Rasterize vector objects but not text

[SimonLinden]

I have been assigned the task of making one of our books available as PDF. Every page of it is made in illustrator and contains lots of text and vector graphics. The PDF I have is 57 MB which is too big for an e-book. I believe that rasterizing all vector graphics would decrease file size but all options of automatic rasterization that I have found entails also rasterizing the text, which I can't do. Is there any script or automated way of rasterizing all vector elements except for text in a PDF file? I have searched but been unable to find this.

I have already tried the save as reduced size PDF and optimized PDF but that doesn't reduce file size unfortunately.

[Test Screen Name]

One thing to check. Save as copy (NOT OVERWRITING THE ORIGINAL!!) with "preserve PDF editing" off. If you haven't already. Does it make a difference?

If not, please use Audit Space Usage from "Save as optimized PDF" and let us know what it says are the big users of space.

[SimonLinden]

Hi!

I didn't know about the Audit Space usage function but this is what it reveals (see image). Content streams is about 22 MB and 88 %. This is not 88% of the files size though (which is 58 MB) but perhaps that is irrelevant.

I don't find a way to uncheck preserve PDF editing when saving from Acrobat Pro. Were you referring to another application?

[Test Screen Name]

This an option when you save the PDF from Illustrator in the first place (and you can't go back, hence the need to be very sure not to lose the editable copy).  Content streams, though, is pretty much vector content so your diagnisis sounds right. However, the 100% should be accurate, I think, something is strange there.

[SimonLinden]

First of all I was wrong - the window is correct to show 25 MB as 100%. As it happens I have more than one of these books and I opened the wrong one. The one referenced is 25MB but the largest one,  which is my greatest concern, is 58MB.

Thanks for your clarification about using Illustrator! Your advice will probably provide a way for me to lower the file size significantly. I have tried reserving pages one at a time without preserving editing and it seems to lower file size. However - is there a way to automate this? The book is 200 pages and I have more than one of them. Im on a mac so Ill see if I can get Automator and apple script to do it for me - but if you have a suggestion I'd gladly take it as I am not very proficient with applescript.

[Test Screen Name]

Making a whole book this way in Illustrator is pretty unusual. Working in InDedign is more usual, but realistically is unlikely to reduce the size.

[SimonLinden]

Yes I know. This is an unusual project where the author himself made the full insert page by page in Illustrator. I have only prepared it for print and now e-publishing.

[Test Screen Name]

On reflection I suspect the Illustrator files were saved with that setting, or you would see huge amounts of "private data" in the Audit Space Usage.