Keep a label intact while swapping a scene: anchor box or mask
BFL's FLUX 3 anchor box preserves a region; its doc example reports 85.5% pixel-identical unmodified regions. On Sume, use a ChatGPT Image 2.5 mask_url edit.
To keep a product label unchanged while the scene changes, FLUX 3 Image has an anchor box that preserves a region, and on Sume the matching tool is a mask_url edit on ChatGPT Image 2.5. FLUX 3 Image is not in the Sume image catalog today; check GET /v1/images/models for the live list. The catalog lists FLUX.2 Pro and FLUX.2 Flex.
What the anchor box does
BFL's bounding-box page defines anchor as preserving content at an identical position, with both src_bbox and tgt_bbox set. Its doc example reports 85.5% pixel-identical preservation of unmodified regions. That is a figure from BFL's own example, not a guarantee for your image, so measure your own label.
| Question | FLUX 3 anchor box | Sume mask_url edit |
|---|---|---|
| Where you say what stays | Anchor box on the 0-1000 grid | Mask image at a public HTTPS URL |
| Which models | FLUX 3 Image (BFL) | ChatGPT Image 2.5 only (both variants) |
| Stated result | Doc example: 85.5% pixel-identical unmodified regions | Not stated in the Sume docs |
| Reference images | Up to 10 on BFL | Up to 16 on ChatGPT Image 2.5 |
The Sume version
Send the source photo as an input_references entry, point mask_url at your mask, and describe the new scene in the prompt. Reference URLs must be public HTTPS. The Sume docs do not say which mask colour means edit, so test one mask on a cheap quality tier first and read the result.
- Model:
openai/gpt-image-2.5(Flare) oropenai/gpt-image-2.5-sunburst. - Quality:
low,medium,high,xhighormax; default ishigh. - Always compare the label region pixel by pixel against the source before you ship.
Safest option
A mask edit is not a pixel lock. If the label must be exact, composite the original label crop back over the output as a final step.
Sources
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