[Koha] dual cover images suport

[Alvaro Cornejo]

Hi David,

Thanks for the advise.

I\ve tested tinypng and it worked great. Pngcrush however, gave me mixed
results with the same setup. In some cases it even increased file size...

I'll need to do some extra tests and look for other options.

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


Le sam. 1 août 2020 à 17:19, David Nind <david.nind at gmail.com> a écrit :

> 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 | david.nind at 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 at 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
>>
>>
>>
>> |----------------------------------------------------------------------------------------|
>>  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
>> Koha at lists.katipo.co.nz
>> Unsubscribe: https://lists.katipo.co.nz/mailman/listinfo/koha
>>
>