Imagen 3 - backward compatibility with the Imagen 2 API

[catwell]

Imagen 3 has been released but the documentation has not been updated yet and the new API is more generic but also more complex than the old one.

For instance, with Imagen 2 you can outcrop like this:

model = ImageGenerationModel.from_pretrained("imagegeneration@006")
images = model.edit_image(
    prompt=prompt,
    edit_mode="outpainting",
    base_image=base_img,
    mask=mask_img,
)

but with Imagen 3 you need to do this:

model = ImageGenerationModel.from_pretrained("imagen-3.0-capability-001")
base_ref = RawReferenceImage(
    reference_id=0,
    image=base_img,
)
mask_ref = MaskReferenceImage(
    reference_id=1,
    image=mask_img,
    mask_mode="user_provided",
    dilation=0.03,
)
images = model.edit_image(
    prompt=prompt,
    edit_mode="outpainting",
    reference_images=[base_ref, mask_ref],
    number_of_images=2,
)

(Note in particular the dilation parameter, which is important and set to the old default.)

I think it would make sense to keep supporting the simpler API by converting it to the new format in the SDK when using Imagen 3.