Fast Stroke Width Transform for Python

This repo contains wrapper for libccv's SWT algorithm for use in Python.

For more information, see my blog post: http://zablo.net/blog/post/stroke-width-transform-swt-python

How to:

1. Checkout libccv (I've forked it at the time when I built this wrapper):

   git clone https://github.com/marrrcin/ccv.git
   

2. Put ccvwrapper.* files from this repo into /lib folder of ccv

3. Use the following script to build the wrapper:

   #!/bin/bash
   swig -python ccvwrapper.i
   
   gcc -fpic -c ccvwrapper.c ccvwrapper_wrap.c ccv_algebra.c ccv_basic.c ccv_cache.c ccv_classic.c ccv_io.c ccv_memory.c ccv_output.c ccv_resample.c ccv_sift.c ccv_swt.c ccv_transform.c ccv_util.c ./3rdparty/sha1/sha1.c -I/usr/include/python2.7
   
   ld -shared ccvwrapper.o ccvwrapper_wrap.o ccv_algebra.o ccv_basic.o ccv_cache.o ccv_classic.o ccv_io.o ccv_memory.o ccv_output.o ccv_resample.o ccv_sift.o ccv_swt.o ccv_transform.o ccv_util.o sha1.o -ljpeg -o _ccvwrapper.so
   
   

4. Copy outputs of the build into your project

   cp ccvwrapper* ~/PycharmProjects/path_to_your_project
   cp _ccvwrapper* ~/PycharmProjects/path_to_your_project
   

5. In Python just use:

   import ccvwrapper
   import numpy as np
   swt_result_raw = ccvwrapper.swt(open("test_input.jpg", "rb").read(), len(bytes), 1024, 1360)
   swt_result = np.reshape(swt_result_raw, (len(swt_result_raw) / 4, 4))
   

6. Done!