cordova-plugin-openalpr/README.md

This Cordova plugin adds support for the OpenALPR (Automatic License Plate Recognition) library, which provides support for retrieving the license plate from a picture.

# Cordova OpenALPR plugin
This Cordova plugin adds support for the [OpenALPR (Automatic License Plate Recognition) library](https://github.com/openalpr/openalpr) which provides support for retrieving the license plate from a picture. You can pass an image using Base64 or the file path to the OpenALPR plugin.

## Supported platforms
The current master branch supports the following platforms:

- iOS (>= 8)
- Android (>= SDK 21)

## Installation
This plugin requires Cordova 5.0+ and can be installed from the [Cordova Plugin Registry](https://cordova.apache.org/plugins/). If you use Ionic 3 or Ionic 4, you should also install the `@ionic-native` binding.

`cordova plugin add cordova-plugin-openalpr`

`npm install @ionic-native/openalpr`

## Examples
### Ionic 1 / PhoneGap
This plugin defines a global `cordova.plugins.OpenALPR` object which provides an API for scanning license plates. It is possible to use the output of [cordova-plugin-camera](https://cordova.apache.org/docs/en/latest/reference/cordova-plugin-camera/) and pass it to the scan function of this plugin.

```javascript
cordova.plugins.OpenALPR.scan(
  filepath,
  { country: "eu", amount: 3 },
  function(results) {
    console.log(results);
  },
  function(error) {
    console.log(error.code + ": " + error.message);
  }
);
```

### Ionic 3
This plugin has a `@ionic-native/openalpr` binding available, which makes it easy to include it in your Ionic 3 project. You can use the output of `@ionic-native/camera` and pass it to the scan function of this plugin.

There is also an [Ionic 3 example project](https://github.com/melvinversluijs/ionic3-sample) available which shows the possible implementation of cordova-plugin-openalpr.

```typescript
import { Camera, CameraOptions } from '@ionic-native/camera';
import { OpenALPR, OpenALPROptions, OpenALPRResult } from 'cordova-plugin-openalpr/native';

constructor(private camera: Camera, private openALPR: OpenALPR) {

}

const cameraOptions: CameraOptions = {
    quality: 100,
    destinationType: this.camera.DestinationType.FILE_URI,
    encodingType: this.camera.EncodingType.JPEG,
    mediaType: this.camera.MediaType.PICTURE,
    sourceType: this.camera.PictureSourceType.CAMERA
}

const scanOptions: OpenALPROptions = {
    country: this.openalpr.Country.EU,
    amount: 3
}

this.camera.getPicture(cameraOptions).then((imageData) => {
    this.openALPR.scan(imageData)
        .then((result: [OpenALPRResult]) => console.log(result[0].number))
        .catch((error: Error) => console.error(error));
});
```

This plugin is only supported on iOS / Android, however in order to speed up development you can make use of [mocking and browser development](https://github.com/ionic-team/ionic-native#mocking-and-browser-development).

### Ionic 4
This plugin has a `@ionic-native/openalpr` binding available, which makes it easy to include it in your Ionic 4 project. You can use the output of `@ionic-native/camera` and pass it to the scan function of this plugin. (Check the code snippet for Ionic 3 for a reference).

There is also an [Ionic 4 example project](https://github.com/melvinversluijs/ionic4-openalpr-sample) available which shows the possible implementation of cordova-plugin-openalpr.

## Known Issues
### Android: PictureSourceType.PHOTOLIBRARY isn't supported (yet)
In Android apps, passing the file uri from PictureSourceType.PHOTOLIBRARY isn't supported yet. This is because the photolibrary returns a different kind of path than the camera does. The cordova-plugin-filepath might provide a workaround for now but this has not been tested yet.

## Notes
- This project includes prebuilt OpenALPR libraries for iOS and Android, because the compilation of the OpenALPR framework requires a lot of effort and dependencies.
- This project is not used in production anymore and won't be maintained actively. We can't guarantee that we can respond quickly to issues / pull requests, however we will keep an eye on the repository.

## License
MIT, but keep in mind that OpenALPR itself is licensed under AGPL-3.0.

## Credits
- License plate scanning based on [OpenALPR](https://github.com/openalpr/openalpr).
- iOS platform support based on [OpenALPR iOS](https://github.com/twelve17/openalpr-ios).
- Android platform support based on [OpenALPR Java bindings](https://github.com/openalpr/openalpr/tree/master/src/bindings/java)
- iOS Base64 implementation by [@baukeroo](https://github.com/baukeroo)