| # Generative Models by Stability AI | |
|  | |
| ## News | |
| **July 4, 2023** | |
| - A technical report on SDXL is now available [here](assets/sdxl_report.pdf). | |
| **June 22, 2023** | |
| - We are releasing two new diffusion models for research purposes: | |
| - `SD-XL 0.9-base`: The base model was trained on a variety of aspect ratios on images with resolution 1024^2. The base model uses [OpenCLIP-ViT/G](https://github.com/mlfoundations/open_clip) and [CLIP-ViT/L](https://github.com/openai/CLIP/tree/main) for text encoding whereas the refiner model only uses the OpenCLIP model. | |
| - `SD-XL 0.9-refiner`: The refiner has been trained to denoise small noise levels of high quality data and as such is not expected to work as a text-to-image model; instead, it should only be used as an image-to-image model. | |
| If you would like to access these models for your research, please apply using one of the following links: | |
| [SDXL-0.9-Base model](https://huggingface.co/stabilityai/stable-diffusion-xl-base-0.9), and [SDXL-0.9-Refiner](https://huggingface.co/stabilityai/stable-diffusion-xl-refiner-0.9). | |
| This means that you can apply for any of the two links - and if you are granted - you can access both. | |
| Please log in to your Hugging Face Account with your organization email to request access. | |
| **We plan to do a full release soon (July).** | |
| ## The codebase | |
| ### General Philosophy | |
| Modularity is king. This repo implements a config-driven approach where we build and combine submodules by calling `instantiate_from_config()` on objects defined in yaml configs. See `configs/` for many examples. | |
| ### Changelog from the old `ldm` codebase | |
| For training, we use [pytorch-lightning](https://www.pytorchlightning.ai/index.html), but it should be easy to use other training wrappers around the base modules. The core diffusion model class (formerly `LatentDiffusion`, now `DiffusionEngine`) has been cleaned up: | |
| - No more extensive subclassing! We now handle all types of conditioning inputs (vectors, sequences and spatial conditionings, and all combinations thereof) in a single class: `GeneralConditioner`, see `sgm/modules/encoders/modules.py`. | |
| - We separate guiders (such as classifier-free guidance, see `sgm/modules/diffusionmodules/guiders.py`) from the | |
| samplers (`sgm/modules/diffusionmodules/sampling.py`), and the samplers are independent of the model. | |
| - We adopt the ["denoiser framework"](https://arxiv.org/abs/2206.00364) for both training and inference (most notable change is probably now the option to train continuous time models): | |
| * Discrete times models (denoisers) are simply a special case of continuous time models (denoisers); see `sgm/modules/diffusionmodules/denoiser.py`. | |
| * The following features are now independent: weighting of the diffusion loss function (`sgm/modules/diffusionmodules/denoiser_weighting.py`), preconditioning of the network (`sgm/modules/diffusionmodules/denoiser_scaling.py`), and sampling of noise levels during training (`sgm/modules/diffusionmodules/sigma_sampling.py`). | |
| - Autoencoding models have also been cleaned up. | |
| ## Installation: | |
| <a name="installation"></a> | |
| #### 1. Clone the repo | |
| ```shell | |
| git clone git@github.com:Stability-AI/generative-models.git | |
| cd generative-models | |
| ``` | |
| #### 2. Setting up the virtualenv | |
| This is assuming you have navigated to the `generative-models` root after cloning it. | |
| **NOTE:** This is tested under `python3.8` and `python3.10`. For other python versions, you might encounter version conflicts. | |
| **PyTorch 1.13** | |
| ```shell | |
| # install required packages from pypi | |
| python3 -m venv .pt1 | |
| source .pt1/bin/activate | |
| pip3 install wheel | |
| pip3 install -r requirements_pt13.txt | |
| ``` | |
| **PyTorch 2.0** | |
| ```shell | |
| # install required packages from pypi | |
| python3 -m venv .pt2 | |
| source .pt2/bin/activate | |
| pip3 install wheel | |
| pip3 install -r requirements_pt2.txt | |
| ``` | |
| ## Inference: | |
| We provide a [streamlit](https://streamlit.io/) demo for text-to-image and image-to-image sampling in `scripts/demo/sampling.py`. The following models are currently supported: | |
| - [SD-XL 0.9-base](https://huggingface.co/stabilityai/stable-diffusion-xl-base-0.9) | |
| - [SD-XL 0.9-refiner](https://huggingface.co/stabilityai/stable-diffusion-xl-refiner-0.9) | |
| - [SD 2.1-512](https://huggingface.co/stabilityai/stable-diffusion-2-1-base/blob/main/v2-1_512-ema-pruned.safetensors) | |
| - [SD 2.1-768](https://huggingface.co/stabilityai/stable-diffusion-2-1/blob/main/v2-1_768-ema-pruned.safetensors) | |
| **Weights for SDXL**: | |
| If you would like to access these models for your research, please apply using one of the following links: | |
| [SDXL-0.9-Base model](https://huggingface.co/stabilityai/stable-diffusion-xl-base-0.9), and [SDXL-0.9-Refiner](https://huggingface.co/stabilityai/stable-diffusion-xl-refiner-0.9). | |
| This means that you can apply for any of the two links - and if you are granted - you can access both. | |
| Please log in to your Hugging Face Account with your organization email to request access. | |
| After obtaining the weights, place them into `checkpoints/`. | |
| Next, start the demo using | |
| ``` | |
| streamlit run scripts/demo/sampling.py --server.port <your_port> | |
| ``` | |
| ### Invisible Watermark Detection | |
| Images generated with our code use the | |
| [invisible-watermark](https://github.com/ShieldMnt/invisible-watermark/) | |
| library to embed an invisible watermark into the model output. We also provide | |
| a script to easily detect that watermark. Please note that this watermark is | |
| not the same as in previous Stable Diffusion 1.x/2.x versions. | |
| To run the script you need to either have a working installation as above or | |
| try an _experimental_ import using only a minimal amount of packages: | |
| ```bash | |
| python -m venv .detect | |
| source .detect/bin/activate | |
| pip install "numpy>=1.17" "PyWavelets>=1.1.1" "opencv-python>=4.1.0.25" | |
| pip install --no-deps invisible-watermark | |
| ``` | |
| To run the script you need to have a working installation as above. The script | |
| is then useable in the following ways (don't forget to activate your | |
| virtual environment beforehand, e.g. `source .pt1/bin/activate`): | |
| ```bash | |
| # test a single file | |
| python scripts/demo/detect.py <your filename here> | |
| # test multiple files at once | |
| python scripts/demo/detect.py <filename 1> <filename 2> ... <filename n> | |
| # test all files in a specific folder | |
| python scripts/demo/detect.py <your folder name here>/* | |
| ``` | |
| ## Training: | |
| We are providing example training configs in `configs/example_training`. To launch a training, run | |
| ``` | |
| python main.py --base configs/<config1.yaml> configs/<config2.yaml> | |
| ``` | |
| where configs are merged from left to right (later configs overwrite the same values). | |
| This can be used to combine model, training and data configs. However, all of them can also be | |
| defined in a single config. For example, to run a class-conditional pixel-based diffusion model training on MNIST, | |
| run | |
| ```bash | |
| python main.py --base configs/example_training/toy/mnist_cond.yaml | |
| ``` | |
| **NOTE 1:** Using the non-toy-dataset configs `configs/example_training/imagenet-f8_cond.yaml`, `configs/example_training/txt2img-clipl.yaml` and `configs/example_training/txt2img-clipl-legacy-ucg-training.yaml` for training will require edits depending on the used dataset (which is expected to stored in tar-file in the [webdataset-format](https://github.com/webdataset/webdataset)). To find the parts which have to be adapted, search for comments containing `USER:` in the respective config. | |
| **NOTE 2:** This repository supports both `pytorch1.13` and `pytorch2`for training generative models. However for autoencoder training as e.g. in `configs/example_training/autoencoder/kl-f4/imagenet-attnfree-logvar.yaml`, only `pytorch1.13` is supported. | |
| **NOTE 3:** Training latent generative models (as e.g. in `configs/example_training/imagenet-f8_cond.yaml`) requires retrieving the checkpoint from [Hugging Face](https://huggingface.co/stabilityai/sdxl-vae/tree/main) and replacing the `CKPT_PATH` placeholder in [this line](configs/example_training/imagenet-f8_cond.yaml#81). The same is to be done for the provided text-to-image configs. | |
| ### Building New Diffusion Models | |
| #### Conditioner | |
| The `GeneralConditioner` is configured through the `conditioner_config`. Its only attribute is `emb_models`, a list of | |
| different embedders (all inherited from `AbstractEmbModel`) that are used to condition the generative model. | |
| All embedders should define whether or not they are trainable (`is_trainable`, default `False`), a classifier-free | |
| guidance dropout rate is used (`ucg_rate`, default `0`), and an input key (`input_key`), for example, `txt` for text-conditioning or `cls` for class-conditioning. | |
| When computing conditionings, the embedder will get `batch[input_key]` as input. | |
| We currently support two to four dimensional conditionings and conditionings of different embedders are concatenated | |
| appropriately. | |
| Note that the order of the embedders in the `conditioner_config` is important. | |
| #### Network | |
| The neural network is set through the `network_config`. This used to be called `unet_config`, which is not general | |
| enough as we plan to experiment with transformer-based diffusion backbones. | |
| #### Loss | |
| The loss is configured through `loss_config`. For standard diffusion model training, you will have to set `sigma_sampler_config`. | |
| #### Sampler config | |
| As discussed above, the sampler is independent of the model. In the `sampler_config`, we set the type of numerical | |
| solver, number of steps, type of discretization, as well as, for example, guidance wrappers for classifier-free | |
| guidance. | |
| ### Dataset Handling | |
| For large scale training we recommend using the data pipelines from our [data pipelines](https://github.com/Stability-AI/datapipelines) project. The project is contained in the requirement and automatically included when following the steps from the [Installation section](#installation). | |
| Small map-style datasets should be defined here in the repository (e.g., MNIST, CIFAR-10, ...), and return a dict of | |
| data keys/values, | |
| e.g., | |
| ```python | |
| example = {"jpg": x, # this is a tensor -1...1 chw | |
| "txt": "a beautiful image"} | |
| ``` | |
| where we expect images in -1...1, channel-first format. | |