Turn a drawing into an image with GPT Image 2.5

To turn a drawing into a finished image with GPT Image 2.5 on Sume, upload the drawing to a public HTTPS URL, pass it in input_references with a prompt that says what the sketch should become, and call openai/gpt-image-2.5 or the Sunburst variant.

What the model release says

According to Wikipedia's GPT Image page, OpenAI released GPT Image 2.5 on September 8, 2026. The page lists a Sketch feature that turns drawings into images, 50 percent lower generation latency, and two variants: Flare for speed and Sunburst for detail.

What Sume documents

Sume lists openai/gpt-image-2.5 (Flare) and openai/gpt-image-2.5-sunburst. Both support text-to-image, up to 16 image references, an optional mask_url, and background set to auto, transparent or opaque. Quality is auto, low, medium, high, xhigh or max, and omitted quality defaults to high.

The Sume docs do not describe a separate Sketch mode, so treat your drawing as a reference image and describe the transformation in the prompt. Reference URLs must be public HTTPS; localhost and private-network URLs are rejected.

curl -X POST https://api.sume.com/v1/images \
  -H "x-api-key: $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: sketch-to-image-001" \
  -d '{
    "model": "openai/gpt-image-2.5",
    "prompt": "Turn this pencil sketch into a clean product render, soft studio light, keep the proportions.",
    "input_references": [
      {"type": "image_url", "image_url": {"url": "https://example.com/sketch.png"}}
    ],
    "aspect_ratio": "auto",
    "mode": "async"
  }'

Tips for sketches

• Use high contrast: dark lines on a plain background read best.
• Say what to keep (layout, proportions) and what to change (materials, light).
• Use Sunburst when detail matters and Flare for quick iterations.
• Use mask_url to limit the change to part of the image.
• Poll the job and read the Sume-hosted signed URL in data[].url.

Billing for image generation is all-or-nothing: a completed generation is billed in full and a failed or cancelled one is not billed.