How to force tesseract not to use TESSDATA_PREFIX

Question

I had tesseract installed on my pc, and it defined TESSDATA_PREFIX enviroment variable. After complete uninstallation of tesseract, i try to use tesseract API in this way:

if (myOCR->Init("C:/Projects/project/Release/tessdata/", "rus")) {
            fprintf(stderr, "Could not initialize tesseract.\n");
            exit(1);
        }

and recieve

Error opening data file C:\Program Files (x86)\Tesseract-OCR\tessdata/rus.traine
ddata
Please make sure the TESSDATA_PREFIX environment variable is set to the parent d
irectory of your "tessdata" directory.
Failed loading language 'rus'
Tesseract couldn't load any languages!
Could not initialize tesseract.

typing set TESSDATA_PREFIX in cmd gives me that there is no such variable. But tesseract remembers it (don't know how). So how can i force tesseract to search traindata in concrete folder? Thanks

Solution

This seems helpful: Tesseract - change language file location

From the answer in that thread, it appears to be the case that tesseract looks for the environment variable, but if it is not set, assumes a fixed location.

The easiest way to fix this would be to run "cmd", then do:

c:\Users\alex> set TESSDATA_PREFIX="C:/Projects/project/Release/tessdata"
c:\Users\alex> cd MyOCRProgDir
c:\Users\alex\MyOCRProgDir> MyProg

Hope that helps!

Comments

[Alex Hoppus]

i don't want to use this, because it wouldn't work on another pc

[Alex Hoppus]

1.) i will have no opportunity to set env variable mannualy on another pc 2.) it is not convinient 3) even after reseting this variable, i dont know why, but it searches in C:\Progamfiles (x86)\tesseract-ocr ...

[Alex Hoppus]

i made full reg scan and deleted all when i met TESSDATA_PREFIX, but it searches in old directory

[Rahul Banerjee]

Firstly, you will put these commands into a "Batch file" (a file with .bat extension) and when you copy your program onto the other computer(s), you'll also copy this .bat file onto their Desktop, making it a "shortcut" that they double-click to launch your OCR program. Secondly, since this did not work, is there any chance you could build Tesseract from source? I know it sounds involved, but if you can do that, you may be able to use the advice on the thread I pointed you to.

[Alex Hoppus]

in this case you can use putenv right from the code rather than bat file. Anyway reboot solves this tricky problem with enviroment variable previously defined by tesseract exe. Thanks

[Rahul Banerjee]

All it needed was a reboot? Hah! Glad you were able to figure it out.