J Kenneth King wrote:
Philip Semanchuk <[EMAIL PROTECTED]> writes:
On Oct 23, 2008, at 11:36 AM, J Kenneth King wrote:
Hey everyone,
I'm working on a python extension wrapper around Rob Hess'
implementation of a SIFT feature detector. I'm working on a
computer-vision based project that requires interfacing with Python at
the higher layers, so I figured the best way to handle this would be
in
C (since my initial implementation in python was ungodly and slow).
I can get distutils to compile the extension and install it in the
python path, but when I go to import it I get the wonderful exception:
ImportError: /usr/lib/python2.5/site-packages/pysift.so: undefined
symbol: _sift_features
Kenneth,
You're close but not interpreting the error quite correctly. This
isn't an error from the compiler or preprocessor, it's a library
error. Assuming this is dynamically linked, your OS is reporting that,
at runtime, it can't find the library that contains _sift_features.
Make sure that it's somewhere where your OS can find it.
This is basically what I was looking for help with. So far the project
directory is:
/pysift
/sift
..
/include
..
sift.h
/src
..
sift.c
/src
pysift.c
setup.py
I thought I could just #include "sift.h" in pysift.c as long as
distutils passed the right -I path to gcc.
Maybe I should compile the sift code as a shared object and link it to
my extension? How would I get distutils to build the makefile and tell
gcc how to link it?
I don't recommend doing that, if you can avoid it. distutils does not really
support that. If you can get the sift files to compile under distutils as part
of the Extension, that is by far the best option.
--
Robert Kern
"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco
--
http://mail.python.org/mailman/listinfo/python-list
