ML Kit Text & Barcode Recognition Extension for App Inventor

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

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. Purchase Extension

6. 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!