Extremely high resolution images in PDF

[Tom_Reczek@adobeforums.com]

When I was inspecting a PDF to resolve an issue regarding some images I picked an image in Acrobat and selected "edit this image" which opened it up in Photoshop. I went to check the images size and resolution and noticed the image in now 0.05 x 0.03 inches AND 32,768 DPI!!!!!! All images in the PDF are like this now.

The original image from the source file is 5.963 x 4.8 inches at 300 dpi.

What would cause this to happen. I have an older PDF of the same document and the image sizes are OK. I did optimize the PDF.

[Michael Kazlow]

Tom,

Use the Preflight capabilities to check dpi---not opening the object in
Photoshop. If you notice the diference the size of embeded image is
reported as 0.05 by 0.03. The original image is approximately 100 times
the size in each dimension. The dpi of the smaller image is
approximately 100 times the resolution. Basically the number of
dots/pixels are the same in each case. The difference is caused by the
scale of the images are being measured in.

Mike

[Tom_Reczek@adobeforums.com]

Thanks Aandi and Mike. I agree with both of you but am still concerned because I have an older version of the file that that Photoshop correctly states the proper resolutions. The reason for this post is that I am have problems with CreateSpace.com and the PDF files I am giving them to output. The offer very little help or clear instructions as to what is wrong with the file. They give you a blanket statement as to how a file should be setup. This is the only issue I have found that seems to be out of character with a properly created PDF.

Acrobat seems to check out the images OK but when the file gets ripped for output it might cause a problem if the rip see the images the same way that Photoshop does...

Thanks

[Jon Bessant]

Please, please listen to Mike's advice about preflight - the object is
now inside Acrobat so use the preflight to check effective ppi.

You will go through an endless loop of confusion if you start to
benchmark Photoshop objects vs Acrobat objects ;-)

Jon

[Aandi_Inston@adobeforums.com]

It sounds as if the resolution is being set incorrectly when exported
to Photoshop. It doesn't sound like a problem in the PDF.

You can double check the resolution of a particular image by
* editing an image in Photoshop
* noting the size in PIXELS only
* printing the page in Acrobat and measuring in INCHES
* Divide width in pixels by width in inches to get dpi.

Aandi Inston

[Aandi_Inston@adobeforums.com]

Photoshop is NOT the way to check this. If it sometimes gives a useful
resolution, that's nice, but doesn't make it the right tool -
really... when Photoshop gives an absurd answer (you can SEE the
resolution is not that by looking at the printed page) it just
confirms this.

Aandi Inston