reduce file sizes

[cy_auyeung]

Acrobat Professional

1) I tried to reduce the file sizes, but it gets an error " The PDF contained image masks that were not downsampled. " and stops.

2) Can I split a large document that it is not exceeded, for example 1M, to ease for web viewing in sequence ?

Thanks

cy

[Leonard_Rosenthol@adobeforums.com]

#1 - this is a known limitation of PDF Optimizer, in that it can't reduce the size of a certain type of image called a "mask". However, it should keep processing the rest of the file. Are you current with Acrobat Pro 7.0.8 or 8.0?

#2 - Document->Extract Pages. however, you will probably have to experiment with page ranges for the size(s) in question. HOWEVER, you would be MUCH better off simply putting the entire document online with "Fast web View" enabled.

Leonard

[cy_auyeung]

Thanks Leonard,

#1 - I use Acrobat Pro 7.0.8.
#2 - Can I run "Document->Extract Pages" in Batch processing?

Thank you

cy

[Leonard_Rosenthol@adobeforums.com]

Not that I can tell - sorry.

LDR

[Doug_Katz@adobeforums.com]

Leonard, may I ask you about those "masks"? I asked once here about them, but none of us really understood exactly their nature and origin. I have a feeling you do.

Are they masks in the same way Photoshop or Illustrator means masks... a clipping path of some kind or raster layer mask? If they are even remotely like these, whence do they come? I mean, I've gotten the same message the OP asks about even with Illustrator files I've made myself that contain nothing that could be characterized as a mask.

I'll certainly understand if the answer is too technical to delve into here... just that I've been curious for some time.

Thanks.

[Leonard_Rosenthol@adobeforums.com]

They are similar to what you call a "raster layer mask".

It's a 1bit bitmap/raster image that is used to determine which pixels of the associated "master" image will draw and which ones will not.

Leonard

[Doug_Katz@adobeforums.com]

Thanks much, Leonard. So I can conclude this:

1) These masks are generated, not by the artist in the authoring program, but during the creation of the PDF (either Print to AdobePDF or through a Distilled PostScript version of the file or in the Save As PDF process).

2) They are created even if the entirety of the associated "master" image is to be drawn... that is, even when the master images in the authoring program are sized and placed such that every pixel should be visible in the PDF.

Do I have it right?

[Leonard_Rosenthol@adobeforums.com]

I wouldn't necessary conclude either...

Usually (though not always) masks are created by Distiller/etc. based on the data passed from the authoring application or print driver. A common case would be the placements of a GIF image into an authoring program or the use of the "make transparent color" wand in an Office app.

I've never seen a mask created for a non-masked image. Though anything is possible.

Leonard

[Doug_Katz@adobeforums.com]

Well if you would conclude neither, I certainly will conclude neither too! :)

I will be more diligent in noting the conditions under which I receive the message ("...image masks were not downsampled...."). I'm now betting that I've never seen a mask created for a non-masked image either. I just haven't been sufficiently observant. In particular, I haven't been as attuned as you've made me to the connection between transparency and this message.

Thanks for your time and expertise.

[MikeKazlow@adobeforums.com]

Leonard,

I have seen these masks generated when I am scanning a document from
an Epson Scanner directly into a Acrobat 7 via Epson's twain driver.
This occured when one page was scanned in as a color document and all
other pages were scanned as greyscale. I tried to convert the color
page back to greyscale and couldn't. I ended up rescaning the color
page as it was the easiest thing to do.

Mike

[Leonard_Rosenthol@adobeforums.com]

If you can ever produce a document like that again from the Epson scanner - please send it along as I'd love to see why they are using a mask.

NOTE: it's rare but not uncommon to see a Mask used for a Black & White (monochrome) image instead of a "standard" B&W image. Perhaps that is it?

Leonard

[MikeKazlow@adobeforums.com]

Leonard,

I'm not at home, but I'll look for the file at home, I may still have
a copy.

Mike

[Lindro@adobeforums.com]

I use Acrobat 7.0.8 on an Intel Mac.
I've never had so much trouble with .eps files with clipping paths and imported from photoshop into quark docs that are sent to acrobat.

When I try to reduce the size, I get an "unable to process images" message. I know it's clipping paths because without them, the doc is fine. I've tried reducing the number of points on the paths and that doesn't work. I have done catalogs, books and many many documents containing clipping paths in earlier versions of the products with no problema.

Does anyone else have this problem?

[Leonard_Rosenthol@adobeforums.com]

It's a Quark problem.

if you were to use InDesign and place the same image there (where you could also place the original PSD file!), then the output PDF would be more viable.

Leonard