/inkflower/p/6642264.html
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()); mand(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
/inkflower/p/6642089.html ←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
另外,博主也在网上看到百度也有图片文字识别的工具
百度OCR企业版
以上这个貌似是付费的,如果要免费的可以网上找找,另外API也可以找找