How to create a custom thumb driver for additional image transformations

possible · August 17, 2019, 4:57pm

Hi there,
i would like to be able to create additional tumbnails with image magick, that transform the images to halftone images, as described here:
http://www.imagemagick.org/Usage/quantize/#halftone

As far as i understood here: https://getkirby.com/docs/reference/plugins/components/thumb
i can extend the thumb drivers functionality.

However, i have not the slightest idea, how i would start from there. How could i implement the option to extend the image filters from grayscale and such to this:
convert source-image.jpg -colorspace Gray -ordered-dither result-image.jpg
?

Any help would be much appreciated.

Also, please note that i would like to keep the original thumb drivers functionality and just simply add the halftone option…

jimbobrjames · August 17, 2019, 3:22pm

Take a look at the excellent focus crop plugin. It contains a thumbs driver that extends the built in driver to add new functionality. It should give you a big hint…

github.com

flokosiol/kirby-focus/blob/master/src/Focus/ImageMagick.php

<?php

namespace Flokosiol\Focus;

use Kirby\Image\Image;
use Kirby\Image\Dimensions;
use Kirby\Image\Darkroom;
use Kirby\Toolkit\F;

class ImageMagick extends Darkroom
{
    protected function defaults(): array
    {
        return parent::defaults() + [
            'bin'       => 'convert',
            'interlace' => false,
        ];
    }

    protected function autoOrient(string $file, array $options)

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possible · August 17, 2019, 8:32pm

Thanks James, i’ll try to figure out how this works…

bnomei · August 18, 2019, 7:04am

i created one as well but its a bit complex under the hood. you might still get some inspiration from it: https://github.com/bnomei/kirby3-thumb-imageoptim

jakobgrommas · February 5, 2020, 12:24pm

Hey, I’m trying to solve something like that as well. Did you do it, any hints?

possible · February 24, 2020, 9:33am

hey jakob, so far, this is out of my league, so i will tackle this hopefully in the future, but right now i wouldn’t even know how to start… have you been making progress with this?

jakobgrommas · February 25, 2020, 10:45am

I need it for a side project and did not get back to it yet. I’m more into simple frontend stuff so it’s kind of hard for me to dive in as well. But I’ll give it a try and gonna inform you!

possible · February 26, 2020, 2:57pm

Ok, so we meet on the same level here. Lets just agree on this: the first to tackle this has to post it here, ok?

jakobgrommas · February 26, 2020, 3:11pm

Deal!