The MlTBRek extension for App Inventor 2 and Kodular enables offline text recognition and barcode scanning using ML Kit. This extension offers modules for barcode and text recognition, including support for various scripts such as Latin, Devanagari, Chinese, Japanese, and Korean. Users can initialize text and barcode recognizers, install and check the availability of necessary modules, and recognize text or barcodes from images, file paths, or content URIs. The extension also provides events for handling module states, recognition results, and errors, making it a powerful tool for integrating advanced recognition features into your apps.

1. Overview

• Offline text and barcode recognition using Google ML Kit.
• Support for multiple language scripts: Latin, Devanagari, Chinese, Japanese, and Korean.
• Initialize text and barcode recognizers separately.
• Install, check availability, and release ML modules as needed.
• Recognize text or barcodes from Image components, file paths, or content URIs.
• Live barcode scanner with camera preview support.
• Detailed events for module states, recognition results (with structured data), and error handling.
• Automatic parsing of QR Codes, Data Matrix, PDF-417, and Aztec values into structured formats (URL, contact, WiFi, geo, email, phone, SMS, calendar, driver license).

Latest Version: 5
Published: 2023-09-02T18:30:00Z
Last Updated: 2026-06-21T18:30:00Z
Aix size: 1.3 mb
Permissions: android.permission.CAMERA android.permission.READ_MEDIA_IMAGES

2. Blocks

MlModules

Text Recognizer


Barcode Recognizer

3. Documentation

BarcodeRecognizer

UrlScanned		Event raised if url was found in barcode title : text url : text
ContactInfoScanned		Event raised if contact info was found in barcode address : text email : text name : text orgName : text phone : text title : text urls : text
EmailScanned		Event raised if email was found in barcode address : text body : text subject : text type : number
WifiScanned		Event raised if wifi info was found in barcode ssid : text pswd : text encryptionType : number
GeoPointScanned		Event raised if geo points were found in barcode lat : number lon : number
PhoneScanned		Event raised if phone was found in barcode number : text type : number
SmsScanned		Event raised if sms was found in barcode phoneNumber : text message : text
CalendarEventScanned		Event raised if calendar event was found in barcode summary : text description : text location : text start : text end : text
DriverLicenseScanned		Event raised if driver license was found in barcode firstName : text lastName : text licenseNumber : text birthDate : text expiryDate : text
BarcodeScanned		Event raised when no specific type of barcode was found and given barcode was decoded in general rawValue : text barFormat : number displayValue : text
BarRecognitionFailed		Event raised if barcode scanning failed errorMsg : text
SetPreviewContainer		Sets the view to be used for camera preview. component : component
StartScanner		Starts the live scanner using the view set by SetPreviewContainer.
StopScanner		Stops the live scanner.
BarRecognitionModules		Modules for barcode recognition
InitBarRecognizer		Initializes Barcode recognizer/scanner
CloseRecognizer		Method for CloseRecognizer
RecogniseBarcode		Tries to decode barcode from given input which can be an Image component, file path or content uri image : any

MlModules

ModulesInstalled		Event raised when modules have been installed type : number
ModulesInstallFailed		Event raised when modules installation failed type : number errorMsg : text
ModulesStateUpdated		Event raised when modules state changes type : number state : number progress : number
GotModulesState		Event raised after checking modules availability type : number areModulesAvailable : boolean
IsPlayServicesAvailable		Returns whether Google Play Services is available on device or not
InstallModules		Install modules of given type type : number
ReleaseModules		Initiates a request to release given modules when they are no longer needed. This method notifies Google Play services that the modules are no longer needed for this app, but it does not guarantee the modules can be removed. Google Play services will try to clean up the modules when they are not used by any apps. type : number
CheckModulesAvailability		Checks given modules availability type : number

TextRecognizer

RecognisedText		Event raised after getting text from image text : text blocks : list
TextRecognitionFailed		Event raised if text recognition failed errorMsg : text
TextRecognitionModules		Modules for text recognition langScript : number
InitTextRecognizer		Initialize Text Recognizer langScript : number
CloseRecognizer		Closes the Text Recognizer and releases resources.
RecogniseText		Tries to recognize text from given input that can be an Image component, file path or content uri image : any
DefaultScript		Default Latin Script Accepts: number
DevanagariScript		Devanagari Script Accepts: number
ChineseScript		Chinese Script Accepts: number
JapaneseScript		Japanese Script Accepts: number
KoreanScript		Korean Script Accepts: number

4. Example Usage

Install required modules

Check modules availability

Text Recognisation
First initialize recognizer.

Then provide input image to RecogniseText block.

RecognisedText event will be raised with result if recognition was successful otherwise TextRecognitionFailed event will be raised with error message.

blocks is a list of dictionaries. Each dictionary contains following keys:
- text : complete text
- lines : a list of lines
- angles : a list of angles corresponding to each line
- confidences : a list of confidence values corresponding to each line

All major language scripts are supported.

• Latin
• Devanagari
• Chinese
• Japanese
• Korean

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Barcode Recognition

Initialize Barcode recogniser.

Then provide input image to RecogniseBarcode block.

Result will be delivered via different events based upon type of barcode.

It reads the following barcode formats:

• 1D barcodes: EAN-13, EAN-8, UPC-A, UPC-E, Code-39, Code-93, Code-128, ITF, Codabar
• 2D barcodes: QR Code, Data Matrix, PDF-417, AZTEC

It automatically parses QR Codes, Data Matrix, PDF-417, and Aztec values, for the following supported formats:

• URL
• Contact information (VCARD, etc.)
• WiFi
• Geo-location (latitude and longitude)
• Email
• Phone number
• SMS
• Calendar Event
• Driver License

Live Scanner
Camera permission is required

4. Demo Video

5. Changelog

Version 2 — 2023-10-26

• Rename extension to MlTBRek from SimpleRecognition

• Some new blocks added and few blocks removed

• Upgrade to ML Kit
  Brings dynamic deps management and thus effectively reducing aix size to just 1.1mb

• Major internal changes wherever there was room for improvement
  Like support for Hindi and other Devanagari Script langs

• Recognise blocks can accept Image component, File Path or Content Uri

• Completely offline purchase verification

Version 3 — 2024-05-04

• Aix size reduced to 1.1 mb
• Extension won't crash Companion now
  Though none of its blocks will work.
• No-conflict version to resolve deps conflict with my other ML Kit extensions like ImageLabelling and ScanKit

Version 4 — 2024-08-30

• Extension has been completely re-written so create a backup of imp projects before importing new version

• Added Chinese, Japanese and Korean language script supported to extension

• Updated Text Recognition (19.0.1) and Bar Recognition (18.3.1) SDKs

• Added license key property so no need to upload license to assets now

Version 4.1 — 2025-12-04

• Online images can also be used now

Simply pass the image url.

Input:

Result:

Version 5 — 2026-06-22

• Architectural Modularization Split the monolithic extension into three specialized components (BarcodeRecognizer, TextRecognizer, MlModules) to keep your projects clean and reduce overhead.

• New Live Camera Scanner Added full support for continuous live barcode scanning through a camera preview (SetPreviewContainer, StartScanner, StopScanner blocks).

• Added CloseRecognizer methods to give you explicit control over freeing up ML Kit resources.

Thank you.
Hope it helps!