On Thu, Feb 21, 2008 at 12:14 AM, Magnus Manske
<magnusmanske(a)googlemail.com> wrote:
<rant>
I'm currently working on the Scott Forseman image donation, cutting
large scanned images into smaller, manually optimized ones.
The category containing the unprocessed images is
http://commons.wikimedia.org/wiki/Category:ScottForesman-raw
It's shameful. Honestly. Look at it. We're the world's #9 top web
site, and this is the best we can do?
Yes, I know that the images are large, both in dimensions
(~5000x5000px) and size (5-15MB each).
Yes, I know that ImageMagick has problems with such images.
But honestly, is there no open source software that can generate a
thumbnail from a 15MB PNG without nuking our servers?
It got me annoyed as well. So I finally got around writing a png
resizer that does not need to load the entire file into memory:
<http://svn.wikimedia.org/viewvc/mediawiki/trunk/pngds/>. I took a
6000x4000 PNG from that category and recompressed it to a 640px image
in only 4 seconds, while taking only a few 100KB of memory.
Couple of downsides:
* It does currently not do any adaptive filtering on compression,
which may lead to somewhat larger file sizes than necessary
* Compression level is hardcoded
* Only RGB, RGBA, Grayscale and Grayscale-Alpha images are supported.
Palette images are unsupported.
* Single color transparency is discarded.
There should probably a MediaWiki mediahandler be written for this as well.
Bryan