How do you prevent Acrobat X from compressing imagery?

[Gregg]

Here's the scenario:

1) I have a PDF exported from ID CS6. The image are not compressed (this is intentional).
2) I open the PDF in Acrobat X and delete a line of text.
3). I save the PDF (File - Save As - PDF).
4). The image in the PDF now has ZIP compression applied.

A different approach:
Repeat steps 1 and 2 from above
3). Close file, without saving. Get "Do you want to Save..." window. Click Save.
4). Image is uncompressed (as I intended it to be).

I went through all of application prefs and couldn't find anything that changed the File-Save As-PDF setting. Is there a fix?

I am hoping we can just answer this question, and not get into a debate on why you should compress images in a PDF.

Thanks in advance.

 

[Mikie]

In the save as dialogue box, select PDF, optimized, beside Format option, and then click the settings button to the right. This allows you to change the settings just like in Indesign. Once set it should retain the last settings every time you select PDF, optimized.

 

[Gregg]

Thanks, Mikie.

It does seem odd, though. You can save the edited PDF without affecting the image compression by going File - Save, but if you want to save the file as an alternate version (e.g. "Edited.pdf") you have to jump through some hoops to have the original image compression settings honored.

 

[Stephen Marsh]

As in InDesign, there is a file level difference between a "save" and a "save as". Acrobat is by nature more complex than InDesign when it comes to the save options. Does Acrobat store and reference copy of the PDF export settings that created the original PDF?

Stephen Marsh

 

[leonardr]

1) I have a PDF exported from ID CS6. The image are not compressed (this is intentional).
2) I open the PDF in Acrobat X and delete a line of text.
3). I save the PDF (File - Save As - PDF).
4). The image in the PDF now has ZIP compression applied.

That is correct. Because you did a Save As, which means you've told us that we can perform any form of LOSSLESS optimizations on the file when we create the new COPY of the file. If you only want the changes you made applied, do a Save.

I went through all of application prefs and couldn't find anything that changed the File-Save As-PDF setting. Is there a fix?

Nothing to do fix. It's by design. And has been this way since Acrobat 3, when we introduced optimization.

I am hoping we can just answer this question, and not get into a debate on why you should compress images in a PDF.

I would like to know why you think that lossless compression of an image is a problem.

 

[Mikie]

zip compression is lossless, but he doesn't want to discuss that PDF, optimized is the only way to control what happens during a save as in acrobat, as far as I know.

Leonardr I haven't tested this, but does doing a save as from acrobat perform only lossless compression? When I pick optimized as the format, it defaults to jpeg medium quality. Not doubting you know what you are talking about, but it forces us to trust acrobat isn't damaging a file since we can not see the settings when just wanting to do a save as to rename the file. My method gets around this which is why I shared it.

If one is overly concerned about this, they should just duplicate the file, rename and then perform their changes and hit save, works out to be about the same amount of clicking buttons, if indeed all the original settings are retained

 

[Stephen Marsh]

If wishing to only rename a file, do so at the file system level outside of Acrobat.

Performing a "save as" will also clean out minor garbage in the file, perhaps resulting in a slightly smaller file than before the save as to rename (InDesign is the same, save as tidies up the save).


Stephen Marsh

 

[Al Ferrari]

I also practice the renaming of pdf files at the finder level, and in my experience the new name works perfectly well when that renamed pdf is placed in a layout application such as Quark or Indesign, or imported into a Preps job. But I have always had the suspicion that the original or prior file name for that pdf continues to exist in the internal code of that pdf, although I don't know what purpose it may serve. Can Leonard or anyone else please comment on my suspicion.

Al

 

[Gregg]

That is correct. Because you did a Save As, which means you've told us that we can perform any form of LOSSLESS optimizations on the file when we create the new COPY of the file. If you only want the changes you made applied, do a Save.



Nothing to do fix. It's by design. And has been this way since Acrobat 3, when we introduced optimization.



I would like to know why you think that lossless compression of an image is a problem.

I'm not saying lossless optimization is a problem. Just trying to figure out if I was overlooking a setting. I've been burned before on image compression (although it was from Quark, not ID), and we had to reject the printing because of the poor image quality. So I proceed very cautiously now.

Turns out I posted a thread back in 2007 which is basically the exact same discussion as this one. In that thread you state "Neither Acrobat nor Distiller will convert to indexed GRAYSCALE, though we
most certainly DO convert to indexed RGB and CMYK when we are able to do inorder to get the file size down significantly.

Since it is 100% lossless and reduces the size of your PDFs, while maintaining 100% compatibility with the original PDF 1.0 specification - I don't see why we need to document it.

It is important to keep document size as small as possible while retaining the best fidelity of your content - and we will use all technology at our disposal to accomplish this."

A lot of people had issue with the indexed CMYK, because of this when trying to edit the image in Photoshop "Could not complete your request because a color was specified using an unsupported color space". Has anything changed since 2007?

 

[leonardr]

zip compression is lossless, but he doesn't want to discuss that PDF, optimized is the only way to control what happens during a save as in acrobat, as far as I know.

However, even using Save as Optimized PDF doesn't control everything. There are still a myriad of other optimizations that take place during Save As (or Save as Optimized) for which there aren't controls.

Leonardr I haven't tested this, but does doing a save as from acrobat perform only lossless compression?

Yes!

When I pick optimized as the format, it defaults to jpeg medium quality.

I am not talking about Save as Optimized. I am talking about regular Save As. Two different things.

 

[leonardr]

I also practice the renaming of pdf files at the finder level, and in my experience the new name works perfectly well when that renamed pdf is placed in a layout application such as Quark or Indesign, or imported into a Preps job. But I have always had the suspicion that the original or prior file name for that pdf continues to exist in the internal code of that pdf, although I don't know what purpose it may serve. Can Leonard or anyone else please comment on my suspicion.

PDF files can contain all sorts of metadata - both at the document level as well as the individual object level. However, there is no standard place for the filename in that metadata, since it's just the name of the file. Of course, if the tool that produced the PDF wrote the filename into the metadata (for example, as the title) and you rename it (or Save As in Acrobat) then the metadata is inconsistent. But that's because the producer was silly, not you.

 

[leonardr]

Turns out I posted a thread back in 2007 which is basically the exact same discussion as this one. In that thread you state "Neither Acrobat nor Distiller will convert to indexed GRAYSCALE, though we
most certainly DO convert to indexed RGB and CMYK when we are able to do inorder to get the file size down significantly.

And when you do a Save As Optimized, that is one of the many lossless operations that we perform. However, for a standard Save As, we do NOT do that image optimization phase for a variety of reasons, including the fact that it can take a while on large images.

A lot of people had issue with the indexed CMYK, because of this when trying to edit the image in Photoshop "Could not complete your request because a color was specified using an unsupported color space". Has anything changed since 2007?

I believe that Photoshop handles that correctly now .

 

[Joe]

I believe that Photoshop handles that correctly now .

It doesn't for me in Photoshop CS6. Has that changed in Photoshop CC?

 

[digitallydrafted]

posting this reply because this was the only relevant google search produced to my issue. I hope to help someone else! sending a pdf to book printing house. indesign could not export the files as one pdf (computer would crash). got indesign to export a few pages at the time. the printer required a single pdf, uncompressed. like the original poster, Im not here to debate lossless compression, ive been bitten before on quality too. but regardless of that - when the printer receives a compressed file (lossless or not) they refuse to print. here's how I prevented acrobat XI pro from compressing my combined files:
oddly enough, I could open a short pdf, make no changes to it, and save as optimized pdf with all the settings to not change from original - and nothing would compress. but if I modified ANYTHING (deleting page, merging files, etc), it would say I had to save before optimizing - and the save file and thereafter "optimized" file would both be compressed.
the solution is after all editing is done: "save" the file, not "save as". that will save a compressed file.. do not close acrobat or the file. now "save as" optimized pdf (with all the settings not to compress) - and acrobat will save a fully uncompressed file. a complete file uncompressed that you can send to the print house.

 

[toronar]

the printer required a single pdf, uncompressed. like the original poster, Im not here to debate lossless compression, ive been bitten before on quality too. but regardless of that - when the printer receives a compressed file (lossless or not) they refuse to print.

In this case I would say "look for another print shop".
I wonder how they stay in business when they refuse compressed PDFs. I also wonder how big their hard drives are

 

[Gregg]

Thanks for the tip. I tried the same process in X and it didn't work. Will look into upgrading to XI.

 

[digitallydrafted]

Thanks for the tip. I tried the same process in X and it didn't work. Will look into upgrading to XI.

I dug a little deeper, and in my process - I overlooked the fact that I was opening even singular files as "combine in acrobat" to make this work.. so my initial SAVE file would be binder1.pdf and thereafter the uncompressed file I could save as whatever I wanted.