Build identity scanning into Android.

Overview

DLens processes camera frames and document payloads on device. Driver licences use PDF417; passports, national IDs, and residence documents use ICAO TD1, TD2, or TD3 machine-readable zones. MRZ results must pass check-digit validation.

Requirements

• Android API 26+ and compile SDK 35+
• Java 17 and AndroidX
• A physical camera device for live scanning
• Credentials issued for the exact Android applicationId

Installation

Unpack the distribution beside your app and include the library module.

include(":dlens-sdk")
project(":dlens-sdk").projectDir =
    file("../DLensAndroid/dlens-sdk")

dependencies {
    implementation(project(":dlens-sdk"))
}

The library manifest contributes camera permission and the private scanner activity.

Initialise

DLens.initialize(
    context = applicationContext,
    apiKey = BuildConfig.DLENS_API_KEY,
    secret = BuildConfig.DLENS_SECRET,
    configuration = DLensConfiguration(
        scanMode = ScanMode.ALL,
        timeoutSeconds = 60,
    ),
)

Present the supplied scanner

DLensScannerActivity requests permission, manages the camera, and returns result JSON.

private val scan = registerForActivityResult(
    ActivityResultContracts.StartActivityForResult()
) { response ->
    when (response.resultCode) {
        Activity.RESULT_OK -> {
            val json = response.data?.getStringExtra(
                DLensScannerActivity.EXTRA_RESULT
            )
        }
        Activity.RESULT_CANCELED -> Unit
        else -> {
            val code = response.data?.getStringExtra(
                DLensScannerActivity.EXTRA_ERROR_CODE
            )
        }
    }
}

scan.launch(
    Intent(this, DLensScannerActivity::class.java)
        .putExtra(DLensScannerActivity.EXTRA_MODE, ScanMode.ALL.name)
)

Result dates are ISO yyyy-MM-dd strings.

Embed a custom preview

Request camera permission, then attach DLensScanner to a CameraX PreviewView.

val scanner = DLensScanner(
    context = this,
    lifecycleOwner = this,
    previewView = binding.preview,
    mode = ScanMode.ALL,
)
scanner.start(
    onResult = ::showResult,
    onError = { showError(it.message.orEmpty()) },
)
scanner.setTorch(true)
scanner.setZoom(1.5f)

// Release in onDestroy:
scanner.stop()

Scan an existing image

DLens.scan(bitmap, mode = ScanMode.ALL) { outcome ->
    outcome.onSuccess(::showResult)
    outcome.onFailure { showError(it.message.orEmpty()) }
}

Parse a payload

val result = DLens.parse(rawAamvaOrMrzText)

Configuration

Visibility preferences are also available for cancel, torch, zoom, tips, instructions, and the mode badge. Use DLens.configure(...) after initialization.

Result model

Required: first name, last name, licence/document number, and raw payload. Optional fields cover other names, dates, licence details, address, country, gender, eye colour, and height. fullName joins present name components.

Errors

Catch DLensException: NotInitialized, InvalidApiKey, InvalidSecret, LicenseExpired, LicenseKeyMismatch, CameraPermissionDenied, Timeout, and ScanningFailed.

Credentials and validation

Keep production credentials out of source control and inject them through protected build configuration.