Image upscale factor 4 on a 1024 square: about 16.8 MP for $0.20

A 1024x1024 image upscaled by factor 4 is 4096x4096, which is 16,777,216 pixels or about 16.8 megapixels. Sume's Image Upscale 1.0 charges $0.20 per image and states that it reserves about 16 megapixels of generative output. The sizes line up, so a 1K input at factor 4 is the case the price was built around.

Input size versus output size

Arithmetic only: output side = input side x factor. The catalog does not publish a per-factor price or an output cap beyond the 16 MP reserve wording, so for larger inputs read the live catalog entry before running a batch.

Request fields

The strict body takes image_url (public HTTPS), upscale_factor (a number from 1 to 4), output_format (png, jpg or webp), metadata, and the communication fields. As with the other Sume model APIs, model and provider endpoint keys are rejected. Endpoint: POST /v1/image-upscale-1.0/upscale; poll the job and read the result.

curl -X POST https://api.sume.com/v1/image-upscale-1.0/upscale \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: upscale-hero-001" \
  -d '{"image_url":"https://example.com/hero-1024.png","upscale_factor":4,"output_format":"png"}'

Cost comparison worth knowing

Sume lists nano-banana-2.1 at $0.20 for a 4K image and $0.15 at 2K. So a 4K output costs the same $0.20 either by generating at 4K or by upscaling an existing image. If you already have the picture you want, the upscale keeps it; regenerating at 4K gives a new image.

Checklist

• Price is $0.20 per image, flat, in the catalog.
• Set output_format explicitly if the next tool needs png.
• Hosted MCP tool: image_upscale_create, with idempotency_key.

Choosing a factor

A bigger factor is not always better. Factor 2 from a 2K image already gives 4096 pixels on a side. If the end use is a 3000 pixel print, an input of 1500 at factor 2 is enough, and you pay the same $0.20 either way because the price is per image. Because price does not rise with factor, the choice is about quality and file size: pick the smallest factor that reaches the target resolution and set output_format to jpg or webp when file weight matters. Every media job follows the same lifecycle: submit with an Idempotency-Key, receive a job, poll GET /v1/jobs/:id/status until it is ready, then read GET /v1/jobs/:id/result. A retry with the same key does not queue a second job, so a network error during submit never doubles a charge.