I am not sure I got what you mean but I am using PIL to convert arrays to images and viceversa see http://mail.python.org/pipermail/image-sig/2006-September/004099.html I embed bmps using wxpython. Zachary Pincus wrote:

Hello all,

I'm curious if people have experience with / preferences for how to display a numpy array onscreen as an image.

Pyglet looks relatively easy -- you can feed an image buffer object with a string or a ctypes pointer. I presume getting a string from an array is plenty fast, but the ctypes pointer option is intriguing as it allows for dealing with simple strided arrays (the image objects allow for an arbitrary number of bytes between rows). Is it possible to get a ctypes pointer to the beginning of the array buffer from numpy without too much ugliness?

wxPython looks pretty easy too, as there are facilities for getting pixels from a buffer. Does anyone have any experience with these? Are there ways of allowing a numpy array and a wxPython image to point to the same memory?

Anyhow, these are specific questions, but I'd also appreciate any general thoughts about good approaches for getting pixels from numpy arrays onscreen.

Thanks,

Zach _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion

-- giorgio@gilestro.tk http://www.cafelamarck.it

On Nov 29, 2007 2:32 PM, Zachary Pincus <zpincus@stanford.edu> wrote:

Hello all,

I'm curious if people have experience with / preferences for how to display a numpy array onscreen as an image.

Pyglet looks relatively easy -- you can feed an image buffer object with a string or a ctypes pointer. I presume getting a string from an array is plenty fast, but the ctypes pointer option is intriguing as it allows for dealing with simple strided arrays (the image objects allow for an arbitrary number of bytes between rows). Is it possible to get a ctypes pointer to the beginning of the array buffer from numpy without too much ugliness?

wxPython looks pretty easy too, as there are facilities for getting pixels from a buffer. Does anyone have any experience with these? Are there ways of allowing a numpy array and a wxPython image to point to the same memory?

Anyhow, these are specific questions, but I'd also appreciate any general thoughts about good approaches for getting pixels from numpy arrays onscreen.

Thanks,

Zach _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion

Have you tried the matplotlib/pylab module? It has pretty simple ways of doing what you're thinking of if I'm understanding your intent correctly.. Josh

Zachary Pincus wrote:

Hello all,

I'm curious if people have experience with / preferences for how to display a numpy array onscreen as an image.

Pyglet looks relatively easy -- you can feed an image buffer object with a string or a ctypes pointer. I presume getting a string from an array is plenty fast, but the ctypes pointer option is intriguing as it allows for dealing with simple strided arrays (the image objects allow for an arbitrary number of bytes between rows). Is it possible to get a ctypes pointer to the beginning of the array buffer from numpy without too much ugliness?

In [16]: from numpy import * In [17]: a = arange(10) In [18]: dir(a.ctypes) Out[18]: ['__class__', '__delattr__', '__dict__', '__doc__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__str__', '__weakref__', '_arr', '_as_parameter_', '_ctypes', '_data', '_zerod', 'data', 'data_as', 'get_as_parameter', 'get_data', 'get_shape', 'get_strides', 'shape', 'shape_as', 'strides', 'strides_as'] In [22]: import ctypes In [24]: a.ctypes.data_as(ctypes.POINTER(ctypes.c_long)) Out[24]: <ctypes.LP_c_long object at 0x1b353a0> In [25]: a.ctypes.get_shape() Out[25]: <numpy.core._internal.c_long_Array_1 object at 0x1c096c0> In [26]: a.ctypes.get_strides() Out[26]: <numpy.core._internal.c_long_Array_1 object at 0x1c09710> In [27]: a.ctypes.get_as_parameter() Out[27]: c_void_p(27442576) You might want to use the new ctypes-based OpenGL 3.0+ package. It has numpy support a bit more directly. You can use Pyglet for its windowing and all of the other surrounding infrastructure and use OpenGL directly for the drawing. -- 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