Admin Forum:Losslessly compressing all images on a wiki

Anyone know of an automated way to losslessly compress all images on a wiki? Or, barring that, anyone know of an automated way of downloading every image on a wiki and then re-uploading new versions to the correct fileame? 05:10: Sun 11 Nov 2012
 * Since the wiki servers are run by Wikia, why would you be interested in that? They don't take up any room on your personal storage devices. It'd be a matter for Wikia's administrative staff.
 * Each file format has different features as well, JPEG, for instance, doesn't support lossless compression, if you recompress it, it will be lossily recompressed. ICO doesn't support compression at all. PNG lossless compression is adjustable though. GIFs don't have adjustable compression settings.
 * -- 70.24.186.245 12:09, November 11, 2012 (UTC)


 * Image compression can reduce loading page loading time, something beneficial to probably every wiki especially pages with lots of files on the page itself. Lots of files on a page is generally a bad idea, but sometimes it can't be helped, so we turn to image compression.
 * I don't know the ins and outs of the code used, but runescape wiki has a bot that can compress png and gif files as well as optimise jpeg files, although the latter option is currently disabled. I believe it features a way to stop reuploading unless there has been significant compression which can be adjusted as you feel necessary. It's written in java, with the source available and released under GPLv3, so you can run it if you wish. The bot is operated by User:A proofreader, who can usually be found on runescape's IRC channel,  on freenode, which is probably the quickest way to get hold of them.


 * MediaWiki resamples and reencodes images uploaded on Wikia, and display a different file from that which is uploaded usually, if the file is big (so if you look at the actual files transferred with the webpage, they usually have a pixelsize number attached to them) The files on the webpage transferred are already resized and shrunk. You only get the original upload if you click on the file. -- 70.24.250.26 13:28, November 13, 2012 (UTC)