Hi Alvaro. Some options I have used to reduce png size (not for Koha cover images though):
- https://tinypng.com/ Does a great job of reducing image size (either one off or smaller batches) - pngcrush: a command line program for reducing png size Some resources for pngcrush: - command I have used: pngcrush -rem alla -nofilecheck -reduce -m 7 -d "/dest/i/ation/folder/" *.png - some resources: . https://zoompf.com/blog/2014/11/png-optimization . http://linuxpoison.blogspot.co.nz/2010/01/pngcrush-optimize-png-file-image-to.html (css not working, but still readable) . https://gist.github.com/tony-landis/3909387 (Script to go through folder and minimise images using pngcrush) As always, test on a non-production system and keep a backup until you are happy with the results. When I tested using pngcrush a few years ago (2018) for the manual, it reduced the image folder size from 82.3 MB to 54.6 MB - about a 33% reduction in size. David Nind | [email protected] PO Box 12367, Thorndon, Wellington, New Zealand 6144 m. +64 21 0537 847 On Sun, 2 Aug 2020 at 06:13, Alvaro Cornejo <[email protected]> wrote: > Hi > > We have seen that the cover images we have been loading into koha, in png > format, are quite big (some over 1Mb) so we are checking a way to optimise > their size. > > One option is to replace those png files with one with a lower > resolution/size keeping the same png format and/or move to jpeg. > > Another option would be to convert them to a better image format like webp. > The issue here is that that webp is not supported by some browsers. > Therefore, we need to have two cover image versions. > > In this last case, we will either need to add a second image column in > mysql for the optimized version or store them somewhere in the network. In > addition to that, we will need to modify opac-image.pl or create another > get-webp-cover.pl script in order to have something like: > > <picture> > <source type="image/webp" srcset="/get-webp-cover.pl?biblionumber=243233 > "> > <img style="-webkit-user-select: none;margin: auto;cursor: zoom-in;" > src=" > > https://biblioteca.celacp.org/cgi-bin/koha/opac-image.pl?biblionumber=243233 > " > > width="445" height="695"> > </picture> > > Instead of just > <img style="-webkit-user-select: none;margin: auto;cursor: zoom-in;" > src=" > > https://biblioteca.celacp.org/cgi-bin/koha/opac-image.pl?biblionumber=243233 > " > > width="445" height="695"> > > And /get-webp-cover.pl will return > <img style="-webkit-user-select: none;margin: auto;cursor: zoom-in;" > src="/image/ 243233.webp" width="445" height="695"> > > Will adding an additional column to mysql break future koha upgrades? > opac-image.pl modifications for sure will be overwritten in future > uogrades, so we will need to keep track of changes and reapply them after > each upgrade. > > Any thoughts on the best way to go? > > Regards, > > Alvaro > > > > |----------------------------------------------------------------------------------------| > Stay safe / Cuídate/ Reste sécurisé > *7* Switch off as you go / Apaga lo que no usas / Débranchez au fur et à > mesure. > *q *Recycle always / Recicla siempre / Recyclez toujours > P Print only if absolutely necessary / Imprime solo si es necesario / > Imprimez seulement si nécessaire > _______________________________________________ > > Koha mailing list http://koha-community.org > [email protected] > Unsubscribe: https://lists.katipo.co.nz/mailman/listinfo/koha > _______________________________________________ Koha mailing list http://koha-community.org [email protected] Unsubscribe: https://lists.katipo.co.nz/mailman/listinfo/koha
