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<ImageReader> 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<ImageWriter> 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<String> cmd = new ArrayList<String>(); 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

←我是链接

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。