Hi everyone,
Bryan Tong Minh has been doing some great work on VipsScaler extension, but there hasn't been a lot of recent chatter on the mailing list about it. Since we're somewhat close to deploying something on the cluster, it probably warrants at least an email.
First, some background. Currently, we use ImageMagick for scaling images on Wikimedia websites. VIPS (http://www.vips.ecs.soton.ac.uk/ ) is an alternative image processing system that has a couple advantages over ImageMagick for our purposes: 1) it's faster, and 2) it's way more efficient with memory. The latter means that we can allow for much larger images with VIPS than we can currently allow using ImageMagick. For example, we currently disallow PNG images greater than 12.5 MP.
Changing image scalers may introduce bugs, so we're proceeding cautiously. We have a three step plan: Step 1: Deploy VipsScaler extension, but only use it for PNGs over 12.5MP and/or TIFFs (which currently generate errors). Let this sit in production a while, fixing any bugs we find with this configuration. Step 2: Deploy a comparison tool (to be written) that allows anyone to rescale an image with VIPS, and compare it to the ImageMagick version. Allow more time for testing and fixing. Step 3: Switch to VIPS for everything
If you're interested in following progress, there's a couple places you can look: * VipsScaler tracking bug: https://bugzilla.wikimedia.org/28135 * Follow changes in SVN: https://www.mediawiki.org/wiki/Special:Code/MediaWiki?path=%2Ftrunk%2Fextens...
Step 1 could go out as early as next week, pending final review of the extension. If anyone is interested in helping accelerate this, the comparison tool in step 2 is only just started (it's the SpecialVipsTest special page code), and Bryan is only working on it when he has time (which isn't right now).
When we're ready to schedule this, we'll update the calendar here: https://wikitech.wikimedia.org/view/Software_deployments
Rob