Tesseract to detect numbers with opencv (c++) and cmake on a raspberry pi

[Adam Richards]

Hi I want to use Tesseract to detect numbers in a sudoku puzzle. I already have all my opencv c++ code that will produce a Mat for every cell with a number in it, to run this I am using Cmake to generate the code. 

I was just wondering how I can install, setup and use tesseract to read the numbers from each cell within this c++ code, as I can only work out how to run it from the command line.

[Zdenko Podobny]

Have a look at wiki APIExample.

And tesseract / tesseractmain.cpp is just example how to use tesseract library... Tesseract is also possible to build with cmake, so all you need is just to have a look at the code...

Zdenko

so 22. 9. 2018 o 8:49 Adam Richards <ajrich...@gmail.com> napísal(a):

Hi I want to use Tesseract to detect numbers in a sudoku puzzle. I already have all my opencv c++ code that will produce a Mat for every cell with a number in it, to run this I am using Cmake to generate the code. 

I was just wondering how I can install, setup and use tesseract to read the numbers from each cell within this c++ code, as I can only work out how to run it from the command line.

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[Adam Richards]

I have managed to run the basic API example from the command line, however I am now trying to incorporate it into my project. 

I have added these lines to my CMakeLists.txt file:

find_package( Tesseract 3.04.01 REQUIRED )

include_directories(${Tesseract_INCLUDE_DIRS})

target_link_libraries(image ${Tesseract_LIBRARIES})

And when I try and make it I get this error:

"CMake Error at CMakeLists.txt:7 (find_package):

  Could not find a package configuration file provided by "Tesseract" with

  any of the following names:

    TesseractConfig.cmake

    tesseract-config.cmake

  Add the installation prefix of "Tesseract" to CMAKE_PREFIX_PATH or set

  "Tesseract_DIR" to a directory containing one of the above files.  If

  "Tesseract" provides a separate development package or SDK, be sure it has

  been installed."

Should there be something else I have to install or do to make this work?

[Adam Richards]

Thank you Zdenko,

I am not overly familiar with how cmake works in compiling everything, I followed through these steps: https://docs.opencv.org/master/d7/d9f/tutorial_linux_install.html and this tutorial: https://www.youtube.com/watch?v=LglRKc2nGeY   to get everything working with opencv. However I am not exactly sure how to integrate in Tesseract with the same cmake commands.

Is there any useful tutorials or examples on how to use Tesseract with cmake?

On Saturday, September 22, 2018 at 5:05:07 PM UTC+10, zdenop wrote:

[Zdenko Podobny]

How did you install tesseract?

Zdenko

so 22. 9. 2018 o 15:23 Adam Richards <ajrich...@gmail.com> napísal(a):

To view this discussion on the web visit https://groups.google.com/d/msgid/tesseract-ocr/65bd7146-d7eb-4ecb-8c6c-8d40bc9344d7%40googlegroups.com.

[Adam Richards]

Pretty sure I installed with just these commands:

sudo apt install tesseract-ocr
sudo apt install libtesseract-dev

When I check the tesseract -v I get this:

tesseract 3.04.01

 leptonica-1.74.1

  libgif 5.1.4 : libjpeg 6b (libjpeg-turbo 1.5.1) : libpng 1.6.28 : libtiff 4.0.8 : zlib 1.2.8 : libwebp 0.5.2 : libopenjp2 2.1.2

[Zdenko Podobny]

Can you check if TesseractConfig.cmake macros are included in these packages? 

Zdenko

ne 23. 9. 2018 o 2:06 Adam Richards <ajrich...@gmail.com> napísal(a):

To view this discussion on the web visit https://groups.google.com/d/msgid/tesseract-ocr/ebc2089a-7526-4850-924e-fc3633d79845%40googlegroups.com.

[Adam Richards]

I did a search on the Pi and it couldn't find A TesseractConfig.cmake file anywhere.

Where should it be exactly?

Should it automatocally come with Tesseract or do I need to download or add it?

[Zdenko Podobny]

This means that your tesseract packages were build with autotools and they did not includes cmake support.

So you need to set your Tesseract_INCLUDE_DIRS and Tesseract_LIBRARIES manually...

Zdenko

po 24. 9. 2018 o 0:24 Adam Richards <ajrich...@gmail.com> napísal(a):

I did a search on the Pi and it couldn't find A TesseractConfig.cmake file anywhere.

Where should it be exactly?

Should it automatocally come with Tesseract or do I need to download or add it?

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[Adam Richards]

Thank you Zdenko,

How exactly would I do this? Is it just entering the directory directly into the cmakelists.txt file?

Is there an easy way to find the location of these directories?

[Adam Richards]

Hi Zdenko,

Sorry, I'm just still unsure how exactly to get this working? What should I be doing to set my Tesseract_INCLUDE_DIRS and Tesseract_LIBRARIES manually...

Any further help you could provide would be appreciated,

thanks,

Adam

[Zdenko Podobny]

Just goole for help. There are plenty examples. e.g.

https://stackoverflow.com/questions/24570916/add-external-libraries-to-cmakelist-txt-c

Zdenko

st 26. 9. 2018 o 14:38 Adam Richards <ajrich...@gmail.com> napísal(a):

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