Remove the background from a single image, returning the subject isolated on a transparent background. Supply the source image (URL or base64); optionally set crop to trim the result to the content, and creative_edit (default true) for higher-quality output that may not match the input pixel-for-pixel - set it false when the subject must stay pixel-identical, e.g. an existing sprite you will animate. The job result is a single image result with a url (not an array). The image is uploaded and validated, and an image larger than 15MB is rejected with HTTP 400. Credits are held when the job is accepted and refunded if it fails or is cancelled. Use removeBackground for this dedicated cutout task; editImage can also remove backgrounds via a prompt but is better for broader edits, while createImage and generateWithStyle produce new images rather than process an existing one. Pass an optional request_id to tag the result so you can retrieve it later via listGenerations (type image). Requires an API key (user scope). The call returns 202 with a job id - poll `GET /assets/jobs/{id}`, honouring poll_after_ms or long-polling with wait=30, until status is succeeded; its result field is exactly the response documented for this operation. Synchronous responses are deprecated but still supported: pass `async: false` to block until the result is ready and receive it as the response body. Synchronous calls run on the same queue: the response carries an X-Ludo-Job-Id header, and a job still running after 15 minutes comes back as 202 with the job instead of an error. Each account may have up to 50 generations queued or running at once via the API; a request beyond that returns 429 (code PENDING_JOBS_LIMIT).