Tesseract-OCR安装简明教程

我就是我 2022-07-16 12:46 159阅读 0赞

引言：  OCR领域大名鼎鼎的Tesseract，开源项目，可以直接将图片中的文字进行识别，转换成文本信息，本文将简介如何安装以及进行数据的训练操作。

1.  Tesseract-OCR

目前最新的tesseract项目已经全部迁移到了github上，我们可以从中获取所有主要的信息。

地址： https://github.com/tesseract-ocr/tesseract

2.  Tesseract-OCR安装

windows下的安装非常简单，直接安装可执行程序即可。这里重点介绍centos下的安装。这里提示一下，当你选择安装各类语言之时，则需要一个稍微耗时的等待操作，比如下图中所示的信息：

![Center][]

操作系统： centos 7， JDK 8

step1:     yum search tesseract

[root@flybird ~]# yum search tesseract-ocr
    Loaded plugins: langpacks
    ========================================================================================================== Matched: tesseract-ocr ===========================================================================================================
    tesseract.x86_64 : Raw OCR Engine
    tesseract-devel.x86_64 : Development files for tesseract
    tesseract-langpack-afr.noarch : Afrikaans language data for tesseract
    tesseract-langpack-amh.noarch : Amharic language data for tesseract
    tesseract-langpack-ara.noarch : Arabic language data for tesseract
    tesseract-langpack-asm.noarch : Assamese language data for tesseract
    tesseract-langpack-aze.noarch : Azerbaijani language data for tesseract
    tesseract-langpack-aze_cyrl.noarch : "Azerbaijani language data for tesseract
    tesseract-langpack-bel.noarch : Belarusian language data for tesseract
    tesseract-langpack-ben.noarch : Bengali language data for tesseract
    tesseract-langpack-bod.noarch : "Tibetan language data for tesseract
    tesseract-langpack-bos.noarch : Bosnian language data for tesseract
    tesseract-langpack-bul.noarch : Bulgarian language data for tesseract
    tesseract-langpack-cat.noarch : Catalan language data for tesseract
    tesseract-langpack-ceb.noarch : Cebuano language data for tesseract
    ............

step2:  yum install tesseract.x86\_64

[root@flybird ~]# yum install tesseract.x86_64
    Loaded plugins: langpacks
    Resolving Dependencies
    --> Running transaction check
    ---> Package tesseract.x86_64 0:3.04.00-3.el7 will be installed
    --> Processing Dependency: liblept.so.4()(64bit) for package: tesseract-3.04.00-3.el7.x86_64
    --> Processing Dependency: libicuuc.so.50()(64bit) for package: tesseract-3.04.00-3.el7.x86_64
    --> Processing Dependency: libicui18n.so.50()(64bit) for package: tesseract-3.04.00-3.el7.x86_64
    --> Running transaction check
    ---> Package leptonica.x86_64 0:1.72-2.el7 will be installed
    ---> Package libicu.x86_64 0:50.1.2-15.el7 will be installed
    --> Finished Dependency Resolution
    
    Dependencies Resolved
    
    =============================================================================================================================================================================================================================================
     Package                                                   Arch                                                   Version                                                         Repository                                            Size
    =============================================================================================================================================================================================================================================
    Installing:
     tesseract                                                 x86_64                                                 3.04.00-3.el7                                                   epel                                                  11 M
    Installing for dependencies:
     leptonica                                                 x86_64                                                 1.72-2.el7                                                      epel                                                 928 k
     libicu                                                    x86_64                                                 50.1.2-15.el7                                                   base                                                 6.9 M
    
    Transaction Summary
    =============================================================================================================================================================================================================================================
    Install  1 Package (+2 Dependent packages)
    
    Total download size: 19 M
    Installed size: 67 M
    Is this ok [y/d/N]: y
    Downloading packages:
    (1/3): leptonica-1.72-2.el7.x86_64.rpm                                                                                                                                                                                | 928 kB  00:00:00     
    (2/3): libicu-50.1.2-15.el7.x86_64.rpm                                                                                                                                                                                | 6.9 MB  00:00:07     
    (3/3): tesseract-3.04.00-3.el7.x86_64.rpm                                                                                                                                                                             |  11 MB  00:00:11     
    ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    Total                                                                                                                                                                                                        1.7 MB/s |  19 MB  00:00:11     
    Running transaction check
    Running transaction test
    Transaction test succeeded
    Running transaction
      Installing : leptonica-1.72-2.el7.x86_64                                                                                                                                                                                               1/3 
      Installing : libicu-50.1.2-15.el7.x86_64                                                                                                                                                                                               2/3 
      Installing : tesseract-3.04.00-3.el7.x86_64                                                                                                                                                                                            3/3 
      Verifying  : tesseract-3.04.00-3.el7.x86_64                                                                                                                                                                                            1/3 
      Verifying  : libicu-50.1.2-15.el7.x86_64                                                                                                                                                                                               2/3 
      Verifying  : leptonica-1.72-2.el7.x86_64                                                                                                                                                                                               3/3 
    
    Installed:
      tesseract.x86_64 0:3.04.00-3.el7                                                                                                                                                                                                           
    
    Dependency Installed:
      leptonica.x86_64 0:1.72-2.el7                                                                                         libicu.x86_64 0:50.1.2-15.el7                                                                                        
    
    Complete!

step 3: 安装devel

[root@flybird ~]# yum install tesseract-devel.x86_64 tesseract-osd.x86_64
    Loaded plugins: langpacks
    Resolving Dependencies
    --> Running transaction check
    ---> Package tesseract-devel.x86_64 0:3.04.00-3.el7 will be installed
    --> Processing Dependency: pkgconfig(lept) for package: tesseract-devel-3.04.00-3.el7.x86_64
    --> Running transaction check
    ---> Package leptonica-devel.x86_64 0:1.72-2.el7 will be installed
    --> Finished Dependency Resolution
    
    Dependencies Resolved
    
    =============================================================================================================================================================================================================================================
     Package                                                        Arch                                                  Version                                                      Repository                                           Size
    =============================================================================================================================================================================================================================================
    Installing:
     tesseract-devel                                                x86_64                                                3.04.00-3.el7                                                epel                                                 80 k
    Installing for dependencies:
     leptonica-devel                                                x86_64                                                1.72-2.el7                                                   epel                                                108 k
    
    Transaction Summary
    =============================================================================================================================================================================================================================================
    Install  1 Package (+1 Dependent package)
    
    Total download size: 188 k
    Installed size: 1.1 M
    Is this ok [y/d/N]: y
    Downloading packages:
    (1/2): tesseract-devel-3.04.00-3.el7.x86_64.rpm                                                                                                                                                                       |  80 kB  00:00:00     
    (2/2): leptonica-devel-1.72-2.el7.x86_64.rpm                                                                                                                                                                          | 108 kB  00:00:00     
    ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    Total                                                                                                                                                                                                        738 kB/s | 188 kB  00:00:00     
    Running transaction check
    Running transaction test
    Transaction test succeeded
    Running transaction
      Installing : leptonica-devel-1.72-2.el7.x86_64                                                                                                                                                                                         1/2 
      Installing : tesseract-devel-3.04.00-3.el7.x86_64                                                                                                                                                                                      2/2 
      Verifying  : leptonica-devel-1.72-2.el7.x86_64                                                                                                                                                                                         1/2 
      Verifying  : tesseract-devel-3.04.00-3.el7.x86_64                                                                                                                                                                                      2/2 
    
    Installed:
      tesseract-devel.x86_64 0:3.04.00-3.el7                                                                                                                                                                                                     
    
    Dependency Installed:
      leptonica-devel.x86_64 0:1.72-2.el7                                                                                                                                                                                                        
    
    Complete!

step 4:  安装lang package tesseract-langpack-chi\_sim.noarch， tesseract-langpack-chi\_tra.noarch

[root@flybird ~]# yum install tesseract-langpack-chi_sim.noarch
    Loaded plugins: langpacks
    Resolving Dependencies
    --> Running transaction check
    ---> Package tesseract-langpack-chi_sim.noarch 0:3.04.00-3.el7 will be installed
    --> Finished Dependency Resolution
    
    Dependencies Resolved
    
    =============================================================================================================================================================================================================================================
     Package                                                                Arch                                               Version                                                    Repository                                        Size
    =============================================================================================================================================================================================================================================
    Installing:
     tesseract-langpack-chi_sim                                             noarch                                             3.04.00-3.el7                                              epel                                              15 M
    
    Transaction Summary
    =============================================================================================================================================================================================================================================
    Install  1 Package
    
    Total download size: 15 M
    Installed size: 40 M
    Is this ok [y/d/N]: y
    Downloading packages:
    tesseract-langpack-chi_sim-3.04.00-3.el7.noarch.rpm                                                                                                                                                                   |  15 MB  00:00:15     
    Running transaction check
    Running transaction test
    Transaction test succeeded
    Running transaction
      Installing : tesseract-langpack-chi_sim-3.04.00-3.el7.noarch                                                                                                                                                                           1/1 
      Verifying  : tesseract-langpack-chi_sim-3.04.00-3.el7.noarch                                                                                                                                                                           1/1 
    
    Installed:
      tesseract-langpack-chi_sim.noarch 0:3.04.00-3.el7                                                                                                                                                                                          
    
    Complete!

3.  Tesseract-OCR的使用

a.  识别图片中的文字信息

命令格式：

tesseract imagename outputbase [-l lang] [-psm pagesegmode] [configfile...]

操作： tesseract ttest.png out -l lang-type

这里我们选取了两种图片，中文和英文图片；然后我们来看看OCR的效果如何。

b. 检查tesseract支持的语言

[root@flybird practice]# tesseract --list-langs
    List of available languages (4):
    eng
    osd
    chi_tra
    chi_sim

基于上述的信息可知，支持四种类型，三种语言， osd是开发的脚本

c.  进行基于中文的OCR

原图信息：

![Center 1][]

进行OCR操作，操作命令： tesseract chin-ocr.png chin-out -l chi\_sim

运行结果：

[root@flybird practice]# tesseract chin-ocr.png chin-out -l chi_sim
    Tesseract Open Source OCR Engine v3.04.00 with Leptonica
    [root@flybird practice]# cat chin-out.txt 
    11月17日痿言 ′ 文童发文透露租妻子马伊蜊合作的新剧 (剃刀边缘) 快要刮作完
    成) 感慨良多′他自称 ″过街者冒″ 租 ″笨人″ ′直言自己虽然忍不任茌片场发脾气′
    但 ″i人亘″ 二字是心安理才寻她受了′

大家可以看到，识别率还是有待提高的，很多的信息并未准确识别出来。这里注意背景中有水印信息，造成了一定干扰。

d. 基于英文的OCR识别

原图信息：

![Center 2][]

进行OCR操作， tesseract english-ocr.png eng-ocr -l eng

运行的结果信息：

[root@flybird practice]# tesseract english-ocr.png eng-ocr -l eng
    Tesseract Open Source OCR Engine v3.04.00 with Leptonica
    [root@flybird practice]# cat eng-ocr.txt 
    I have lived in China for a long time and we all like it very much. We do have it done.
    It is very funny in a good lucky state.

基于本次的OCR结果还是非常理想的，当然这里是基于干扰非常少的情况下进行的。

4. 总结

这里只是简要介绍了其安装信息与过程，更多的信息还是需要大家自行到tesseract上去获取信息，并自行实践的。

[Center]: /images/20220715/cfd18d2ff5d74ae8ab3702f9e3958c70.png
[Center 1]: /images/20220715/bcdc8f9861cd4627bf78666825d06f44.png
[Center 2]: /images/20220715/e7f193de125641378e1627b81217d439.png