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1 project in Math · Show all

LiveMathProduct Design

Handwriting Biometrics

Sign on a pad and see your signature as equations: fitted curves, how you signed, and a replay of the signing you can export. Everything runs in your browser; nothing you draw is uploaded.

Built on Browser drawing · Pen and touch input · Equation typesetting · Video recording

Try it

A signature is not a picture. It is a movement through time, with a position, a speed and a pressure, and this tool records it as one. Sign on the pad and it fits the stroke with two mathematical models, writes them out as equations, measures how you signed, and replays the signing with a pen.

It stops before the writer model, on purpose: one signature measures a moment, not an identity.

  1. Capture

    Pointer events sampled as position, time, pressure and tilt, on a fixed 1000 × 400 pad.

  2. Process

    Each stroke resampled every 1.5 units, then lightly smoothed.

  3. Model

    Bézier curves by Schneider's algorithm, and a cosine series by a type-I DCT.

  4. Measure

    Curvature, speed, pressure, slant, pen lifts and pauses.

  5. Replay

    The recorded rhythm or one steady speed, exported as video or GIF.

To load the whole tool
116 KB
compressed; the equations' fonts load only when needed
Requests to a server
0
fitting, replay and export run in the browser
Models of every stroke
2
Bézier and Fourier
Runs
In the browser
Stores
Nothing: no upload, no account
Input
Pen with pressure, mouse or touch
Exports
MP4 or WebM, GIF, LaTeX