Idea for Srcset

I’m looking for a method to render diffrent image sizes for srcsets="". I think kirby’s resize() or the thumb() could be a solution. But this only is useful, if those image sizes would not be rendered on the http-request.
Does anybody know anything about this?

Resize() and the thumb() methods are perfect for srcset. The thumbs are generated on first page load, after that the existing thumbs are used.

For kirbytext i used this plugin:

Outside of kirbytext i used this code:

      <a href="<?= $flyer->url() ?>" data-caption="<?php echo($month.', '.$year) ?>"
          data-at-450="<?php echo thumb($flyer, array('width' => 450))->url(); ?>"
          data-at-800="<?php echo thumb($flyer, array('width' => 800))->url(); ?>"
          data-at-1366="<?php echo thumb($flyer, array('width' => 1350))->url(); ?>"
          data-at-1920="<?php echo thumb($flyer, array('width' => 1920))->url(); ?>">
              <img src ="<?php echo thumb($flyer, array('width' => 200))->url(); ?>">
      <figcaption><?php echo($month.', '.$year) ?></figcaption>

It’s also possible to do the same, but shorter, with the plugin:

<?= kirbytext("(image:flyer/".$image->filename().")") ?>

And it would really use less resource this way, than loading the big ones?
I built a slider with 10 images in 1500px width. Ripping them down is needing some time, doesn’t it?

Yes, thumbnail generation takes a while (not very long with 10 images that are not very big), but only on first page load, not after that.

There’s also another plugin for images in templates:

Oh, now I got it: “You meant on the first page load EVER!” The resized images ar physically stored in my project. That’s awesome.