I am trying to implement some ocr using a guide from on stackoverflow. the example code for the use of the application is using java and i am trying to run it on android. Here is the code from the example;
// OCRScannerDemo.java
// Copyright (c) 2003-2009 Ronald B. Cemer
// All rights reserved.
/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.roncemer.ocr.main;
import java.awt.Frame;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.ScrollPane;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.ImageProducer;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import com.roncemer.ocr.CharacterRange;
import com.roncemer.ocr.OCRImageCanvas;
import com.roncemer.ocr.OCRScanner;
import com.roncemer.ocr.PixelImage;
import com.roncemer.ocr.TrainingImageLoader;
import com.roncemer.ocr.tracker.MediaTrackerProxy;
/**
* Demo application to demonstrate OCR document scanning and decoding.
* @author Ronald B. Cemer
*/
public class OCRScannerDemo extends Frame {
private static final long serialVersionUID = -8030499184564680363L;
private boolean debug = true;
private Image image;
private OCRImageCanvas imageCanvas;
private OCRScanner scanner;
public OCRScannerDemo() {
super("OCR from a scanned image");
setSize(1024, 768);
ScrollPane scrollPane = new ScrollPane();
imageCanvas = new OCRImageCanvas();
scrollPane.add(imageCanvas);
add(scrollPane);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
((Frame)(e.getSource())).hide();
System.exit(0);
}
});
scanner = new OCRScanner();
show();
}
/**
* Load demo training images.
* @param trainingImageDir The directory from which to load the images.
*/
public void loadTrainingImages(String trainingImageDir) {
if (debug) System.err.println("loadTrainingImages(" + trainingImageDir + ")");
if (!trainingImageDir.endsWith(File.separator)) {
trainingImageDir += File.separator;
}
try {
scanner.clearTrainingImages();
TrainingImageLoader loader = new TrainingImageLoader();
HashMap images = new HashMap();
if (debug) System.err.println("ascii.png");
loader.load(
this,
trainingImageDir + "ascii.png",
new CharacterRange('!', '~'),
images);
if (debug) System.err.println("hpljPica.jpg");
loader.load(
this,
trainingImageDir + "hpljPica.jpg",
new CharacterRange('!', '~'),
images);
if (debug) System.err.println("digits.jpg");
loader.load(
this,
trainingImageDir + "digits.jpg",
new CharacterRange('0', '9'),
images);
if (debug) System.err.println("adding images");
scanner.addTrainingImages(images);
if (debug) System.err.println("loadTrainingImages() done");
}
catch(IOException ex) {
ex.printStackTrace();
System.exit(2);
}
}
public void process(String imageFilename) {
if (debug) System.err.println("process(" + imageFilename + ")");
String imageFileUrlString = "";
try {
imageFileUrlString = new File(imageFilename).toURL().toString();
} catch (MalformedURLException e) {
e.printStackTrace();
}
try {
ImageProducer imageProducer = (ImageProducer)
(new URL(imageFileUrlString).getContent());
image = createImage(imageProducer);
}
catch(IOException e) {
e.printStackTrace();
}
if (image == null) {
System.err.println("Cannot find image file at " + imageFileUrlString);
return;
}
MediaTracker mt = new MediaTrackerProxy(this);
mt.addImage(image, 0);
try {
mt.waitForAll();
} catch(InterruptedException ex) {}
if (debug) System.err.println("image loaded");
/* int w = image.getWidth(null);
int h = image.getHeight(null);
if ( (w > 0) && (h > 0) ) {
float scaleFactor = 2048.0f/(float)Math.max(w, h);
if (scaleFactor < 1.0f) {
image = image.getScaledInstance(
(int)((float)w*scaleFactor),
(int)((float)h*scaleFactor), Image.SCALE_SMOOTH);
mt = new MediaTrackerProxy(this);
mt.addImage(image, 0);
try { mt.waitForAll(); } catch(InterruptedException ex) {}
}
}*/
imageCanvas.setSize(image.getWidth(null), image.getHeight(null));
if (debug) System.err.println("constructing new PixelImage");
PixelImage pixelImage = new PixelImage(image);
if (debug) System.err.println("converting PixelImage to grayScale");
pixelImage.toGrayScale(true);
if (debug) System.err.println("filtering");
pixelImage.filter();
if (debug) System.err.println("setting image for display");
imageCanvas.setImage(
pixelImage.rgbToImage(
pixelImage.grayScaleToRGB(pixelImage.pixels),
pixelImage.width,
pixelImage.height,
imageCanvas));
System.out.println(imageFilename + ":");
String text = scanner.scan(image, 0, 0, 0, 0, null, imageCanvas.getGraphics());
System.out.println("[" + text + "]");
}
public static void main(String[]args) {
if (args.length < 1) {
System.err.println("Please specify one or more image filenames.");
System.exit(1);
}
String trainingImageDir = System.getProperty("TRAINING_IMAGE_DIR");
if (trainingImageDir == null) {
System.err.println
("Please specify -DTRAINING_IMAGE_DIR=<dir> on " +
"the java command line.");
return;
}
OCRScannerDemo demo = new OCRScannerDemo();
demo.loadTrainingImages(trainingImageDir);
for (int i = 0; i < args.length; i++)
demo.process(args[i]);
System.out.println("done.");
}
}
In the process method an ImageProducer is used. Is there an alternative for android or had i might as well give up using this approach?
Kind regards
