dependencies {
    compile 'com.rmtheis:tess-two:6.0.2'
}

public String detectText(Bitmap bitmap) {

        TessBaseAPI tessBaseAPI = new TessBaseAPI();
        tessBaseAPI.setDebug(true);
        tessBaseAPI.init(DATA_PATH, "eng"); //Init the Tess with the trained data file, with english language

        //For example if we want to only detect numbers
        tessBaseAPI.setVariable(TessBaseAPI.VAR_CHAR_WHITELIST, "1234567890");
        tessBaseAPI.setVariable(TessBaseAPI.VAR_CHAR_BLACKLIST, "!@#$%^&*()_+=-qwertyuiop[]}{POIU" +
                "YTREWQasdASDfghFGHjklJKLl;L:'"\|~`xcvXCVbnmBNM,./<>?");


        tessBaseAPI.setImage(bitmap);

        String text = tessBaseAPI.getUTF8Text();

        tessBaseAPI.end();

        return text;
    }

DATA_PATH = Environment.getRootDirectory().getPath()+"/data/";

DATA_PATH = Environment.getRootDirectory().getPath();

DATA_PATH = Environment.getRootDirectory().getPath()+"/data/tessdata/";

DATA_PATH = Environment.getRootDirectory().getPath()+"/tessdata/";

DATA_PATH = Environment.getExternalStorageDirectory() + "/";