Automated resizing of JPEG image + making slices?

[Chuck Rhode]

Michiel Sikma wrote this on Thu, 15 Feb 2007 22:21:34 +0100.  My reply
is below.

-snip-

> I initially hired someone to do it in PHP (don't bite, please :-)
> but it seems that I forgot about one thing: the people updating the
> site would have been able to upload a huge 30 MB JPEG image, which
> PHP would then resize to various sizes and cut them into 200x200
> pieces, which would be fed to the Google Maps API. However, this
> costs a lot of memory, and PHP by default only has 8 MB.

-snip-

> I know some Python (but not much since I've never actually written
> that many things in it), and with some effort I could probably make
> a simple image manipulator frontend in it, but only if I can find a
> good library for doing the actual manipulation. Do any of you know
> such libraries?

I can't make head or tail of your project's constraints, so the
following advice probably isn't worth much.

IMHO, slicing and dicing is best done by stand-alone, special-purpose,
image-manipulation routines that do their own I/O.  Here is a library
of such routines:

o http://netpbm.sourceforge.net/doc/directory.html

These can be chained together (piped) in shell script (or in *python*
if you prefer) if they're installed on your server.  There is an API
(and maybe even a *python* interface), but I've never needed it.  For
security, the parameters passed to these routines from the wild (such
as file names) need to be scrubbed clean of any delimiters that would
look like executable shell script code, variable substitutions, or
even spurious path names.

-- 
.. Chuck Rhode, Sheboygan, WI, USA
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