README.md

---
pipeline_tag: text-to-image
license: creativeml-openrail-m
base_model: CompVis/stable-diffusion-v1-2
library_name: zeromodels
language:
- en
tags:
- keras
- zeromodels
- stable-diffusion
- stable-diffusion-diffusers
- text-to-image
- diffusion
- latent-diffusion
- arxiv:2112.10752
- pytorch
- jax
- tf
---
*See [our collection](https://huggingface.co/zeromodels) for all Stable Diffusion 1.x checkpoints.*

# Run Stable Diffusion 1.x with Keras 3: JAX, PyTorch, or TensorFlow

[![GitHub](https://img.shields.io/badge/GitHub-ZeroModels-181717?logo=github)](https://github.com/IMvision12/ZeroModels) [![Docs](https://img.shields.io/badge/Docs-Stable_Diffusion_1.x-1f6feb)](https://imvision12.github.io/ZeroModels/diffusers/#stable-diffusion) [![HuggingFace](https://img.shields.io/badge/HuggingFace-Stable_Diffusion_1.x-ffd21e?logo=huggingface&logoColor=black)](https://huggingface.co/zeromodels)

# zeromodels/stable-diffusion-v1-2

Paper: [High-Resolution Image Synthesis with Latent Diffusion Models (arXiv:2112.10752)](https://arxiv.org/abs/2112.10752) | [HF Papers](https://huggingface.co/papers/2112.10752)

Pure-**Keras 3** conversion of [`CompVis/stable-diffusion-v1-2`](https://huggingface.co/CompVis/stable-diffusion-v1-2) for
[zeromodels](https://github.com/IMvision12/ZeroModels). One implementation runs unmodified on
**TensorFlow / Torch / JAX**. The whole text-to-image model ships as **one container**:
the UNet denoiser, the VAE and the CLIP ViT-L/14 text encoder in `model.weights.h5`
(1.07B parameters, 3.97 GB), plus `zm_config.json` (the three
component configs, the checkpoint's `PNDMScheduler` schedule with its `epsilon` objective
and the default generation settings) and the tokenizer as `tokenizer.json`. Weights are stored in **float32**, exactly as released.
This checkpoint generates **512x512** images (a 64x64 latent).

For model details, intended use and limitations, see the upstream
[model card](https://huggingface.co/CompVis/stable-diffusion-v1-2).

## Architecture

| Component | zeromodels class | Details |
| --- | --- | --- |
| Denoiser | `UNet2DConditionModel` | (320, 640, 1280, 1280) channels, 2 ResNet blocks per level, 8 attention heads on the 768-d text context, 1x1 conv token projection, 64x64x4 latent |
| Autoencoder | `AutoencoderKL` | (128, 256, 512, 512) channels, x8 spatial compression to 4 latent channels, `scaling_factor` 0.18215 |
| Text encoder | `CLIPTextModel` | CLIP ViT-L/14 text encoder: 768-d, 12 layers, 12 heads, 77 tokens, `quick_gelu` |
| Scheduler | `PNDMScheduler` | scaled_linear betas 0.00085 to 0.012 over 1000 steps, `epsilon`; DDIM / PNDM / Euler / Euler-ancestral are drop-in |

## Quick start

```python
import os
os.environ["KERAS_BACKEND"] = "torch"  # or "jax" / "tensorflow"

from PIL import Image
from zeromodels.diffusers import ZMDiffusion, ZMDiffusionTokenizer

model = ZMDiffusion.from_weights("zeromodels/stable-diffusion-v1-2")
tokenizer = ZMDiffusionTokenizer.from_weights("zeromodels/stable-diffusion-v1-2")

inputs = tokenizer("a photograph of an astronaut riding a horse")
images = model.generate(**inputs, num_inference_steps=50, guidance_scale=7.5, seed=0)
Image.fromarray(images[0]).save("astronaut.png")  # (512, 512, 3) uint8
```

`generate` takes the tokenizer's `input_ids` (batch them for several prompts), an optional
`negative_input_ids` (tokenize the negative prompt), `num_inference_steps`, `guidance_scale`,
a `seed`, or explicit `latents` of shape `(batch, 64, 64, 4)` for results that are
identical across backends.

Load any Stable Diffusion 1.x checkpoint the same way with `from_weights("zeromodels/<variant>")`:

| Variant | Hub | Training |
| --- | --- | --- |
| `stable-diffusion-v1-1` | [zeromodels/stable-diffusion-v1-1](https://huggingface.co/zeromodels/stable-diffusion-v1-1) | 237k steps at 256px on laion2B-en, then 194k steps at 512px on laion-high-resolution |
| `stable-diffusion-v1-2` | [zeromodels/stable-diffusion-v1-2](https://huggingface.co/zeromodels/stable-diffusion-v1-2) | v1-1 + 515k steps at 512px on laion-aesthetics v2 5+ |
| `stable-diffusion-v1-3` | [zeromodels/stable-diffusion-v1-3](https://huggingface.co/zeromodels/stable-diffusion-v1-3) | v1-2 + 195k steps at 512px, 10% text-conditioning dropout (classifier-free guidance) |
| `stable-diffusion-v1-4` | [zeromodels/stable-diffusion-v1-4](https://huggingface.co/zeromodels/stable-diffusion-v1-4) | v1-2 + 225k steps at 512px, 10% text-conditioning dropout (classifier-free guidance) |
| `stable-diffusion-v1-5` | [zeromodels/stable-diffusion-v1-5](https://huggingface.co/zeromodels/stable-diffusion-v1-5) | v1-2 + 595k steps at 512px, 10% text-conditioning dropout (classifier-free guidance) |

## Tips

- Set `KERAS_BACKEND` **before** importing Keras / zeromodels.
- `AutoZModel` / `AutoZMTokenizer` (`from zeromodels import ...`) load this repo too;
  they resolve to `ZMDiffusion` / `ZMDiffusionTokenizer` from its `model_type`.
- The graphs are built for 512px. Pass `unet_sample_size=<px / 8>, vae_sample_size=<px>` to
  `from_weights` to build for another multiple of 64px (the weights are resolution-independent).
- Swap the sampler any time: `model.scheduler = EulerDiscreteScheduler.from_config(model.config.scheduler_config)`
  (`zeromodels.base.base_scheduler`).
- The trained components are attributes of the loaded `ZMDiffusion`
  (UNet / VAE / text encoder as `.unet` / `.vae` / `.text_encoder`), each callable on its own.

- Both `channels_last` and `channels_first` are supported (`keras.config.set_image_data_format`
  before loading); `generate` always returns `(batch, H, W, 3)` uint8.
- On-the-fly `hf:` conversion is not supported for diffusion models; the checkpoints are
  hosted here, converted once.
- See the [Stable Diffusion 1.x docs](https://imvision12.github.io/ZeroModels/diffusers/#stable-diffusion).

## License

The weights are redistributed under the [CreativeML OpenRAIL-M License](https://huggingface.co/spaces/CompVis/stable-diffusion-license/blob/main/license.txt) of the upstream
checkpoint, including its use-based restrictions. By using them you agree to those terms.

## Notice

Modifications by zeromodels (https://github.com/IMvision12/ZeroModels): the checkpoint
released at https://huggingface.co/CompVis/stable-diffusion-v1-2 was converted to the Keras
3 weights layout of zeromodels (`model.weights.h5, zm_config.json, tokenizer.json`), stored
in float32 as released. The model architecture and the parameter values are unchanged; the
weight names and the file format differ from the release.

## Special Thanks

Thank you to the CompVis group at LMU Munich, Runway and Stability AI for training and releasing Stable Diffusion, and to the
Hugging Face diffusers team, whose implementation this port was verified against.