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# small modification to allow negative image embeds
# 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 dataclasses import dataclass
from math import ceil
from typing import Callable, Dict, List, Optional, Union
import numpy as np
import PIL
import torch
from transformers import CLIPImageProcessor, CLIPTextModelWithProjection, CLIPTokenizer, CLIPVisionModelWithProjection
from diffusers.models import StableCascadeUNet
from diffusers.schedulers import DDPMWuerstchenScheduler
from diffusers.utils import BaseOutput, logging, replace_example_docstring
from diffusers.utils.torch_utils import randn_tensor
from diffusers.pipelines.pipeline_utils import DiffusionPipeline, ImagePipelineOutput
from diffusers.pipelines.wuerstchen.modeling_paella_vq_model import PaellaVQModel
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
DEFAULT_STAGE_C_TIMESTEPS = list(np.linspace(1.0, 2 / 3, 20)) + list(np.linspace(2 / 3, 0.0, 11))[1:]
EXAMPLE_DOC_STRING = """
Examples:
```py
>>> import torch
>>> from diffusers import StableCascadePriorPipeline
>>> prior_pipe = StableCascadePriorPipeline.from_pretrained(
... "stabilityai/stable-cascade-prior", torch_dtype=torch.bfloat16
... ).to("cuda")
>>> prompt = "an image of a shiba inu, donning a spacesuit and helmet"
>>> prior_output = pipe(prompt)
```
"""
@dataclass
class StableCascadePriorPipelineOutput(BaseOutput):
"""
Output class for WuerstchenPriorPipeline.
Args:
image_embeddings (`torch.Tensor` or `np.ndarray`)
Prior image embeddings for text prompt
prompt_embeds (`torch.Tensor`):
Text embeddings for the prompt.
negative_prompt_embeds (`torch.Tensor`):
Text embeddings for the negative prompt.
"""
image_embeddings: Union[torch.Tensor, np.ndarray]
prompt_embeds: Union[torch.Tensor, np.ndarray]
prompt_embeds_pooled: Union[torch.Tensor, np.ndarray]
negative_prompt_embeds: Union[torch.Tensor, np.ndarray]
negative_prompt_embeds_pooled: Union[torch.Tensor, np.ndarray]
class StableCascadePriorPipeline_DoE(DiffusionPipeline):
"""
Pipeline for generating image prior for Stable Cascade.
This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods the
library implements for all the pipelines (such as downloading or saving, running on a particular device, etc.)
Args:
prior ([`StableCascadeUNet`]):
The Stable Cascade prior to approximate the image embedding from the text and/or image embedding.
text_encoder ([`CLIPTextModelWithProjection`]):
Frozen text-encoder
([laion/CLIP-ViT-bigG-14-laion2B-39B-b160k](https://huggingface.co/laion/CLIP-ViT-bigG-14-laion2B-39B-b160k)).
feature_extractor ([`~transformers.CLIPImageProcessor`]):
Model that extracts features from generated images to be used as inputs for the `image_encoder`.
image_encoder ([`CLIPVisionModelWithProjection`]):
Frozen CLIP image-encoder ([clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14)).
tokenizer (`CLIPTokenizer`):
Tokenizer of class
[CLIPTokenizer](https://huggingface.co/docs/transformers/v4.21.0/en/model_doc/clip#transformers.CLIPTokenizer).
scheduler ([`DDPMWuerstchenScheduler`]):
A scheduler to be used in combination with `prior` to generate image embedding.
resolution_multiple ('float', *optional*, defaults to 42.67):
Default resolution for multiple images generated.
"""
unet_name = "prior"
text_encoder_name = "text_encoder"
model_cpu_offload_seq = "image_encoder->text_encoder->prior"
_optional_components = ["image_encoder", "feature_extractor"]
_callback_tensor_inputs = ["latents", "text_encoder_hidden_states", "negative_prompt_embeds"]
def __init__(
self,
tokenizer: CLIPTokenizer,
text_encoder: CLIPTextModelWithProjection,
prior: StableCascadeUNet,
scheduler: DDPMWuerstchenScheduler,
resolution_multiple: float = 42.67,
feature_extractor: Optional[CLIPImageProcessor] = None,
image_encoder: Optional[CLIPVisionModelWithProjection] = None,
) -> None:
super().__init__()
self.register_modules(
tokenizer=tokenizer,
text_encoder=text_encoder,
image_encoder=image_encoder,
feature_extractor=feature_extractor,
prior=prior,
scheduler=scheduler,
)
self.register_to_config(resolution_multiple=resolution_multiple)
def prepare_latents(
self, height, width, num_images_per_prompt, dtype, device, generator, latents, scheduler
):
latent_shape = (
num_images_per_prompt,
self.prior.config.in_channels,
ceil(height / self.config.resolution_multiple),
ceil(width / self.config.resolution_multiple),
)
if latents is None:
latents = randn_tensor(latent_shape, generator=generator, device=device, dtype=dtype)
else:
if latents.shape != latent_shape:
raise ValueError(f"Unexpected latents shape, got {latents.shape}, expected {latent_shape}")
latents = latents.to(device)
latents = latents * scheduler.init_noise_sigma
return latents
@property
def guidance_scale(self):
return self._guidance_scale
@property
def do_classifier_free_guidance(self):
return self._guidance_scale > 1
@property
def num_timesteps(self):
return self._num_timesteps
def get_timestep_ratio_conditioning(self, t, alphas_cumprod):
s = torch.tensor([0.003])
clamp_range = [0, 1]
min_var = torch.cos(s / (1 + s) * torch.pi * 0.5) ** 2
var = alphas_cumprod[t]
var = var.clamp(*clamp_range)
s, min_var = s.to(var.device), min_var.to(var.device)
ratio = (((var * min_var) ** 0.5).acos() / (torch.pi * 0.5)) * (1 + s) - s
return ratio
@torch.no_grad()
@replace_example_docstring(EXAMPLE_DOC_STRING)
def __call__(
self,
height: int = 1024,
width: int = 1024,
num_inference_steps: int = 20,
timesteps: List[float] = None,
guidance_scale: float = 4.0,
prompt_embeds: Optional[torch.Tensor] = None,
prompt_embeds_pooled: Optional[torch.Tensor] = None,
negative_prompt_embeds: Optional[torch.Tensor] = None,
negative_prompt_embeds_pooled: Optional[torch.Tensor] = None,
image_embeds: Optional[torch.Tensor] = None,
negative_image_embeds: Optional[torch.Tensor] = None,
num_images_per_prompt: Optional[int] = 1,
generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
latents: Optional[torch.Tensor] = None,
output_type: Optional[str] = "pt",
return_dict: bool = True,
callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
callback_on_step_end_tensor_inputs: List[str] = ["latents"],
):
"""
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 1024):
The height in pixels of the generated image.
width (`int`, *optional*, defaults to 1024):
The width in pixels of the generated image.
num_inference_steps (`int`, *optional*, defaults to 60):
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 8.0):
Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).
`decoder_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
`decoder_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 `decoder_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.
prompt_embeds_pooled (`torch.Tensor`, *optional*):
Pre-generated pooled text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting.
If not provided, pooled 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.
negative_prompt_embeds_pooled (`torch.Tensor`, *optional*):
Pre-generated negative pooled text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt
weighting. If not provided, negative_prompt_embeds_pooled will be generated from `negative_prompt`
input argument.
image_embeds (`torch.Tensor`, *optional*):
Pre-generated image embeddings. Can be used to easily tweak image inputs, *e.g.* prompt weighting. If
not provided, image embeddings will be generated from `image` input argument if existing.
num_images_per_prompt (`int`, *optional*, defaults to 1):
The number of images to generate per prompt.
generator (`torch.Generator` or `List[torch.Generator]`, *optional*):
One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html)
to make generation deterministic.
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"` (`PIL.Image.Image`), `"np"`
(`np.array`) or `"pt"` (`torch.Tensor`).
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~pipelines.ImagePipelineOutput`] instead of a plain tuple.
callback_on_step_end (`Callable`, *optional*):
A function that calls at the end of each denoising steps during the inference. The function is called
with the following arguments: `callback_on_step_end(self: DiffusionPipeline, step: int, timestep: int,
callback_kwargs: Dict)`. `callback_kwargs` will include a list of all tensors as specified by
`callback_on_step_end_tensor_inputs`.
callback_on_step_end_tensor_inputs (`List`, *optional*):
The list of tensor inputs for the `callback_on_step_end` function. The tensors specified in the list
will be passed as `callback_kwargs` argument. You will only be able to include variables listed in the
`._callback_tensor_inputs` attribute of your pipeline class.
Examples:
Returns:
[`StableCascadePriorPipelineOutput`] or `tuple` [`StableCascadePriorPipelineOutput`] if `return_dict` is
True, otherwise a `tuple`. When returning a tuple, the first element is a list with the generated image
embeddings.
"""
# 0. Define commonly used variables
device = self._execution_device
dtype = next(self.prior.parameters()).dtype
self._guidance_scale = guidance_scale
# 2. caption + images
image_embeds_pooled = image_embeds.repeat(num_images_per_prompt, 1, 1)
# uncond_image_embeds_pooled = torch.zeros_like(image_embeds_pooled)
# 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
if self.do_classifier_free_guidance:
uncond_image_embeds_pooled = negative_image_embeds.repeat(num_images_per_prompt, 1, 1)
image_embeds = torch.cat([image_embeds_pooled, uncond_image_embeds_pooled], dim=0)
text_encoder_hidden_states = torch.cat([prompt_embeds, negative_prompt_embeds])
text_encoder_pooled = torch.cat([prompt_embeds_pooled, negative_prompt_embeds_pooled])
else:
image_embeds = image_embeds_pooled
text_encoder_hidden_states = prompt_embeds
text_encoder_pooled = prompt_embeds_pooled
# 4. Prepare and set timesteps
self.scheduler.set_timesteps(num_inference_steps, device=device)
timesteps = self.scheduler.timesteps
# 5. Prepare latents
latents = self.prepare_latents(
height, width, num_images_per_prompt, dtype, device, generator, latents, self.scheduler
)
if isinstance(self.scheduler, DDPMWuerstchenScheduler):
timesteps = timesteps[:-1]
# 6. Run denoising loop
if hasattr(self.scheduler, "betas"):
alphas = 1.0 - self.scheduler.betas
alphas_cumprod = torch.cumprod(alphas, dim=0)
else:
alphas_cumprod = []
self._num_timesteps = len(timesteps)
for i, t in enumerate(self.progress_bar(timesteps)):
if not isinstance(self.scheduler, DDPMWuerstchenScheduler):
if len(alphas_cumprod) > 0:
timestep_ratio = self.get_timestep_ratio_conditioning(t.long().cpu(), alphas_cumprod)
timestep_ratio = timestep_ratio.expand(latents.size(0)).to(dtype).to(device)
else:
timestep_ratio = t.float().div(self.scheduler.timesteps[-1]).expand(latents.size(0)).to(dtype)
else:
timestep_ratio = t.expand(latents.size(0)).to(dtype)
# 7. Denoise image embeddings
predicted_image_embedding = self.prior(
sample=torch.cat([latents] * 2) if self.do_classifier_free_guidance else latents,
timestep_ratio=torch.cat([timestep_ratio] * 2) if self.do_classifier_free_guidance else timestep_ratio,
clip_text_pooled=text_encoder_pooled,
clip_text=text_encoder_hidden_states,
clip_img=image_embeds,
return_dict=False,
)[0]
# 8. Check for classifier free guidance and apply it
if self.do_classifier_free_guidance:
predicted_image_embedding_text, predicted_image_embedding_uncond = predicted_image_embedding.chunk(2)
predicted_image_embedding = torch.lerp(
predicted_image_embedding_uncond, predicted_image_embedding_text, self.guidance_scale
)
# 9. Renoise latents to next timestep
if not isinstance(self.scheduler, DDPMWuerstchenScheduler):
timestep_ratio = t
latents = self.scheduler.step(
model_output=predicted_image_embedding, timestep=timestep_ratio, sample=latents, generator=generator
).prev_sample
if callback_on_step_end is not None:
callback_kwargs = {}
for k in callback_on_step_end_tensor_inputs:
callback_kwargs[k] = locals()[k]
callback_outputs = callback_on_step_end(self, i, t, callback_kwargs)
latents = callback_outputs.pop("latents", latents)
prompt_embeds = callback_outputs.pop("prompt_embeds", prompt_embeds)
negative_prompt_embeds = callback_outputs.pop("negative_prompt_embeds", negative_prompt_embeds)
# Offload all models
self.maybe_free_model_hooks()
if output_type == "np":
latents = latents.cpu().float().numpy() # float() as bfloat16-> numpy doesnt work
prompt_embeds = prompt_embeds.cpu().float().numpy() # float() as bfloat16-> numpy doesnt work
negative_prompt_embeds = (
negative_prompt_embeds.cpu().float().numpy() if negative_prompt_embeds is not None else None
) # float() as bfloat16-> numpy doesnt work
if not return_dict:
return (
latents,
prompt_embeds,
prompt_embeds_pooled,
negative_prompt_embeds,
negative_prompt_embeds_pooled,
)
return StableCascadePriorPipelineOutput(
image_embeddings=latents,
prompt_embeds=prompt_embeds,
prompt_embeds_pooled=prompt_embeds_pooled,
negative_prompt_embeds=negative_prompt_embeds,
negative_prompt_embeds_pooled=negative_prompt_embeds_pooled,
)
class StableCascadeDecoderPipeline_DoE(DiffusionPipeline):
unet_name = "decoder"
model_cpu_offload_seq = "decoder->vqgan"
_callback_tensor_inputs = [
"latents",
"prompt_embeds_pooled",
"negative_prompt_embeds",
"image_embeddings",
]
def __init__(
self,
decoder: StableCascadeUNet,
scheduler: DDPMWuerstchenScheduler,
vqgan: PaellaVQModel,
latent_dim_scale: float = 10.67,
) -> None:
super().__init__()
self.register_modules(
decoder=decoder,
scheduler=scheduler,
vqgan=vqgan,
)
self.register_to_config(latent_dim_scale=latent_dim_scale)
def prepare_latents(
self, image_embeddings, num_images_per_prompt, dtype, device, generator, latents, scheduler
):
_, channels, height, width = image_embeddings.shape
latents_shape = (
num_images_per_prompt,
4,
int(height * self.config.latent_dim_scale),
int(width * self.config.latent_dim_scale),
)
if latents is None:
latents = randn_tensor(latents_shape, generator=generator, device=device, dtype=dtype)
else:
if latents.shape != latents_shape:
raise ValueError(f"Unexpected latents shape, got {latents.shape}, expected {latents_shape}")
latents = latents.to(device)
latents = latents * scheduler.init_noise_sigma
return latents
@property
def guidance_scale(self):
return self._guidance_scale
@property
def do_classifier_free_guidance(self):
return self._guidance_scale > 1
@property
def num_timesteps(self):
return self._num_timesteps
def get_timestep_ratio_conditioning(self, t, alphas_cumprod):
s = torch.tensor([0.003])
clamp_range = [0, 1]
min_var = torch.cos(s / (1 + s) * torch.pi * 0.5) ** 2
var = alphas_cumprod[t]
var = var.clamp(*clamp_range)
s, min_var = s.to(var.device), min_var.to(var.device)
ratio = (((var * min_var) ** 0.5).acos() / (torch.pi * 0.5)) * (1 + s) - s
return ratio
@torch.no_grad()
def __call__(
self,
image_embeddings: Union[torch.Tensor, List[torch.Tensor]],
prompt: Union[str, List[str]] = None,
num_inference_steps: int = 10,
guidance_scale: float = 0.0,
negative_prompt: Optional[Union[str, List[str]]] = None,
prompt_embeds: Optional[torch.Tensor] = None,
prompt_embeds_pooled: Optional[torch.Tensor] = None,
negative_prompt_embeds: Optional[torch.Tensor] = None,
negative_prompt_embeds_pooled: Optional[torch.Tensor] = None,
num_images_per_prompt: int = 1,
generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
latents: Optional[torch.Tensor] = None,
output_type: Optional[str] = "pil",
return_dict: bool = True,
callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
callback_on_step_end_tensor_inputs: List[str] = ["latents"],
):
# 0. Define commonly used variables
device = self._execution_device
dtype = self.decoder.dtype
self._guidance_scale = guidance_scale
# 1. Check inputs. Raise error if not correct
if isinstance(image_embeddings, list):
image_embeddings = torch.cat(image_embeddings, dim=0)
# 2. Encode caption
# The pooled embeds from the prior are pooled again before being passed to the decoder
prompt_embeds_pooled = (
torch.cat([prompt_embeds_pooled, negative_prompt_embeds_pooled])
if self.do_classifier_free_guidance
else prompt_embeds_pooled
)
effnet = (
torch.cat([image_embeddings, torch.zeros_like(image_embeddings)])
if self.do_classifier_free_guidance
else image_embeddings
)
self.scheduler.set_timesteps(num_inference_steps, device=device)
timesteps = self.scheduler.timesteps
# 5. Prepare latents
latents = self.prepare_latents(
image_embeddings, num_images_per_prompt, dtype, device, generator, latents, self.scheduler
)
if isinstance(self.scheduler, DDPMWuerstchenScheduler):
timesteps = timesteps[:-1]
# 6. Run denoising loop
if hasattr(self.scheduler, "betas"):
alphas = 1.0 - self.scheduler.betas
alphas_cumprod = torch.cumprod(alphas, dim=0)
else:
alphas_cumprod = []
self._num_timesteps = len(timesteps)
for i, t in enumerate(self.progress_bar(timesteps)):
if not isinstance(self.scheduler, DDPMWuerstchenScheduler):
if len(alphas_cumprod) > 0:
timestep_ratio = self.get_timestep_ratio_conditioning(t.long().cpu(), alphas_cumprod)
timestep_ratio = timestep_ratio.expand(latents.size(0)).to(dtype).to(device)
else:
timestep_ratio = t.float().div(self.scheduler.timesteps[-1]).expand(latents.size(0)).to(dtype)
else:
timestep_ratio = t.expand(latents.size(0)).to(dtype)
# 7. Denoise latents
predicted_latents = self.decoder(
sample=torch.cat([latents] * 2) if self.do_classifier_free_guidance else latents,
timestep_ratio=torch.cat([timestep_ratio] * 2) if self.do_classifier_free_guidance else timestep_ratio,
clip_text_pooled=prompt_embeds_pooled,
effnet=effnet,
return_dict=False,
)[0]
# 8. Check for classifier free guidance and apply it
if self.do_classifier_free_guidance:
predicted_latents_text, predicted_latents_uncond = predicted_latents.chunk(2)
predicted_latents = torch.lerp(predicted_latents_uncond, predicted_latents_text, self.guidance_scale)
# 9. Renoise latents to next timestep
if not isinstance(self.scheduler, DDPMWuerstchenScheduler):
timestep_ratio = t
latents = self.scheduler.step(
model_output=predicted_latents,
timestep=timestep_ratio,
sample=latents,
generator=generator,
).prev_sample
if callback_on_step_end is not None:
callback_kwargs = {}
for k in callback_on_step_end_tensor_inputs:
callback_kwargs[k] = locals()[k]
callback_outputs = callback_on_step_end(self, i, t, callback_kwargs)
latents = callback_outputs.pop("latents", latents)
prompt_embeds = callback_outputs.pop("prompt_embeds", prompt_embeds)
negative_prompt_embeds = callback_outputs.pop("negative_prompt_embeds", negative_prompt_embeds)
if output_type not in ["pt", "np", "pil", "latent"]:
raise ValueError(
f"Only the output types `pt`, `np`, `pil` and `latent` are supported not output_type={output_type}"
)
if not output_type == "latent":
# 10. Scale and decode the image latents with vq-vae
latents = self.vqgan.config.scale_factor * latents
images = self.vqgan.decode(latents).sample.clamp(0, 1)
if output_type == "np":
images = images.permute(0, 2, 3, 1).cpu().float().numpy() # float() as bfloat16-> numpy doesnt work
elif output_type == "pil":
images = images.permute(0, 2, 3, 1).cpu().float().numpy() # float() as bfloat16-> numpy doesnt work
images = self.numpy_to_pil(images)
else:
images = latents
# Offload all models
self.maybe_free_model_hooks()
if not return_dict:
return images
return ImagePipelineOutput(images)
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