识别率很高的java文字识别技术

java文字识别程序的关键是寻找一个可以调用的OCR引擎。tesseract-ocr就是一个这样的OCR引擎，在1985年到1995年由HP实验室开发，现在在Google。tesseract-ocr 3.0发布，支持中文。不过tesseract-ocr 3.0不是图形化界面的客户端，别人写的FreeOCR图形化客户端还不支持导入新的 3.0 traineddata。但这标志着，现在有自由的中文OCR软件了。

java中使用tesseract-ocr3.01的步骤如下：

1.下载安装tesseract-ocr-setup-3.01-1.exe（3.0以上版本才增加了中文识别）

2.在安装向导中可以选择需要下载的语言包。

3.到网上搜索下载java图形处理所需的2个包：jai_imageio-1.1-alpha.jar，swingx-1.6.1.jar

4.java程序清单：

ImageIOHelper 类：

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									import java.awt.image.BufferedImage;

									import java.io.File;

									import java.io.IOException;

									import java.util.Iterator;

									import java.util.Locale;

									import javax.imageio.IIOImage;

									import javax.imageio.ImageIO;

									import javax.imageio.ImageReader;

									import javax.imageio.ImageWriteParam;

									import javax.imageio.ImageWriter;

									import javax.imageio.metadata.IIOMetadata;

									import javax.imageio.stream.ImageInputStream;

									import javax.imageio.stream.ImageOutputStream;

									import com.sun.media.imageio.plugins.tiff.TIFFImageWriteParam;

									public class ImageIOHelper { 

									 public static File createImage(File imageFile, String imageFormat) { 

									  File tempFile = null; 

									  try { 

									   Iterator readers = ImageIO.getImageReadersByFormatName(imageFormat); 

									   ImageReader reader = readers.next(); 

									   ImageInputStream iis = ImageIO.createImageInputStream(imageFile); 

									   reader.setInput(iis); 

									   //Read the stream metadata 

									   IIOMetadata streamMetadata = reader.getStreamMetadata(); 

									   //Set up the writeParam 

									   TIFFImageWriteParam tiffWriteParam = new TIFFImageWriteParam(Locale.CHINESE); 

									   tiffWriteParam.setCompressionMode(ImageWriteParam.MODE_DISABLED); 

									   //Get tif writer and set output to file 

									   Iterator writers = ImageIO.getImageWritersByFormatName("tiff"); 

									   ImageWriter writer = writers.next(); 

									   BufferedImage bi = reader.read(0); 

									   IIOImage image = new IIOImage(bi,null,reader.getImageMetadata(0)); 

									   tempFile = tempImageFile(imageFile); 

									   ImageOutputStream ios = ImageIO.createImageOutputStream(tempFile); 

									   writer.setOutput(ios); 

									   writer.write(streamMetadata, image, tiffWriteParam); 

									   ios.close(); 

									   writer.dispose(); 

									   reader.dispose(); 

									  } catch (IOException e) { 

									   e.printStackTrace(); 

									  } 

									  return tempFile; 

									 } 

									 private static File tempImageFile(File imageFile) { 

									  String path = imageFile.getPath(); 

									  StringBuffer strB = new StringBuffer(path); 

									  strB.insert(path.lastIndexOf('.'),0); 

									  return new File(strB.toString().replaceFirst("(?<=//.)(//w+)$", "tif")); 

									 } 

									}

OCR 类：

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									package com.hhp.util;

									import java.io.BufferedReader; 

									import java.io.File; 

									import java.io.FileInputStream; 

									import java.io.InputStreamReader; 

									import java.util.ArrayList; 

									import java.util.List; 

									import org.jdesktop.swingx.util.OS; 

									public class OCR { 

									 private final String LANG_OPTION = "-l"; //英文字母小写l，并非数字1 

									 private final String EOL = System.getProperty("line.separator"); 

									 private String tessPath = "C://Program Files (x86)//Tesseract-OCR"; 

									 //private String tessPath = new File("tesseract").getAbsolutePath(); 

									 public String recognizeText(File imageFile,String imageFormat)throws Exception{ 

									  File tempImage = ImageIOHelper.createImage(imageFile,imageFormat); 

									  File outputFile = new File(imageFile.getParentFile(),"output"); 

									  StringBuffer strB = new StringBuffer(); 

									  List cmd = new ArrayList(); 

									  if(OS.isWindowsXP()){ 

									   cmd.add(tessPath+"//tesseract"); 

									  }else if(OS.isLinux()){ 

									   cmd.add("tesseract"); 

									  }else{ 

									   cmd.add(tessPath+"//tesseract"); 

									  } 

									  cmd.add(""); 

									  cmd.add(outputFile.getName()); 

									  cmd.add(LANG_OPTION); 

									  cmd.add("chi_sim"); 

									  //cmd.add("eng"); 

									  ProcessBuilder pb = new ProcessBuilder(); 

									  pb.directory(imageFile.getParentFile()); 

									  cmd.set(1, tempImage.getName()); 

									  pb.command(cmd); 

									  pb.redirectErrorStream(true); 

									  Process process = pb.start(); 

									  //tesseract.exe 1.jpg 1 -l chi_sim 

									  int w = process.waitFor(); 

									  //删除临时正在工作文件 

									  tempImage.delete(); 

									  if(w==0){ 

									   BufferedReader in = new BufferedReader(new InputStreamReader(new FileInputStream(outputFile.getAbsolutePath()+".txt"),"UTF-8")); 

									   String str; 

									   while((str = in.readLine())!=null){ 

									    strB.append(str).append(EOL); 

									   } 

									   in.close(); 

									  }else{ 

									   String msg; 

									   switch(w){ 

									    case 1: 

									     msg = "Errors accessing files.There may be spaces in your image's filename."; 

									     break; 

									    case 29: 

									     msg = "Cannot recongnize the image or its selected region."; 

									     break; 

									    case 31: 

									     msg = "Unsupported image format."; 

									     break; 

									    default: 

									     msg = "Errors occurred."; 

									   } 

									   tempImage.delete(); 

									   throw new RuntimeException(msg); 

									  } 

									  new File(outputFile.getAbsolutePath()+".txt").delete(); 

									  return strB.toString(); 

									 } 

									}

测试类TestOCR ：

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									import java.io.File;

									import java.io.IOException;

									import com.hhp.util.OCR;

									public class OcrTest {

									 public static void main(String[] args) {

									  String path = "C://temp//OCRcode//4.png";  

									  System.out.println("ORC Test Begin......");

									  try {  

									   String valCode = new OCR().recognizeText(new File(path), "png");  

									   System.out.println(valCode);  

									  } catch (IOException e) {  

									   e.printStackTrace();  

									  } catch (Exception e) { 

									   e.printStackTrace(); 

									  }  

									  System.out.println("ORC Test End......");

									 } 

									}