Tesseract安装

【1】直接安装
1）Ubuntu 14.04下，可以直接安装发行包tesseract-ocr

sudo apt-get install tesseract-ocr

这样安装的系统在/usr/bin下，数据文件在/usr/share/tesseract-ocr/tessdata下（已经安装了eng包）
在/usr/local/lib/python*.*/dist-package下有一个文件夹pytesseract
（也许是我不小心装上去的，GitHub[https://github.com/madmaze/pytesseract]上写的是sudo pip install pytesseract安装），
这样就可以在Python中用tesseract了，例子如下：
import Image
import pytesseract
PRint pytesseract.image_to_string(Image.open('./Test/Python/t2.png'))
print pytesseract.image_to_string(Image.open('./Test/Python/t2.png'), lang='eng')
把我训练好的数字样本文件num.traineddata拷贝到数据文件目录下
print pytesseract.image_to_string(Image.open('./Test/Python/t2.png'), lang='num')
特殊的数字识别就很准了！
2）这样安装好的tesseract-ocr有一个问题，就是在Terminal下无法使用tesseract命令解析，报如下错误（但Python中可用）：
Tesseract Open Source OCR Engine v3.03 with Leptonica
Error in pixReadStreamPng: function not present
Error in pixReadStream: png: no pix returned
Error in pixRead: pix not read
Error in pixGetInputFormat: pix not defined
Reading ./Test/Python/t2.png as a list of filenames...
Error in fopenReadStream: file not found
Error in pixRead: image file not found: �PNG
Image file �PNG cannot be read!
Error during processing.
网上说是因为Leptonica不认识png,tif,jpg格式（其实基本上什么格式都不认识，真不知道为什么还要基于这个库？）
（这个问题我还没有解决？？？？？？？？？？？？？？？？？）
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【2】从源码安装
1）首先需要安装leptonica，下载地址：www.leptonica.org/download.html，例如下载leptonica-1.68.tar.gz
然后安装，使用如下的基本安装方式就可以了（leptonica的定制安装有兴趣的再弄吧）：
./configure         [build the Makefile]
make                [builds the library and shared library versions of all the progs]
sudo make install   [as root; this puts liblept.a into /usr/local/lib/ and all the progs into /usr/local/bin/ ]
2）下载Tesseract，现在Tesseract托管到GitHub了（https://github.com/tesseract-ocr）。（不用FQ了去googlecode了下了！）
从GitHub下载代码，解压缩到某个目录（例如/tmp/tesseract）
3）安装
./autogen.sh
./configure
make
sudo make install
sudo ldconfig
注意这样安装好的系统在/usr/local/bin下，数据文件在/usr/local/share/tessdata下！
其中可能会有如下错误：
[1]./autogen.sh时，报错一堆工具没有，则需要补齐相应工具：
没有aclocal        sudo apt-get install automake
没有libtoolize     sudo apt-get install libtool
如果再报没有其他工具，则执行这个工具，Ubuntu会告诉你如何安装它。
[2]数据问题
源码make出来的系统是没有数据的，必须至少安装一个数据包（一般是eng）才能运行系统，安装方法：
先下载数据包，然后解压缩到/usr/local/share/tessdata
[3]测试是否安装成功
先测试系统安装，运行tesseract，出现以下内容说明安装成功！
searchware@ubuntu:/usr/local/share/tessdata$ tesseract
Usage:tesseract imagename outputbase [-l lang] [-psm pagesegmode] [configfile...]

pagesegmode values 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.
-l lang and/or -psm pagesegmode must occur before anyconfigfile.

Single options:
  -v --version: version info
  --list-langs: list available languages for tesseract engine
常见错误是没有语言数据，如下，这是需要按照前面说的安装好语言数据（最好装上eng，系统默认是eng，而且eng肯定用得上）：
Error opening data file /usr/local/share/tessdata/eng.traineddata
Please make sure the TESSDATA_PREFIX environment variable is set to the parent directory of your "tessdata" directory.
Failed loading language 'eng'
Tesseract couldn't load any languages!
Could not initialize tesseract.
然后测试文件识别，源码目录下有个phototest.tif文件，可以作为测试用。
tesseract phototest.tif test1 -l eng
常见错误是Leptonica不匹配，如下：
Tesseract Open Source OCR Engine v3.02.02 with Leptonica
Error in findTiffCompression: function not present
Error in pixReadStreamTiff: function not present
Error in pixReadStream: tiff: no pix returned
Error in pixRead: pix not read
Unsupported image type.
这个问题我还没有解决，网上说的方法不行（在Ubuntu 14.04上没试通）????????????????????????????????