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-t... (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 | david.nind@gmail.com PO Box 12367, Thorndon, Wellington, New Zealand 6144 m. +64 21 0537 847 On Sun, 2 Aug 2020 at 06:13, Alvaro Cornejo <cornejo.alvaro@gmail.com> 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
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