[Pythonmac-SIG] real-time video capturing and processing
zachary.pincus at yale.edu
Mon Jan 12 22:57:45 CET 2009
> thanks a lot for your help. so far i made first steps using PySight
> which works fine with my iSight camera.
Cool, I'm glad this worked. I'll have to try PySight out.
> i'm able to aquire images and to process them, using code-snippets
> from here and there, but i lack an idea of PyObjC and i am still a
> bit overwhelmed by it. i would prefer to do as little as possible
> with it, just acquiring data.
You and me both.
> scipy/numpy (together with ipython) are what i use for data analysis
> in general and i'm going to work with them for pattern detection,
> though up to now i lack a systematic approach to pass them 'a chunk
> of memory' .
If you can get from C code a python object exporting the "buffer
protocol" (maybe a string representing image bytes, or whatever), it's
pretty easy to construct a numpy array, from a variety of functions
(like numpy.frombuffer/fromstring, or just using the numpy.ndarray
constructor). Alternately, and this I find to be the easiest way of
dealing with C-level stuff, I construct the array first using
numpy.ones/zeros/empty, and then grab a pointer to the memory from
that array, and pass that into the C function to fill in, or process,
or whatever. This is pretty easy with ctypes:
> for visualisation i find pyglet very interesting. i'd be happy if
> you could send me your code that allows to run a pyglet window in
> the background.
I'll send that off-list. Anyone should feel free to contact me for
more information about this!
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