openalpr-android

OpenALPR is an open source Automatic License Plate Recognition library written in C++ with bindings in C#, Java, Node.js, and Python. This project ports this library to Android.

Gradle Dependency

Repository

First, add the following to your app's build.gradle file:

repositories {
    maven { url "https://jitpack.io" }
}

Them include the openalpr-android dependency:

dependencies {

    // ... other dependencies here.    	
    compile('com.github.SandroMachado:openalpr-android:1.0.0@aar') {
        transitive = true
    }
}

Usage

Code

Copy the OpenALPR configuration file to your android project assets directory /main/assets/runtime_data/openalpr.conf and update the runtime_dir to your project directory (for instance, for the sample project the directory is: runtime_dir = /data/data/com.sandro.openalprsample/runtime_data). After that just follow the code example bellow. To see a full example check the sample application.

static final String ANDROID_DATA_DIR = "/data/data/com.sandro.openalprsample";

final String openAlprConfFile = ANDROID_DATA_DIR + File.separatorChar + "runtime_data" + File.separatorChar + "openalpr.conf";

String result = OpenALPR.Factory.create(MainActivity.this, ANDROID_DATA_DIR).recognizeWithCountryRegionNConfig("us", "", image.getAbsolutePath(), openAlprConfFile, 10);

Interface

/*
 Method interface.
*/

/**
 * Recognizes the licence plate.
 *
 * @param country        - Country code to identify (either us for USA or eu for Europe). Default=us.
 * @param region         -  Attempt to match the plate number against a region template (e.g., md for Maryland, ca for California).
 * @param imgFilePath    - Image containing the license plate.
 * @param configFilePath - Config file path (default /etc/openalpr/openalpr.conf)
 * @param topN           - Max number of possible plate numbers to return(default 10)
 *
 * @return - JSON string of results
 */
 
public String recognizeWithCountryRegionNConfig(String country, String region, String configFilePath, String imgFilePath, int topN);

Sample Application

The repository also includes a sample application that can be tested with Android Studio.

Credits

https://github.com/openalpr/openalpr (the project repository)
https://github.com/sujaybhowmick/OpenAlprDroidApp (for the compiled sources and for the sample that helped me to port the project to an android library)

AshokRevanna / openalpr-android