Symphony.

Hello

For a website I use JIT to render images in different sizes. I am using already a pretty high quality for jpg but I would like to further increase quality. The website is about architecture and quality is very important.

When scaling images down, a black and a white pixel reduce to a grey one. Images lose sharpness this way. In Photoshop I would use the filter sharpen/unsharp mask to counteract.

Is there a way to sharpen images in Symphony? Would it need to be a postprocessing server-side program that watches for new images in the manifest folder?

Thanks Moritz

Can you use png?

And/or maybe also Multi Upload Field extension to drop several optimized image sizes.

png would help against compression loss but it would not solve the loss of quality through resizing.

Uploading multiple files, prepared with Photoshop and a script, would be a possibility. However, I have more than 1.600 images and preparing them all would be a hell lot of work. Additionally it would not be future proof as a change in design would lead to preparing all images again.

I guess I need to look at Imagemagick used with a cronjob. I will need to flag the images already processed so that the will not be processed repeatedly. That's not Symphony then but outside the system.

but it would not solve the loss of quality through resizing.

Actually I haven't tried out myself how much does it degrades in this case.

Also, I guess you already played with the jpeg quality value for JIT, though I don't thing there is a major quality difference from lets say 92-93 and up. I would try the lowest possible from it to have also a reasonable image file size too.

The multi image idea was about to have a few approximate image size versions of a high quality image (maybe 2 would be enough, big medium, plus retina versions if you care), and you would use for your JIT recipes with the nearest top quality image size from those image sets, so the recipe resizing wouldn't have to make a big resize operations and by that wouldn't reduce the image quality / sharpness so much. Additionally to this, I would let the browser do some resizing on its own too, if some in-between sizes would be needed in presentation, cropping with HTML/CSS if needed, so you could also benefit from the cache by reusing the same image (lazyloaded).

Just trying to look at it from the front-end dev side.

Imagemagick sounds definitely good.

Thanks four your thoughts, juro. I have to admit that what I am trying to get is a luxury problem and a high end aim. The images I get now with JIT are more than ok. It's on of our professional architecture photographers who aproached me with the quality topic. I think I will have a look at Imagemagick and how to flag files as processed.

Yes. Good luck!

I'm way out of my depth here, but JIT uses the PHP library GD right?

There's some info here on how images can be sharpened with GD, so it may be possible to do what you're after with that?

Yes, johnpuddephatt, this is exactly what I want to do. Thanks for the link! I guess I need an adaptation of the JIT extension.

I had a look into it whether I can tweak it by myself. As I have never programmed an extension it is hard to find the right place to insert my code. I will try for a while and get back here with a report. Thanks so for!

What about using a service such as mapbox.com to produce the scaled tiles of the high res images? https://www.mapbox.com/mapbox.js/example/v1.0.0/

This would be a bit laborious as you mentioned above.

Also to note that images larger the 4000pixels x 4000pixels become an issue for JIT to deal with on normal servers and you will quickly run out of memory generating files of this size with the extension.