Webp converter plugin reduces quality

I’m using the webp converter plugin

But I see that my images are reduced in quality even with these options set :

'kirby3-webp' => true,
'kirby3-webp.quality' => 100,
'kirby3-webp.maxQuality' => 100,
'kirby3-webp.defaultQuality' => 100,

Has anyone seen this before?

Tested with a fresh starterkit with same options and a gradient image, same thing. :face_with_raised_eyebrow:

Not familiar with the plugin, but it seems there is some automatic lossy/lossless conversion feature which with GD is always lossy. Which image conversion library are you using?

Following your advice, I’ve installed Imagick for testing a different library. Same thing, the image is converted containing an aliazing aspect.

To be sure the library is well installed, I’ve wrote print(class_exists('imagick')); and get 1. So that doesn’t come from my installation right ?

But this is not what the doc from rosel-dk says :

Note that gd and ewww doesn’t support this feature. gd can only produce lossy, and will simply do that.

So that’s supposed to work with imagick ?!

Oups, sorry, this is working well now with Imagick, I’ve forgot to set

'kirby3-webp.encoding' => 'lossless',

Good to know about this plugin !

Mhmm doesn’t seem to work now on server. On php.info, Imagick is enable. Do you know a way to be sure Imagick is well installed on server ? Do we need to set a specifi path on server for the bin ?

I’ve just set 'driver' => 'im',

It might be necessary to point to the binary in your config, yes.