INSTALL TESSERACT 3.04 ON CENTOS 7

OCR
Tesseract installation is supported beautifully with Ubuntu, but with Centos it requires effort to build. Below is a description of how to install Tesseract on CentOs.

Used versions:
Tesseract: 3.04.01 tesseract-3.04.01.tar.gz
Leptonica: 1.73 leptonica-1.73.tar.gz
Tesseract-ocr 3.02 tesseract-ocr-3.02.deu.tar.gz, tesseract-ocr-3.02.eng.tar.gz, tesseract-ocr-3.02.nld.tar.gz
GhostScript: Install Tesseract 3.04 on CentOs 7

I executed all commands as root, but if you prefer, you can use another account and ‘sudo‘ the commands

1) First update your system:
yum update

Because Tesseract-ocr is not available using yum, we need to download source and build both Tesseract-ocr and leptonica.
This requires development tools to be installed.
yum groupinstall “Development tools”
yum -y install automake autoconf libtool zlib-devel libjpeg-devel giflib libtiff-devel libwebp libwebp-devel libicu-devel openjpeg-devel cairo-devel

2) Now download and install Leptonica:
wget http://www.leptonica.com/source/leptonica-1.73.tar.gz
tar xzvf leptonica-1.73.tar.gz
cd leptonica-1.73
./configure
make
make install

3) Download and install Tesseract:
wget https://github.com/tesseract-ocr/tesseract/archive/3.04.01.tar.gz
mv 3.04.01.tar.gz tesseract-3.04.01.tar.gz
tar xzvf tesseract-3.04.01.tar.gz
cd tesseract-3.04.01/
./autogen.sh
./configure
make
make install
ldconfig

4) Download and install Tesseract trainer files:
wget https://sourceforge.net/projects/tesseract-ocr-alt/files/tesseract-ocr-3.02.eng.tar.gz
wget https://sourceforge.net/projects/tesseract-ocr-alt/files/tesseract-ocr-3.02.nld.tar.gz
wget https://sourceforge.net/projects/tesseract-ocr-alt/files/tesseract-ocr-3.02.deu.tar.gz
tar xzvf tesseract-ocr-3.02.eng.tar.gz
tar xzvf tesseract-ocr-3.02.nld.tar.gz
tar xzvf tesseract-ocr-3.02.deu.tar.gz

5) Export TESSDATA_PREFIX:
export TESSDATA_PREFIX=/usr/share/tesseract-ocr/tessdata

6) Last, install Ghostscript for processing png:
wget https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs920/ghostscript-9.20.tar.gz
tar xzvf ghostscript-9.20.tar.gz
cd ghostscript-9.20/
./autogen.sh
./configure
make
make install

That’s it!