Latent Diffusion Models

arXiv | BibTeX

High-Resolution Image Synthesis with Latent Diffusion Models
Robin Rombach*, Andreas Blattmann*, Dominik Lorenz, Patrick Esser, Björn Ommer
* equal contribution

Requirements

A suitable conda environment named ldm can be created and activated with:

conda env create -f environment.yaml
conda activate ldm

Model Zoo

Pretrained Autoencoding Models

Model FID vs val PSNR PSIM Link Comments

f=4, VQ (Z=8192, d=3) 0.58 27.43 +/- 4.26 0.53 +/- 0.21 https://ommer-lab.com/files/latent-diffusion/vq-f4.zip

f=4, VQ (Z=8192, d=3) 1.06 25.21 +/- 4.17 0.72 +/- 0.26 https://heibox.uni-heidelberg.de/f/9c6681f64bb94338a069/?dl=1 no attention

f=8, VQ (Z=16384, d=4) 1.14 23.07 +/- 3.99 1.17 +/- 0.36 https://ommer-lab.com/files/latent-diffusion/vq-f8.zip

f=8, VQ (Z=256, d=4) 1.49 22.35 +/- 3.81 1.26 +/- 0.37 https://ommer-lab.com/files/latent-diffusion/vq-f8-n256.zip

f=16, VQ (Z=16384, d=8) 5.15 20.83 +/- 3.61 1.73 +/- 0.43 https://heibox.uni-heidelberg.de/f/0e42b04e2e904890a9b6/?dl=1

f=4, KL 0.27 27.53 +/- 4.54 0.55 +/- 0.24 https://ommer-lab.com/files/latent-diffusion/kl-f4.zip

f=8, KL 0.90 24.19 +/- 4.19 1.02 +/- 0.35 https://ommer-lab.com/files/latent-diffusion/kl-f8.zip

f=16, KL (d=16) 0.87 24.08 +/- 4.22 1.07 +/- 0.36 https://ommer-lab.com/files/latent-diffusion/kl-f16.zip

f=32, KL (d=64) 2.04 22.27 +/- 3.93 1.41 +/- 0.40 https://ommer-lab.com/files/latent-diffusion/kl-f32.zip

Get the models

Running the following script downloads und extracts all available pretrained autoencoding models.

bash scripts/download_first_stages.sh

The first stage models can then be found in models/first_stage_models/<model_spec>

Pretrained LDMs

Datset Task Model FID IS Prec Recall Link Comments

CelebA-HQ Unconditional Image Synthesis LDM-VQ-4 (200 DDIM steps, eta=0) 5.11 (5.11) 3.29 0.72 0.49 https://ommer-lab.com/files/latent-diffusion/celeba.zip

FFHQ Unconditional Image Synthesis LDM-VQ-4 (200 DDIM steps, eta=1) 4.98 (4.98) 4.50 (4.50) 0.73 0.50 https://ommer-lab.com/files/latent-diffusion/ffhq.zip

LSUN-Churches Unconditional Image Synthesis LDM-KL-8 (400 DDIM steps, eta=0) 4.02 (4.02) 2.72 0.64 0.52 https://ommer-lab.com/files/latent-diffusion/lsun_churches.zip

LSUN-Bedrooms Unconditional Image Synthesis LDM-VQ-4 (200 DDIM steps, eta=1) 2.95 (3.0) 2.22 (2.23) 0.66 0.48 https://ommer-lab.com/files/latent-diffusion/lsun_bedrooms.zip

ImageNet Class-conditional Image Synthesis LDM-VQ-8 (200 DDIM steps, eta=1) 7.77(7.76)* /15.82** 201.56(209.52)* /78.82** 0.84* / 0.65** 0.35* / 0.63** https://ommer-lab.com/files/latent-diffusion/cin.zip *: w/ guiding, classifier_scale 10 **: w/o guiding, scores in bracket calculated with script provided by ADM

Conceptual Captions Text-conditional Image Synthesis LDM-VQ-f4 (100 DDIM steps, eta=0) 16.79 13.89 N/A N/A https://ommer-lab.com/files/latent-diffusion/text2img.zip finetuned from LAION

OpenImages Super-resolution LDM-VQ-4 N/A N/A N/A N/A https://ommer-lab.com/files/latent-diffusion/sr_bsr.zip BSR image degradation

OpenImages Layout-to-Image Synthesis LDM-VQ-4 (200 DDIM steps, eta=0) 32.02 15.92 N/A N/A https://ommer-lab.com/files/latent-diffusion/layout2img_model.zip

Landscapes Semantic Image Synthesis LDM-VQ-4 N/A N/A N/A N/A https://ommer-lab.com/files/latent-diffusion/semantic_synthesis256.zip

Landscapes Semantic Image Synthesis LDM-VQ-4 N/A N/A N/A N/A https://ommer-lab.com/files/latent-diffusion/semantic_synthesis.zip finetuned on resolution 512x512

Get the models

The LDMs listed above can jointly be downloaded and extracted via

bash scripts/download_models.sh

The models can then be found in models/ldm/<model_spec>.

Sampling with unconditional models

We provide a first script for sampling from our unconditional models. Start it via

CUDA_VISIBLE_DEVICES=<GPU_ID> python scripts/sample_diffusion.py -r models/ldm/<model_spec>/model.ckpt -l <logdir> -n <\#samples> --batch_size <batch_size> -c <\#ddim steps> -e <\#eta> 

Inpainting

Download the pre-trained weights

wget -O models/ldm/inpainting_big/last.ckpt https://heibox.uni-heidelberg.de/f/4d9ac7ea40c64582b7c9/?dl=1

and sample with

python scripts/inpaint.py --indir data/inpainting_examples/ --outdir outputs/inpainting_results

indir should contain images *.png and masks <image_fname>_mask.png like the examples provided in data/inpainting_examples.

Train your own LDMs

Data preparation

Faces

For downloading the CelebA-HQ and FFHQ datasets, proceed as described in the taming-transformers repository.

The LSUN datasets can be conveniently downloaded via the script available here. We performed a custom split into training and validation images, and provide the corresponding filenames at https://ommer-lab.com/files/lsun.zip. After downloading, extract them to ./data/lsun. The beds/cats/churches subsets should also be placed/symlinked at ./data/lsun/bedrooms/./data/lsun/cats/./data/lsun/churches, respectively.

ImageNet

The code will try to download (through Academic Torrents) and prepare ImageNet the first time it is used. However, since ImageNet is quite large, this requires a lot of disk space and time. If you already have ImageNet on your disk, you can speed things up by putting the data into ${XDG_CACHE}/autoencoders/data/ILSVRC2012_{split}/data/ (which defaults to ~/.cache/autoencoders/data/ILSVRC2012_{split}/data/), where {split} is one of train/validation. It should have the following structure:

${XDG_CACHE}/autoencoders/data/ILSVRC2012_{split}/data/
├── n01440764
│   ├── n01440764_10026.JPEG
│   ├── n01440764_10027.JPEG
│   ├── ...
├── n01443537
│   ├── n01443537_10007.JPEG
│   ├── n01443537_10014.JPEG
│   ├── ...
├── ...

If you haven't extracted the data, you can also place ILSVRC2012_img_train.tar/ILSVRC2012_img_val.tar (or symlinks to them) into ${XDG_CACHE}/autoencoders/data/ILSVRC2012_train/ / ${XDG_CACHE}/autoencoders/data/ILSVRC2012_validation/, which will then be extracted into above structure without downloading it again. Note that this will only happen if neither a folder ${XDG_CACHE}/autoencoders/data/ILSVRC2012_{split}/data/ nor a file ${XDG_CACHE}/autoencoders/data/ILSVRC2012_{split}/.ready exist. Remove them if you want to force running the dataset preparation again.

Model Training

Logs and checkpoints for trained models are saved to logs/<START_DATE_AND_TIME>_<config_spec>.

Training autoencoder models

Configs for training a KL-regularized autoencoder on ImageNet are provided at configs/autoencoder. Training can be started by running

CUDA_VISIBLE_DEVICES=<GPU_ID> python main.py --base configs/autoencoder/<config_spec>.yaml -t --gpus 0,    

where config_spec is one of {autoencoder_kl_8x8x64(f=32, d=64), autoencoder_kl_16x16x16(f=16, d=16), autoencoder_kl_32x32x4(f=8, d=4), autoencoder_kl_64x64x3(f=4, d=3)}.

For training VQ-regularized models, see the taming-transformers repository.

Training LDMs

In configs/latent-diffusion/ we provide configs for training LDMs on the LSUN-, CelebA-HQ, FFHQ and ImageNet datasets. Training can be started by running

CUDA_VISIBLE_DEVICES=<GPU_ID> python main.py --base configs/latent-diffusion/<config_spec>.yaml -t --gpus 0,

where <config_spec> is one of {celebahq-ldm-vq-4(f=4, VQ-reg. autoencoder, spatial size 64x64x3),ffhq-ldm-vq-4(f=4, VQ-reg. autoencoder, spatial size 64x64x3), lsun_bedrooms-ldm-vq-4(f=4, VQ-reg. autoencoder, spatial size 64x64x3), lsun_churches-ldm-vq-4(f=8, KL-reg. autoencoder, spatial size 32x32x4),cin-ldm-vq-8(f=8, VQ-reg. autoencoder, spatial size 32x32x4)}.

Coming Soon...

• More inference scripts for conditional LDMs.
• In the meantime, you can play with our colab notebook https://colab.research.google.com/drive/1xqzUi2iXQXDqXBHQGP9Mqt2YrYW6cx-J?usp=sharing
• We will also release some further pretrained models.

Comments

• Our codebase for the diffusion models builds heavily on OpenAI's codebase and https://github.com/lucidrains/denoising-diffusion-pytorch. Thanks for open-sourcing!

• The implementation of the transformer encoder is from x-transformers by lucidrains.

BibTeX

@misc{rombach2021highresolution,
      title={High-Resolution Image Synthesis with Latent Diffusion Models}, 
      author={Robin Rombach and Andreas Blattmann and Dominik Lorenz and Patrick Esser and Björn Ommer},
      year={2021},
      eprint={2112.10752},
      archivePrefix={arXiv},
      primaryClass={cs.CV}
}