alpha_layers = alpha_layers.to(device) self.threshold = threshold class AttentionControlEdit(AttentionStore, abc.ABC): def step_callback(self, x_t): if self.local_blend is not None: x_t = self.local_blend(x_t, self.attention_store) return x_t def replace_self_attention(self, attn_base, att_replace): if att_replace.shape[2] <= 16**2: return attn_base.unsqueeze(0).expand(att_replace.shape[0], *attn_base.shape) else: return att_replace @abc.abstractmethod def replace_cross_attention(self, attn_base, att_replace): raise NotImplementedError def forward(self, attn, is_cross: bool, place_in_unet: str): super(AttentionControlEdit, self).forward(attn, is_cross, place_in_unet) # FIXME not replace correctly if is_cross or (self.num_self_replace[0] <= self.cur_step < self.num_self_replace[1]): h = attn.shape[0] // (self.batch_size) attn = attn.reshape(self.batch_size, h, *attn.shape[1:]) attn_base, attn_repalce = attn[0], attn[1:] if is_cross: alpha_words = self.cross_replace_alpha[self.cur_step] attn_repalce_new = ( self.replace_cross_attention(attn_base, attn_repalce) * alpha_words + (1 - alpha_words) * attn_repalce ) attn[1:] = attn_repalce_new else: attn[1:] = self.replace_self_attention(attn_base, attn_repalce) attn = attn.reshape(self.batch_size * h, *attn.shape[2:]) return attn def __init__( self, prompts, num_steps: int, cross_replace_steps: Union[float, Tuple[float, float], Dict[str, Tuple[float, float]]], self_replace_steps: Union[float, Tuple[float, float]], local_blend: Optional[LocalBlend], tokenizer, device, ): super(AttentionControlEdit, self).__init__() # add tokenizer and device here self.tokenizer = tokenizer self.device = device self.batch_size = len(prompts) self.cross_replace_alpha = get_time_words_attention_alpha( prompts, num_steps, cross_replace_steps, self.tokenizer ).to(self.device) if isinstance(self_replace_steps, float): self_replace_steps = 0, self_replace_steps self.num_self_replace = int(num_steps * self_replace_steps[0]), int(num_steps * self_replace_steps[1]) self.local_blend = local_blend # 在外面定义后传进来 class AttentionReplace(AttentionControlEdit): def replace_cross_attention(self, attn_base, att_replace): return torch.einsum("hpw,bwn->bhpn", attn_base, self.mapper) def __init__( self, prompts, num_steps: int, cross_replace_steps: float, self_replace_steps: float, local_blend: Optional[LocalBlend] = None, tokenizer=None, device=None, ): super(AttentionReplace, self).__init__( prompts, num_steps, cross_replace_steps, self_replace_steps, local_blend, tokenizer, device, ) self.mapper = get_replacement_mapper(prompts, self.tokenizer).to(self.device) class AttentionRefine(AttentionControlEdit): def replace_cross_attention(self, attn_base, att_replace): attn_base_replace = attn_base[:, :, self.mapper].permute(2, 0, 1, 3) attn_replace = attn_base_replace * self.alphas + att_replace * (1 - self.alphas) return attn_replace def __init__( self, prompts, num_steps: int, cross_replace_steps: float, self_replace_steps: float, local_blend: Optional[LocalBlend] = None, tokenizer=None, device=None, ): super(AttentionRefine, self).__init__( prompts, num_steps, cross_replace_steps, self_replace_steps, local_blend, tokenizer, device, ) self.mapper, alphas = get_refinement_mapper(prompts, self.tokenizer) self.mapper, alphas = self.mapper.to(self.device), alphas.to(self.device) self.alphas = alphas.reshape(alphas.shape[0], 1, 1, alphas.shape[1]) class AttentionReweight(AttentionControlEdit): def replace_cross_attention(self, attn_base, att_replace): if self.prev_controller is not None: attn_base = self.prev_controller.replace_cross_attention(attn_base, att_replace) attn_replace = attn_base[None, :, :, :] * self.equalizer[:, None, None, :] return attn_replace def __init__( self, prompts, num_steps: int, cross_replace_steps: float, self_replace_steps: float, equalizer, local_blend: Optional[LocalBlend] = None, controller: Optional[AttentionControlEdit] = None, tokenizer=None, device=None, ): super(AttentionReweight, self).__init__( prompts, num_steps, cross_replace_steps, self_replace_steps, local_blend, tokenizer, device, ) self.equalizer = equalizer.to(self.device) self.prev_controller = controller ### util functions for all Edits def update_alpha_time_word( alpha, bounds: Union[float, Tuple[float, float]], prompt_ind: int, word_inds: Optional[torch.Tensor] = None, ): if isinstance(bounds, float): bounds = 0, bounds start, end = int(bounds[0] * alpha.shape[0]), int(bounds[1] * alpha.shape[0]) if word_inds is None: word_inds = torch.arange(alpha.shape[2]) alpha[:start, prompt_ind, word_inds] = 0 alpha[start:end, prompt_ind, word_inds] = 1 alpha[end:, prompt_ind, word_inds] = 0 return alpha def get_time_words_attention_alpha( prompts, num_steps, cross_replace_steps: Union[float, Dict[str, Tuple[float, float]]], tokenizer, max_num_words=77, ): if not isinstance(cross_replace_steps, dict): cross_replace_steps = {"default_": cross_replace_steps} if "default_" not in cross_replace_steps: cross_replace_steps["default_"] = (0.0, 1.0) alpha_time_words = torch.zeros(num_steps + 1, len(prompts) - 1, max_num_words) for i in range(len(prompts) - 1): alpha_time_words = update_alpha_time_word(alpha_time_words, cross_replace_steps["default_"], i) for key, item in cross_replace_steps.items(): if key != "default_": inds = [get_word_inds(prompts[i], key, tokenizer) for i in range(1, len(prompts))] for i, ind in enumerate(inds): if len(ind) > 0: alpha_time_words = update_alpha_time_word(alpha_time_words, item, i, ind) alpha_time_words = alpha_time_words.reshape(num_steps + 1, len(prompts) - 1, 1, 1, max_num_words) return alpha_time_words ### util functions for LocalBlend and ReplacementEdit def get_word_inds(text: str, word_place: int, tokenizer): split_text = text.split(" ") if isinstance(word_place, str): word_place = [i for i, word in enumerate(split_text) if word_place == word] elif isinstance(word_place, int): word_place = [word_place] out = [] if len(word_place) > 0: words_encode = [tokenizer.decode([item]).strip("#") for item in tokenizer.encode(text)][1:-1] cur_len, ptr = 0, 0 for i in range(len(words_encode)): cur_len += len(words_encode[i]) if ptr in word_place: out.append(i + 1) if cur_len >= len(split_text[ptr]): ptr += 1 cur_len = 0 return np.array(out) ### util functions for ReplacementEdit def get_replacement_mapper_(x: str, y: str, tokenizer, max_len=77): words_x = x.split(" ") words_y = y.split(" ") if len(words_x) != len(words_y): raise ValueError( f"attention replacement edit can only be applied on prompts with the same length" f" but prompt A has {len(words_x)} words and prompt B has {len(words_y)} words." ) inds_replace = [i for i in range(len(words_y)) if words_y[i] != words_x[i]] inds_source = [get_word_inds(x, i, tokenizer) for i in inds_replace] inds_target = [get_word_inds(y, i, tokenizer) for i in inds_replace] mapper = np.zeros((max_len, max_len)) i = j = 0 cur_inds = 0 while i < max_len and j < max_len: if cur_inds < len(inds_source) and inds_source[cur_inds][0] == i: inds_source_, inds_target_ = inds_source[cur_inds], inds_target[cur_inds] if len(inds_source_) == len(inds_target_): mapper[inds_source_, inds_target_] = 1 else: ratio = 1 / len(inds_target_) for i_t in inds_target_: mapper[inds_source_, i_t] = ratio cur_inds += 1 i += len(inds_source_) j += len(inds_target_) elif cur_inds < len(inds_source): mapper[i, j] = 1 i += 1 j += 1 else: mapper[j, j] = 1 i += 1 j += 1 return torch.from_numpy(mapper).float() def get_replacement_mapper(prompts, tokenizer, max_len=77): x_seq = prompts[0] mappers = [] for i in range(1, len(prompts)): mapper = get_replacement_mapper_(x_seq, prompts[i], tokenizer, max_len) mappers.append(mapper) return torch.stack(mappers) ### util functions for ReweightEdit def get_equalizer( text: str, word_select: Union[int, Tuple[int, ...]], values: Union[List[float], Tuple[float, ...]], tokenizer, ): if isinstance(word_select, (int, str)): word_select = (word_select,) equalizer = torch.ones(len(values), 77) values = torch.tensor(values, dtype=torch.float32) for word in word_select: inds = get_word_inds(text, word, tokenizer) equalizer[:, inds] = values return equalizer ### util functions for RefinementEdit class ScoreParams: def __init__(self, gap, match, mismatch): self.gap = gap self.match = match self.mismatch = mismatch def mis_match_char(self, x, y): if x != y: return self.mismatch else: return self.match def get_matrix(size_x, size_y, gap): matrix = np.zeros((size_x + 1, size_y + 1), dtype=np.int32) matrix[0, 1:] = (np.arange(size_y) + 1) * gap matrix[1:, 0] = (np.arange(size_x) + 1) * gap return matrix def get_traceback_matrix(size_x, size_y): matrix = np.zeros((size_x + 1, size_y + 1), dtype=np.int32) matrix[0, 1:] = 1 matrix[1:, 0] = 2 matrix[0, 0] = 4 return matrix def global_align(x, y, score): matrix = get_matrix(len(x), len(y), score.gap) trace_back = get_traceback_matrix(len(x), len(y)) for i in range(1, len(x) + 1): for j in range(1, len(y) + 1): left = matrix[i, j - 1] + score.gap up = matrix[i - 1, j] + score.gap diag = matrix[i - 1, j - 1] + score.mis_match_char(x[i - 1], y[j - 1]) matrix[i, j] = max(left, up, diag) if matrix[i, j] == left: trace_back[i, j] = 1 elif matrix[i, j] == up: trace_back[i, j] = 2 else: trace_back[i, j] = 3 return matrix, trace_back def get_aligned_sequences(x, y, trace_back): x_seq = [] y_seq = [] i = len(x) j = len(y) mapper_y_to_x = [] while i > 0 or j > 0: if trace_back[i, j] == 3: x_seq.append(x[i - 1]) y_seq.append(y[j - 1]) i = i - 1 j = j - 1 mapper_y_to_x.append((j, i)) elif trace_back[i][j] == 1: x_seq.append("-") y_seq.append(y[j - 1]) j = j - 1 mapper_y_to_x.append((j, -1)) elif trace_back[i][j] == 2: x_seq.append(x[i - 1]) y_seq.append("-") i = i - 1 elif trace_back[i][j] == 4: break mapper_y_to_x.reverse() return x_seq, y_seq, torch.tensor(mapper_y_to_x, dtype=torch.int64) def get_mapper(x: str, y: str, tokenizer, max_len=77): x_seq = tokenizer.encode(x) y_seq = tokenizer.encode(y) score = ScoreParams(0, 1, -1) matrix, trace_back = global_align(x_seq, y_seq, score) mapper_base = get_aligned_sequences(x_seq, y_seq, trace_back)[-1] alphas = torch.ones(max_len) alphas[: mapper_base.shape[0]] = mapper_base[:, 1].ne(-1).float() mapper = torch.zeros(max_len, dtype=torch.int64) mapper[: mapper_base.shape[0]] = mapper_base[:, 1] mapper[mapper_base.shape[0] :] = len(y_seq) + torch.arange(max_len - len(y_seq)) return mapper, alphas def get_refinement_mapper(prompts, tokenizer, max_len=77): x_seq = prompts[0] mappers, alphas = [], [] for i in range(1, len(prompts)): mapper, alpha = get_mapper(x_seq, prompts[i], tokenizer, max_len) mappers.append(mapper) alphas.append(alpha) return torch.stack(mappers), torch.stack(alphas)