[Zope] Re: image hot fix

marc lindahl marc@bowery.com
Mon, 27 Aug 2001 11:48:03 -0400


> From: "Ausum" <augusto@artlover.com>
>
> However, because  without the use of caching the rendering of a simple
> thumbnail page may become a real pain, (the thumbnails will always
> regenerate from the original images, over a over again every time the page
> is loaded), it would be really helpful that you provide a how-to/readme on
> the subject of the use of RAMCache along with your product.

I will as soon as I figure out how that stuff works!!!
I put in code, looking at the tiny bit of examples on the cache API, but I
can't find any other doc or anything explaining how this stuff works, so I'm
a little stuck myself.

Without the RAMCache set up, the thumbs will be regenerated for every
different client - but I did set up the headers so that each client's
browser will cache the thumbs locally.

> 
> On the other hand I'd like to point out that PIL - although it's a familiar
> Python native library to work with-  has serious lacks of image quality
> after resampling. The jaggy look of thumbnails is unpleasant for a
> professional site. Why is that?  I've tested the three available methods
> (nearest, bilinear and bicubic), with a large-size image (2000 X 1500 or so)
> finding that at a thumbnail level all the samples looked the same. And
> bicubic is the best known (and costly) resample method. A search at the
> Image-sig archives also reveals the problem, apparently leading  to the use
> of GIMP with a Python interface -instead of PIL-, when quality becomes a
> concern.

Actually, looking at PIL's doc's - the thumbnail command (which I'm using)
calls the 'draft' command which doesn't have any interpolation.  Possibly by
using different commands in PIL you can get interpolation.