String Embed In Image (RGB)

Don't let the "MP3" in the slug fool you - feed this node an audio file and it'll do nothing useful with it. Both the schema and, more tellingly, the node's actual display name ("String Embed In Image (RGB)") agree on what it really does: take an image and a text string, and hand back an image with that string hidden inside its pixel data.

The mechanism, and how it relates to something ComfyUI already does. This is image steganography, not audio embedding, despite what the slug suggests. ComfyUI has its own well-known version of a related idea already baked in: every image it saves carries its full generation graph as PNG metadata, which is exactly why you can drag someone's output image back into ComfyUI and get their workflow reconstructed automatically. This node is doing something related but mechanically different - instead of writing to a metadata chunk in the file container (something any tool that re-saves or converts the file can strip without even trying to), it alters the RGB pixel values themselves to carry the payload. Done right, that's visually invisible, but it's baked into the actual image data rather than sitting in metadata a re-save could wipe.

Inputs and outputs. Two required inputs: image (IMAGE) and data_string (a plain string - this is the text getting hidden). One output: image_out, the modified IMAGE.

What you'd actually use this for isn't documented anywhere in the pack, but given how many other nodes in this same author's collection carry a license_key field, a reasonable guess is that this exists to stamp a tracking ID, filename, or license token invisibly into generated output. That's a guess based on pattern-matching against the rest of the pack, not a documented feature - worth being clear about the difference.

Its companion node, String Extract From Image (RGB), is the one that reads the string back out.

Installing it. Search comfyui-huyl2-nodes in ComfyUI Manager, or clone directly:

cd ComfyUI/custom_nodes
git clone https://github.com/huyl3-cpu/comfyui-sortlist

Restart ComfyUI.

Troubleshooting. If you can't get your string back out on the extraction side, the most likely culprit is the image getting re-encoded somewhere between the two nodes. Any lossy round-trip - saving as JPEG, resizing, running it through an upscaler, even some color-correction nodes - will corrupt a payload that's living in individual pixel values, because those operations are specifically in the business of changing pixel values, just for reasons that have nothing to do with your hidden string. Keep the image as a lossless PNG and don't run anything between embed and extract that touches pixels, and the round-trip should hold.