Scaling PDF documents?

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Level 1

35 points

Scaling PDF documents?

When the printing drop-down window appears, one is given the choice of "Scale each page to fit paper". When that is selected, how is that supposed to work?

I would have thought that the document content would be scaled and centered in the printable area while maintaining aspect ratio. And that the printable area would be defined in the printer's PPD file with the ImageableArea parameter.

*ImageableArea Letter/US Letter: "14 0 612 785"

Where the numbers are left, bottom, right and top in points.

However, no amount of playing around I did with those coordinates would print the bottom of the document. Some always fell in the printer's physical, unprintable bottom margin.

So, how does one tell the system where the printable area is, so all of each document page appears on the sheet of paper?

Glenn

Dual PPC G5 2GHz, Mac OS X (10.5.6)

Posted on Feb 18, 2009 10:00 AM

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Answer 1

PAHU

Level 6

16,723 points

Feb 18, 2009 4:43 PM in response to Glenn R

Hi Glenn,

Reading the values that you have given for the Imageable Area, are these the default values or what you have tested?

I ask because the 0 co-orodinate would indicate a bottom margin at the actual edge of the paper, which would be well inside the engines physical limits. If you were wanting the scale to invoke, I would have thought that you would need a value inside the printable area, such as "14 14 612 785".

PaHu

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Answer 2

Glenn R Author

Level 1

35 points

Feb 19, 2009 3:03 PM in response to PAHU

Hi PaHu,

The printable area is actually 34 points up from the bottom of the paper. If I specify

*ImageableArea Letter/US Letter: "14 34 612 785"

Then, after scaling and printing, the top of the document is printed 0.59"=42.75pts from the top of the paper and the bottom of the document is moved down ~0.04"=3pts (i.e. about 3pts more of the printed document is put below the bottom physical limit of the printer, so that information is not seen) when compared to the test below.

When

*ImageableArea Letter/US Letter: "14 0 612 785"

is specified, the top of the document is printed 0.28"=20.25pts down from the top of the paper and the bottom edge of the printed information is about ~0.04"=3pts higher than the test above.

In other words: changing ImageableArea from "14 0 612 785" to "14 34 612 785" made the printed information smaller in the vertical direction (as expected) and moved all the printed information down on the paper, with the top moving down much more than the bottom (which is not expected).

However, one thinks "Aha -- someone has the meaning of the second and fourth coordinates mixed up. The second one really refers to the top and the fourth to the bottom." So I try "14 0 612 700" to get the information at the bottom of the document to print away from the bottom of the paper.

No joy! That chops about the same amount of information off the bottom of the document and about 0.72" more off the top than "14 0 612 785" did! This last test did indeed scale the information to a smaller size, but it makes it look like the printable area starts 0.72" down from the top of the paper, rather than the 0.06" that it really is.

Next hypothesis: scaling is being done as expected, but the information is not translated to be centered in the printable area: it always pins the lower left of the information to the lower left of the paper.

What CUPS filter actually does the scaling? Can I get access to the source to fix it?

Take care,

Glenn

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Answer 3

Feb 19, 2009 3:31 PM in response to Glenn R

I have the same issue. Some PDFs (but not all, note) scale towards a corner instead of towards the center. That is true for both of my printers (I use the standard HP drivers). I think it must be a bug in preview, not the printing system. If I print out from Acrobat, the pages are correctly scaled towards the center.

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Answer 4

Glenn R Author

Level 1

35 points

Feb 20, 2009 11:35 AM in response to ahostmadsen

ahostmadsen,

Thanks for the tip. Adobe Reader 9 is now my default PDF viewer. It prints much better, since it scales to (somewhere near) the center of the paper. Its print window is pretty cool since it shows the paper size and the printable area within that. It isn't completely anomaly free because printing introduces a lift-right offset that can be corrected through the PPD file; a printable area that clearly shows as off center is needed to get a centered document! What ever happened to WYSIWYG?

Glenn

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