# Implementation of Stable Diffusion Upscale Pipeline with Perturbed-Attention Guidance import inspect import warnings from typing import Any, Callable, Dict, List, Optional, Union import numpy as np import PIL.Image import torch import torch.nn.functional as F from transformers import CLIPImageProcessor, CLIPTextModel, CLIPTokenizer from diffusers.image_processor import PipelineImageInput, VaeImageProcessor from diffusers.loaders import FromSingleFileMixin, LoraLoaderMixin, TextualInversionLoaderMixin from diffusers.models import AutoencoderKL, UNet2DConditionModel from diffusers.models.attention_processor import ( Attention, AttnProcessor2_0, LoRAAttnProcessor2_0, LoRAXFormersAttnProcessor, XFormersAttnProcessor, ) from diffusers.models.lora import adjust_lora_scale_text_encoder from diffusers.schedulers import DDPMScheduler, KarrasDiffusionSchedulers from diffusers.utils import USE_PEFT_BACKEND, deprecate, logging, scale_lora_layers, unscale_lora_layers from diffusers.utils.torch_utils import randn_tensor from diffusers.pipelines.pipeline_utils import DiffusionPipeline, StableDiffusionMixin from diffusers.pipelines.stable_diffusion import StableDiffusionPipelineOutput logger = logging.get_logger(__name__) # pylint: disable=invalid-name class PAGIdentitySelfAttnProcessor: r""" Processor for implementing scaled dot-product attention (enabled by default if you're using PyTorch 2.0). """ def __init__(self): if not hasattr(F, "scaled_dot_product_attention"): raise ImportError("AttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0.") def __call__( self, attn: Attention, hidden_states: torch.FloatTensor, encoder_hidden_states: Optional[torch.FloatTensor] = None, attention_mask: Optional[torch.FloatTensor] = None, temb: Optional[torch.FloatTensor] = None, *args, **kwargs, ) -> torch.FloatTensor: if len(args) > 0 or kwargs.get("scale", None) is not None: deprecation_message = "The `scale` argument is deprecated and will be ignored. Please remove it, as passing it will raise an error in the future. `scale` should directly be passed while calling the underlying pipeline component i.e., via `cross_attention_kwargs`." deprecate("scale", "1.0.0", deprecation_message) residual = hidden_states if attn.spatial_norm is not None: hidden_states = attn.spatial_norm(hidden_states, temb) input_ndim = hidden_states.ndim if input_ndim == 4: batch_size, channel, height, width = hidden_states.shape hidden_states = hidden_states.view(batch_size, channel, height * width).transpose(1, 2) # chunk hidden_states_org, hidden_states_ptb = hidden_states.chunk(2) # original path batch_size, sequence_length, _ = hidden_states_org.shape if attention_mask is not None: attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) # scaled_dot_product_attention expects attention_mask shape to be # (batch, heads, source_length, target_length) attention_mask = attention_mask.view(batch_size, attn.heads, -1, attention_mask.shape[-1]) if attn.group_norm is not None: hidden_states_org = attn.group_norm(hidden_states_org.transpose(1, 2)).transpose(1, 2) query = attn.to_q(hidden_states_org) key = attn.to_k(hidden_states_org) value = attn.to_v(hidden_states_org) inner_dim = key.shape[-1] head_dim = inner_dim // attn.heads query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2) key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2) value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2) # the output of sdp = (batch, num_heads, seq_len, head_dim) # TODO: add support for attn.scale when we move to Torch 2.1 hidden_states_org = F.scaled_dot_product_attention( query, key, value, attn_mask=attention_mask, dropout_p=0.0, is_causal=False ) hidden_states_org = hidden_states_org.transpose(1, 2).reshape(batch_size, -1, attn.heads * head_dim) hidden_states_org = hidden_states_org.to(query.dtype) # linear proj hidden_states_org = attn.to_out[0](hidden_states_org) # dropout hidden_states_org = attn.to_out[1](hidden_states_org) if input_ndim == 4: hidden_states_org = hidden_states_org.transpose(-1, -2).reshape(batch_size, channel, height, width) # perturbed path (identity attention) batch_size, sequence_length, _ = hidden_states_ptb.shape if attention_mask is not None: attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) # scaled_dot_product_attention expects attention_mask shape to be # (batch, heads, source_length, target_length) attention_mask = attention_mask.view(batch_size, attn.heads, -1, attention_mask.shape[-1]) if attn.group_norm is not None: hidden_states_ptb = attn.group_norm(hidden_states_ptb.transpose(1, 2)).transpose(1, 2) value = attn.to_v(hidden_states_ptb) # hidden_states_ptb = torch.zeros(value.shape).to(value.get_device()) hidden_states_ptb = value hidden_states_ptb = hidden_states_ptb.to(query.dtype) # linear proj hidden_states_ptb = attn.to_out[0](hidden_states_ptb) # dropout hidden_states_ptb = attn.to_out[1](hidden_states_ptb) if input_ndim == 4: hidden_states_ptb = hidden_states_ptb.transpose(-1, -2).reshape(batch_size, channel, height, width) # cat hidden_states = torch.cat([hidden_states_org, hidden_states_ptb]) if attn.residual_connection: hidden_states = hidden_states + residual hidden_states = hidden_states / attn.rescale_output_factor return hidden_states class PAGCFGIdentitySelfAttnProcessor: r""" Processor for implementing scaled dot-product attention (enabled by default if you're using PyTorch 2.0). """ def __init__(self): if not hasattr(F, "scaled_dot_product_attention"): raise ImportError("AttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0.") def __call__( self, attn: Attention, hidden_states: torch.FloatTensor, encoder_hidden_states: Optional[torch.FloatTensor] = None, attention_mask: Optional[torch.FloatTensor] = None, temb: Optional[torch.FloatTensor] = None, *args, **kwargs, ) -> torch.FloatTensor: if len(args) > 0 or kwargs.get("scale", None) is not None: deprecation_message = "The `scale` argument is deprecated and will be ignored. Please remove it, as passing it will raise an error in the future. `scale` should directly be passed while calling the underlying pipeline component i.e., via `cross_attention_kwargs`." deprecate("scale", "1.0.0", deprecation_message) residual = hidden_states if attn.spatial_norm is not None: hidden_states = attn.spatial_norm(hidden_states, temb) input_ndim = hidden_states.ndim if input_ndim == 4: batch_size, channel, height, width = hidden_states.shape hidden_states = hidden_states.view(batch_size, channel, height * width).transpose(1, 2) # chunk hidden_states_uncond, hidden_states_org, hidden_states_ptb = hidden_states.chunk(3) hidden_states_org = torch.cat([hidden_states_uncond, hidden_states_org]) # original path batch_size, sequence_length, _ = hidden_states_org.shape if attention_mask is not None: attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) # scaled_dot_product_attention expects attention_mask shape to be # (batch, heads, source_length, target_length) attention_mask = attention_mask.view(batch_size, attn.heads, -1, attention_mask.shape[-1]) if attn.group_norm is not None: hidden_states_org = attn.group_norm(hidden_states_org.transpose(1, 2)).transpose(1, 2) query = attn.to_q(hidden_states_org) key = attn.to_k(hidden_states_org) value = attn.to_v(hidden_states_org) inner_dim = key.shape[-1] head_dim = inner_dim // attn.heads query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2) key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2) value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2) # the output of sdp = (batch, num_heads, seq_len, head_dim) # TODO: add support for attn.scale when we move to Torch 2.1 hidden_states_org = F.scaled_dot_product_attention( query, key, value, attn_mask=attention_mask, dropout_p=0.0, is_causal=False ) hidden_states_org = hidden_states_org.transpose(1, 2).reshape(batch_size, -1, attn.heads * head_dim) hidden_states_org = hidden_states_org.to(query.dtype) # linear proj hidden_states_org = attn.to_out[0](hidden_states_org) # dropout hidden_states_org = attn.to_out[1](hidden_states_org) if input_ndim == 4: hidden_states_org = hidden_states_org.transpose(-1, -2).reshape(batch_size, channel, height, width) # perturbed path (identity attention) batch_size, sequence_length, _ = hidden_states_ptb.shape if attention_mask is not None: attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) # scaled_dot_product_attention expects attention_mask shape to be # (batch, heads, source_length, target_length) attention_mask = attention_mask.view(batch_size, attn.heads, -1, attention_mask.shape[-1]) if attn.group_norm is not None: hidden_states_ptb = attn.group_norm(hidden_states_ptb.transpose(1, 2)).transpose(1, 2) value = attn.to_v(hidden_states_ptb) hidden_states_ptb = value hidden_states_ptb = hidden_states_ptb.to(query.dtype) # linear proj hidden_states_ptb = attn.to_out[0](hidden_states_ptb) # dropout hidden_states_ptb = attn.to_out[1](hidden_states_ptb) if input_ndim == 4: hidden_states_ptb = hidden_states_ptb.transpose(-1, -2).reshape(batch_size, channel, height, width) # cat hidden_states = torch.cat([hidden_states_org, hidden_states_ptb]) if attn.residual_connection: hidden_states = hidden_states + residual hidden_states = hidden_states / attn.rescale_output_factor return hidden_states def preprocess(image): warnings.warn( "The preprocess method is deprecated and will be removed in a future version. Please" " use VaeImageProcessor.preprocess instead", FutureWarning, ) if isinstance(image, torch.Tensor): return image elif isinstance(image, PIL.Image.Image): image = [image] if isinstance(image[0], PIL.Image.Image): w, h = image[0].size w, h = (x - x % 64 for x in (w, h)) # resize to integer multiple of 64 image = [np.array(i.resize((w, h)))[None, :] for i in image] image = np.concatenate(image, axis=0) image = np.array(image).astype(np.float32) / 255.0 image = image.transpose(0, 3, 1, 2) image = 2.0 * image - 1.0 image = torch.from_numpy(image) elif isinstance(image[0], torch.Tensor): image = torch.cat(image, dim=0) return image class StableDiffusionUpscalePipeline( DiffusionPipeline, StableDiffusionMixin, TextualInversionLoaderMixin, LoraLoaderMixin, FromSingleFileMixin ): r""" Pipeline for text-guided image super-resolution using Stable Diffusion 2. 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.LoraLoaderMixin.load_lora_weights`] for loading LoRA weights - [`~loaders.LoraLoaderMixin.save_lora_weights`] for saving LoRA weights - [`~loaders.FromSingleFileMixin.from_single_file`] for loading `.ckpt` files 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. low_res_scheduler ([`SchedulerMixin`]): A scheduler used to add initial noise to the low resolution conditioning image. It must be an instance of [`DDPMScheduler`]. 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`]. """ model_cpu_offload_seq = "text_encoder->unet->vae" _optional_components = ["watermarker", "safety_checker", "feature_extractor"] _exclude_from_cpu_offload = ["safety_checker"] def __init__( self, vae: AutoencoderKL, text_encoder: CLIPTextModel, tokenizer: CLIPTokenizer, unet: UNet2DConditionModel, low_res_scheduler: DDPMScheduler, scheduler: KarrasDiffusionSchedulers, safety_checker: Optional[Any] = None, feature_extractor: Optional[CLIPImageProcessor] = None, watermarker: Optional[Any] = None, max_noise_level: int = 350, ): super().__init__() if hasattr( vae, "config" ): # check if vae has a config attribute `scaling_factor` and if it is set to 0.08333, else set it to 0.08333 and deprecate is_vae_scaling_factor_set_to_0_08333 = ( hasattr(vae.config, "scaling_factor") and vae.config.scaling_factor == 0.08333 ) if not is_vae_scaling_factor_set_to_0_08333: deprecation_message = ( "The configuration file of the vae does not contain `scaling_factor` or it is set to" f" {vae.config.scaling_factor}, which seems highly unlikely. If your checkpoint is a fine-tuned" " version of `stabilityai/stable-diffusion-x4-upscaler` you should change 'scaling_factor' to" " 0.08333 Please make sure to update the config accordingly, as not doing so 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 `vae/config.json` file" ) deprecate("wrong scaling_factor", "1.0.0", deprecation_message, standard_warn=False) vae.register_to_config(scaling_factor=0.08333) self.register_modules( vae=vae, text_encoder=text_encoder, tokenizer=tokenizer, unet=unet, low_res_scheduler=low_res_scheduler, scheduler=scheduler, safety_checker=safety_checker, watermarker=watermarker, feature_extractor=feature_extractor, ) self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1) self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor, resample="bicubic") self.register_to_config(max_noise_level=max_noise_level) def run_safety_checker(self, image, device, dtype): if self.safety_checker is not None: feature_extractor_input = self.image_processor.postprocess(image, output_type="pil") safety_checker_input = self.feature_extractor(feature_extractor_input, return_tensors="pt").to(device) image, nsfw_detected, watermark_detected = self.safety_checker( images=image, clip_input=safety_checker_input.pixel_values.to(dtype=dtype), ) else: nsfw_detected = None watermark_detected = None if hasattr(self, "unet_offload_hook") and self.unet_offload_hook is not None: self.unet_offload_hook.offload() return image, nsfw_detected, watermark_detected # 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.FloatTensor] = None, negative_prompt_embeds: Optional[torch.FloatTensor] = 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.FloatTensor] = None, negative_prompt_embeds: Optional[torch.FloatTensor] = 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.FloatTensor`, *optional*): Pre-generated text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not provided, text embeddings will be generated from `prompt` input argument. negative_prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated negative text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not provided, negative_prompt_embeds will be generated from `negative_prompt` input argument. 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, LoraLoaderMixin): 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, LoraLoaderMixin) 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.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.decode_latents def decode_latents(self, latents): deprecation_message = "The decode_latents method is deprecated and will be removed in 1.0.0. Please use VaeImageProcessor.postprocess(...) instead" deprecate("decode_latents", "1.0.0", deprecation_message, standard_warn=False) latents = 1 / self.vae.config.scaling_factor * latents image = self.vae.decode(latents, return_dict=False)[0] image = (image / 2 + 0.5).clamp(0, 1) # we always cast to float32 as this does not cause significant overhead and is compatible with bfloat16 image = image.cpu().permute(0, 2, 3, 1).float().numpy() return image def check_inputs( self, prompt, image, noise_level, callback_steps, negative_prompt=None, prompt_embeds=None, negative_prompt_embeds=None, ): if (callback_steps is None) or ( callback_steps is not None and (not isinstance(callback_steps, int) or callback_steps <= 0) ): raise ValueError( f"`callback_steps` has to be a positive integer but is {callback_steps} of type" f" {type(callback_steps)}." ) if prompt is not None and prompt_embeds is not None: raise ValueError( f"Cannot forward both `prompt`: {prompt} and `prompt_embeds`: {prompt_embeds}. Please make sure to" " only forward one of the two." ) elif prompt is None and prompt_embeds is None: raise ValueError( "Provide either `prompt` or `prompt_embeds`. Cannot leave both `prompt` and `prompt_embeds` undefined." ) elif prompt is not None and (not isinstance(prompt, str) and not isinstance(prompt, list)): raise ValueError(f"`prompt` has to be of type `str` or `list` but is {type(prompt)}") if negative_prompt is not None and negative_prompt_embeds is not None: raise ValueError( f"Cannot forward both `negative_prompt`: {negative_prompt} and `negative_prompt_embeds`:" f" {negative_prompt_embeds}. Please make sure to only forward one of the two." ) if prompt_embeds is not None and negative_prompt_embeds is not None: if prompt_embeds.shape != negative_prompt_embeds.shape: raise ValueError( "`prompt_embeds` and `negative_prompt_embeds` must have the same shape when passed directly, but" f" got: `prompt_embeds` {prompt_embeds.shape} != `negative_prompt_embeds`" f" {negative_prompt_embeds.shape}." ) if ( not isinstance(image, torch.Tensor) and not isinstance(image, PIL.Image.Image) and not isinstance(image, np.ndarray) and not isinstance(image, list) ): raise ValueError( f"`image` has to be of type `torch.Tensor`, `np.ndarray`, `PIL.Image.Image` or `list` but is {type(image)}" ) # verify batch size of prompt and image are same if image is a list or tensor or numpy array if isinstance(image, list) or isinstance(image, torch.Tensor) or isinstance(image, np.ndarray): 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 isinstance(image, list): image_batch_size = len(image) else: image_batch_size = image.shape[0] if batch_size != image_batch_size: raise ValueError( f"`prompt` has batch size {batch_size} and `image` has batch size {image_batch_size}." " Please make sure that passed `prompt` matches the batch size of `image`." ) # check noise level if noise_level > self.config.max_noise_level: raise ValueError(f"`noise_level` has to be <= {self.config.max_noise_level} but is {noise_level}") 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 prepare_latents(self, batch_size, num_channels_latents, height, width, dtype, device, generator, latents=None): shape = (batch_size, num_channels_latents, height, width) if latents is None: latents = randn_tensor(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 def upcast_vae(self): dtype = self.vae.dtype self.vae.to(dtype=torch.float32) use_torch_2_0_or_xformers = isinstance( self.vae.decoder.mid_block.attentions[0].processor, ( AttnProcessor2_0, XFormersAttnProcessor, LoRAXFormersAttnProcessor, LoRAAttnProcessor2_0, ), ) # if xformers or torch_2_0 is used attention block does not need # to be in float32 which can save lots of memory if use_torch_2_0_or_xformers: self.vae.post_quant_conv.to(dtype) self.vae.decoder.conv_in.to(dtype) self.vae.decoder.mid_block.to(dtype) @property def guidance_scale(self): return self._guidance_scale @property def do_classifier_free_guidance(self): return self._guidance_scale > 1 and self.unet.config.time_cond_proj_dim is None @property def pag_scale(self): return self._pag_scale @property def do_perturbed_attention_guidance(self): return self._pag_scale > 0 @property def pag_adaptive_scaling(self): return self._pag_adaptive_scaling @property def do_pag_adaptive_scaling(self): return self._pag_adaptive_scaling > 0 @property def pag_applied_layers_index(self): return self._pag_applied_layers_index @torch.no_grad() def __call__( self, prompt: Union[str, List[str]] = None, image: PipelineImageInput = None, num_inference_steps: int = 75, guidance_scale: float = 9.0, pag_scale: float = 0.0, pag_adaptive_scaling: float = 0.0, pag_applied_layers_index: List[str] = ["d4"], # ['d4', 'd5', 'm0'] noise_level: int = 20, 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.FloatTensor] = None, prompt_embeds: Optional[torch.FloatTensor] = None, negative_prompt_embeds: Optional[torch.FloatTensor] = None, output_type: Optional[str] = "pil", return_dict: bool = True, callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None, callback_steps: int = 1, cross_attention_kwargs: Optional[Dict[str, Any]] = None, clip_skip: int = None, ): r""" The call function to the pipeline for generation. Args: prompt (`str` or `List[str]`, *optional*): The prompt or prompts to guide image generation. If not defined, you need to pass `prompt_embeds`. image (`torch.FloatTensor`, `PIL.Image.Image`, `np.ndarray`, `List[torch.FloatTensor]`, `List[PIL.Image.Image]`, or `List[np.ndarray]`): `Image` or tensor representing an image batch to be upscaled. 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): A higher guidance scale value encourages the model to generate images closely linked to the text `prompt` at the expense of lower image quality. Guidance scale is enabled when `guidance_scale > 1`. negative_prompt (`str` or `List[str]`, *optional*): The prompt or prompts to guide what to not include in image generation. If not defined, you need to pass `negative_prompt_embeds` instead. Ignored when not using guidance (`guidance_scale < 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) from the [DDIM](https://arxiv.org/abs/2010.02502) paper. Only applies to the [`~schedulers.DDIMScheduler`], and is ignored in other schedulers. generator (`torch.Generator` or `List[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 is generated by sampling using the supplied random `generator`. prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated text embeddings. Can be used to easily tweak text inputs (prompt weighting). If not provided, text embeddings are generated from the `prompt` input argument. negative_prompt_embeds (`torch.FloatTensor`, *optional*): Pre-generated negative text embeddings. Can be used to easily tweak text inputs (prompt weighting). If not provided, `negative_prompt_embeds` are generated from the `negative_prompt` input argument. output_type (`str`, *optional*, defaults to `"pil"`): The output format of the generated image. Choose between `PIL.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 calls every `callback_steps` steps during inference. The function is called with the following arguments: `callback(step: int, timestep: int, latents: torch.FloatTensor)`. callback_steps (`int`, *optional*, defaults to 1): The frequency at which the `callback` function is called. If not specified, the callback is 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). 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. Examples: ```py >>> import requests >>> from PIL import Image >>> from io import BytesIO >>> from diffusers import StableDiffusionUpscalePipeline >>> import torch >>> # load model and scheduler >>> model_id = "stabilityai/stable-diffusion-x4-upscaler" >>> pipeline = StableDiffusionUpscalePipeline.from_pretrained( ... model_id, revision="fp16", torch_dtype=torch.float16 ... ) >>> pipeline = pipeline.to("cuda") >>> # let's download an image >>> url = "https://huggingface.co/datasets/hf-internal-testing/diffusers-images/resolve/main/sd2-upscale/low_res_cat.png" >>> response = requests.get(url) >>> low_res_img = Image.open(BytesIO(response.content)).convert("RGB") >>> low_res_img = low_res_img.resize((128, 128)) >>> prompt = "a white cat" >>> upscaled_image = pipeline(prompt=prompt, image=low_res_img).images[0] >>> upscaled_image.save("upsampled_cat.png") ``` Returns: [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] or `tuple`: If `return_dict` is `True`, [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] is returned, otherwise a `tuple` is returned where the first element is a list with the generated images and the second element is a list of `bool`s indicating whether the corresponding generated image contains "not-safe-for-work" (nsfw) content. """ # 1. Check inputs self.check_inputs( prompt, image, noise_level, callback_steps, negative_prompt, prompt_embeds, negative_prompt_embeds, ) self._guidance_scale = guidance_scale self._pag_scale = pag_scale self._pag_adaptive_scaling = pag_adaptive_scaling self._pag_applied_layers_index = pag_applied_layers_index if image is None: raise ValueError("`image` input cannot be undefined.") # 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. # 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, negative_prompt_embeds = self.encode_prompt( prompt, device, num_images_per_prompt, self.do_classifier_free_guidance, negative_prompt, prompt_embeds=prompt_embeds, negative_prompt_embeds=negative_prompt_embeds, lora_scale=text_encoder_lora_scale, clip_skip=clip_skip, ) # For classifier free guidance, we need to do two forward passes. # Here we concatenate the unconditional and text embeddings into a single batch # to avoid doing two forward passes # cfg if self.do_classifier_free_guidance and not self.do_perturbed_attention_guidance: prompt_embeds = torch.cat([negative_prompt_embeds, prompt_embeds]) # pag elif not self.do_classifier_free_guidance and self.do_perturbed_attention_guidance: prompt_embeds = torch.cat([prompt_embeds, prompt_embeds]) # both elif self.do_classifier_free_guidance and self.do_perturbed_attention_guidance: prompt_embeds = torch.cat([negative_prompt_embeds, prompt_embeds, prompt_embeds]) # 4. Preprocess image image = self.image_processor.preprocess(image) image = image.to(dtype=prompt_embeds.dtype, device=device) # 5. set timesteps self.scheduler.set_timesteps(num_inference_steps, device=device) timesteps = self.scheduler.timesteps # 5. Add noise to image noise_level = torch.tensor([noise_level], dtype=torch.long, device=device) noise = randn_tensor(image.shape, generator=generator, device=device, dtype=prompt_embeds.dtype) image = self.low_res_scheduler.add_noise(image, noise, noise_level) image = torch.cat([image] * num_images_per_prompt) noise_level = torch.cat([noise_level] * image.shape[0]) # 6. Prepare latent variables height, width = image.shape[2:] num_channels_latents = self.vae.config.latent_channels latents = self.prepare_latents( batch_size * num_images_per_prompt, num_channels_latents, height, width, prompt_embeds.dtype, device, generator, latents, ) # 7. Check that sizes of image and latents match num_channels_image = image.shape[1] if num_channels_latents + num_channels_image != self.unet.config.in_channels: raise ValueError( f"Incorrect configuration settings! The config of `pipeline.unet`: {self.unet.config} expects" f" {self.unet.config.in_channels} but received `num_channels_latents`: {num_channels_latents} +" f" `num_channels_image`: {num_channels_image} " f" = {num_channels_latents+num_channels_image}. Please verify the config of" " `pipeline.unet` or your `image` input." ) # 8. 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) # 9. Denoising loop if self.do_perturbed_attention_guidance: down_layers = [] mid_layers = [] up_layers = [] for name, module in self.unet.named_modules(): if "attn1" in name and "to" not in name: layer_type = name.split(".")[0].split("_")[0] if layer_type == "down": down_layers.append(module) elif layer_type == "mid": mid_layers.append(module) elif layer_type == "up": up_layers.append(module) else: raise ValueError(f"Invalid layer type: {layer_type}") # change attention layer in UNet if use PAG if self.do_perturbed_attention_guidance: if self.do_classifier_free_guidance: replace_processor = PAGCFGIdentitySelfAttnProcessor() else: replace_processor = PAGIdentitySelfAttnProcessor() drop_layers = self.pag_applied_layers_index for drop_layer in drop_layers: try: if drop_layer[0] == "d": down_layers[int(drop_layer[1])].processor = replace_processor elif drop_layer[0] == "m": mid_layers[int(drop_layer[1])].processor = replace_processor elif drop_layer[0] == "u": up_layers[int(drop_layer[1])].processor = replace_processor else: raise ValueError(f"Invalid layer type: {drop_layer[0]}") except IndexError: raise ValueError( f"Invalid layer index: {drop_layer}. Available layers: {len(down_layers)} down layers, {len(mid_layers)} mid layers, {len(up_layers)} up layers." ) 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): # cfg if self.do_classifier_free_guidance and not self.do_perturbed_attention_guidance: latent_model_input = torch.cat([latents] * 2) image_input = torch.cat([image] * 2) # pag elif not self.do_classifier_free_guidance and self.do_perturbed_attention_guidance: latent_model_input = torch.cat([latents] * 2) image_input = torch.cat([image] * 2) # both elif self.do_classifier_free_guidance and self.do_perturbed_attention_guidance: latent_model_input = torch.cat([latents] * 3) image_input = torch.cat([image] * 3) # no else: latent_model_input = latents image_input = image # concat latents, mask, masked_image_latents in the channel dimension latent_model_input = self.scheduler.scale_model_input(latent_model_input, t) latent_model_input = torch.cat([latent_model_input, image_input], dim=1) # predict the noise residual noise_pred = self.unet( latent_model_input, t, encoder_hidden_states=prompt_embeds, cross_attention_kwargs=cross_attention_kwargs, class_labels=noise_level, return_dict=False, )[0] # perform guidance # cfg if self.do_classifier_free_guidance and not self.do_perturbed_attention_guidance: noise_pred_uncond, noise_pred_text = noise_pred.chunk(2) delta = noise_pred_text - noise_pred_uncond noise_pred = noise_pred_uncond + self.guidance_scale * delta # pag elif not self.do_classifier_free_guidance and self.do_perturbed_attention_guidance: noise_pred_original, noise_pred_perturb = noise_pred.chunk(2) signal_scale = self.pag_scale if self.do_pag_adaptive_scaling: signal_scale = self.pag_scale - self.pag_adaptive_scaling * (1000 - t) if signal_scale < 0: signal_scale = 0 noise_pred = noise_pred_original + signal_scale * (noise_pred_original - noise_pred_perturb) # both elif self.do_classifier_free_guidance and self.do_perturbed_attention_guidance: noise_pred_uncond, noise_pred_text, noise_pred_text_perturb = noise_pred.chunk(3) signal_scale = self.pag_scale if self.do_pag_adaptive_scaling: signal_scale = self.pag_scale - self.pag_adaptive_scaling * (1000 - t) if signal_scale < 0: signal_scale = 0 noise_pred = ( noise_pred_text + (self.guidance_scale - 1.0) * (noise_pred_text - noise_pred_uncond) + signal_scale * (noise_pred_text - noise_pred_text_perturb) ) # compute the previous noisy sample x_t -> x_t-1 latents = self.scheduler.step(noise_pred, t, latents, **extra_step_kwargs, return_dict=False)[0] # call the callback, if provided if i == len(timesteps) - 1 or ((i + 1) > num_warmup_steps and (i + 1) % self.scheduler.order == 0): progress_bar.update() if callback is not None and i % callback_steps == 0: step_idx = i // getattr(self.scheduler, "order", 1) callback(step_idx, t, latents) if not output_type == "latent": # make sure the VAE is in float32 mode, as it overflows in float16 needs_upcasting = self.vae.dtype == torch.float16 and self.vae.config.force_upcast if needs_upcasting: self.upcast_vae() # Ensure latents are always the same type as the VAE latents = latents.to(next(iter(self.vae.post_quant_conv.parameters())).dtype) image = self.vae.decode(latents / self.vae.config.scaling_factor, return_dict=False)[0] # cast back to fp16 if needed if needs_upcasting: self.vae.to(dtype=torch.float16) image, has_nsfw_concept, _ = self.run_safety_checker(image, device, prompt_embeds.dtype) else: image = latents has_nsfw_concept = None 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) # 11. Apply watermark if output_type == "pil" and self.watermarker is not None: image = self.watermarker.apply_watermark(image) # Offload all models self.maybe_free_model_hooks() # change attention layer in UNet if use PAG if self.do_perturbed_attention_guidance: drop_layers = self.pag_applied_layers_index for drop_layer in drop_layers: try: if drop_layer[0] == "d": down_layers[int(drop_layer[1])].processor = AttnProcessor2_0() elif drop_layer[0] == "m": mid_layers[int(drop_layer[1])].processor = AttnProcessor2_0() elif drop_layer[0] == "u": up_layers[int(drop_layer[1])].processor = AttnProcessor2_0() else: raise ValueError(f"Invalid layer type: {drop_layer[0]}") except IndexError: raise ValueError( f"Invalid layer index: {drop_layer}. Available layers: {len(down_layers)} down layers, {len(mid_layers)} mid layers, {len(up_layers)} up layers." ) if not return_dict: return (image, has_nsfw_concept) return StableDiffusionPipelineOutput(images=image, nsfw_content_detected=has_nsfw_concept)