DigitalInk `Extension`

With DigitalInk recognition extension, you can recognize handwritten text and classify gestures on a digital surface (Canvas) in hundreds of languages, as well as classify sketches. The digital ink recognition uses the same technology that powers handwriting recognition in Gboard, Google Translate, and the Quick, Draw! game.

1. Overview

LatestVersion: 2
Released: April 18, 2024
Last Updated: May 18, 2026
Min SDK: 21
Permissions: ACCESS_NETWORK_STATE

Aix Size: 3.2mb

Key Features:

Converts handwritten text to sequences of unicode characters
Runs on the device in near real time
The user's handwriting stays on the device, recognition is performed without any network connection
Supports 300+ languages and 25+ writing systems, see the complete list of supported languages
- Supports gesture classification for these languages via -x-gesture extensions
Recognizes emojis and basic shapes
Keeps on-device storage low by dynamically downloading language packs as needed

2. Blocks

3. Documentation

Events

ModelDownloaded	Event raised when model is downloaded successfully
ModelDownloadFailed	Event raised when model downloading fails _{errorMsg \| text}
ModelStateRetrieved	Event raised after retrieving model state _{isDownloaded \| boolean}
GotDeleteModelResult	Event raised after getting 'DeleteModel' method's result. 'errorMsg' is empty if model was deleted successfully. _{deleted \| boolean errorMsg \| text}
RecognizationSuccessful	Event raised when recognition was successful _{text \| text}
RecognizationFailed	Event raised when recognition failed _{errorMsg \| text}

Methods

RegisterCanvas	Register Canvas component from which handwritten text will be recognized _{canvas \| component}
ClearCanvas	Clear Canvas drawing. You must use this method instead of Clear method of Canvas component.
DownloadModel	Download specified language model _{langTag \| text}
CheckModelState	Checks whether model for specified language has been downloaded or not _{langTag \| text}
DeleteModel	Remove specified model from device. _{langTag \| text}
SetPreContext	Recognizer will use this pre-context to identify work breaks and differentiate between ambiguous letter _{context \| text}
Initialize	Initialize Recognizer for specified language _{langTag \| text}
Recognize	Process Canvas text for recognition

4. Example Usage

First register canvas component

Check language model state

You can list of languages and gestures tag here: https://developers.google.com/ml-kit/vision/digital-ink-recognition/base-models?hl=en

If model doesn't exist then we'll download it otherwise if it exists then we are good to go.

Download Model if not exists

each language model is of ~20mb

If model was downloaded successfully then we can initialize Recognizer

Now we can start recognition process

Draw and Clear canvas when needed

You must use ClearCanvas block of extension

Delete Language Model when not needed further

5. Samples and Demos

Gesture	Example
`arch:above` `arch:below`
`caret:above` `caret:below`
`circle`
corner:downleft
`scribble`
`strike`
`verticalbar`
`writing`

Demo Video

6. Inject Native libs to APK/AAB

You'll get 4 native libs files:

but only arm64-v8a and armeabi-v7a are required to run apk on real devices.
Remaining two are required to run apk on Emulators.

Use NativeUtils extension to load native libs at runtime.

7. Purchase Extension

Thank you.
Hope it helps!

DigitalInk Extension