Direct Load Image From S3

Say your input images live in an S3 bucket - a shared team bucket, or a pick from a pipeline you're not about to re-download by hand. The normal ComfyUI answer is to grab the file into ComfyUI/input and hope it doesn't get clobbered. Direct Load Image From S3 cuts that out: give it a bucket and a key, and it hands you the IMAGE and MASK tensors as if you'd loaded them from disk. It's the read-side sibling to this pack's Direct Save Image To S3.

This is the least-seen of the three nodes in KunmyonChoi's ComfyUI_S3_direct (barely any impressions - which is a shame, because it's the one that makes a bucket usable as an input rather than just an archive). It's also the most faithful port of ComfyUI's own Load Image: same EXIF handling, same alpha-channel behavior, same truncated-image fallback. If you've ever stared at Load Image's inner workings, this will feel familiar.

How it works

The node calls client.download_fileobj(bucket, key, outfile) into an in-memory BytesIO buffer - nothing written to disk - then opens it with PIL using the same LOAD_TRUNCATED_IMAGES fallback the core Load Image node uses (so slightly-corrupt JPEGs won't hard-crash your run). It transposes EXIF rotation, walks multi-frame images, and, like core Load Image, turns the alpha channel into a MASK (inverted, so opaque = 0, transparent = 1). No alpha? You get an empty 64×64 mask tensor, same as core.

Inputs and outputs

Two required inputs:

• s3_bucket - your bucket name (default "s3_bucket" is a placeholder).
• pathname - the exact object key to fetch. There's no browser and no listing; this node is "load by key or fail." You have to know the key.

Optional region, aws_ak, aws_sk for credentials. Outputs are IMAGE and MASK, both single tensors (not lists), and the node is not an output node - so it wires straight into any image input downstream: a VAE Encode, an Upscale Image, a ControlNet prep, whatever.

Install and credentials

One install for all three nodes in the pack:

cd ComfyUI/custom_nodes
git clone https://github.com/KunmyonChoi/ComfyUI_S3_direct

Restart ComfyUI after. ComfyUI Manager can do it - search "ComfyUI_S3_direct". The only real dependency is boto3 (torch is already there with ComfyUI); no models or heavy downloads.

Credentials work the same as the pack's save nodes: environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_DEFAULT_REGION) override the node fields, then the node fields, then boto3's default chain. Two gotchas from the source worth repeating: filling aws_ak without aws_sk silently falls back to the default chain, and there's no endpoint_url option - so MinIO, Cloudflare R2, and other custom-endpoint S3-compatible stores can't be reached by this pack. Real AWS, or bust.