Local image sizes compression

Resolved norbou
(@norbou)

1 year, 8 months ago

Hei folks, this plugin is very well done, thank you! ♥♥♥

The setup is very simple and after resetting all caches everything seems to work.

I have red your guide and I would just like to know more about how Optimole works.
I assume it takes the images at the largest size and scales those itself as needed.
We have some really large originals on the site, which WordPress has started to automatically scale to 2560×2560 since version 5.3.
1) In this case, does Optimole take the _scaled one or the original one for processing?
2) Can we possibly delete the original ones from the site?
3) Does the quality of the local versions of the image sizes generated by WordPress matter?
I ask question 3 because I was thinking of compressing the local scaled images more.
I know it’s even possible to delete local images, but I’m not considering that yet,
In the context of your technology, I find the generation of 17 fixed sizes defined in the theme on a local server somewhat absurd.
I probably can’t avoid that to work with them in the editor, but at least I could compress them more 🙂

Thank you very much for a great plugin,
Jiri

Viewing 5 replies - 1 through 5 (of 5 total)

Plugin Support Vytis
(@bvytis)

1 year, 8 months ago
Hi @norbou,

Thank you for using Optimole and for your feedback!

Let’s get through your questions:

1) In this case, does Optimole take the _scaled one or the original one for processing?
Optimole uses the original image size and then scales down optimized version of the image to whatever is requested by the visitors’ screen.

2) Can we possibly delete the original ones from the site?
You shouldn’t delete original images from your served, in case you’re interested in offloading your images to save disk space usage in your server, you can use this feature: https://docs.optimole.com/article/1323-cloud-library-browsing#enable (Enable offloading images)

3) Does the quality of the local versions of the image sizes generated by WordPress matter?
The quality of the main original image definitely matters, we use that image as a base, and all the other versions (optimized and scaled) are used from that image.

If the image is already compressed and is lossy, this might cause an increase in file size.
Running a lossy compressed image through a second lossy compression process for webp can increase file size because the artifacts already generated from the first compression get amplified.

This is why we recommend that you use a good quality image as a base, and we don’t recommend optimizing them before using Optimole.
You don’t get any real benefits from subsequent optimizations.

I hope it helps!
- This reply was modified 1 year, 8 months ago by Vytis.
Thread Starter norbou
(@norbou)

1 year, 8 months ago

Thank you very much for the explanation.
In point 1 I meant _scaled to 2560×2560. The originals are up to 6000 px, and I think WP doesn’t even store the link in the database since 5.3, so I was pleasantly surprised by your answer. So if optimole works with the unscaled ones, we leave them on the server.
I’ll try to ensure that small sizes on our server are generated only on demand and not automatically, and high compression is used for them. That way we’ll have enough space to preserve the originals.

Regards,
Jiri

Plugin Support Vytis
(@bvytis)

1 year, 8 months ago

Hi @norbou,

That’s a good point, if the original is that big, Optimole might ignore it. We have a hard limit, and images that are bigger than ~ 5000px x 5000px will not get picked.

If that happens, you’ll see that image is not served by Optimole, so such big images need to be optimized before using them with Optimole just that it’s really rare to have that big images on a website, and that’s why I haven’t mentioned this scenario before.
Thread Starter norbou
(@norbou)

1 year, 8 months ago
Hei Vytis,
when the oroginal is too big, you can request the filename_scaled.jpg version, which is generated by WordPress since version 5.3 in size 2560×2560 without asking anyone. But it was a good idea. I don’t know how to test it, but we hope it works that way.
- This reply was modified 1 year, 8 months ago by norbou.
- This reply was modified 1 year, 8 months ago by norbou.
Plugin Support Vytis
(@bvytis)

1 year, 8 months ago

Hi @norbou,

You’re right but that -scaled is added automatically when an image is uploaded and this becomes the original image uploaded. Hence, we use this “Scaled” version of the image before there is no different “original” image as only the scaled version was uploaded.

The answer then is yes we use that version but we don’t do anything specific around it, just use the uploaded image.

Let me know if I’m missing the point here and if you have any issues with it. Thanks!