Which model name should be used to call Seedream 4.5?
Submit the full doubao-seedream-4-5-251128 to POST /seedream/images and provide a prompt. Do not use the Seedream 4.5 display name as the invocation value. When editing an existing image, add image and describe what content to retain and what content needs to be modified.
What sizes does 4.5 support, and how do I specify the aspect ratio?
Presets support 2K and 4K. You can specify landscape, portrait, or square composition in the prompt; you can also specify width x height pixel values through size, but they must comply with the size range. Do not directly apply 1K or 3K presets from other versions to 4.5, and do not mix the two size expression methods at the same time.
What is the difference between multi-image references and related image groups?
Multi-image references use multiple images as creative inputs to help express subjects, scenes, or styles; related image groups generate a set of related images. The former is provided through image, while the latter is enabled by setting sequential_image_generation to auto. Neither guarantees one-to-one correspondence between inputs and outputs.
Can I use 4.5 to create posters with text?
You can write short titles, slogans, and placement requirements into the prompt, and explore poster visuals with sizes and reference images. It is recommended to clearly specify the text that needs to appear to reduce ambiguity. After generation, spelling errors, repeated characters, and layout should still be checked; formal brand materials can additionally undergo manual text overlay and proofreading.
How should I choose between background generation and streaming display?
For background tasks, set async to true, obtain the task_id and query it through /seedream/tasks, or use callback_url to receive completion notifications. When images need to be displayed progressively, use stream and receive application/x-ndjson; streaming cannot be combined with async or callbacks.