de.hhn.android.licenseplatedecoder.decoder.CountryExtractor.java Source code

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Here is the source code for de.hhn.android.licenseplatedecoder.decoder.CountryExtractor.java

Source

package de.hhn.android.licenseplatedecoder.decoder;

import java.util.ArrayList;

import org.opencv.android.Utils;
import org.opencv.core.Mat;

import android.annotation.SuppressLint;
import android.graphics.Bitmap;

import com.googlecode.tesseract.android.TessBaseAPI;

/*
 ** CLASS NAME: 
 **     CountryExtractor
 **
 ** DESCRIPTION:
 **   This class represents the JNI wrapper for the implemented C++ country extractor
 **
 **
 ** DEVELOPED BY:
 **   Mario Orozco Borrego (MOB)
 **
 ** SUPERVISED BY:
 **     Prof. Dr.-Ing. Permantier, Gerald
 **
 **      
 ** NOTES:
 **   
 **
 */

@SuppressLint("SdCardPath")
public class CountryExtractor {

    private long nativeInputAddr;
    private long withoutStripInputAddr;
    private TessBaseAPI baseApi;
    private Mat withoutBlueStrip;
    private String result;

    /**
     * Result getter
     * @return the result
     */
    public String getResult() {
        return this.result;
    }

    /**
     * Constructor
     * @param nativeAddress input image pointer address
     * @param withoutStripInputAddr image pointer address in order to store the cropped image without the blue strip
     */
    public CountryExtractor(long nativeAddress, long withoutStripInputAddr) {
        this.nativeInputAddr = nativeAddress;
        this.withoutStripInputAddr = withoutStripInputAddr;
        this.withoutBlueStrip = new Mat();

        /** OCR ENGINE INIT */
        this.baseApi = new TessBaseAPI();
        this.baseApi.setDebug(true);
        this.baseApi.init("/sdcard/", "blueBand"); // myDir + "/tessdata/eng.traineddata" must be present
        this.baseApi.setVariable("tessedit_char_whitelist", "ABCDFGHIKLOPRSTZ");
        this.baseApi.setPageSegMode(TessBaseAPI.PageSegMode.PSM_SINGLE_CHAR);

        ArrayList<Mat> countryCode = getCharacters();

        StringBuffer strb = new StringBuffer();
        for (Mat elem : countryCode) {

            Bitmap pass = Bitmap.createBitmap(elem.cols(), elem.rows(), Bitmap.Config.ARGB_8888);
            Utils.matToBitmap(elem, pass, true);

            baseApi.setImage(pass);
            String recognizedText = baseApi.getUTF8Text();
            strb.append(recognizedText);
            baseApi.clear();
            pass.recycle();
        }
        this.result = strb.toString();
        baseApi.end();
        baseApi = null;
        countryCode = null;
    }

    /**
     * Native method which carries out the algorithm
     * @return
     */
    private native long[] process();

    /**
     * Gets the characters from the input image calling process method
     * @return the list of cropped images
     */
    private ArrayList<Mat> getCharacters() {
        ArrayList<Mat> result = new ArrayList<Mat>();
        long[] address = this.process();
        if (address == null)
            return new ArrayList<Mat>();
        for (long elem : address) {
            result.add(new Mat(elem));
        }
        return result;
    }
}