[Zope] Photo product: how to recreate thumbnails with Imagemagick

[marc lindahl]

> From: Timothy Wilson <wilson@visi.com>
> 
> If I understand the product correctly, the Photo product works by rendering
> all the various sizes at the time you create the Photo instance. Therefore,
> once you've created the 'Photo' the program used to create the images should
> have no bearing on how fast the images appear on your Web site. In other
> words, Photo doesn't create the thumbnails on the fly.

Right... that's fine for some types of sites.  Others would benefit more
from cached on-the-fly generation.

> 
> In my experience with 1024x768 images, the difference in speed between
> ImageMagick and PIL is unnoticeable. I've got a pretty fast machine though.

Well, the thing to do then is benchmark 1000 or 10000 or how ever many it
becomes not only noticeable, but significant enough to swamp extraneous
first-order overheads, so you can get the relative performance....