agent failed to verify the receipt signature: image too low-res error

TL;DR

The image lacks the detail needed to verify a signature, and no algorithm can invent it. Request a higher-resolution capture of the receipt, and until one arrives, route the expense to manual review rather than auto-failing it.

Error

agent failed to verify the receipt signature: image too low-res

Steps

1. Check the image resolution and the signature region's pixel size. Expected: you confirm the signature area is too small to analyze.
2. Request a re-capture at higher resolution, with the signature area filling a good portion of the frame. Expected: a submittable higher-res image.
3. While waiting, route the expense to manual review with a note that signature verification is pending. Expected: the expense is not auto-rejected for a capture problem.
4. When the new image arrives, re-run verification. Expected: a definitive pass or fail on adequate pixels.
5. Set a minimum capture resolution in the submission guidance. Expected: fewer low-res submissions over time.

When to use

• Signature verification fails specifically on low resolution.
• The signature exists but cannot be analyzed.

When not to use

• There is no signature at all (request the signature, not a better photo).
• Verification fails on a high-res image (a matcher problem, different fix).

Tool compatibility

• Custom agent verification pipelines; mobile capture guidance.

Variant phrasings

Signature unverifiable: resolution too low

Same failure, alternate wording.

Image quality insufficient for signature check

The quality-gate phrasing.

Why it happens

Signature verification needs fine stroke detail. Downscaled or distant photos destroy that detail, and the verifier correctly refuses to judge what it cannot see.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_nCruHNVlL2raAnhZW1VndQ