PDF Export: Option to only compress when necessary?

[Steps]

I optimize my JPGs outside the application with JPEGMini before I drag them in my document.

This is because I want the best quality at lowest file size. Setting here a compression of
85% or 90% would make them bigger again if the specific image can already be compressed at 50% without visual loss.

The second reason is that in general I don't want a second JPEG compression step.
Every compression hurts the image quality a little bit.

For the layers of type "Image" and "Image Frame" that I placed without cropping not allowing
"JPEG compression" behaves as expected: I can extract the JPG back out of the PDF and it has not been changed.

I noticed if I crop the image using the Image Layer it gets converted to a really big TIF in the resulting PDF.
You can check that by opening it again with Publisher (see attached screenshot).

I think this is correct behaviour of Publisher as it tries to save the image quality and so TIF is the way to go.

Now I thought about how nice it would be to have a checkbox in the export settings to control that behaviour.
I want to enanble JPEG compression only for images that really need to be changed and leave all others as they are.

I hope you see a benefit in that, too.

image.afpub

image.pdf

picture_frame.afpub

picture_frame.pdf

[Dave Harris]

Currently Affinity should only recompress the image if doing so would reduce the file size by at least 10%. In future we plan to make it always use the original compressed data if it is available, even if it is bigger. Either way, if you set the compression quality to a high number, I'd expect it to use the original compressed data as the original will probably be smaller.

[Steps]

1 hour ago, Dave Harris said:

Currently Affinity should only recompress the image if doing so would reduce the file size by at least 10%. In future we plan to make it always use the original compressed data if it is available, even if it is bigger. Either way, if you set the compression quality to a high number, I'd expect it to use the original compressed data as the original will probably be smaller.

Nice! Thank you!

I did further testing with some other images and was able to confirm this working as you described for the current beta build. This is a smart behaviour and solves my problem if I export everything with 95% compression quality as this only affects cropped images in my case. I like.

Regarding the plan to always leave compressed images even if they would get bigger I'm unsure if this shouldn't be controlled by a checkbox option. In my workflow I'll always work with optimized images before I use them in Publisher. So I'm perfectly fine with that.

But I saw in another topic that people drag in 10+ MB photos out of camera and expect Publisher to do the JPEG optimization on that. They may surprised if the compression does not take place.

Maybe making the hard-coded 10% configurable as an option would suit people. I'm not sure about that.

If it should stay the way it is right now I would suggest to document in a tooltip how JPEG compression works so people do not hesitate to use that option (as I did before).

[fde101]

Most of the export settings in the Affinity apps are quite sparse on options.

As they seek to be professional design applications that lack of control is quite unfortunate.

[Steps]

1 hour ago, fde101 said:

Most of the export settings in the Affinity apps are quite sparse on options.

As they seek to be professional design applications that lack of control is quite unfortunate.

It's true that I wish to have more control, but on the other hand I can understand if Serifs wants to have as few options as possible as too many options can be quite confusing. I recall seeing some tools presenting me a lot of granular options where I did not understand what they do.

Already in the current export dialog I had to do research what "Honour spot colors" should do as there is no explaining tooltip.
EDIT: I found that in the Affinity help documents. They may include a "question mark" button to get there faster.

So I acknowledge that Serif wants to handle new options with care but I think this topic is worth a new checkbox/textfield right unter "Quality:".

[Dave Harris]

2 hours ago, Steps said:

But I saw in another topic that people drag in 10+ MB photos out of camera and expect Publisher to do the JPEG optimization on that. They may surprised if the compression does not take place.

Maybe making the hard-coded 10% configurable as an option would suit people. I'm not sure about that.

I think they would be best served by down-sampling. Like cropping, down-sampling will prevent Affinity from using the original compressed bytes.

[Steps]

4 minutes ago, Dave Harris said:

I think they would be best served by down-sampling. Like cropping, down-sampling will prevent Affinity from using the original compressed bytes.

That's fair. I agree.