చామంతి

Mission

This project aims to build a very ambitious OCR framework, that should work on any language. It will not rely on segmentation algorithms (at least at the glyph level), making it ideal for highly agglutinative scripts like Arabic, Devanagari etc. We will be starting with Telugu however. The core technology behind this is going to be Recurrent Neural Networks using CTC. The support for this will be coming from the repo rnn_ctc.

Code so far

Date 2016, Mar, 8

1. akshara_regexp: Regular expression to split a Telugu sentence into aksharas(syllables).
2. cffi_wrapper.py: A wrapper around functions to render text to images. (Uses cairo via cffi)
3. indic_scribe.py: Uses cffi_wrapper to render given text to image.
4. linedraw.py: Class wrapper around indic_scribe and a labeler.
5. print_utils.py
6. scribe_corpus.py: Given a corpus of unicode text. It will write each line to an image and save the numpy arrays. Uses indic_scribe.
7. telugu_fonts.py: List of telugu fonts and their properties.
8. telugu_labeler_basic.py: A labler, takes a string of unicode text and returns a sequence of labels. These labels could be at the akshara level or unicode character level or at an intermediate level. The basic labeler just returns one label for each unicode character.
9. line_seperate.py: Detects lines in a binary text image.

Testing

For now you can see if indic_scribe.py is working properly by running it as

python3 indic_scribe.py <(echo 'క్రైః') > kraih.txt

The output should contain the text rendered in various fonts!

• You can get the various fonts from this repo. Just copy all the fonts to your ~/.fonts directory.
• But before running ensure you have the following

Pre-requisites

You need libffi, cffi and cairocffi. These are constantly changing and are works in progress. More over you might need root privileges to install libraires.

In the simplest case try

pip3 install cffi==0.8.6
pip3 install cairocffi==0.6

If that works then fine.

Else if cffi is complaining that it needs libffi then try to install it as

sudo apt-get install libffi
# OR
yum install libffi

But then if you are not root on an RHEL machine (which is the case if you are on a server) then

mkdir ~/software/
cd ~/software/
wget ftp://sourceware.org/pub/libffi/libffi-3.2.1.tar.gz
tar -xvf libffi-3.2.1.tar.gz 
cd libffi-3.2.1/
./configure --prefix=/home/<NAME>/usr 
make -j4
make check
make install
vim /home/<NAME>/.bashrc 
# Add these lines
export PATH=$PATH:~/usr/bin:~/software/eclipse
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:~/usr/lib:~/usr/lib64
export C_INCLUDE_PATH=$C_INCLUDE_PATH:~/usr/include:~/usr/lib/libffi-3.2.1/include
export CPLUS_INCLUDE_PATH=$CPLUS_INCLUDE_PATH:~/usr/include:~/usr/lib/libffi-3.2.1/include

LDFLAGS=-L/home/<NAME>/usr/lib64 pip3 install cffi==0.8.6
pip3 install cairocffi==0.6

Other Problems

• If your PIL / Pillow is not able to open tiff image files. Follow this: http://stackoverflow.com/a/10109941 If you do not have root priveleges are installing libtiff etc. locally, make sure your LD_LIBRARY_PATH points to something like ~/usr/lib that has libtiff etc.