Error opening data file ./tessdata/eng.traineddata

在生成tesseract-ocr后，执行exe遇到一个错误，如下

E:\BuildFolder\tesseract-ocr\testing>tesseract-dlld.exe eurotext.tif eurotext
Error opening data file ./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.

解决：参考：tesseract-ocr/vs2008/doc/building.html

It’s usually better to make a separate directory to test tesseract.exe. To run tesseract, you either need to make sure your test directory contains the tessdata tesseract language data folder or you set theTESSDATA_PREFIX environment variable to point to it. Seehttp://code.google.com/p/tesseract-ocr/wiki/ReadMe for important details.

For example, you can use the following directory structure:

C:\BuildFolder\
  include\
  lib\
  tesseract-3.02\
  testing\
     tessdata\

简单就是说把tessdata拷贝到exe的所在目录，或者设置TESSDATA_PREFIX环境变量