Microsoft Advertising image max 2592x2048: send JPEG, not PNG

Microsoft's Image data object accepts GIF, JPEG and PNG up to 2592 pixels wide and 2048 high, and says a PNG is converted to JPEG and animation is not supported. Ask Sume for output_format: "jpeg" so the file you checked is the file Microsoft serves.

Microsoft facts are from the Learn page for the Image data object, read 2026-10-01. Sume facts are from the Images API docs, where output_format is png, jpeg, webp or svg.

What are the limits?

Why does the format matter?

A PNG with a transparent background has no transparent JPEG equivalent, so Microsoft's conversion can change how it looks. Make the background opaque in the first place. On openai/gpt-image-2.5, background takes auto, transparent or opaque; pick opaque for this destination.

curl -X POST "https://api.sume.com/v1/images" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-image-2.5",
    "prompt": "Leather backpack on a solid light gray background, centered, no text",
    "image_size": "1584x832",
    "background": "opaque",
    "output_format": "jpeg"
  }'

What do I check next?

The size above is inside Microsoft's maximum and both edges are multiples of 16. Check that the base64 text of the file stays within 102,400 characters; Sume cannot set compression in v1, so shrink the file in your own tool if it does not. Confirm current rules on Microsoft's page.