Tesseract OCR on AWS Lambda via virtualenv

Question

I have spent all week attempting this, so this is a bit of a hail mary.

I am attempting to package up Tesseract OCR into AWS Lambda running on Python (I am also usin

Answer 1

Adapatations for tesseract 4:

Tesseract offers much improvements in version 4, thanks to a neural network. I've tried it with some scans and the improvements are quite substantial. Plus the whole package was 25% smaller in my case. Planned release date of version 4 is first half of 2018.

The build steps are similar to tesseract 3 with some tweaks, that's why I wanted to share them in full. I also made a github repo with ready made binary files (most of it is based on Jose's post above, which was very helpful), plus a blog post how to use it as a processing step after a raspberrypi3 powered scanner step.

To compile the tesseract4 binaries, do these steps on a fresh 64bit AWS AIM instance:

Compile leptonica

cd ~
sudo yum install clang -y
sudo yum install libpng-devel libtiff-devel zlib-devel libwebp-devel libjpeg-turbo-devel -y
wget https://github.com/DanBloomberg/leptonica/releases/download/1.75.1/leptonica-1.75.1.tar.gz
tar -xzvf leptonica-1.75.1.tar.gz
cd leptonica-1.75.1
./configure && make && sudo make install

Compile autoconf-archive

Unfortunately, since some weeks tesseract needs autoconf-archive, which is not available for amazon AIMs, so you'd need to compile it on your own:

cd ~
wget http://mirror.switch.ch/ftp/mirror/gnu/autoconf-archive/autoconf-archive-2017.09.28.tar.xz
tar -xvf autoconf-archive-2017.09.28.tar.xz
cd autoconf-archive-2017.09.28
./configure && make && sudo make install
sudo cp m4/* /usr/share/aclocal/

Compile tesseract

cd ~
sudo yum install git-core libtool pkgconfig -y
git clone --depth 1  https://github.com/tesseract-ocr/tesseract.git tesseract-ocr
cd tesseract-ocr
export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
./autogen.sh
./configure
make
sudo make install

Get all needed files and zip

cd ~
mkdir tesseract-standalone
cd tesseract-standalone
cp /usr/local/bin/tesseract .
mkdir lib
cp /usr/local/lib/libtesseract.so.4 lib/
cp /usr/local/lib/liblept.so.5 lib/
cp /usr/lib64/libjpeg.so.62 lib/
cp /usr/lib64/libwebp.so.4 lib/
cp /usr/lib64/libstdc++.so.6 lib/
mkdir tessdata
cd tessdata
wget https://github.com/tesseract-ocr/tessdata_fast/raw/master/osd.traineddata
wget https://github.com/tesseract-ocr/tessdata_fast/raw/master/eng.traineddata
# additionally any other language you want to use, e.g. `deu` for Deutsch
mkdir configs
cp /usr/local/share/tessdata/configs/pdf configs/
cp /usr/local/share/tessdata/pdf.ttf .
cd ..
zip -r ~/tesseract-standalone.zip *