centos7下安装tesseract-ocr进行验证码识别

摘要：

　　centos7安装依赖库

　　tesseract配置

　　代码例子

centos7安装依赖库

• 安装centos系统依赖

  yum install -y automake autoconf libtool gcc gcc-c++
  yum install -y libpng-devel libjpeg-devel libtiff-devel

• 安装leptonica

  wget http://www.leptonica.org/source/leptonica-1.72.tar.gz
  tar xvzf leptonica-1.72.tar.gz
  cd leptonica-1.72/
  ./configure
  make && make install

• 安装tesseract-ocr

  wget https://github.com/tesseract-ocr/tesseract/archive/3.04.zip
  unzip 3.04.zip
  cd tesseract-3.04/
  ./configure
  make && make install
  sudo ldconfig

• 部署模型

  • 在https://github.com/tesseract-ocr/tessdata 下载对应语言的模型文件
  • 将模型文件移动到/usr/local/share/tessdata

• 安装requirements.txt中的python依赖库

  pip install -r requirements.txt

tesseract配置

• 在/usr/local/share/tessdata创建eng.user-patterns写入

  \n\n\n\n\n\n

  表示识别6位字符（或数字）

• 在/usr/local/share/tessdata/configs创建myconfig写入

  #识别白名单
  tessedit_char_whitelist abcdefghijklmnopqrstuvwxyz0123546789
  #用户正则模式匹配
  user_patterns_suffix user-patterns

• psm参数说明

  -psm N
    Set Tesseract to only run a subset of layout analysis and assume a certain form of image. The options for N are:
  
    0 = Orientation and script detection (OSD) only.
    1 = Automatic page segmentation with OSD.
    2 = Automatic page segmentation, but no OSD, or OCR.
    3 = Fully automatic page segmentation, but no OSD. (Default)
    4 = Assume a single column of text of variable sizes.
    5 = Assume a single uniform block of vertically aligned text.
    6 = Assume a single uniform block of text.
    7 = Treat the image as a single text line.
    8 = Treat the image as a single word.
    9 = Treat the image as a single word in a circle.
    10 = Treat the image as a single character.

代码例子

 import pytesseract
 from PIL import Image

 image = Image.open('code.png')
 code = pytesseract.image_to_string(image)
 print code