[Image-SIG] Remove Noise from a National Weather Service Radar Image (.gif)

Fredrik Lundh fredrik at pythonware.com
Wed Apr 22 21:31:10 CEST 2009

On Tue, Apr 21, 2009 at 1:34 AM, Christopher Barker
<Chris.Barker at noaa.gov> wrote:

> the glory (or, one of the glories) or numpy is that you don't have to
> loop, you can operate in the whole array as a unit.

Or use PIL's "point" method, which does this in no time at all without
having to roundtrip all the data through yet another library...

> Also, the new gif is twice as big as the old -- is it not compressed the
> same way?

The LZW patent expired in 2004, but Unisys still claims to have
patents that cover some uses of it, and nobody's yet contributed a
patent-free replacement for the alternative compression method used by
PIL.  GIF is a dead format anyway; I'd recommend using PNG instead.


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