img_str = ""

for i, image in enumerate(images):

image.save(os.path.join(repo_folder, f"image_{i}.png"))

img_str += f"\n"

model_description = f"""

model_card = load_or_create_model_card(

repo_id_or_path=repo_id,

from_training=True,

license="creativeml-openrail-m",

base_model=base_model,

prompt=prompt,

model_description=model_description,

inference=True,

)

tags = [

"text-to-image",

"diffusers",

"stable-diffusion",

"stable-diffusion-diffusers",

"custom-diffusion",

"diffusers-training",

]

model_card = populate_model_card(model_card, tags=tags)

text_encoder_config = PretrainedConfig.from_pretrained(

pretrained_model_name_or_path,

subfolder="text_encoder",

revision=revision,

)

model_class = text_encoder_config.architectures[0]

if model_class == "CLIPTextModel":

from transformers import CLIPTextModel

return CLIPTextModel

elif model_class == "RobertaSeriesModelWithTransformation":

from diffusers.pipelines.alt_diffusion.modeling_roberta_series import RobertaSeriesModelWithTransformation

return RobertaSeriesModelWithTransformation

else:

input_ids = [example["instance_prompt_ids"] for example in examples]

pixel_values = [example["instance_images"] for example in examples]

mask = [example["mask"] for example in examples]

# Concat class and instance examples for prior preservation.

# We do this to avoid doing two forward passes.

if with_prior_preservation:

input_ids += [example["class_prompt_ids"] for example in examples]

pixel_values += [example["class_images"] for example in examples]

mask += [example["class_mask"] for example in examples]

input_ids = torch.cat(input_ids, dim=0)

pixel_values = torch.stack(pixel_values)

mask = torch.stack(mask)

pixel_values = pixel_values.to(memory_format=torch.contiguous_format).float()

mask = mask.to(memory_format=torch.contiguous_format).float()

batch = {"input_ids": input_ids, "pixel_values": pixel_values, "mask": mask.unsqueeze(1)}

"""A simple dataset to prepare the prompts to generate class images on multiple GPUs."""

def __init__(self, prompt, num_samples):

self.prompt = prompt

self.num_samples = num_samples

def __len__(self):

return self.num_samples

def __getitem__(self, index):

example = {}

example["prompt"] = self.prompt

example["index"] = index

"""

def __init__(

self,

concepts_list,

tokenizer,

size=512,

mask_size=64,

center_crop=False,

with_prior_preservation=False,

num_class_images=200,

hflip=False,

aug=True,

):

self.size = size

self.mask_size = mask_size

self.center_crop = center_crop

self.tokenizer = tokenizer

self.interpolation = Image.BILINEAR

self.aug = aug

self.instance_images_path = []

self.class_images_path = []

self.with_prior_preservation = with_prior_preservation

for concept in concepts_list:

inst_img_path = [

(x, concept["instance_prompt"]) for x in Path(concept["instance_data_dir"]).iterdir() if x.is_file()

]

self.instance_images_path.extend(inst_img_path)

if with_prior_preservation:

class_data_root = Path(concept["class_data_dir"])

if os.path.isdir(class_data_root):

class_images_path = list(class_data_root.iterdir())

class_prompt = [concept["class_prompt"] for _ in range(len(class_images_path))]

else:

with open(class_data_root, "r") as f:

class_images_path = f.read().splitlines()

with open(concept["class_prompt"], "r") as f:

class_prompt = f.read().splitlines()

class_img_path = list(zip(class_images_path, class_prompt))

self.class_images_path.extend(class_img_path[:num_class_images])

random.shuffle(self.instance_images_path)

self.num_instance_images = len(self.instance_images_path)

self.num_class_images = len(self.class_images_path)

self._length = max(self.num_class_images, self.num_instance_images)

self.flip = transforms.RandomHorizontalFlip(0.5 * hflip)

self.image_transforms = transforms.Compose(

[

self.flip,

transforms.Resize(size, interpolation=transforms.InterpolationMode.BILINEAR),

transforms.CenterCrop(size) if center_crop else transforms.RandomCrop(size),

transforms.ToTensor(),

transforms.Normalize([0.5], [0.5]),

]

)

def __len__(self):

return self._length

def preprocess(self, image, scale, resample):

outer, inner = self.size, scale

factor = self.size // self.mask_size

if scale > self.size:

outer, inner = scale, self.size

top, left = np.random.randint(0, outer - inner + 1), np.random.randint(0, outer - inner + 1)

image = image.resize((scale, scale), resample=resample)

image = np.array(image).astype(np.uint8)

image = (image / 127.5 - 1.0).astype(np.float32)

instance_image = np.zeros((self.size, self.size, 3), dtype=np.float32)

mask = np.zeros((self.size // factor, self.size // factor))

if scale > self.size:

instance_image = image[top : top + inner, left : left + inner, :]

mask = np.ones((self.size // factor, self.size // factor))

else:

instance_image[top : top + inner, left : left + inner, :] = image

mask[

top // factor + 1 : (top + scale) // factor - 1, left // factor + 1 : (left + scale) // factor - 1

] = 1.0

return instance_image, mask

def __getitem__(self, index):

example = {}

instance_image, instance_prompt = self.instance_images_path[index % self.num_instance_images]

instance_image = Image.open(instance_image)

if not instance_image.mode == "RGB":

instance_image = instance_image.convert("RGB")

instance_image = self.flip(instance_image)

# apply resize augmentation and create a valid image region mask

random_scale = self.size

if self.aug:

random_scale = (

np.random.randint(self.size // 3, self.size + 1)

if np.random.uniform() < 0.66

else np.random.randint(int(1.2 * self.size), int(1.4 * self.size))

)

instance_image, mask = self.preprocess(instance_image, random_scale, self.interpolation)

if random_scale < 0.6 * self.size:

instance_prompt = np.random.choice(["a far away ", "very small "]) + instance_prompt

elif random_scale > self.size:

instance_prompt = np.random.choice(["zoomed in ", "close up "]) + instance_prompt

example["instance_images"] = torch.from_numpy(instance_image).permute(2, 0, 1)

example["mask"] = torch.from_numpy(mask)

example["instance_prompt_ids"] = self.tokenizer(

instance_prompt,

truncation=True,

padding="max_length",

max_length=self.tokenizer.model_max_length,

return_tensors="pt",

).input_ids

if self.with_prior_preservation:

class_image, class_prompt = self.class_images_path[index % self.num_class_images]

class_image = Image.open(class_image)

if not class_image.mode == "RGB":

class_image = class_image.convert("RGB")

example["class_images"] = self.image_transforms(class_image)

example["class_mask"] = torch.ones_like(example["mask"])

example["class_prompt_ids"] = self.tokenizer(

class_prompt,

truncation=True,

padding="max_length",

max_length=self.tokenizer.model_max_length,

return_tensors="pt",

).input_ids

"""Saves the new token embeddings from the text encoder."""

logger.info("Saving embeddings")

learned_embeds = accelerator.unwrap_model(text_encoder).get_input_embeddings().weight

for x, y in zip(modifier_token_id, args.modifier_token):

learned_embeds_dict = {}

learned_embeds_dict[y] = learned_embeds[x]

filename = f"{output_dir}/{y}.bin"

if safe_serialization:

safetensors.torch.save_file(learned_embeds_dict, filename, metadata={"format": "pt"})

else:

parser = argparse.ArgumentParser(description="Custom Diffusion training script.")

parser.add_argument(

"--pretrained_model_name_or_path",

type=str,

default=None,

required=True,

help="Path to pretrained model or model identifier from huggingface.co/models.",

)

parser.add_argument(

"--revision",

type=str,

default=None,

required=False,

help="Revision of pretrained model identifier from huggingface.co/models.",

)

parser.add_argument(

"--variant",

type=str,

default=None,

help="Variant of the model files of the pretrained model identifier from huggingface.co/models, 'e.g.' fp16",

)

parser.add_argument(

"--tokenizer_name",

type=str,

default=None,

help="Pretrained tokenizer name or path if not the same as model_name",

)

parser.add_argument(

"--instance_data_dir",

type=str,

default=None,

help="A folder containing the training data of instance images.",

)

parser.add_argument(

"--class_data_dir",

type=str,

default=None,

help="A folder containing the training data of class images.",

)

parser.add_argument(

"--instance_prompt",

type=str,

default=None,

help="The prompt with identifier specifying the instance",

)

parser.add_argument(

"--class_prompt",

type=str,

default=None,

help="The prompt to specify images in the same class as provided instance images.",

)

parser.add_argument(

"--validation_prompt",

type=str,

default=None,

help="A prompt that is used during validation to verify that the model is learning.",

)

parser.add_argument(

"--num_validation_images",

type=int,

default=2,

help="Number of images that should be generated during validation with `validation_prompt`.",

)

parser.add_argument(

"--validation_steps",

type=int,

default=50,

help=(

"Run dreambooth validation every X epochs. Dreambooth validation consists of running the prompt"

" `args.validation_prompt` multiple times: `args.num_validation_images`."

),

)

parser.add_argument(

"--with_prior_preservation",

default=False,

action="store_true",

help="Flag to add prior preservation loss.",

)

parser.add_argument(

"--real_prior",

default=False,

action="store_true",

help="real images as prior.",

)

parser.add_argument("--prior_loss_weight", type=float, default=1.0, help="The weight of prior preservation loss.")

parser.add_argument(

"--num_class_images",

type=int,

default=200,

help=(

"Minimal class images for prior preservation loss. If there are not enough images already present in"

" class_data_dir, additional images will be sampled with class_prompt."

),

)

parser.add_argument(

"--output_dir",

type=str,

default="custom-diffusion-model",

help="The output directory where the model predictions and checkpoints will be written.",

)

parser.add_argument("--seed", type=int, default=42, help="A seed for reproducible training.")

parser.add_argument(

"--resolution",

type=int,

default=512,

help=(

"The resolution for input images, all the images in the train/validation dataset will be resized to this"

" resolution"

),

)

parser.add_argument(

"--center_crop",

default=False,

action="store_true",

help=(

"Whether to center crop the input images to the resolution. If not set, the images will be randomly"

" cropped. The images will be resized to the resolution first before cropping."

),

)

parser.add_argument(

"--train_batch_size", type=int, default=4, help="Batch size (per device) for the training dataloader."

)

parser.add_argument(

"--sample_batch_size", type=int, default=4, help="Batch size (per device) for sampling images."

)

parser.add_argument("--num_train_epochs", type=int, default=1)

parser.add_argument(

"--max_train_steps",

type=int,

default=None,

help="Total number of training steps to perform. If provided, overrides num_train_epochs.",

)

parser.add_argument(

"--checkpointing_steps",

type=int,

default=250,

help=(

"Save a checkpoint of the training state every X updates. These checkpoints can be used both as final"

" checkpoints in case they are better than the last checkpoint, and are also suitable for resuming"

" training using `--resume_from_checkpoint`."

),

)

parser.add_argument(

"--checkpoints_total_limit",

type=int,

default=None,

help=("Max number of checkpoints to store."),

)

parser.add_argument(

"--resume_from_checkpoint",

type=str,

default=None,

help=(

"Whether training should be resumed from a previous checkpoint. Use a path saved by"

' `--checkpointing_steps`, or `"latest"` to automatically select the last available checkpoint.'

),

)

parser.add_argument(

"--gradient_accumulation_steps",

type=int,

default=1,

help="Number of updates steps to accumulate before performing a backward/update pass.",

)

parser.add_argument(

"--gradient_checkpointing",

action="store_true",

help="Whether or not to use gradient checkpointing to save memory at the expense of slower backward pass.",

)

parser.add_argument(

"--learning_rate",

type=float,

default=1e-5,

help="Initial learning rate (after the potential warmup period) to use.",

)

parser.add_argument(

"--scale_lr",

action="store_true",

default=False,

help="Scale the learning rate by the number of GPUs, gradient accumulation steps, and batch size.",

)

parser.add_argument(

"--dataloader_num_workers",

type=int,

default=2,

help=(

"Number of subprocesses to use for data loading. 0 means that the data will be loaded in the main process."

),

)

parser.add_argument(

"--freeze_model",

type=str,

default="crossattn_kv",

choices=["crossattn_kv", "crossattn"],

help="crossattn to enable fine-tuning of all params in the cross attention",

)

parser.add_argument(

"--lr_scheduler",

type=str,

default="constant",

help=(

'The scheduler type to use. Choose between ["linear", "cosine", "cosine_with_restarts", "polynomial",'

' "constant", "constant_with_warmup"]'

),

)

parser.add_argument(

"--lr_warmup_steps", type=int, default=500, help="Number of steps for the warmup in the lr scheduler."

)

parser.add_argument(

"--use_8bit_adam", action="store_true", help="Whether or not to use 8-bit Adam from bitsandbytes."

)

parser.add_argument("--adam_beta1", type=float, default=0.9, help="The beta1 parameter for the Adam optimizer.")

parser.add_argument("--adam_beta2", type=float, default=0.999, help="The beta2 parameter for the Adam optimizer.")

parser.add_argument("--adam_weight_decay", type=float, default=1e-2, help="Weight decay to use.")

parser.add_argument("--adam_epsilon", type=float, default=1e-08, help="Epsilon value for the Adam optimizer")

parser.add_argument("--max_grad_norm", default=1.0, type=float, help="Max gradient norm.")

parser.add_argument("--push_to_hub", action="store_true", help="Whether or not to push the model to the Hub.")

parser.add_argument("--hub_token", type=str, default=None, help="The token to use to push to the Model Hub.")

parser.add_argument(

"--hub_model_id",

type=str,

default=None,

help="The name of the repository to keep in sync with the local `output_dir`.",

)

parser.add_argument(

"--logging_dir",

type=str,

default="logs",

help=(

"[TensorBoard](https://www.tensorflow.org/tensorboard) log directory. Will default to"

" *output_dir/runs/**CURRENT_DATETIME_HOSTNAME***."

),

)

parser.add_argument(

"--allow_tf32",

action="store_true",

help=(

"Whether or not to allow TF32 on Ampere GPUs. Can be used to speed up training. For more information, see"

" https://pytorch.org/docs/stable/notes/cuda.html#tensorfloat-32-tf32-on-ampere-devices"

),

)

parser.add_argument(

"--report_to",

type=str,

default="tensorboard",

help=(

'The integration to report the results and logs to. Supported platforms are `"tensorboard"`'

' (default), `"wandb"` and `"comet_ml"`. Use `"all"` to report to all integrations.'

),

)

parser.add_argument(

"--mixed_precision",

type=str,

default=None,

choices=["no", "fp16", "bf16"],

help=(

"Whether to use mixed precision. Choose between fp16 and bf16 (bfloat16). Bf16 requires PyTorch >="

" 1.10.and an Nvidia Ampere GPU. Default to the value of accelerate config of the current system or the"

" flag passed with the `accelerate.launch` command. Use this argument to override the accelerate config."

),

)

parser.add_argument(

"--prior_generation_precision",

type=str,

default=None,

choices=["no", "fp32", "fp16", "bf16"],

help=(

"Choose prior generation precision between fp32, fp16 and bf16 (bfloat16). Bf16 requires PyTorch >="

" 1.10.and an Nvidia Ampere GPU. Default to fp16 if a GPU is available else fp32."

),

)

parser.add_argument(

"--concepts_list",

type=str,

default=None,

help="Path to json containing multiple concepts, will overwrite parameters like instance_prompt, class_prompt, etc.",

)

parser.add_argument("--local_rank", type=int, default=-1, help="For distributed training: local_rank")

parser.add_argument(

"--enable_xformers_memory_efficient_attention", action="store_true", help="Whether or not to use xformers."

)

parser.add_argument(

"--set_grads_to_none",

action="store_true",

help=(

"Save more memory by using setting grads to None instead of zero. Be aware, that this changes certain"

" behaviors, so disable this argument if it causes any problems. More info:"

" https://pytorch.org/docs/stable/generated/torch.optim.Optimizer.zero_grad.html"

),

)

parser.add_argument(

"--modifier_token",

type=str,

default=None,

help="A token to use as a modifier for the concept.",

)

parser.add_argument(

"--initializer_token", type=str, default="ktn+pll+ucd", help="A token to use as initializer word."

)

parser.add_argument("--hflip", action="store_true", help="Apply horizontal flip data augmentation.")

parser.add_argument(

"--noaug",

action="store_true",

help="Dont apply augmentation during data augmentation when this flag is enabled.",

)

parser.add_argument(

"--no_safe_serialization",

action="store_true",

help="If specified save the checkpoint not in `safetensors` format, but in original PyTorch format instead.",

)

if input_args is not None:

args = parser.parse_args(input_args)

else:

args = parser.parse_args()

env_local_rank = int(os.environ.get("LOCAL_RANK", -1))

if env_local_rank != -1 and env_local_rank != args.local_rank:

args.local_rank = env_local_rank

if args.with_prior_preservation:

if args.concepts_list is None:

if args.class_data_dir is None:

raise ValueError("You must specify a data directory for class images.")

if args.class_prompt is None:

raise ValueError("You must specify prompt for class images.")

else:

# logger is not available yet

if args.class_data_dir is not None:

warnings.warn("You need not use --class_data_dir without --with_prior_preservation.")

if args.class_prompt is not None:

warnings.warn("You need not use --class_prompt without --with_prior_preservation.")

if args.report_to == "wandb" and args.hub_token is not None:

raise ValueError(

"You cannot use both --report_to=wandb and --hub_token due to a security risk of exposing your token."

" Please use `huggingface-cli login` to authenticate with the Hub."

)

logging_dir = Path(args.output_dir, args.logging_dir)

accelerator_project_config = ProjectConfiguration(project_dir=args.output_dir, logging_dir=logging_dir)

accelerator = Accelerator(

gradient_accumulation_steps=args.gradient_accumulation_steps,

mixed_precision=args.mixed_precision,

log_with=args.report_to,

project_config=accelerator_project_config,

)

# Disable AMP for MPS.

if torch.backends.mps.is_available():

accelerator.native_amp = False

if args.report_to == "wandb":

if not is_wandb_available():

raise ImportError("Make sure to install wandb if you want to use it for logging during training.")

import wandb

# Currently, it's not possible to do gradient accumulation when training two models with accelerate.accumulate

# This will be enabled soon in accelerate. For now, we don't allow gradient accumulation when training two models.

# TODO (patil-suraj): Remove this check when gradient accumulation with two models is enabled in accelerate.

# Make one log on every process with the configuration for debugging.

logging.basicConfig(

format="%(asctime)s - %(levelname)s - %(name)s - %(message)s",

datefmt="%m/%d/%Y %H:%M:%S",

level=logging.INFO,

)

logger.info(accelerator.state, main_process_only=False)

if accelerator.is_local_main_process:

transformers.utils.logging.set_verbosity_warning()

diffusers.utils.logging.set_verbosity_info()

else:

transformers.utils.logging.set_verbosity_error()

diffusers.utils.logging.set_verbosity_error()

# We need to initialize the trackers we use, and also store our configuration.

# The trackers initializes automatically on the main process.

if accelerator.is_main_process:

accelerator.init_trackers("custom-diffusion", config=vars(args))

# If passed along, set the training seed now.

if args.seed is not None:

set_seed(args.seed)

if args.concepts_list is None:

args.concepts_list = [

{

"instance_prompt": args.instance_prompt,

"class_prompt": args.class_prompt,

"instance_data_dir": args.instance_data_dir,

"class_data_dir": args.class_data_dir,

}

]

else:

with open(args.concepts_list, "r") as f:

args.concepts_list = json.load(f)

# Generate class images if prior preservation is enabled.

if args.with_prior_preservation:

for i, concept in enumerate(args.concepts_list):

class_images_dir = Path(concept["class_data_dir"])

if not class_images_dir.exists():

class_images_dir.mkdir(parents=True, exist_ok=True)

if args.real_prior:

assert (

class_images_dir / "images"

).exists(), f"Please run: python retrieve.py --class_prompt \"{concept['class_prompt']}\" --class_data_dir {class_images_dir} --num_class_images {args.num_class_images}"

assert (

len(list((class_images_dir / "images").iterdir())) == args.num_class_images

), f"Please run: python retrieve.py --class_prompt \"{concept['class_prompt']}\" --class_data_dir {class_images_dir} --num_class_images {args.num_class_images}"

assert (

class_images_dir / "caption.txt"

).exists(), f"Please run: python retrieve.py --class_prompt \"{concept['class_prompt']}\" --class_data_dir {class_images_dir} --num_class_images {args.num_class_images}"

assert (

class_images_dir / "images.txt"

).exists(), f"Please run: python retrieve.py --class_prompt \"{concept['class_prompt']}\" --class_data_dir {class_images_dir} --num_class_images {args.num_class_images}"

concept["class_prompt"] = os.path.join(class_images_dir, "caption.txt")

concept["class_data_dir"] = os.path.join(class_images_dir, "images.txt")

args.concepts_list[i] = concept

accelerator.wait_for_everyone()

else:

cur_class_images = len(list(class_images_dir.iterdir()))

if cur_class_images < args.num_class_images:

torch_dtype = torch.float16 if accelerator.device.type == "cuda" else torch.float32

if args.prior_generation_precision == "fp32":

torch_dtype = torch.float32

elif args.prior_generation_precision == "fp16":

torch_dtype = torch.float16

elif args.prior_generation_precision == "bf16":

torch_dtype = torch.bfloat16

pipeline = DiffusionPipeline.from_pretrained(

args.pretrained_model_name_or_path,

torch_dtype=torch_dtype,

safety_checker=None,

revision=args.revision,

variant=args.variant,

)

pipeline.set_progress_bar_config(disable=True)

num_new_images = args.num_class_images - cur_class_images

logger.info(f"Number of class images to sample: {num_new_images}.")

sample_dataset = PromptDataset(concept["class_prompt"], num_new_images)

sample_dataloader = torch.utils.data.DataLoader(sample_dataset, batch_size=args.sample_batch_size)

sample_dataloader = accelerator.prepare(sample_dataloader)

pipeline.to(accelerator.device)

for example in tqdm(

sample_dataloader,

desc="Generating class images",

disable=not accelerator.is_local_main_process,

):

images = pipeline(example["prompt"]).images

for i, image in enumerate(images):

hash_image = insecure_hashlib.sha1(image.tobytes()).hexdigest()

image_filename = (

class_images_dir / f"{example['index'][i] + cur_class_images}-{hash_image}.jpg"

)

image.save(image_filename)

del pipeline

if torch.cuda.is_available():

torch.cuda.empty_cache()

# Handle the repository creation

if accelerator.is_main_process:

if args.output_dir is not None:

os.makedirs(args.output_dir, exist_ok=True)

if args.push_to_hub:

repo_id = create_repo(

repo_id=args.hub_model_id or Path(args.output_dir).name, exist_ok=True, token=args.hub_token

).repo_id

# Load the tokenizer

if args.tokenizer_name:

tokenizer = AutoTokenizer.from_pretrained(

args.tokenizer_name,

revision=args.revision,

use_fast=False,

)

elif args.pretrained_model_name_or_path:

tokenizer = AutoTokenizer.from_pretrained(

args.pretrained_model_name_or_path,

subfolder="tokenizer",

revision=args.revision,

use_fast=False,

)

# import correct text encoder class

text_encoder_cls = import_model_class_from_model_name_or_path(args.pretrained_model_name_or_path, args.revision)

# Load scheduler and models

noise_scheduler = DDPMScheduler.from_pretrained(args.pretrained_model_name_or_path, subfolder="scheduler")

text_encoder = text_encoder_cls.from_pretrained(

args.pretrained_model_name_or_path, subfolder="text_encoder", revision=args.revision, variant=args.variant

)

vae = AutoencoderKL.from_pretrained(

args.pretrained_model_name_or_path, subfolder="vae", revision=args.revision, variant=args.variant

)

unet = UNet2DConditionModel.from_pretrained(

args.pretrained_model_name_or_path, subfolder="unet", revision=args.revision, variant=args.variant

)

# Adding a modifier token which is optimized ####

# Code taken from https://github.com/huggingface/diffusers/blob/main/examples/textual_inversion/textual_inversion.py

modifier_token_id = []

initializer_token_id = []

if args.modifier_token is not None:

args.modifier_token = args.modifier_token.split("+")

args.initializer_token = args.initializer_token.split("+")

if len(args.modifier_token) > len(args.initializer_token):

raise ValueError("You must specify + separated initializer token for each modifier token.")

for modifier_token, initializer_token in zip(

args.modifier_token, args.initializer_token[: len(args.modifier_token)]

):

# Add the placeholder token in tokenizer

num_added_tokens = tokenizer.add_tokens(modifier_token)

if num_added_tokens == 0:

raise ValueError(

f"The tokenizer already contains the token {modifier_token}. Please pass a different"

" `modifier_token` that is not already in the tokenizer."

)

# Convert the initializer_token, placeholder_token to ids

token_ids = tokenizer.encode([initializer_token], add_special_tokens=False)

print(token_ids)

# Check if initializer_token is a single token or a sequence of tokens

if len(token_ids) > 1:

raise ValueError("The initializer token must be a single token.")

initializer_token_id.append(token_ids[0])

modifier_token_id.append(tokenizer.convert_tokens_to_ids(modifier_token))

# Resize the token embeddings as we are adding new special tokens to the tokenizer

text_encoder.resize_token_embeddings(len(tokenizer))

# Initialise the newly added placeholder token with the embeddings of the initializer token

token_embeds = text_encoder.get_input_embeddings().weight.data

for x, y in zip(modifier_token_id, initializer_token_id):

token_embeds[x] = token_embeds[y]

# Freeze all parameters except for the token embeddings in text encoder

params_to_freeze = itertools.chain(

text_encoder.text_model.encoder.parameters(),

text_encoder.text_model.final_layer_norm.parameters(),

text_encoder.text_model.embeddings.position_embedding.parameters(),

)

freeze_params(params_to_freeze)

########################################################

########################################################

vae.requires_grad_(False)

if args.modifier_token is None:

text_encoder.requires_grad_(False)

unet.requires_grad_(False)

# For mixed precision training we cast the text_encoder and vae weights to half-precision

# as these models are only used for inference, keeping weights in full precision is not required.

weight_dtype = torch.float32

if accelerator.mixed_precision == "fp16":

weight_dtype = torch.float16

elif accelerator.mixed_precision == "bf16":

weight_dtype = torch.bfloat16

# Move unet, vae and text_encoder to device and cast to weight_dtype

if accelerator.mixed_precision != "fp16" and args.modifier_token is not None:

text_encoder.to(accelerator.device, dtype=weight_dtype)

unet.to(accelerator.device, dtype=weight_dtype)

vae.to(accelerator.device, dtype=weight_dtype)

attention_class = (

CustomDiffusionAttnProcessor2_0 if hasattr(F, "scaled_dot_product_attention") else CustomDiffusionAttnProcessor

)

if args.enable_xformers_memory_efficient_attention:

if is_xformers_available():

import xformers

xformers_version = version.parse(xformers.__version__)

if xformers_version == version.parse("0.0.16"):

logger.warning(

"xFormers 0.0.16 cannot be used for training in some GPUs. If you observe problems during training, please update xFormers to at least 0.0.17. See https://huggingface.co/docs/diffusers/main/en/optimization/xformers for more details."

)

attention_class = CustomDiffusionXFormersAttnProcessor

else:

raise ValueError("xformers is not available. Make sure it is installed correctly")

# now we will add new Custom Diffusion weights to the attention layers

# It's important to realize here how many attention weights will be added and of which sizes

# The sizes of the attention layers consist only of two different variables:

# 1) - the "hidden_size", which is increased according to `unet.config.block_out_channels`.

# 2) - the "cross attention size", which is set to `unet.config.cross_attention_dim`.

# Let's first see how many attention processors we will have to set.

# For Stable Diffusion, it should be equal to:

# - down blocks (2x attention layers) * (2x transformer layers) * (3x down blocks) = 12

# - mid blocks (2x attention layers) * (1x transformer layers) * (1x mid blocks) = 2

# - up blocks (2x attention layers) * (3x transformer layers) * (3x down blocks) = 18

# => 32 layers

# Only train key, value projection layers if freeze_model = 'crossattn_kv' else train all params in the cross attention layer

train_kv = True

train_q_out = False if args.freeze_model == "crossattn_kv" else True

custom_diffusion_attn_procs = {}

st = unet.state_dict()

for name, _ in unet.attn_processors.items():

cross_attention_dim = None if name.endswith("attn1.processor") else unet.config.cross_attention_dim

if name.startswith("mid_block"):

hidden_size = unet.config.block_out_channels[-1]

elif name.startswith("up_blocks"):

block_id = int(name[len("up_blocks.")])

hidden_size = list(reversed(unet.config.block_out_channels))[block_id]

elif name.startswith("down_blocks"):

block_id = int(name[len("down_blocks.")])

hidden_size = unet.config.block_out_channels[block_id]

layer_name = name.split(".processor")[0]

weights = {

"to_k_custom_diffusion.weight": st[layer_name + ".to_k.weight"],

"to_v_custom_diffusion.weight": st[layer_name + ".to_v.weight"],

}

if train_q_out:

weights["to_q_custom_diffusion.weight"] = st[layer_name + ".to_q.weight"]

weights["to_out_custom_diffusion.0.weight"] = st[layer_name + ".to_out.0.weight"]

weights["to_out_custom_diffusion.0.bias"] = st[layer_name + ".to_out.0.bias"]

if cross_attention_dim is not None:

custom_diffusion_attn_procs[name] = attention_class(

train_kv=train_kv,

train_q_out=train_q_out,

hidden_size=hidden_size,

cross_attention_dim=cross_attention_dim,

).to(unet.device)

custom_diffusion_attn_procs[name].load_state_dict(weights)

else:

custom_diffusion_attn_procs[name] = attention_class(

train_kv=False,

train_q_out=False,

hidden_size=hidden_size,

cross_attention_dim=cross_attention_dim,

)

del st

unet.set_attn_processor(custom_diffusion_attn_procs)

custom_diffusion_layers = AttnProcsLayers(unet.attn_processors)

accelerator.register_for_checkpointing(custom_diffusion_layers)

if args.gradient_checkpointing:

unet.enable_gradient_checkpointing()

if args.modifier_token is not None:

text_encoder.gradient_checkpointing_enable()

# Enable TF32 for faster training on Ampere GPUs,

# cf https://pytorch.org/docs/stable/notes/cuda.html#tensorfloat-32-tf32-on-ampere-devices

if args.allow_tf32:

torch.backends.cuda.matmul.allow_tf32 = True

if args.scale_lr:

args.learning_rate = (

args.learning_rate * args.gradient_accumulation_steps * args.train_batch_size * accelerator.num_processes

)

if args.with_prior_preservation:

args.learning_rate = args.learning_rate * 2.0

# Use 8-bit Adam for lower memory usage or to fine-tune the model in 16GB GPUs

if args.use_8bit_adam:

try:

import bitsandbytes as bnb

except ImportError:

raise ImportError(

"To use 8-bit Adam, please install the bitsandbytes library: `pip install bitsandbytes`."

)