Ideogram Precise Edit can change part of an 8K image

Ideogram Precise Edit lets you edit a region up to 2K inside an image up to 8K. The context window sets the area the model reads, and pixels outside it stay untouched.

It's available in the app and API. Use a context window or an automatic fit around your mask to keep the full upload resolution. Editing the whole image above 2048 by 2048 downscales the result.