Android AutoCapture

Overview

BiometridStandardAutoCapture provides automatic document capture and camera functionality for Android. It supports two capture modes: document capture (using TensorFlow Lite for detection) and face comparison (using ONNX for face detection). The module can operate in auto-capture mode with ML-powered detection or as a simple manual camera.

Prerequisites

• BiometridStandardCore must be initialized first
• Android minSdk 24 or higher
• Camera permission granted

Initialization

BiometridStandardAutoCapture is accessed through a singleton object. On Android, you must call initialize with a Context before using the module.

import com.biometrid.autocapture.BiometridStandardAutoCapture
import com.biometrid.autocapture.BiometridStandardAutoCaptureCallback
import com.biometrid.autocapture.CaptureOrientation
import com.biometrid.autocapture.model.AutoCaptureModelType
import com.biometrid.autocapture.model.DocumentSide
import com.biometrid.biometridstandard.model.BiometridErrorInfo
import android.graphics.Bitmap

// Initialize with context
BiometridStandardAutoCapture.initialize(context)

Available Methods

initialize

fun initialize(context: Context)

Initializes the AutoCapture module with the Android application context. Must be called before any other AutoCapture operation.

Parameter	Type	Description
context	Context	Android application context

---

set

fun set(callback: BiometridStandardAutoCaptureCallback)

Sets the callback to receive capture results.

Parameter	Type	Description
callback	BiometridStandardAutoCaptureCallback	Callback to receive capture results

---

configure

fun configure(modelType: AutoCaptureModelType)

Configures the ML model type used for auto-capture detection.

Parameter	Type	Description
modelType	AutoCaptureModelType	The detection model to use

---

startCapture

fun startCapture(side: DocumentSide, orientation: CaptureOrientation = CaptureOrientation.LANDSCAPE)

Starts the auto-capture camera with ML-powered document detection. The camera will automatically capture when a valid document is detected.

Parameter	Type	Default	Description
side	DocumentSide	-	Which side of the document to capture (FRONT or BACK)
orientation	CaptureOrientation	LANDSCAPE	Camera orientation (PORTRAIT or LANDSCAPE)

---

startCamera

fun startCamera(orientation: CaptureOrientation = CaptureOrientation.LANDSCAPE)

Starts a simple manual camera without auto-capture detection. The user manually triggers the capture.

Parameter	Type	Default	Description
orientation	CaptureOrientation	LANDSCAPE	Camera orientation (PORTRAIT or LANDSCAPE)

---

stopCapture

fun stopCapture()

Stops the current capture session and closes the camera activity.

---

setStrings

fun setStrings(strings: AutoCaptureStrings)

Sets custom localized strings for the capture UI.

Parameter	Type	Description
strings	AutoCaptureStrings	Custom strings for the capture screens

Callback Interface

BiometridStandardAutoCaptureCallback

interface BiometridStandardAutoCaptureCallback {
    fun capturedWithSuccess(result: PlatformImage?)
    fun capturedWithError(error: BiometridErrorInfo?)
    fun captureCancelled()
}

On Android, PlatformImage is a type alias for android.graphics.Bitmap.

Method	Description
capturedWithSuccess(result)	Called when a document is successfully captured. Returns a Bitmap of the captured image.
capturedWithError(error)	Called when capture fails.
captureCancelled()	Called when the user cancels the capture.

Enums

AutoCaptureModelType

enum class AutoCaptureModelType {
    DOCUMENT_CAPTURE,   // TensorFlow Lite model for document detection
    FACE_COMPARE        // ONNX model for face comparison/detection
}

DocumentSide

enum class DocumentSide {
    FRONT,   // Front side of document
    BACK     // Back side of document
}

CaptureOrientation

enum class CaptureOrientation {
    PORTRAIT,    // Portrait camera orientation
    LANDSCAPE    // Landscape camera orientation
}

Data Models

BiometridErrorInfo

@Serializable
data class BiometridErrorInfo(
    val code: String? = null,
    val message: String? = null,
    val data: JsonElement? = null
)

AutoCaptureStrings

data class AutoCaptureStrings(
    val camera: CameraStrings = CameraStrings(),
    val simpleCamera: SimpleCameraStrings = SimpleCameraStrings(),
    val permissions: ACPermissionsStrings = ACPermissionsStrings()
)

data class CameraStrings(
    val centerCard: String = "Please center your card within the frame",
    val verifying: String = "We are verifying....",
    val taskValidated: String = "Card successfully scanned, thank you!"
)

data class SimpleCameraStrings(
    val centerCard: String = "Please center your card within the frame",
    val validateOrRetry: String = "Please validate the picture or try again"
)

data class ACPermissionsStrings(
    val cameraRequired: String = "Camera Permission Required",
    val cameraNeeded: String = "Camera permission is needed to capture photos. Please grant access to continue.",
    val grantPermission: String = "Grant Permission",
    val cancel: String = "Cancel",
    val permissionDenied: String = "Permission Denied",
    val permanentlyDenied: String = "Camera permission was permanently denied. Please go to app settings and enable the camera permission to use this feature.",
    val openSettings: String = "Open Settings"
)

Error Codes

AutoCapture errors use the prefix MSA. Common error codes:

Code	Description
MSABACSC001	SDK not initialized (startCapture called before initialize)
MSABACSA001	SDK not initialized (context not set)
MSABSCA001	Inference error during ML detection
MSABSCA002	Camera cancelled by user
MSABSCA003	Camera permission denied

Error Handling

Errors are returned as BiometridErrorInfo objects through the capturedWithError callback. All error codes are prefixed with MSA (AutoCapture module).

Usage Example

class DocumentCaptureActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // Step 1: Initialize the module
        BiometridStandardAutoCapture.initialize(this)

        // Step 2: Set the callback
        BiometridStandardAutoCapture.set(object : BiometridStandardAutoCaptureCallback {
            override fun capturedWithSuccess(result: Bitmap?) {
                result?.let { bitmap ->
                    // Process the captured document image
                    // Convert to base64 or upload to server
                }
            }

            override fun capturedWithError(error: BiometridErrorInfo?) {
                Log.e("AutoCapture", "Capture failed: ${error?.message}")
            }

            override fun captureCancelled() {
                Log.d("AutoCapture", "Capture cancelled by user")
            }
        })

        // Step 3: Configure the model type
        BiometridStandardAutoCapture.configure(AutoCaptureModelType.DOCUMENT_CAPTURE)

        // Step 4: Start auto-capture for front of document
        BiometridStandardAutoCapture.startCapture(DocumentSide.FRONT, CaptureOrientation.LANDSCAPE)
    }

    // To capture back side later:
    private fun captureBackSide() {
        BiometridStandardAutoCapture.startCapture(DocumentSide.BACK, CaptureOrientation.LANDSCAPE)
    }

    // To use simple manual camera in portrait:
    private fun useManualCamera() {
        BiometridStandardAutoCapture.startCamera(CaptureOrientation.PORTRAIT)
    }

    // To customize UI strings:
    private fun customizeStrings() {
        BiometridStandardAutoCapture.setStrings(
            AutoCaptureStrings(
                camera = CameraStrings(
                    centerCard = "Centre o seu cartão na moldura",
                    verifying = "A verificar...",
                    taskValidated = "Cartão digitalizado com sucesso!"
                )
            )
        )
    }

    override fun onDestroy() {
        super.onDestroy()
        BiometridStandardAutoCapture.stopCapture()
    }
}