Error setting up the tesseract OCR in gem in rails

[seanhinton]

I'm trying to setup the tesseract-ocr gem in my rails environment. I have ran brew install tesseract and then ran a bundle install on the app and that all runs without errors however when starting the app (rails s) the following error is throw:

/Users/xxxx/.rvm/gems/ruby-1.9.2-p290@xxxx/gems/ffi-inline-0.0.4.3/lib/ffi/inline/compilers/gcc.rb:35:in `compile': compile error: see logs at /var/folders/66/pm_j0lp94gvcj0qnlcnsx9pw0000gn/T/.ffi-inline-501/4239dac38f2a721e0dc5b3750d71ce2e6fa4acb6.log (CompilationError)

It reference the following log file:

g++ -dynamic -bundle -fPIC  -L/usr/local/Cellar/tesseract/3.02.02/lib -I/usr/local/Cellar/tesseract/3.02.02/include -o /var/folders/66/pm_j0lp94gvcj0qnlcnsx9pw0000gn/T/.ffi-inline-501/4239dac38f2a721e0dc5b3750d71ce2e6fa4acb6.dylib /var/folders/66/pm_j0lp94gvcj0qnlcnsx9pw0000gn/T/.ffi-inline-501/4239dac38f2a721e0dc5b3750d71ce2e6fa4acb6.cpp -llept 2>>/var/folders/66/pm_j0lp94gvcj0qnlcnsx9pw0000gn/T/.ffi-inline-501/4239dac38f2a721e0dc5b3750d71ce2e6fa4acb6.log
/var/folders/66/pm_j0lp94gvcj0qnlcnsx9pw0000gn/T/.ffi-inline-501/4239dac38f2a721e0dc5b3750d71ce2e6fa4acb6.cpp:1:10: fatal error: 'leptonica/allheaders.h' file not found
#include <leptonica/allheaders.h>

I followed these two issues:
#3 and #21

It talks about setting ENV vars which i have done. I created a test.rb file in the initalizers folder with the following vars set:

ENV['CFLAGS'] = '-I/usr/local/Cellar/tesseract/3.02.02/include' 
ENV['LDFLAGS'] = '-L/usr/local/Cellar/tesseract/3.02.02/lib'

However this makes no difference to the error when starting the app.

I don't understand what it means when it says update the headers. I was wondering if someone could tell me exactly what to do to get this working.

Thanks.

[meh]

Are the environment variables set before the gem is required?

[seanhinton]

Hi, thanks for replying, here's some more details to answer you question...

I haven't put 'require' anywhere yet because the rails server is throwing the error on start up.

The only place 'tesseract-ocr' is referenced is in the Gemfile and the Gemfile.lock file.

The ENV vars are sat in the initializer folder. However I tried putting them in the application.rb before the rails app is initialized and even putting them at the start of the Gemfile before gem tesseract-ocr but that made no difference.

[meh]

I don't know much about rails, so I don't know when it runs the Bundler.required, but you should try exporting the env variables in the shell before starting the rails app.

[seanhinton]

I tried running:

export CFLAGS=-I/usr/local/Cellar/tesseract/3.02.02/include
export LDFLAGS=-L/usr/local/Cellar/tesseract/3.02.02/lib

In the shell before running 'rails s' however that still threw the same error on start up.

I don't know if this is relevant but I'm on Mavericks.

[meh]

Could you give me the output of find /usr/local/Cellar/tesseract/3.02.02/include please?

[seanhinton]

Sure it's:

/usr/local/Cellar/tesseract/3.02.02/include
/usr/local/Cellar/tesseract/3.02.02/include/tesseract
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/apitypes.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/baseapi.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/basedir.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/capi.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/errcode.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/fileerr.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/genericvector.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/helpers.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/host.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/ltrresultiterator.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/memry.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/ndminx.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/pageiterator.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/params.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/platform.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/publictypes.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/resultiterator.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/serialis.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/strngs.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/tesscallback.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/thresholder.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/unichar.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/unicharmap.h
/usr/local/Cellar/tesseract/3.02.02/include/tesseract/unicharset.h

[meh]

Oh right, it was looking for the leptonica headers, I think you have to also add the path to leptonica.

[seanhinton]

Ok, how do I do that? Do I first need to brew install leptonica too? (thanks for your help by the way)

[meh]

No, it's a dependency of tesseract, it should have installed it along, you just have to find where it put it.

[seanhinton]

I did a locate and found /usr/local/Library/Formula/leptonica.rb and brew says it's already installed.

Sorry about all the questions, now where do I put the reference to '/usr/local/Library/Formula/leptonica.rb' does this need another env var?

[meh]

It's not that one, it should have its own include dir like tesseract, try installing it tho.

[seanhinton]

I've brew re-installed leptonica and it has it's own dir like tesseract now in '/usr/local/Cellar/leptonica/1.69' with a lib and bin, however the error is still getting throw.

[meh]

So there's no include dir? The error is thrown because it can't find leptonica's headers.

Try running a locate for allheaders.h (and make sure to updatedb, or use find instead).

[seanhinton]

Yep, there's an include folder too with those files in it:

/usr/local/Cellar/leptonica/1.69/include/leptonica
/usr/local/Cellar/leptonica/1.69/include/leptonica/allheaders.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/alltypes.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/array.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/arrayaccess.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/bbuffer.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/bmf.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/bmp.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/ccbord.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/dewarp.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/endianness.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/environ.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/gplot.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/heap.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/imageio.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/jbclass.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/leptwin.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/list.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/morph.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/pix.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/ptra.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/queue.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/readbarcode.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/regutils.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/stack.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/sudoku.h
/usr/local/Cellar/leptonica/1.69/include/leptonica/watershed.h

So that's all there too.

[meh]

Then just add those paths to the two env vars too.