Are duplicate graphics thrown away?

[Christine_Edwards@adobeforums.com]

Hi,

I am working on a project that requires the pdf to be 8 MB or smaller for the client and its employees to download from a website and print on their personal printer. I am working in InDesign CS2.

It contains many screen shots and I made a test document with 45 pages of 2 up screen shots by just using 2 of the same images over and over, the imported screenshots were about 400K each. When I made this test pdf, it was 8MB.

Now, when I actually put in the screen shots that are to be used in the real job the pdf is about 11MB with all the same settings I had been using, and the screenshots are even smaller in file size (170K). Plus there are maybe only 15 pages of 2 up screenshots.

This doesnt make sense to me at all. Any insight would be greatly appreciated.

[Aandi_Inston@adobeforums.com]

Under certain situations, duplicate images are detected and all
removed except one. This can happen if you do a SAVE AS with fast web
view selected. It isn't guaranteed to happen.

I don't know what you mean by "and the screenshots are even smaller in
file size". The size needed in the PDF has almost no connection to the
original file size. It depends on the original size in pixels, and
how well compression works.

My advice is to
1. Use only TIFF for screen shots (BMP is ok, but never, never JPEG)
2. Use settings to create the PDF using only Flate.
3. Keep the screen shots simple so they can compress well. I recently
found I could get a screen shot of Acrobat down to about 20% of its
original size by removing the Acrobat toolbars, for instance. Make
them as small in pixels as you can while showing the detail you need.
If you have areas of background make sure they are uniform, etc.

Aandi Inston

[Garrett_Cobarr@adobeforums.com]

Christine, there is an odd aspect to Acrobat that many do not realize and catches them off guard (me included when they start to learn the ins and outs of Acrobat.

As you edit in Acrobat, Acrobat does not remove material until you do a Save As... This means your project will continue to balloon in size after each of your edit sessions, this includes your first export from InDesign. Do a simple test comparison: export your PDF from InDesign, keep that version and then do a Save As... to a different file name, then compare sizes, the Acrobat PDF should be smaller sometimes a lot smaller.

Your option in Save As... is to save as the the same name with a Replace or a new version of different name, whatever works best for you.

Also, don't forget the PDF Optimizer for squeezing a bit more juice out of your PDFs.

[Garrett_Cobarr@adobeforums.com]

Aandi, I was very curious about this statement..."My advice is to
1. Use only TIFF for screen shots (BMP is ok, but never, never JPEG)"

TIFFs are typically substantially larger than even Maximum setting JPEGs because they contain so much more information. Does Acrobat/PDF handle these differently? Making for a smaller image file somehow?

This would be a very valuable tip since it is kind of counter intuitive...

[Garrett_Cobarr@adobeforums.com]

Sorry Aandi forgot 2 things: Is your statement only apply to just screen shots? And in Mac OS X screenshots are delivered as PDFs how would you create a TIFF except by a conversion?

[Aandi_Inston@adobeforums.com]

>TIFFs are typically substantially larger than even Maximum setting JPEGs because they contain so much more information.

Actually, they arguably contain exactly the same amount of
information, in terms of number of pixels.

There's two parts to this advice

1. JPEG files are designed for photographs and only photographs (the
"P" in JPEG). They introduce damage to the original data, in such a
way that in a photo you don't see it. Screen shots look ugly and
fuzzy. Also they compress less well if you then use Flate.

2. The graphic will in any case be decompressed first and then
recompressed when making the PDF. So the original graphic size is of
no interest at all.

Counterintuitive it is.

Use LZW compression in your TIFF files if you want. It won't damage
them, and will make them smaller. It won't affect the PDF size.

Aandi Inston

[Aandi_Inston@adobeforums.com]

>Sorry Aandi forgot 2 things: Is your statement only apply to just screen shots?

Yes. Very specifically.

>And in Mac OS X screenshots are delivered as PDFs how would you create a TIFF except by a conversion?

1. I get them as TIFF (Mac OS X.3).
2. Using a PDF is OK if it was made without JPEG compression.


Aandi Inston

[Garrett_Cobarr@adobeforums.com]

aandi, I am in 10.3.9 using the simple keystroke Command-Shift-3 for my screenshots. Are you using a third party app or have I (quite likely) overlooked a setting for screenshots in the OS itself?

I just get PDFs.

[Aandi_Inston@adobeforums.com]

I haven't heard of Cmd+Shift+3 (though I've read about it now, and I
vaguely remember using something like that in Mac OS 9). I use the
Grab utility that comes with Mac OS X. I've tested this and the PDF
files it makes use ZIP (Flate) compression which is OK.

In general, though, take care with PDF unless you know the exact kind
of compression used. TIFF is safe so long as it wasn't JPEG
compressed.

One other thing: if you have screen shots as JPEG, you CANNOT UNDO THE
DAMAGE by saving as TIFF. You have to start again.

Aandi Inston

[Doug_Katz@adobeforums.com]

Very informative thread. Aandi, would you mind a paragraph or two on "Flate"? I see the term in the Optimizer options but haven't the slightest what it refers to. (Conjures up notions of passing wind, which I'm sure are not on the mark).

It is a form of compression?

Thanks.

[MikeKazlow@adobeforums.com]

Doug,

See <http://www.prepressure.com/techno/compressionflate.htm>

Mike

[Doug_Katz@adobeforums.com]

Excellent. Thanks Mike. That site says Acrobat is the only product using Flate/Deflate. Interesting.

And I AM right that we access this compression option through Optimizer? In other words, Acrobat doesn't "auto-Flate" a PDF, right?

[Aandi_Inston@adobeforums.com]

> That site says Acrobat is the only product using Flate/Deflate. Interesting.

And wrong. Flate is now widely used as a compression format for TIFF
as well as for PDF.

>
>And I AM right that we access this compression option through Optimizer? In other words, Acrobat doesn't "auto-Flate" a PDF, right?

No, this is the normal compression used. Check your Distiller options,
which may refer to it as "ZIP".


Aandi Inston

[Doug_Katz@adobeforums.com]

OK. Thanks, Aandi. I'm smarter now.