Tesseract3TextExtractor.java

/**
 *  OpenKM, Open Document Management System (http://www.openkm.com)
 *  Copyright (c) 2006-2011  Paco Avila & Josep Llort
 *
 *  No bytes were intentionally harmed during the development of this application.
 *
 *  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; either version 2 of the License, or
 *  (at your option) any later version.
 *  
 *  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, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

package com.openkm.extractor;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.util.HashMap;

import org.apache.commons.io.IOUtils;
import org.apache.jackrabbit.extractor.AbstractTextExtractor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.openkm.core.Config;
import com.openkm.util.DocumentUtils;
import com.openkm.util.ExecutionUtils;
import com.openkm.util.FileUtils;
import com.openkm.util.TemplateUtils;

/**
 * Text extractor for image documents.
 * Use OCR from http://code.google.com/p/tesseract-ocr/ 
 */
public class Tesseract3TextExtractor extends AbstractTextExtractor {

    /**
     * Logger instance.
     */
    private static final Logger log = LoggerFactory.getLogger(Tesseract3TextExtractor.class);
    
    /**
     * Creates a new <code>TextExtractor</code> instance.
     */
    public Tesseract3TextExtractor() {
    	 super(new String[] { "image/tiff", "image/gif", "image/jpg", "image/png" });
    }
    
    //-------------------------------------------------------< TextExtractor >

    /**
     * {@inheritDoc}
     */ 
    public Reader extractText(InputStream stream, String type, String encoding) throws IOException {
    	BufferedReader stdout = null;
    	File tmpFileIn = null;
    	File tmpFileOut = null;
    	String cmd = null;
    	
		if (!Config.SYSTEM_OCR.equals("")) {
			try {
    			// Create temp file
    			tmpFileIn = FileUtils.createTempFileFromMime(type);
    			tmpFileOut = File.createTempFile("okm", "");
    			FileOutputStream fos = new FileOutputStream(tmpFileIn);
    			IOUtils.copy(stream, fos);
    			fos.close();
    			
    			// Performs OCR
    			HashMap<String, Object> hm = new HashMap<String, Object>();
    			hm.put("fileIn", tmpFileIn.getPath());
    			hm.put("fileOut", tmpFileOut.getPath());
    			String tpl = Config.SYSTEM_OCR + " ${fileIn} ${fileOut}";
    			cmd = TemplateUtils.replace("SYSTEM_OCR", tpl, hm);
    			ExecutionUtils.runCmd(cmd);
    			
    			// Read result
    			String text = IOUtils.toString(new FileInputStream(tmpFileOut.getPath()+".txt"));
    			
    			// Spellchecker
    			if (Config.SYSTEM_OPENOFFICE_DICTIONARY.equals("")) {
    				log.info("TEXT: {}", text);
    				return new StringReader(text);
    			} else {
    				text = DocumentUtils.spellChecker(text);
        			log.info("TEXT: {}", text);
        			return new StringReader(text);
    			}
			} catch (SecurityException e) {
				log.warn("Security exception executing command: " + cmd, e);
				return new StringReader("");
	    	} catch (IOException e) {
				log.warn("IO exception executing command: " + cmd, e);
				return new StringReader("");
	    	} catch (InterruptedException e) {
				log.warn("Interrupted exception executing command: " + cmd, e);
				return new StringReader("");
			} catch (Exception e) {
				log.warn("Failed to extract OCR text", e);
				return new StringReader("");
			} finally {
				IOUtils.closeQuietly(stream);
				IOUtils.closeQuietly(stdout);
				FileUtils.deleteQuietly(tmpFileIn);
				FileUtils.deleteQuietly(tmpFileOut);
				FileUtils.deleteQuietly(new File(tmpFileOut.getPath()+".txt"));
			}
		} else {
			log.warn("Undefined OCR application");
			return new StringReader("");
		}
    }
}