【1】直接安裝
1）Ubuntu 14.04下，可以直接安裝發行包tesseract-ocr

sudo apt-get install tesseract-ocr

這樣安裝的系統在/usr/bin下，數據文件在/usr/share/tesseract-ocr/tessdata下（已經安裝了eng包）
在/usr/local/lib/python*.*/dist-package下有一個文件夾pytesseract
（也許是我不小心裝上去的，GitHub[https://github.com/madmaze/pytesseract]上寫的是sudo pip install pytesseract安裝），
這樣就可以在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')
把我訓練好的數字樣本文件num.traineddata拷貝到數據文件目錄下
print pytesseract.image_to_string(Image.open('./Test/Python/t2.png'), lang='num')
特殊的數字識別就很準了！
2）這樣安裝好的tesseract-ocr有一個問題，就是在Terminal下無法使用tesseract命令解析，報如下錯誤（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.
網上說是因為Leptonica不認識png,tif,jpg格式（其實基本上什么格式都不認識，真不知道為什么還要基于這個庫？）
（這個問題我還沒有解決？？？？？？？？？？？？？？？？？）
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【2】從源碼安裝
1）首先需要安裝leptonica，下載地址：www.leptonica.org/download.html，例如下載leptonica-1.68.tar.gz
然后安裝，使用如下的基本安裝方式就可以了（leptonica的定制安裝有興趣的再弄吧）：
./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）下載Tesseract，現在Tesseract托管到GitHub了（https://github.com/tesseract-ocr）。（不用FQ了去googlecode了下了！）
從GitHub下載代碼，解壓縮到某個目錄（例如/tmp/tesseract）
3）安裝
./autogen.sh
./configure
make
sudo make install
sudo ldconfig
注意這樣安裝好的系統在/usr/local/bin下，數據文件在/usr/local/share/tessdata下！
其中可能會有如下錯誤：
[1]./autogen.sh時，報錯一堆工具沒有，則需要補齊相應工具：
沒有aclocal        sudo apt-get install automake
沒有libtoolize     sudo apt-get install libtool
如果再報沒有其他工具，則執行這個工具，Ubuntu會告訴你如何安裝它。
[2]數據問題
源碼make出來的系統是沒有數據的，必須至少安裝一個數據包（一般是eng）才能運行系統，安裝方法：
先下載數據包，然后解壓縮到/usr/local/share/tessdata
[3]測試是否安裝成功
先測試系統安裝，運行tesseract，出現以下內容說明安裝成功！
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
常見錯誤是沒有語言數據，如下，這是需要按照前面說的安裝好語言數據（最好裝上eng，系統默認是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.
然后測試文件識別，源碼目錄下有個phototest.tif文件，可以作為測試用。
tesseract phototest.tif test1 -l eng
常見錯誤是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.
這個問題我還沒有解決，網上說的方法不行（在Ubuntu 14.04上沒試通）????????????????????????????????