最近在开发的时候需要识别图片中的一些文字，网上找了相关资料之后，发现google有一个离线的工具，以下为java使用的demo

在此之前，使用这个工具需要在本地安装OCR工具：

下面一个是一定要安装的离线包，建议默认安装

上面一个是中文的语言包，如果网络可以FQ的童鞋可以在安装的时候就选择语言包在线安装，有多种语言可供选择，默认只有英文的

exe安装好之后，把上面一个文件拷到安装目录下tessdata文件夹下

如C:\Program Files (x86)\Tesseract-OCR\tessdata下

然后下面两个是可选包，如果图片不做临时文件处理的话，可以不需要带的

首先是一个临时文件生成用的类以防源文件损坏，参考某位博友的例子@Gunner

package org.ink.image.textrz;

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 {

private Locale locale=Locale.CHINESE;

/**

* user set locale Construct

* @param locale

*/

public ImageIOHelper(Locale locale){

this.locale=locale;

}

/**

* default construct using default locale Locale.CHINESE

*/

public ImageIOHelper(){

}

/**

* create tempFile of Image in order to prevent damaging original file

* @param imageFile

* @param imageFormat like png,jps .etc

* @return TempFile of Image

* @throws IOException

*/

public File createImage(File imageFile, String imageFormat) throws IOException {

Iterator readers = ImageIO.getImageReadersByFormatName(imageFormat);

ImageReader reader = readers.next();

ImageInputStream iis = ImageIO.createImageInputStream(imageFile);

reader.setInput(iis);

IIOMetadata streamMetadata = reader.getStreamMetadata();

TIFFImageWriteParam tiffWriteParam = new TIFFImageWriteParam(Locale.CHINESE);

tiffWriteParam.setCompressionMode(ImageWriteParam.MODE_DISABLED);

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

ImageWriter writer = writers.next();

BufferedImage bi = reader.read(0);

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

File tempFile = tempImageFile(imageFile);

ImageOutputStream ios = ImageIO.createImageOutputStream(tempFile);

writer.setOutput(ios);

writer.write(streamMetadata, image, tiffWriteParam);

ios.close();

iis.close();

writer.dispose();

reader.dispose();

return tempFile;

}

/**

* add suffix to tempfile

* @param imageFile

* @return

* @throws IOException

*/

private File tempImageFile(File imageFile) throws IOException {

String path = imageFile.getPath();

StringBuffer strB = new StringBuffer(path);

strB.insert(path.lastIndexOf('.'),"_text_recognize_temp");

String s=strB.toString().replaceFirst("(?<=//.)(//w+)$", "tif");

Runtime.getRuntime().exec("attrib "+"\""+s+"\""+" +H"); //设置文件隐藏

return new File(strB.toString());

}

}

下面是真正识别的内容：

package org.ink.image.textrz;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.ArrayList;

import java.util.List;

import java.util.Locale;

import org.jdesktop.swingx.util.OS;

/**

* TEXT Recognize Utils

* @author ink.Flower

*

*/

public class OCRUtil {

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";//ocr默认安装路径

private String transname="chi_sim";//默认中文语言包，识别中文

/**

* Construct method of OCR ,set Tesseract-OCR install path

* @param tessPath Tesseract-OCR install path

* @param transFileName traningFile name like eng.traineddata

*/

public OCRUtil(String tessPath,String transFileName){

this.tessPath=tessPath;

this.transname=transFileName;

}

/**

* Construct method of OCR,default path is "C://Program Files (x86)//Tesseract-OCR"

*/

public OCRUtil(){ }

public String getTessPath() {

return tessPath;

}

public void setTessPath(String tessPath) {

this.tessPath = tessPath;

}

public String getTransname() {

return transname;

}

public void setTransname(String transname) {

this.transname = transname;

}

public String getLANG_OPTION() {

return LANG_OPTION;

}

public String getEOL() {

return EOL;

}

/**

* recognize text in image

* @param imageFile

* @param imageFormat

* @return text recognized in image

* @throws Exception

*/

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

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

return ocrImages(tempImage, imageFile);

}

/**

* recognize text in image

* @param imageFile

* @param imageFormat

* @param locale

* @return text recognized in image

* @throws Exception

*/

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

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

return ocrImages(tempImage, imageFile);

}

/**

*

* @param tempImage

* @param imageFile

* @return

* @throws IOException

* @throws InterruptedException

*/

private String ocrImages(File tempImage,File imageFile) throws IOException, InterruptedException{

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

Runtime.getRuntime().exec("attrib "+"\""+outputFile.getAbsolutePath()+"\""+" +H"); //设置文件隐藏

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(transname);

ProcessBuilder pb = new ProcessBuilder();

pb.directory(imageFile.getParentFile());

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

pb.command(cmd);

pb.redirectErrorStream(true);

Process process = pb.start();

int w = process.waitFor();

tempImage.delete();//删除临时正在工作文件

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();

}

}

在实验中发现，如果对有多个文字的大图进行直接识别的话，效果可能比较差，所以可以参考另一篇切图的博文，将图片取一块之后再识别

这样成功率会提高很多。

以上为离线识别版本，效率因图而已，具体使用的时候可以总结分析，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。