Overview
Capturing a signature and confirming it is genuine are two different problems. The Wacom Ink SDK for verification solves the second: it compares a signature against reference samples already on file and returns a score between 0 and 1 — an instant accept or reject — so a teller, claims handler or registrar gets an answer while the customer is still in front of them.
It handles both kinds of comparison in a single product, which is unusual. Dynamic verification uses the biometric data captured as the person signs — how fast the pen moved, how much pressure was applied — alongside the shape of the signature, comparing it against up to six reference examples. Static verification works from an image alone, comparing the visual proportions of a signature against stored samples, and accepts PNG, BMP, TIF and JPEG files with preprocessing to adjust contrast, remove speckle and normalise the signature before comparison. That second mode is what makes archives usable, because historic signatures usually exist only as scans.
One design decision makes it markedly easier to deploy in regulated environments: the software does not store the signature data it processes. Verification happens without building a server-side repository of customer biometrics, which removes a whole category of compliance exposure that affects hosted verification services. The scoring engine is also deliberately tuned in favour of a low false acceptance rate, meaning it errs toward rejecting a doubtful signature rather than waving it through — the correct bias for banking, insurance and government use.
What it does not do is capture signatures — it evaluates them. You need a capture route first, normally the Wacom Ink SDK for signature on a Wacom pad or display, or an existing archive of signature images for static comparison. It also returns a score, not a decision: your process decides what threshold means accept, refer or reject, and setting that threshold sensibly is part of the implementation work we scope with clients.
Wacom Ink SDK for Verification at a Glance
| Purpose | Verifying whether a handwritten signature matches reference samples on file |
|---|---|
| Verification modes | Dynamic (biometric) and static (image-based) in a single product |
| Dynamic comparison | Biometric data such as speed and pressure, plus signature shape |
| Reference samples | Compares against up to six reference signatures |
| Static comparison | Visual feature proportions and similarity against stored samples |
| Image formats (static) | PNG, BMP, TIF, JPEG |
| Image preprocessing | Contrast adjustment, speckle removal, signature normalisation |
| Output | Accept or reject score between 0 and 1 |
| Tuning bias | Built in favour of a low false acceptance rate |
| Data storage | Does not store the signature data it processes |
| Typical sectors | Banking, insurance, government registries, high-value contract processes |
| Requires | A capture route such as the Wacom Ink SDK for signature, or an existing signature archive |
Which Wacom SDK Do I Need?
Five Wacom products cover signing, and they are not interchangeable. This table is the short version of the advice we give clients before any integration work is scoped.
| Product | Use it when you need to… | Platforms | Development effort |
|---|---|---|---|
| Wacom Ink SDK for signature | Capture a handwritten signature with biometric data inside your own application | Windows, iOS, Android | Moderate – you build the surrounding workflow |
| sign pro PDF API | Sign complete PDF documents from an existing CRM, ERP or contract system | Windows, iOS, Android | Light to moderate – document handling is provided |
| sign pro PDF app | Sign and fill PDFs by hand with no integration at all | Windows | None – install and use |
| Wacom Ink SDK for verification | Check whether a signature matches reference samples already on file | See product page | Moderate – scoring integrated into your process |
| Wacom Ink SDK for ink | Capture, store and replay digital ink generally – notes, annotation, forms | Multiple | Moderate to high – a toolkit, not a solution |
Not sure which fits your process? Talk to our integration team — we scope this against your actual systems before recommending anything.
Frequently Asked Questions
What does the Wacom Ink SDK for verification do?
It checks whether a handwritten signature is genuine by comparing it against reference samples on file, then returns an accept or reject score between 0 and 1. The result is immediate, so it can be used while a customer is still at the counter.
What is the difference between dynamic and static verification?
Dynamic verification uses biometric data captured during signing, such as pen speed and pressure, so it needs a live signature. Static verification compares a signature image against stored samples, which is what makes archived and scanned signatures verifiable.
How many reference signatures does it need?
Dynamic verification compares a new signature against up to six reference examples. More references generally give a more reliable comparison, since they capture the natural variation in how a person signs.
Does it store our customers’ signature data?
No. The software does not store the signature data it processes, which avoids the compliance exposure that comes with server-based services holding customer biometrics. Your own systems remain the only place signatures are retained.
Can it verify signatures on old paper documents?
Yes, through static verification. It accepts PNG, BMP, TIF and JPEG images and can preprocess them — adjusting contrast, removing speckle and normalising the signature — before comparing against reference samples.
Does it capture signatures as well as verify them?
No. It evaluates signatures but does not capture them. You need a capture route first, normally the Wacom Ink SDK for signature with a Wacom pad or display, or an existing archive of signature images.
Assessing signature verification for a bank, insurer or registry in the UAE? Talk to our team about capture, verification and where to set your accept threshold.