DEPRECATED Mojo Perception Flutter API

⚠️ Unfortunately, this repository is no longer maintained as it has been moved to internal project. We are sorry for the inconvenience.

Facial Expression Recognition for your Flutter application in a few lines of code.

Mojo Facial Expression Recognition provides :

❤️ 3 emotions :

• amusement
• confusion
• surprise

🎉 3 social cues :

• attention
• engagement
• interaction status

💡 Open Source API ⚡️ Real-time 🔐 private-by-design

No images are never sent to the the cloud.

Handle your user's emotional reactions to build on top of your amazing app

Requirement

Get your free trial API key.

Installation

Add this line like this to your project's pubspec.yaml and run flutter pub get:

dependencies:
  mojo_perception: ^2.0.0

(Important) Initial setup

IOS:

Permissions

Add row to the ios/Runner/Info.plist with the key Privacy - Camera Usage Description and a usage description :

<key>NSCameraUsageDescription</key>
<string>Can I use the camera please?</string>

Model

In the pubspec.yaml add the following line:

assets:
    - packages/mojo_perception/assets/face_landmark_with_attention.tflite
    - packages/mojo_perception/assets/face_detection_short_range.tflite

Run

flutter pub get

Dynamic libraries

1. Download TensorFlowLiteC.framework.zip (TensorFlowLiteC framework with Mediapipe special ops).

2. Unzip TensorFlowLiteC.framework in the pub-cache folder of tflite_flutter package: Pub-Cache folder location:

• ~/.pub-cache/hosted/pub.dartlang.org/tflite_flutter-0.9.0/ios/ (Linux/ Mac)
• %LOCALAPPDATA%\Pub\Cache\hosted\pub.dartlang.org\tflite_flutter-0.9.0\ios\ (Windows)

ANDROID:

Dynamic libraries

1. Download jniLibs.zip.

2. Extract in your project path : android > app > src > main

Model

In the pubspec.yaml add the following line:

assets:
    - packages/mojo_perception/assets/face_landmark_with_attention.tflite
    - packages/mojo_perception/assets/face_detection_short_range.tflite

Run

flutter pub get

minSdkVersion

If you encounter an error concerning minSdkVersion:

• Go to android > src > app > build.gradle

• Find line minSdkVersion flutter.minSdkVersion

• Change flutter.minSdkVersion by 21

Usage

Import it:

import 'package:mojo_perception/mojo_perception.dart';

Create an object MojoPerceptionAPI:

MojoPerceptionAPI mojoPerceptionApi = MojoPerceptionAPI(
      '<auth_token>',
      '<host>',
      '<port>',
      '<user_namespace>');

Please note that the user token 'auth_token' is different from the API Key.

🙏 We take a particular care with publishable user token for applications. See below for more info and best practices.

Best Practices : One token per user

To make things safe and easy, we have a REST API ready to create user tokens on-the-fly.

When using the API for a web application, you should implement a backend function that will get a token for each user. We recommend to use tokens with expiration date.

To do so, you can use the REST API of Mojo Perception API.

Below, an example using curl : In your terminal, replace <YOUR_API_KEY_HERE> by one of your API Keys and run :

curl -X PUT -i -H 'Authorization: <YOUR_API_KEY_HERE>' -d '{"datetime": "2022-01-01T00:00:00.000000","expiration":360}' -H 'Content-Type: application/json' https://api.mojo.ai/mojo_perception_api/user

This will give you something like this, and note that we have set expiration: 360, for a 60 x 60 seconds duration period :

HTTP/2 200 
server: nginx
date: Tue, 18 Jan 2022 16:53:54 GMT
content-type: application/json
content-length: 350

{"user_namespace": "a5fa97ded6584cb4a7ff3933aa66025c", "auth_token": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpYXQiOjE2NDI1MjQ4MzQsInN1YiI6ImE1ZmE5N2RlLWQ2NTgtNGNiNC1hN2ZmLTM5MzliYTY2MDI1YyIsImV4cCI6MTY0MjUyNDg0NH0.7FuLJ6Hmozi2DbX9zooVxYvnp_f91H4vzodstDZbLzI", "host_name": "socket.mojo.ai", "port": "443"}

You can use the auth_token and given host_name,port and user_namespace to configure your API endpoint in the API, with the setOptions() method.

Checkout the Tutorials

💡   Have a look to the tutorials section

Troubleshooting

If you face a "JsonWebTokenError", maybe that's because of the expiration. You can try to increase the user token duration to match your need. Default value of 360 seconds might be too short.

mojo_perception_flutter Documentation

• mojo_perception_flutter Docs & API References
• mojo_perception_flutter Tutorials

Acknowledgement

Special thanks to JaeHeee for this project that inspired us implementing mediapipe part.