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：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
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：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
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 ：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
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......"); } } |
经过测试，tesseract-ocr 3.01的文字识别率很高，对于网站中常见的验证码识别率也很高。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/tiny_lxf/article/details/78533485
