Optimize (Compress) PDF

[Swiler]

Hi,

Has anyone had any issues with this setting causing any issues with artwork, etc...  I am not sure if the Advanced or Basic setting would affect any transparencies, etc...

Looking for any feedback you may have.  Thanks.

[ThomasLewis]

I use the Basic setting for just about every job. I don't believe it applies any lossy compression. It seems to mainly just dedupe images and compress the PDF data structure, which can make a huge difference in output file sizes.

In my experience, the Advanced setting causes significant slowdowns for complex artwork jobs with a minimal difference in file size compared to Basic. It's ok for text and vector based stuff, but those files are already small. For the type of work I mainly do, I find it far more of a hinderance than a help if I accidentally forget to change it, Basic is great though. I really wish we could change the default setting under User Preferences.

[Swiler]

Thank you!  I was able to get the size from 200MB+ down to about 40MB using the Advanced.  Basic was cutting it about in half.  Thanks again for the feedback.

[ThomasLewis]

I think it really just depends on what you are doing and how well the original PDF was made. I never see that sort of reduction in the work I do, but I recall Dan saying something similar in the tests they did.

Recently I had a rather huge calendar job I ran a test on where the output file was close to 5GB. It took 45 minutes to process with Basic and ran for just over 4 days with Advanced and shaved off about 5% more file size. But with smaller postcard jobs, the time to run is noticeably slower with insignificant file size reduction. These settings are just one of those "mileage may vary" sort of things where you need to test what works for you and decide if the processing time is worth the difference.

[Dan Korn]

Yes, in terms of the file size reduction, the answer is "it depends."  That's why it's an option, because the tradeoff in composition time versus file size is going to be different for different jobs, which can have graphics in various formats, color spaces, and compression options.  Note also that a smaller sized file may process faster on the RIP when printing, as well as transfer faster in online workflows.  (Though different optimizations may be needed for PDFs intended for printing, which may include things like spot colors, versus PDFs intended for "digital delivery" which will primarily be viewed online or in Reader, and which tend to include things like bookmarks and even accessibility tags for screen readers.)

As to the original question, whether advanced compression negatively affects transparency or other aspects of graphics, I don't think so.  At least I haven't seen that.  But it's impossible to prove a negative, and we obviously haven't seen every possible job.

I have seen rare cases where compression incorrectly merges duplicate fonts from different PDFs brought into the job as resources, but that's rare.

This is all just a feature (actually a set of features) in the Adobe PDF Library.  We expose these optimizations as an option for the convenience of our users.  We just call some optimization functions in the PDFL API, and exactly what they do, or if there are any bugs, are really questions that we would have to ask or report to Adobe.

That said, Advanced Optimization pretty much does most of what you see on the dialog that comes up when you use the Advanced Optimization tool in Acrobat.  We turn off a few of those things, but mostly it's what you see there.  We have considered exposing those options individually, but decided not to because it would be a much more complicated UI; though if someone really needs more granular control over those, let us know.

Note that, in the upcoming 13.2 release, the optimization/compression level will be a preference, which you can set to control how the setting is applied to any new FusionPro PDF templates by default.  (You will still be able to change it for individual templates after creation.)

[Swiler]

Thanks all for the information.