[Core] add: controlnet support for SDXL (#4038)

* add: controlnet sdxl.

* modifications to controlnet.

* run styling.

* add: __init__.pys

* incorporate #4019 changes.

* run make fix-copies.

* resize the conditioning images.

* remove autocast.

* run styling.

* disable autocast.

* debugging

* device placement.

* back to autocast.

* remove comment.

* save some memory by reusing the vae and unet in the pipeline.

* apply styling.

* Allow low precision sd xl

* finish

* finish

* changes to accommodate the improved VAE.

* modifications to how we handle vae encoding in the training.

* make style

* make existing controlnet fast tests pass.

* change vae checkpoint cli arg.

* fix: vae pretrained paths.

* fix: steps in get_scheduler().

* debugging.

* debugging./

* fix: weight conversion.

* add: docs.

* add: limited tests./

* add: datasets to the requirements.

* update docstrings and incorporate the usage of watermarking.

* incorporate fix from #4083

* fix watermarking dependency handling.

* run make-fix-copies.

* Empty-Commit

* Update requirements_sdxl.txt

* remove vae upcasting part.

* Apply suggestions from code review

Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

* run make style

* run make fix-copies.

* disable suppot for multicontrolnet.

* Apply suggestions from code review

Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

* run make fix-copies.

* dtyle/.

* fix-copies.

---------

Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

examples/controlnet/README.md

@@ -274,9 +274,9 @@ pipe = StableDiffusionControlNetPipeline.from_pretrained(
 
 # speed up diffusion process with faster scheduler and memory optimization
 pipe.scheduler = UniPCMultistepScheduler.from_config(pipe.scheduler.config)
-# remove following line if xformers is not installed
+# remove following line if xformers is not installed or when using Torch 2.0.
 pipe.enable_xformers_memory_efficient_attention()
-
+# memory optimization.
 pipe.enable_model_cpu_offload()
 
 control_image = load_image("./conditioning_image_1.png")
@@ -285,9 +285,8 @@ prompt = "pale golden rod circle with old lace background"
 # generate image
 generator = torch.manual_seed(0)
 image = pipe(
-     prompt, num_inference_steps=20, generator=generator, image=control_image
+    prompt, num_inference_steps=20, generator=generator, image=control_image
 ).images[0]
-
 image.save("./output.png")
 ```
 
@@ -460,3 +459,7 @@ The profile can then be inspected at http://localhost:6006/#profile
 Sometimes you'll get version conflicts (error messages like `Duplicate plugins for name projector`), which means that you have to uninstall and reinstall all versions of Tensorflow/Tensorboard (e.g. with `pip uninstall tensorflow tf-nightly tensorboard tb-nightly tensorboard-plugin-profile && pip install tf-nightly tbp-nightly tensorboard-plugin-profile`).
 
 Note that the debugging functionality of the Tensorboard `profile` plugin is still under active development. Not all views are fully functional, and for example the `trace_viewer` cuts off events after 1M (which can result in all your device traces getting lost if you for example profile the compilation step by accident).
+
+## Support for Stable Diffusion XL
+
+We provide a training script for training a ControlNet with [Stable Diffusion XL](https://huggingface.co/papers/2307.01952). Please refer to [README_sdxl.md](./README_sdxl.md) for more details.

examples/controlnet/README_sdxl.md

@@ -0,0 +1,131 @@
+# DreamBooth training example for Stable Diffusion XL (SDXL)
+
+The `train_controlnet_sdxl.py` script shows how to implement the training procedure and adapt it for [Stable Diffusion XL](https://huggingface.co/papers/2307.01952).
+
+## Running locally with PyTorch
+
+### Installing the dependencies
+
+Before running the scripts, make sure to install the library's training dependencies:
+
+**Important**
+
+To make sure you can successfully run the latest versions of the example scripts, we highly recommend **installing from source** and keeping the install up to date as we update the example scripts frequently and install some example-specific requirements. To do this, execute the following steps in a new virtual environment:
+
+```bash
+git clone https://github.com/huggingface/diffusers
+cd diffusers
+pip install -e .
+```
+
+Then cd in the `examples/controlnet` folder and run
+```bash
+pip install -r requirements_sdxl.txt
+```
+
+And initialize an [🤗Accelerate](https://github.com/huggingface/accelerate/) environment with:
+
+```bash
+accelerate config
+```
+
+Or for a default accelerate configuration without answering questions about your environment
+
+```bash
+accelerate config default
+```
+
+Or if your environment doesn't support an interactive shell (e.g., a notebook)
+
+```python
+from accelerate.utils import write_basic_config
+write_basic_config()
+```
+
+When running `accelerate config`, if we specify torch compile mode to True there can be dramatic speedups. 
+
+## Circle filling dataset
+
+The original dataset is hosted in the [ControlNet repo](https://huggingface.co/lllyasviel/ControlNet/blob/main/training/fill50k.zip). We re-uploaded it to be compatible with `datasets` [here](https://huggingface.co/datasets/fusing/fill50k). Note that `datasets` handles dataloading within the training script.
+
+## Training
+
+Our training examples use two test conditioning images. They can be downloaded by running
+
+```sh
+wget https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/conditioning_image_1.png
+
+wget https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/conditioning_image_2.png
+```
+
+Then run `huggingface-cli login` to log into your Hugging Face account. This is needed to be able to push the trained ControlNet parameters to Hugging Face Hub.
+
+```bash
+export MODEL_DIR="stabilityai/stable-diffusion-xl-base-0.9"
+export OUTPUT_DIR="path to save model"
+
+accelerate launch train_controlnet_sdxl.py \
+ --pretrained_model_name_or_path=$MODEL_DIR \
+ --output_dir=$OUTPUT_DIR \
+ --dataset_name=fusing/fill50k \
+ --mixed_precision="fp16" \
+ --resolution=1024 \
+ --learning_rate=1e-5 \
+ --max_train_steps=15000 \
+ --validation_image "./conditioning_image_1.png" "./conditioning_image_2.png" \
+ --validation_prompt "red circle with blue background" "cyan circle with brown floral background" \
+ --validation_steps=100 \
+ --train_batch_size=1 \
+ --gradient_accumulation_steps=4 \
+ --report_to="wandb" \
+ --seed=42 \
+ --push_to_hub
+```
+
+To better track our training experiments, we're using the following flags in the command above:
+
+* `report_to="wandb` will ensure the training runs are tracked on Weights and Biases. To use it, be sure to install `wandb` with `pip install wandb`.
+* `validation_image`, `validation_prompt`, and `validation_steps` to allow the script to do a few validation inference runs. This allows us to qualitatively check if the training is progressing as expected. 
+
+Our experiments were conducted on a single 40GB A100 GPU.
+
+### Inference
+
+Once training is done, we can perform inference like so:
+
+```python
+from diffusers import StableDiffusionXLControlNetPipeline, ControlNetModel, UniPCMultistepScheduler
+from diffusers.utils import load_image
+import torch
+
+base_model_path = "stabilityai/stable-diffusion-xl-base-0.9"
+controlnet_path = "path to controlnet"
+
+controlnet = ControlNetModel.from_pretrained(controlnet_path, torch_dtype=torch.float16)
+pipe = StableDiffusionXLControlNetPipeline.from_pretrained(
+    base_model_path, controlnet=controlnet, torch_dtype=torch.float16
+)
+
+# speed up diffusion process with faster scheduler and memory optimization
+pipe.scheduler = UniPCMultistepScheduler.from_config(pipe.scheduler.config)
+# remove following line if xformers is not installed or when using Torch 2.0.
+pipe.enable_xformers_memory_efficient_attention()
+# memory optimization.
+pipe.enable_model_cpu_offload()
+
+control_image = load_image("./conditioning_image_1.png")
+prompt = "pale golden rod circle with old lace background"
+
+# generate image
+generator = torch.manual_seed(0)
+image = pipe(
+    prompt, num_inference_steps=20, generator=generator, image=control_image
+).images[0]
+image.save("./output.png")
+```
+
+## Notes
+
+### Specifying a better VAE
+
+SDXL's VAE is known to suffer from numerical instability issues. This is why we also expose a CLI argument namely `--pretrained_vae_model_name_or_path` that lets you specify the location of a better VAE (such as [this one](https://huggingface.co/madebyollin/sdxl-vae-fp16-fix)).

examples/controlnet/requirements_sdxl.txt

@@ -0,0 +1,9 @@
+accelerate>=0.16.0
+torchvision
+transformers>=4.25.1
+ftfy
+tensorboard
+Jinja2
+invisible-watermark>=0.2.0
+datasets
+wandb