Re: Image rescaling

[David Kastrup]

Stefan Monnier <address@hidden> writes:

>> Rescaling is apparently a pretty tricky thing that is mostly implemented
>> wrong:
>
>> http://www.4p8.com/eric.brasseur/gamma.html
>
> Rescaling an image is exactly the same problem as resampling an audio
> file (e.g. to play it at 48KHz instead of the 44.1KHz used on the CD
> from which it came).
>
> Doing it naively works, but in some cases gives very poor
> results, indeed.

Nice meditation but not related to the referenced article.  The article
is concerned about non-linear quantization.  That's "exactly the same
problem" as using a good 48kHz to 44.1kHz resampling algorithm on
uLaw-quantized audio data rather than linearly-quantized data.

Entirely different problem to mess up on.

-- 
David Kastrup