Since no one else has done so yet, I just want to give a big thanks to Brian for working on this. This is a problem that has especially plagued big GLAM content contributions with high-resolution scans, and it's great to see those finally rendered. Your work is appreciated!
Dominic On 2 October 2014 21:08, Brian Wolff <[email protected]> wrote: > On 10/2/14, Brian Wolff <[email protected]> wrote: > > Hi everyone. > > > > tl;dr: Can we do https://gerrit.wikimedia.org/r/164476 > > > > Now that the pre-requisite patches for using VIPS with tiff has been > > merged (Woo!), lets umm use it. > > > > So for those who don't know what vips is, vips is an alternative to > > image magick which can scale certain file formats in essentially > > constant memory (Or probably to be pedantic, linear in the number of > > pixels in the resulting file, instead of linear in the number of > > pixels in the source). This means we would be able to make thumbnails > > no matter how big the source file is. Which is good because we have > > lots of very high resolution tiff files, such as [[File:Zoomit2.tif]] > > and [[File:Zentralbibliothek Zürich - Mittelalterliche Stadt - > > 000005203.tif]]. We already use VIPS to scale png files larger than 20 > > megapixels, and non-progressive jpeg files can be scaled efficiently > > with image magick, so tiff is the current pain point in terms of > > scaling limits (although GIF is also painful). > > > > I would like to propose the following: > > > > First we experiment with turning it on for files > 50 megapixels. > > Currently we do not even try to render such files, so I doubt this > > will cause any community angst. To that end I proposed a patch ( > > https://gerrit.wikimedia.org/r/164476 ) that uses the following > > settings: > > > > array( > > 'conditions' => array( > > 'mimeType' => 'image/tiff', > > 'minShrinkFactor' => 1.2, > > 'minArea' => 5e7, > > ), > > 'sharpen' => array( 'sigma' => 0.8 ), > > ) > > > > This will turn the feature on for big files (which currently do not > > render), and also enable sharpening (Most tiff images benefit from it > > and the community has asked for it repeatedly, I think its less > > disruptive to enable sharpening at the same time as VIPS, instead of > > two separate changes to tiff rendering). > > > > I would propose we let that sit for a little bit. We should than have > > a community discussion (With the commons community, since its hard to > > have a discussion with every community, and commons (+esp. Glams) are > > the people who care the most about this) to see if the community likes > > that. Hopefully if all is well we could move to stage 2, which would > > be something like: > > > > array( > > 'conditions' => array( > > 'mimeType' => 'image/tiff', > > 'minShrinkFactor' => 1.2, > > ), > > 'sharpen' => array( 'sigma' => 0.8 ), > > ), > > array( > > 'conditions' => array( > > 'mimeType' => 'image/tiff', > > ), > > ), > > > > > > Anyways, thoughts. Does this sound like a good plan? Someone want to > > be bold and deploy my change ;) > > > > --bawolff > > > > > This is live now. First results look promising, however some images > don't seem to be working > > *Really big images (>350 megapixels) seem to run into a timeout > (especially lzw compressed images, but that could be a coincidence, > very small sample size) > *https://commons.wikimedia.org/wiki/File:Carr_wilbur_j_honorable.tif > and > https://commons.wikimedia.org/wiki/File:Amelia_earhart_received_by_president_coolidge.tif > are broken. Not sure what the deal with those two are yet. They do not > appear broken (locally anyways) if converting directly instead of > using intermediary step. Random theory is something to do with colour > profiles as they're both greyscale images, but needs further > investigation. > > _______________________________________________ > Multimedia mailing list > [email protected] > https://lists.wikimedia.org/mailman/listinfo/multimedia >
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