Last modified: 2014-03-26 18:12:31 UTC
From bug 51370c2 (Eduard): > One question regarding JPGs: > You apply sharpening depending on how much they are shrunk. Have you tried to > use a continuous function for the amount of sharpening instead of discrete > values at fixed steps (as also indicated in the source code comment above)? > > Without having done any tests I could imagine this would yield more consistent > quality for all sizes.
Are there default options that we can rely upon instead of guessing best settings on our own? It seems 7.36.0 added something that may of use, optimize_coding option; and 7.38 some more. http://libvips.blogspot.it/2013/11/tips-and-tricks-for-vipsthumbnail.html has some info «$ vipsthumbnail 42-32157534.jpg -o x.jpg[optimize_coding,strip] $ ls -l x.jpg -rw-r--r-- 1 john john 3600 Nov 12 21:27 x.jpg Tiny! About half the size of where we started with no quality loss.» (Compared to itself, not to imagemagick.) Note that thumb weight is now a concern, especially on mobile which is an increasing portion of Wikimedia traffic: https://www.mediawiki.org/wiki/Talk:Requests_for_comment/Reducing_image_quality_for_mobile#Fundamentals
