Tesseract OCR on AWS Lambda with Python

lambda-tesseract.md

References:

https://github.com/tesseract-ocr/tesseract/wiki/Compiling

http://stackoverflow.com/questions/33588262/tesseract-ocr-on-aws-lambda-via-virtualenv

https://github.com/sirfz/tesserocr

Instructions for running Tesseract OCR on AWS Lambda with Python

1. Launch an Amazon Linux AMI instance

2. Connect to the instance and generate an AWS Lambda Package

# system libs
sudo yum -y update
sudo yum -y upgrade
sudo yum -y groupinstall "Development Tools"

# tesseract / leptonica / pillow dependencies
sudo yum -y install gcc gcc-c++ make autoconf aclocal automake libtool \
                    libjpeg-devel libpng-devel libtiff-devel zlib-devel \
                    libzip-devel freetype-devel lcms2-devel libwebp-devel \
                    tcl-devel tk-devel

# install leptonica
cd ~
mkdir leptonica
cd leptonica
wget http://www.leptonica.org/source/leptonica-1.74.4.tar.gz
tar -zxvf leptonica-*.tar.gz
cd leptonica-*
./configure
make
sudo make install

# install tesseract
cd ~
git clone --branch 4.00.00alpha https://github.com/tesseract-ocr/tesseract.git
cd tesseract
./autogen.sh
./configure --enable-debug
LDFLAGS="-L/usr/local/lib" CFLAGS="-I/usr/local/include" make
sudo make install

# prepare the zip package
cd ~
mkdir lambda-tesseract
cd lambda-tesseract
cp /usr/local/bin/tesseract .
mkdir lib
cp /usr/local/lib/libtesseract.so.4 lib/
cp /usr/local/lib/liblept.so.5 lib/
cp /lib64/librt.so.1 lib/
cp /lib64/libz.so.1 lib/
cp /usr/lib64/libpng12.so.0 lib/
cp /usr/lib64/libjpeg.so.62 lib/
cp /usr/lib64/libtiff.so.5 lib/
cp /lib64/libpthread.so.0 lib/
cp /usr/lib64/libstdc++.so.6 lib/
cp /lib64/libm.so.6 lib/
cp /lib64/libgcc_s.so.1 lib/
cp /lib64/libc.so.6 lib/
cp /lib64/ld-linux-x86-64.so.2 lib/
cp /usr/lib64/libjbig.so.2.0 lib/

cp -r ~/tesseract/tessdata/ tessdata
wget https://github.com/tesseract-ocr/tessdata/raw/master/eng.traineddata -O tessdata/eng.traineddata

# Create lambda_function.py file

3. You may then copy the zip package to your computer and upload it to S3

cd ~
zip -r lambda-tesseract.zip lambda-tesseract
scp -i key.pem ec2-user@AWS_EC2_INSTANCE_IP:~/lambda-tesseract.zip .

4. Use the zip url in S3 to configure AWS Lambda.

5. Create an environment variable with key "TESSDATA_PREFIX" and leave the value empty.