diff --git a/docs/source/en/_toctree.yml b/docs/source/en/_toctree.yml index f205046ffc90..e8f825244552 100644 --- a/docs/source/en/_toctree.yml +++ b/docs/source/en/_toctree.yml @@ -62,6 +62,8 @@ title: Overview - local: training/create_dataset title: Create a dataset for training + - local: training/adapt_a_model + title: Adapt a model to a new task - local: training/unconditional_training title: Unconditional image generation - local: training/text_inversion diff --git a/docs/source/en/training/adapt_a_model.mdx b/docs/source/en/training/adapt_a_model.mdx new file mode 100644 index 000000000000..f1af5fca57a2 --- /dev/null +++ b/docs/source/en/training/adapt_a_model.mdx @@ -0,0 +1,42 @@ +# Adapt a model to a new task + +Many diffusion systems share the same components, allowing you to adapt a pretrained model for one task to an entirely different task. + +This guide will show you how to adapt a pretrained text-to-image model for inpainting by initializing and modifying the architecture of a pretrained [`UNet2DConditionModel`]. + +## Configure UNet2DConditionModel parameters + +A [`UNet2DConditionModel`] by default accepts 4 channels in the [input sample](https://huggingface.co/docs/diffusers/v0.16.0/en/api/models#diffusers.UNet2DConditionModel.in_channels). For example, load a pretrained text-to-image model like [`runwayml/stable-diffusion-v1-5`](https://huggingface.co/runwayml/stable-diffusion-v1-5) and take a look at the number of `in_channels`: + +```py +from diffusers import StableDiffusionPipeline + +pipeline = StableDiffusionPipeline.from_pretrained("runwayml/stable-diffusion-v1-5") +pipeline.unet.config["in_channels"] +4 +``` + +Inpainting requires 9 channels in the input sample. You can check this value in a pretrained inpainting model like [`runwayml/stable-diffusion-inpainting`](https://huggingface.co/runwayml/stable-diffusion-inpainting): + +```py +from diffusers import StableDiffusionPipeline + +pipeline = StableDiffusionPipeline.from_pretrained("runwayml/stable-diffusion-inpainting") +pipeline.unet.config["in_channels"] +9 +``` + +To adapt your text-to-image model for inpainting, you'll need to change the number of `in_channels` from 4 to 9. + +Initialize a [`UNet2DConditionModel`] with the pretrained text-to-image model weights, and change `in_channels` to 9. Changing the number of `in_channels` means you need to set `ignore_mismatched_sizes=True` and `low_cpu_mem_usage=False` to avoid a size mismatch error because the shape is different now. + +```py +from diffusers import UNet2DConditionModel + +model_id = "runwayml/stable-diffusion-v1-5" +unet = UNet2DConditionModel.from_pretrained( + model_id, subfolder="unet", in_channels=9, low_cpu_mem_usage=False, ignore_mismatched_sizes=True +) +``` + +The pretrained weights of the other components from the text-to-image model are initialized from their checkpoints, but the input channel weights (`conv_in.weight`) of the `unet` are randomly initialized. It is important to finetune the model for inpainting because otherwise the model returns noise.