ubuntu linux 1604 编译安装tesseract-ocr 4.0

主要参考官方的编译，梳理一下整个流程

Linux

The build instructions for Linux also apply to other UNIX like operating systems.

Dependencies

A compiler for C and C++: GCC or Clang
GNU Autotools: autoconf, automake, libtool
autoconf-archive
pkg-config
Leptonica
libpng, libjpeg, libtiff

Ubuntu

If they are not already installed, you need the following libraries (Ubuntu 16.04/14.04):

一、安装依赖：

sudo apt-get install g++ autoconf automake libtool autoconf-archive pkg-config libpng12-dev libjpeg8-dev libtiff5-dev zlib1g-dev  libleptonica-dev -y

或者一条一条复制：

sudo apt-get install g++ # or clang++ (presumably)
sudo apt-get install autoconf automake libtool
sudo apt-get install autoconf-archive
sudo apt-get install pkg-config
sudo apt-get install libpng12-dev
sudo apt-get install libjpeg8-dev
sudo apt-get install libtiff5-dev
sudo apt-get install zlib1g-dev

if you plan to install the training tools, you also need the following libraries:

安装训练所依赖的库：

sudo apt-get install libicu-dev libpango1.0-dev  libcairo2-dev


或者：
sudo apt-get install libicu-dev
sudo apt-get install libpango1.0-dev
sudo apt-get install libcairo2-dev

Leptonica

You also need to install Leptonica. Ensure that the development headers for Leptonica are installed before compiling Tesseract.

Tesseract versions and the minimum version of Leptonica required:

二、安装leptonica，

因为tesseract依赖这个库，否则在configure的时候会提示

最新的tesseract 4.0 及3.05 需要从Leptonica 源代码编译

git clone https://github.com/DanBloomberg/leptonica.git

cd leptonica

./configure

make -j8 && make install

Tesseract	Leptonica	Ubuntu
4.00	1.74.2	Must build from source
3.05	1.74.0	Must build from source
3.04	1.71	Ubuntu 16.04
3.03	1.70	Ubuntu 14.04
3.02	1.69	Ubuntu 12.04
3.01	1.67

One option is to install the distro's Leptonica package:

sudo apt-get install libleptonica-dev

but if you are using an oldish version of Linux, the Leptonica version may be too old, so you will need to build from source.

The sources are at https://github.com/DanBloomberg/leptonica . The instructions for building are given in Leptonica README.

Note that if building Leptonica from source, you may need to ensure that /usr/local/lib is in your library path. This is a standard Linux bug, and the information at Stackoverflow is very helpful.

Installing Tesseract from Git

Please follow instructions in https://github.com/tesseract-ocr/tesseract/wiki/Compiling--GitInstallation

Also read Install Instructions

三、编译tesseract


clone源代码 :

git clone https://github.com/tesseract-ocr/tesseract.git  tesseract-ocr

cd tesseract-ocr
    ./autogen.sh
　　 autoreconf -i
    ./configure
    
这时会提示：
Configuration is done.
You can now build and install tesseract by running:

$ make
$ sudo make install

Training tools can be built and installed with:

$ make training
$ sudo make training-install

继续编译，先编译tesseract，在编译安装 training

　　 make　　
    sudo make install
　　
　　make training
　　make training-install

    sudo ldconfig

到这就完成了真个编译过程，这个时候 在命令行中 输入tesseract 会提示怎么用。

四、配置字体库

tesseract/tessdata是一个配置目录可以以此为基础把所有用的语言包放在这里面

cd tesseract的父目录
cp -r  tesseract/tessdata/ tessdata/
下载需要的语言包 https://github.com/tesseract-ocr/tessdata_best 里面有各种语言包，这是训练好的语言包。简体中文下载：chi_sim.traineddata   chi_sim_vert.traineddata

下载好的语言包放在tessdata目录里面

设置环境变量 tessdata的父目录。如：export TESSDATA_PREFIX=/media/sf_E_DRIVE/src-test/tesseract_all/tesseract_linux

五、使用tesseract
具体用法可参考tesseract的使用说明

tesseract /home/app/1.png output -l chi_sim
识别/home/app/1.png这张图片。输出到output.txt 里面，用chi_sim 识别（不用加.traineddata，会默认加）
cat output.txt 可以查看刚才的内容

Install elsewhere / without root

Tesseract can be configured to install anywhere, which makes it possible to install it without root access.

To install it in $HOME/local:

./autogen.sh
./configure --prefix=$HOME/local/
make install

To install it in $HOME/local using Leptonica libraries also installed in $HOME/local:

./autogen.sh
LIBLEPT_HEADERSDIR=$HOME/local/include ./configure 
  --prefix=$HOME/local/ --with-extra-libraries=$HOME/local/lib
make install

Video representation of the Compiling process for Tesseract 4.0 and Leptonica 1.7.4 on Ubuntu 16.xx

Video Build from Source Leptonica 1.7.4
Video Build from Source Tesseract-OCR 4.0

Language Data

Download the data file(s) for the language(s) you interest in.
Move it to the tessdata directory (e.g. 'mv tessdata $TESSDATA_PREFIX' if defined TESSDATA_PREFIX)

You can also use:

export TESSDATA_PREFIX=/some/path/to/tessdata

to point to your tessdata directory (example: if your tessdata path is '/usr/local/share/tessdata' you have to use 'export TESSDATA_PREFIX='/usr/local/share/').