如何在java项目中利用ocr实现一个图片文字识别功能
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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();
}
}
上述就是小编为大家分享的如何在java项目中利用ocr实现一个图片文字识别功能了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注创新互联行业资讯频道。
分享名称：如何在java项目中利用ocr实现一个图片文字识别功能
文章起源：http://myzitong.com/article/jjodee.html