Replace an old logo on 40 product photos with Ideogram 4.5

To replace an old logo on existing product photos, send each photo as the first input_references entry and the new logo file as the second, to POST /v1/images with model: "ideogram/ideogram-v4.5". The first reference is the image that gets edited and up to four more act as references. On Sume, 40 photos cost $1.50 at low, $3.00 at medium and $11.00 at high.

Ideogram's own model page calls 4.5 its most precise edit model and shows text modification examples, including translating packaging text, which is the same capability a logo swap leans on. The risk in a batch is not the happy path but the photos where the logo is small, curved or partly hidden, so plan a review step.

Request shape

Host the new logo as a public HTTPS PNG on a plain background. Name both images in the prompt: image one is the product photo, image two is the new logo; replace the old logo on the front of the product with the logo from image two, same position and size, and keep everything else. Do not send output_format or mask_url; the model does not accept them. Leave aspect_ratio out so the edit keeps the source shape.

while read -r url; do
  curl -s -X POST https://api.sume.com/v1/images \
    -H "Authorization: Bearer $SUME_API_KEY" \
    -H "Content-Type: application/json" \
    -d "{
      \"model\": \"ideogram/ideogram-v4.5\",
      \"prompt\": \"Image 1 is a product photo. Replace the old logo on the product with the logo from image 2, same position and size. Keep everything else unchanged.\",
      \"input_references\": [
        {\"type\": \"image_url\", \"image_url\": {\"url\": \"$url\"}},
        {\"type\": \"image_url\", \"image_url\": {\"url\": \"https://example.com/new-logo.png\"}}
      ],
      \"quality\": \"medium\"
    }" >> results.jsonl
done < photos.txt

Cost for the batch

Prices are Sume's per-image amounts: provider list times 1.25. Quality sets the price and size does not.

Where batches go wrong

The first failure mode is a logo that is only partly visible. If the old mark wraps around a bottle, the new one has to wrap as well, and a model will often paste a flat version at the visible part. Check these against the original curve. The second is a product with two logos, such as a brand mark on the cap and a sub-brand on the label; the prompt has to say which one is replaced. The third is a photo with the logo in a reflection, which the edit may leave as the old logo.

Run a pilot of five photos that cover the hard cases before you queue the rest. At medium the pilot costs $0.375, which is less than the time to explain a bad batch to a client.

Preparing the logo file

The logo reference matters as much as the prompt. Send a clean PNG, cropped close to the mark, on a plain light background, at a size where the lettering is easy to read. A logo screenshot with a drop shadow or a busy background gives the model a messy target to copy. If the new logo has a wordmark and an icon, say which of them goes on the product: the full lockup on a large label, the icon alone on a small cap.

Keep a record per photo: the source URL, the logo version, the quality tier, the Sume job id and whether a human accepted the result. When the brand changes again next year you will be able to re-run exactly the photos that used the old file.

Review and retries

A completed edit is billed whether or not the logo is right, and a failed job is not billed. So the retry budget is the number of photos you reject. Sort the batch by logo size in frame: large front-facing logos usually succeed first time, small side or curved ones need a second pass or a higher tier.

Check each result at full size. The new logo must be spelled correctly, its colours must match the file, and the product shape must not change. A diff against the original that lights up outside the logo area is a sign the model redrew more than it should. Mark those for a rerun at high or for manual editing.

When a model edit is the wrong tool

If every product has the logo in exactly the same place on the same photo template, a template composite in Pillow is deterministic and free. If the photos are all different, curved bottles and fabric folds make a flat paste look fake, and an edit does a better job. And if the old logo must disappear for legal reasons, keep the original files archived and record which version of each photo went live.