<!--Copyright 2023 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.
-->

# ControlNet

[Adding Conditional Control to Text-to-Image Diffusion Models](https://arxiv.org/abs/2302.05543) (ControlNet) by Lvmin Zhang and Maneesh Agrawala.

This example is based on the [training example in the original ControlNet repository](https://github.com/lllyasviel/ControlNet/blob/main/docs/train.md). It trains a ControlNet to fill circles using a [small synthetic dataset](https://huggingface.co/datasets/fusing/fill50k).

## Installing the dependencies

Before running the scripts, make sure to install the library's training dependencies.

<Tip warning={true}>

To successfully run the latest versions of the example scripts, we highly recommend **installing from source** and keeping the installation up to date. We update the example scripts frequently and install example-specific requirements.

</Tip>

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 navigate into the [example folder](https://github.com/huggingface/diffusers/tree/main/examples/controlnet)
```bash
cd examples/controlnet
```

Now run:
```bash
pip install -r requirements.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 like a notebook:

```python
from accelerate.utils import write_basic_config

write_basic_config()
```

## Circle filling dataset

The original dataset is hosted in the ControlNet [repo](https://huggingface.co/lllyasviel/ControlNet/blob/main/training/fill50k.zip), but we re-uploaded it [here](https://huggingface.co/datasets/fusing/fill50k) to be compatible with 🤗 Datasets so that it can handle the data loading within the training script.

Our training examples use [`runwayml/stable-diffusion-v1-5`](https://huggingface.co/runwayml/stable-diffusion-v1-5) because that is what the original set of ControlNet models was trained on. However, ControlNet can be trained to augment any compatible Stable Diffusion model (such as [`CompVis/stable-diffusion-v1-4`](https://huggingface.co/CompVis/stable-diffusion-v1-4)) or [`stabilityai/stable-diffusion-2-1`](https://huggingface.co/stabilityai/stable-diffusion-2-1).

## Training

Download the following images to condition our training with:

```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
```

Specify the `MODEL_NAME` environment variable (either a Hub model repository id or a path to the directory containing the model weights) and pass it to the [`~diffusers.DiffusionPipeline.from_pretrained.pretrained_model_name_or_path`] argument.

```bash
export MODEL_DIR="runwayml/stable-diffusion-v1-5"
export OUTPUT_DIR="path to save model"

accelerate launch train_controlnet.py \
 --pretrained_model_name_or_path=$MODEL_DIR \
 --output_dir=$OUTPUT_DIR \
 --dataset_name=fusing/fill50k \
 --resolution=512 \
 --learning_rate=1e-5 \
 --validation_image "./conditioning_image_1.png" "./conditioning_image_2.png" \
 --validation_prompt "red circle with blue background" "cyan circle with brown floral background" \
 --train_batch_size=4
```

This default configuration requires ~38GB VRAM.

By default, the training script logs outputs to tensorboard. Pass `--report_to wandb` to use Weights &
Biases.

Gradient accumulation with a smaller batch size can be used to reduce training requirements to ~20 GB VRAM.

```bash
export MODEL_DIR="runwayml/stable-diffusion-v1-5"
export OUTPUT_DIR="path to save model"

accelerate launch train_controlnet.py \
 --pretrained_model_name_or_path=$MODEL_DIR \
 --output_dir=$OUTPUT_DIR \
 --dataset_name=fusing/fill50k \
 --resolution=512 \
 --learning_rate=1e-5 \
 --validation_image "./conditioning_image_1.png" "./conditioning_image_2.png" \
 --validation_prompt "red circle with blue background" "cyan circle with brown floral background" \
 --train_batch_size=1 \
 --gradient_accumulation_steps=4
```

## Training with multiple GPUs

`accelerate` allows for seamless multi-GPU training. Follow the instructions [here](https://huggingface.co/docs/accelerate/basic_tutorials/launch)
for running distributed training with `accelerate`. Here is an example command:

```bash 
export MODEL_DIR="runwayml/stable-diffusion-v1-5"
export OUTPUT_DIR="path to save model"

accelerate launch --mixed_precision="fp16" --multi_gpu train_controlnet.py \
 --pretrained_model_name_or_path=$MODEL_DIR \
 --output_dir=$OUTPUT_DIR \
 --dataset_name=fusing/fill50k \
 --resolution=512 \
 --learning_rate=1e-5 \
 --validation_image "./conditioning_image_1.png" "./conditioning_image_2.png" \
 --validation_prompt "red circle with blue background" "cyan circle with brown floral background" \
 --train_batch_size=4 \
 --mixed_precision="fp16" \
 --tracker_project_name="controlnet-demo" \
 --report_to=wandb
```

## Example results

#### After 300 steps with batch size 8

| |  | 
|-------------------|:-------------------------:|
| | red circle with blue background  | 
![conditioning image](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/conditioning_image_1.png) | ![red circle with blue background](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/red_circle_with_blue_background_300_steps.png) |
| | cyan circle with brown floral background | 
![conditioning image](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/conditioning_image_2.png) | ![cyan circle with brown floral background](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/cyan_circle_with_brown_floral_background_300_steps.png) |


#### After 6000 steps with batch size 8:

| |  | 
|-------------------|:-------------------------:|
| | red circle with blue background  | 
![conditioning image](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/conditioning_image_1.png) | ![red circle with blue background](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/red_circle_with_blue_background_6000_steps.png) |
| | cyan circle with brown floral background | 
![conditioning image](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/conditioning_image_2.png) | ![cyan circle with brown floral background](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/controlnet_training/cyan_circle_with_brown_floral_background_6000_steps.png) |

## Training on a 16 GB GPU

Enable the following optimizations to train on a 16GB GPU:

- Gradient checkpointing
- bitsandbyte's 8-bit optimizer (take a look at the [installation]((https://github.com/TimDettmers/bitsandbytes#requirements--installation) instructions if you don't already have it installed)

Now you can launch the training script:

```bash
export MODEL_DIR="runwayml/stable-diffusion-v1-5"
export OUTPUT_DIR="path to save model"

accelerate launch train_controlnet.py \
 --pretrained_model_name_or_path=$MODEL_DIR \
 --output_dir=$OUTPUT_DIR \
 --dataset_name=fusing/fill50k \
 --resolution=512 \
 --learning_rate=1e-5 \
 --validation_image "./conditioning_image_1.png" "./conditioning_image_2.png" \
 --validation_prompt "red circle with blue background" "cyan circle with brown floral background" \
 --train_batch_size=1 \
 --gradient_accumulation_steps=4 \
 --gradient_checkpointing \
 --use_8bit_adam
```

## Training on a 12 GB GPU

Enable the following optimizations to train on a 12GB GPU:
- Gradient checkpointing
- bitsandbyte's 8-bit optimizer (take a look at the [installation]((https://github.com/TimDettmers/bitsandbytes#requirements--installation) instructions if you don't already have it installed)
- xFormers (take a look at the [installation](https://huggingface.co/docs/diffusers/training/optimization/xformers) instructions if you don't already have it installed)
- set gradients to `None`

```bash
export MODEL_DIR="runwayml/stable-diffusion-v1-5"
export OUTPUT_DIR="path to save model"

accelerate launch train_controlnet.py \
 --pretrained_model_name_or_path=$MODEL_DIR \
 --output_dir=$OUTPUT_DIR \
 --dataset_name=fusing/fill50k \
 --resolution=512 \
 --learning_rate=1e-5 \
 --validation_image "./conditioning_image_1.png" "./conditioning_image_2.png" \
 --validation_prompt "red circle with blue background" "cyan circle with brown floral background" \
 --train_batch_size=1 \
 --gradient_accumulation_steps=4 \
 --gradient_checkpointing \
 --use_8bit_adam \
 --enable_xformers_memory_efficient_attention \
 --set_grads_to_none
```

When using `enable_xformers_memory_efficient_attention`, please make sure to install `xformers` by `pip install xformers`. 

## Training on an 8 GB GPU

We have not exhaustively tested DeepSpeed support for ControlNet. While the configuration does
save memory, we have not confirmed whether the configuration trains successfully. You will very likely
have to make changes to the config to have a successful training run.

Enable the following optimizations to train on a 8GB GPU:
- Gradient checkpointing
- bitsandbyte's 8-bit optimizer (take a look at the [installation]((https://github.com/TimDettmers/bitsandbytes#requirements--installation) instructions if you don't already have it installed)
- xFormers (take a look at the [installation](https://huggingface.co/docs/diffusers/training/optimization/xformers) instructions if you don't already have it installed)
- set gradients to `None`
- DeepSpeed stage 2 with parameter and optimizer offloading
- fp16 mixed precision

[DeepSpeed](https://www.deepspeed.ai/) can offload tensors from VRAM to either 
CPU or NVME. This requires significantly more RAM (about 25 GB).

You'll have to configure your environment with `accelerate config` to enable DeepSpeed stage 2.

The configuration file should look like this:

```yaml
compute_environment: LOCAL_MACHINE
deepspeed_config:
  gradient_accumulation_steps: 4
  offload_optimizer_device: cpu
  offload_param_device: cpu
  zero3_init_flag: false
  zero_stage: 2
distributed_type: DEEPSPEED
```

<Tip>

See [documentation](https://huggingface.co/docs/accelerate/usage_guides/deepspeed) for more DeepSpeed configuration options.

<Tip>

Changing the default Adam optimizer to DeepSpeed's Adam
`deepspeed.ops.adam.DeepSpeedCPUAdam` gives a substantial speedup but
it requires a CUDA toolchain with the same version as PyTorch. 8-bit optimizer
does not seem to be compatible with DeepSpeed at the moment.

```bash
export MODEL_DIR="runwayml/stable-diffusion-v1-5"
export OUTPUT_DIR="path to save model"

accelerate launch train_controlnet.py \
 --pretrained_model_name_or_path=$MODEL_DIR \
 --output_dir=$OUTPUT_DIR \
 --dataset_name=fusing/fill50k \
 --resolution=512 \
 --validation_image "./conditioning_image_1.png" "./conditioning_image_2.png" \
 --validation_prompt "red circle with blue background" "cyan circle with brown floral background" \
 --train_batch_size=1 \
 --gradient_accumulation_steps=4 \
 --gradient_checkpointing \
 --enable_xformers_memory_efficient_attention \
 --set_grads_to_none \
 --mixed_precision fp16
```

## Inference

The trained model can be run with the [`StableDiffusionControlNetPipeline`].
Set `base_model_path` and `controlnet_path` to the values `--pretrained_model_name_or_path` and 
`--output_dir` were respectively set to in the training script.

```py
from diffusers import StableDiffusionControlNetPipeline, ControlNetModel, UniPCMultistepScheduler
from diffusers.utils import load_image
import torch

base_model_path = "path to model"
controlnet_path = "path to controlnet"

controlnet = ControlNetModel.from_pretrained(controlnet_path, torch_dtype=torch.float16)
pipe = StableDiffusionControlNetPipeline.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
pipe.enable_xformers_memory_efficient_attention()

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")
```
