Tune capture quality

Quality is gated on the device (vendor SDK) and on the server (Slade ID service). You tune the device side through FingerprintReaderCaptureConfig, passed when you open a session.

val session = sdk.createFingerprintReaderSession(
    reader.id,
    FingerprintReaderCaptureConfig(
        captureTimeoutSeconds = 45,  // wait longer for a good frame
        dpi = 500,                   // optional — only if you know your sensor (else omit)
    ),
)

captureTimeoutSeconds (default 30)

How long the vendor capture call blocks polling for a frame that clears its internal quality bar before failing with a CaptureError.

• Raise it for difficult fingers (dry, worn) or high-throughput operators who need more time to place well.
• Lower it for a snappier “bad capture, try again” loop where you’d rather reprompt quickly.

Must be > 0.

dpi (default null)

The scanner resolution sent with enroll/verify/search so the Slade ID service tunes its matching thresholds. Most single-finger USB fingerprint scanners are 500 DPI (the FBI/ISO standard).

[!TIP] If you don’t know your sensor’s DPI, leave it null — the server applies a safe default. Only set dpi when you can confirm the value from the device datasheet; a wrong value hurts matching more than omitting it.

Must be in 1..4000 when set.

Server-side quality

The Slade ID service scores every submitted image. You don’t configure that from the SDK; it’s driven by the modality and the dpi you send. If enroll/verify frequently reports quality problems, first confirm the reader is clean and the finger is placed flat, then consider raising captureTimeoutSeconds.

Used in

• Configuration reference