tce-load -i compiletc cmake leptonica-dev pango-dev icu61-dev opencl_headers ocl-icd

https://github.com/tesseract-ocr/tesseract/archive/4.0.0.tar.gz

cd tesseract-4.0.0

mkdir build
cd build

cmake -LAH -DCMAKE_C_FLAGS_RELEASE="-flto -fuse-linker-plugin -mtune=generic -Os -pipe" -DCMAKE_CXX_FLAGS_RELEASE="-flto -fuse-linker-plugin -mtune=generic -Os -pipe -fno-exceptions -fno-rtti" -DCMAKE_INSTALL_PREFIX=/usr/local -DCMAKE_BUILD_TYPE=Release -DCMAKE_VERBOSE_MAKEFILE=TRUE -DTESSDATA_PREFIX=/usr/local/share/tesseract-ocr/4.00/tessdata ../

make [2m 39.43s]
sudo make install

pdfimages -png /tmp/test_scan.pdf /tmp/test_scan.png
TESSDATA_PREFIX=/usr/local/share/tesseract-ocr/4.00/tessdata tesseract /tmp/test_scan.png ~


/usr/local/share/tesseract-ocr/4.00/tessdata/eng.traineddata
/home/tc/.config/tessdata

 https://github.com/tesseract-ocr/tessdata_best/raw/master/eng.traineddata

/usr/local/share/hunspell/en_US.aff
/usr/local/share/hunspell/en_US.dic
/home/tc/.config/enchant/hunspell

wget -O en_US.aff  https://cgit.freedesktop.org/libreoffice/dictionaries/plain/en/en_US.aff?id=a4473e06b56bfe35187e302754f6baaa8d75e54f
wget -O en_US.dic https://cgit.freedesktop.org/libreoffice/dictionaries/plain/en/en_US.dic?id=a4473e06b56bfe35187e302754f6baaa8d75e54f