Does picture viewer affect quality of PDF created by printer driver?

[Zak]

I want to get a hard copy document into a PDF.

First, I scan the document into a TIFF-group4 at about 450 dpi.
(Thanks to you people who explained this to me.)

Then I open the TIFF in Acdsee and "print" the image to a fake
printer driver which creates my PDF. I can't fimd freeware which
gies from TIFF to PDF.

I usually use Acdsee v3.from year 2000 because it's fast and nimble
and it renders images slightly better than many other apps.

I have a choice of viewer: Photoshop (CS and Elements), PSP (pro and
pro studio), Picasa, Paintstar, Irfanview, etc.

Does the viewer noticeably affect the quality of the image in the
final PDF?

In other words, am I better off using Photoshop than an old Acdsee?

Or does the image go straight from the source file to to the printer
driver and it does not atter how the piture viewer renders it?

 

[Wayne]

I want to get a hard copy document into a PDF.

First, I scan the document into a TIFF-group4 at about 450 dpi.
(Thanks to you people who explained this to me.)

Then I open the TIFF in Acdsee and "print" the image to a fake
printer driver which creates my PDF. I can't fimd freeware which
gies from TIFF to PDF.

I usually use Acdsee v3.from year 2000 because it's fast and nimble
and it renders images slightly better than many other apps.

I have a choice of viewer: Photoshop (CS and Elements), PSP (pro and
pro studio), Picasa, Paintstar, Irfanview, etc.

Does the viewer noticeably affect the quality of the image in the
final PDF?

In other words, am I better off using Photoshop than an old Acdsee?

Or does the image go straight from the source file to to the printer
driver and it does not atter how the piture viewer renders it?

It is NOT the "The" viewer, it is "a" viewer.

An 11 inch tall page scanned at 450 dpi will be 11x450 = 4950 pixels
tall. It is a huge image, which should print on paper very well, which
would be the purpose of the 450 dpi.

If viewing PDF on the computer screen, that computer screen is probably
only about 768 or 1024 pixels tall (and the document will be somewhat
less due to menus, etc). The 4950 pixel image (which is good for
printing) is way too huge for the video screen.

So the PDF software viewer must resample the view of that huge image to
be smaller, to fit the smaller video screen. Normally video software
uses a quick and dirty nearest neighbor resampling, because it is very
fast, virtually immediate to do, but quality is not as good as a slower
resample menu could be. Line art text in particular often doesnt look
very well after that low quality resample. It is common that a large
line art pdf prints great, but looks tacky on the video screen.

So on the video screen, you only see the smaller resampled view, of
lesser quality, but this does not affect the original data, which is
what prints. The data is not affected, only your video view of that data
is affected.

If purpose of the PDF is to be viewed on on the video screen, then 75 or
100 dpi would be much more suitable size and better appearance. However
the smaller image won't print nearly so well.

PDF is a compromise. The image needs to be one size for printing, and
another size for video viewing. It cannot be two sizes.

 

[Zak]

It is NOT the "The" viewer, it is "a" viewer.

An 11 inch tall page scanned at 450 dpi will be 11x450 = 4950
pixels tall. It is a huge image, which should print on paper very
well, which would be the purpose of the 450 dpi.

If viewing PDF on the computer screen, that computer screen is
probably only about 768 or 1024 pixels tall (and the document will
be somewhat less due to menus, etc). The 4950 pixel image (which
is good for printing) is way too huge for the video screen.

So the PDF software viewer must resample the view of that huge
image to be smaller, to fit the smaller video screen. Normally
video software uses a quick and dirty nearest neighbor resampling,
because it is very fast, virtually immediate to do, but quality is
not as good as a slower resample menu could be. Line art text in
particular often doesnt look very well after that low quality
resample. It is common that a large line art pdf prints great, but
looks tacky on the video screen.

So on the video screen, you only see the smaller resampled view, of
lesser quality, but this does not affect the original data, which
is what prints. The data is not affected, only your video view of
that data is affected.

If purpose of the PDF is to be viewed on on the video screen, then
75 or 100 dpi would be much more suitable size and better
appearance. However the smaller image won't print nearly so well.

PDF is a compromise. The image needs to be one size for printing,
and another size for video viewing. It cannot be two sizes.

Wayne, thank you for the info. OK so I am with you so far. The PDF can
not optimally suit a screen and a printer. It is one or the other and
that is in part decided by the original scanning resolution.

However I was asking about something slightly different. A viewer comes
into my question because it is needed to produce the PDF. This is
because the method of PDF creation I am using involved substituting a
"PDF creating driver" in place of the regular printer driver.

I was wondering more if the fact that a viewer was involved in my method
at all meant that the viewer would interpret the picture in order to
render it (to show it on the screen for its own purposes) and if this
interpretation would affect the quality of the final PDF.

If this is so, then I was wondering is it was important to use a
particular picture viewer because it would be an important factor in the
final quality - whether on screen or printed.

 

[Wayne]

Wayne, thank you for the info. OK so I am with you so far. The PDF can
not optimally suit a screen and a printer. It is one or the other and
that is in part decided by the original scanning resolution.

However I was asking about something slightly different. A viewer comes
into my question because it is needed to produce the PDF. This is
because the method of PDF creation I am using involved substituting a
"PDF creating driver" in place of the regular printer driver.

I was wondering more if the fact that a viewer was involved in my method
at all meant that the viewer would interpret the picture in order to
render it (to show it on the screen for its own purposes) and if this
interpretation would affect the quality of the final PDF.

If this is so, then I was wondering is it was important to use a
particular picture viewer because it would be an important factor in the
final quality - whether on screen or printed.

OK, sorry, I missed your point regarding the "viewer". I think of a
viewer as a program that views the PDF (like the free Acroabat reader),
and that is what I assumed and was discussing. I would call the other a
PDF printer driver that creates the PDF file.

Yes, the PDF printer driver can do and does do what it wishes to your
embedded images that you print to it. Acrobat Distiller (original PDF
printer driver) seems the ultimate, designed for heavy commercial
production use, and the Distiller (PDF print driver) has configurable
options, to resample the documents embedded images that are actually put
into the PDF, to be either large for printing (like 300 dpi color images)
or small for video (like 75 dpi).... to suit the selected purpose for the
PDF file. I doubt it ever resamples larger, I dont imply that, but it
definitely resamples much smaller if you declare a video purpose.

But you can specify what you wish, and that is what you get. Your
original document probably has large images suitable for printing.. the
450 dpi purpose presumably. So you can create (print) the PDF for
printing purposes, which means keep the large images. Or you can create it
for video viewing purposes, for example web purposes, and that means
relatively tiny images suitable for the video screen.

Some other simpler pdf print drivers simply always default to 150 dpi
images in their PDF (sort of a compromise for either purpose - but not
great for either). And I would guess there may be some that leave your
images unchanged, as is, but I dont know, just guessing (but that would
normally be wrong for video purposes). Your PDF documention surely
discusses what your specific program does or offers for images when you
print to PDF. It seems rather important to your purpose.

You probably must judge this result by actually printing on paper. If
your 450 dpi images print with the same quality as when printing the
original image, or when printing the PDF, then it surely left them large
and unchanged. If they print more poorly, or very poorly, then they are
now smaller, maybe 150 dpi size or 75 dpi size now (in the PDF file).

Another way, on the video screen viewer program, you can zoom the viewed
PDF page image to be very large on the screen, like to 600% viewing size
(450 dpi is 6x 75 dpi size), and if the video quality improves greatly at
that huge size, then the actual data image pixels are surely closer to 450
dpi than to 75 dpi video size in the PDF file. Or perhaps 200% is most
sharp (150 dpi size). The exact number is wide and vague, but the overall
effect is very clear.

But whatever the print driver put into the PDF at creation, then the
program that views the PDF on the video screen also has its own problems
with large images, in that the video screen is rather small (pixels) as
compared to the printed page (pixels). All it can do then with a large
image is a quick and dirty fast resample to be closer to video screen
size. The point above is that the 600% view would skip that poor resample
if that was the actual size of the data. Because this quick viewing
resample doesnt always come out so great, esp for line art - which is one
reason the creation purpose is configurable. File size is the other
reason of course.

 

[Jasen Betts]

I can't fimd freeware which goes from TIFF to PDF.

if you want something scriptable: netpbm + ghostscript

Bye.
Jasen

 

[George N. White III]

I want to get a hard copy document into a PDF.

First, I scan the document into a TIFF-group4 at about 450 dpi.
(Thanks to you people who explained this to me.)

Then I open the TIFF in Acdsee and "print" the image to a fake
printer driver which creates my PDF. I can't fimd freeware which
gies from TIFF to PDF.

Try sam2p (http://www.inf.bme.hu/~pts/sam2p-latest-win32.zip) or
ImageMagick's "convert". These are command-line tools. ImageMagick can
also do a number of Photoshop style manipulations to alter image
appearance. When creating pdf's apps may change the colorspace and
compression (lossless or lossy), and may resample the image. Don't trust
apps that don't let you control these things, as they can make a big
difference in the result.

Using OpenOffice.org you can "place" images and export to PDF, but you
don't get a lot of control over how the PDF is created.

I usually use Acdsee v3.from year 2000 because it's fast and nimble
and it renders images slightly better than many other apps.

I have a choice of viewer: Photoshop (CS and Elements), PSP (pro and
pro studio), Picasa, Paintstar, Irfanview, etc.

Does the viewer noticeably affect the quality of the image in the
final PDF?

In other words, am I better off using Photoshop than an old Acdsee?

That depends on your budget. If you are one of those Microsoft
zillionaires buying Photoshop CS won't force you to park your SUV for a
couple days to make ends meet.

Or does the image go straight from the source file to to the printer
driver and it does not atter how the piture viewer renders it?

Apps that don't give full control are making decisions that may not be
appropriate to your image. If you find an app that works you, fine.
If not, a command-line tool or Photoshop CS gives you full control, but
you need to understand the options in order to make the right choices.