[GRASS-dev] PIL needs to be a GRASS dependency

Anna Kratochvílová kratochanna at gmail.com
Wed Nov 23 15:12:47 EST 2011

On Wed, Nov 23, 2011 at 8:31 PM, Glynn Clements
<glynn at gclements.plus.com> wrote:
> Michael Barton wrote:
>> Since the Python Imaging Library (PIL) is needed to fully use the
>> cartographic composer, this needs to be a dependency of GRASS, just like
>> numpy. Since both of these packages do not come with the standard Python
>> distribution, it would be good if we could package/bundle them in binary
>> distributions. Otherwise, stuff will not work. This is needed for GRASS
>> 6.4 as well as GRASS 7. I'm not sure what is needed for this to happen,
>> but it will be helpful to users (and very frustrating to them if not
>> there).
> We should not be trying to bundle either Python or any of its
> libraries.
> If the user already has a suitable version of Python on their system,
> GRASS should use it (in 7.0, there isn't really any choice, as Windows
> will have associated the .py extension with the installed version),
> and any libraries will need to be compatible with that version (i.e.
> if the user has Python 2.7, 64-bit, providing libararies for 2.6 or
> 32-bit won't work).
> Also, GUI components should fail gracefully in the absence of required
> libraries, i.e. a lack of PIL should result in the cartographic
> composer not working (at worst), not the GUI not working.
> BTW: what does PIL offer that wxImage doesn't? wxPython is already a
> required dependency, so PIL seems a bit gratuitous. Apart from its
> image format readers and writers, most of PIL'S other functionality is
> easily (and often better) performed using NumPy.

Map Composer needs PIL to read PostScript (created by ps.map). If it's
not available, 'preview' is not possible, however the rest of composer


> --
> Glynn Clements <glynn at gclements.plus.com>

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