Best common file format to use to create PDFs?

Hi Nils and others. I understand now that when I create a PDF from a
image file that the format of the image file is not used inside the
PDF. Instead some other format is used in the PDF (which Nils kindly
suggests may be a specialized form of TIFF).
It is this conversion from my image file format to the internal PDF
format which I want to be done smoothly. I am on XP and I am
wondering if it is better to start with a GIF or a JPG or BMP or
whatever to feed into my PDF creation utility.
I should say that I am starting with a hard copy of a document
created on a word processor. I want to avoid artefacts, unecessarily
jagged lines, moire effects and all that stuff which might come from
transforming from an "awkward2 image format to a PDF.
My PDFs will be for public distribution. I have preferred to scan to
a GIF file rather than a TIFF because I have assumed that when I
circulate the basic image file among certain people that the best
balance between image size and the best chance of them being able to
see the file is a GIF.
To me TIFF feels a bit specialized. For example, I never see a web
page with TIFF images but I see lots of pages with GIFs.
Also there seem to be various compression options for a TIFF (group 3
or 4, LZW, JPEG deflate, none) which might makes it even harder for
me to know what to choose as a common format! The Wikipedia says
documents are often scanned to TIFF group 4 but is that something
which has the best chance of being seen on various PCs in various
organisations that I might need to send it to?

Zak

Re: Best common file format to use to create PDFs?

["Followup-To:" header set to comp.periphs.scanners.]
On Thu, 01 Jun 2006 12:43:10 GMT, tacit staggered into the Black Sun and said:
Fax machines use Group3, not Group4. Group3 is less efficient than
Group4.
TIFF has supported having different horizontal and vertical resolutions
since the format started up; this is not a fax-specific thing. Not many
people use this TIFF capability, and some programs will barf if they
read different values for TIFFTAG_XRESOLUTION and TIFFTAG_YRESOLUTION,
but it's in the TIFF spec.
Group4 is A) lossless B) more efficient than any other compression
method for bilevel data. These qualities make Group4 an excellent
choice for storing black-and-white images. Zak was scanning documents
that consisted mostly of text, which is typically very high-contrast and
works really well in black-and-white. So every page with just text (no
graphics) on it could easily be turned into a Group4 TIFF with no loss
of data. HTH,
--
Matt G|There is no Darkness in eternity/But only Light too dim for us to see
Frustration is annoying, but the *real* disasters in life begin when you
get exactly what you want.

Dances With Crows

Re: Best common file format to use to create PDFs?

In article <Xns97D4A912095C464A18E@127.0.0.1>,
Group 4 compression is the compression used by FAX machines. When you
send a FAX, the vertical and horizontal resolutions are different; FAX
machines use pixels that are not square.
TIFF supports Group 4 primarily to facilitate software that receives
FAXes on a computer, or computer programs designed to make scans and
then send FAXes. Since that's not what you're doing, there's no reason
to use CCITT Group 3 or Group 4 compression (which really only works
well on simple bitmaps anyway).
--
Art, photography, shareware, polyamory, literature, kink:
all at http://www.xeromag.com/franklin.html
Nanohazard, Geek shirts, and more: http://www.villaintees.com

Tacit

Re: Best common file format to use to create PDFs?

Can I add about an additional point to do with TIFFs.
When I go into Acdsee and launch Twain, I am asked what format I want
to scan to.
I say TIFF and then I have an option where I can select Group 4. I
am also asked to fill in the dpi value horizontally and vertically.
I don't get asked this when I choose to scan to GIF or to JPEG.
When I get into the actual Twain screen I choose the scanning
resolution as usual.
So, what values should go into those horizontal and vertical boxes
for TIF? Do I need to put in the same value as I use for Twain's
scanning resoultion? (This can be awkward.)
The software is slow to load and if I put in 200 for these TIF value
and scan at 266 or 300 then does that lead to problems or loss of
quality?
I have tried 200, 300 and 600 in the H & V boxes (at scanning
resolutions of 200, 240, 266, 300) and the 200, 300 or 600 seems to
make no difference at all to the final size.
I will have to look closely to see the quality.
Can you or annyone else comment on this extra pair of values.

Zak

Re: Best common file format to use to create PDFs?

DOWNSAMPLE. That's the word! I ahve just written one if not two
paragraphs trying to explain what I man and then you come along and
express the idea in a single word!
OK, so TIFF it is going to be. And to swagger my newly gained
knowledge I will add that it might be group 4 or LZW (and I nod very
slowly as if I know what I am talking about - which I don't).

Zak

Re: Best common file format to use to create PDFs?

Unfortunately, some of the documents have been sent to me in hard copy
form.
Yes, I feared that once I had mastered the basics then my next task is
to identify is my PDF creator is doing as good a job as I might want it
to.

Zak

Re: Best common file format to use to create PDFs?

When i creat a document that is going to be a PDF I always use TIF
files, mainly because Indesign handles TIF files well. I generally use
LZW compression on my TIFs, seems to make no difference.
Once the PDF is created the image files, in my understanding are
converted to Jpeg files, at least that is how they can be extracted.
With the file already being downsampled for the web it is very unlikely
you will see jpeg artifacts coming from an orginal TIF. Multiple
compressions or resampling from a jpeg is another story.
Working from graphics or drawings GIF may be applicable, but for
photographs GIFs should be avoided.
Tom

Tomm42

Re: Best common file format to use to create PDFs?

Snipped and trimmed to context.
I think you are "echoing" what I have just been reading from Dances-
With-Crows.
I should explain the artifacts notion i was asking about. If I scan to
a GIF which I understand is lossless, then it still has a certain
number of "lines" and a certain block size or whatever it is that is
inside a GIF. If these blocks and lines do not match up with those used
by the image it is converted to inside the PDF then there may be
additional irregularities introduced at those places of mismatch.
It's a bit like memory and a system bus on a motherboard. If they are
both 100 MHz then they sing in harmony. If the memory is 133 MHz (and
can not fall back to 100 MHz) then they may give a slightly "off"
performance.
Are you not saying that it is important to choose the internal image
inside the TIFF correctly? I think you are. Then I guess you would
concur with Dances-With-Crows about using Group IV. Remember that I do
want the option of sending the raw image to colleagues (rather than the
shrink-wrapped and sealed PDF).
Thank you for any extra info.

Zak

Re: Best common file format to use to create PDFs?

In article <Xns97D3A7EDC887F64A18E@127.0.0.1>,
Why don't you just start with the word processor file, and not with a
hardcopy at all? Go straight from the word processor file to PDF.
A GIF is almost the worst possible choice to use, because GIF images
contain a very small number of colors, and because of this they don't
tend to downsample smoothly.
Use TIFF. Anything that can read a PDF, can read a PDF, period. It does
not matter what you start with; once it is turned into a PDF, it is a
PDF. However, a TIFF image will downsample and compress smoothly.
That doesn't mean a GIF is the best format to use for general purposes,
however.
You do not need to choose any of these. You do not need to compress the
TIFF at all.
Scan a TIFF, make a PDF, send out the PDF, you're done. Or, better yet,
do not use your scanner at all. Start with the word processor file, make
a PDF--it'll be smaller and far higher quality. :)
--
Art, photography, shareware, polyamory, literature, kink:
all at http://www.xeromag.com/franklin.html
Nanohazard, Geek shirts, and more: http://www.villaintees.com

Tacit

Re: Best common file format to use to create PDFs?

No. The size of the original will usually have no effect whatsoever,
though some PDF creation methods are influenced by it.
With Acrobat Pro or Acrobat Standard, any file you can print can be
converted directly to a PDF.
Or, you could use Acrobat options to reduce the resolution.
----------------------------------------
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Quite@dial.pipex.con (Aandi Inston)

Re: Best common file format to use to create PDFs?

As far as I can see there really is no best common file format to
convert. If it'll convert it'll work. However the size of the
original file will have a direct bearing on the size of the pdf.
If you are doing something like creating a newsletter, flyer, or
Internet distribution then why not use the original doc file?
I handle several newsletters on line and in print.
With Adobe pro any Office and I believe Word Perfect doc can be
converted directly to a pdf. However any images in the documents
should be of the proper size and resolution for the end media. I've
had Word docs sent to me that had the full original images with just
the physical dimensions set. They were still the original one or two
meg images set to a dimension of 2 X 3 inches. These produced nice
looking pdfs, but of many megabytes. Having the images set to the
proper resolution (300 ppi for print and about 100 ppi for screen)
dropped the pdf to less than 100K.
Also not all pdf creators are created equal. About a year ago I tried
using open office to convert a word doc and produced one that was
about 3 to 4 times the size of one using Adobe Pro. This is fine for
printed media, but may (or may not) be a royal pain in the back side
for on-line viewing.
For on-line I much prefer HTML rather than pdfs as the HTML will be
faster to load and more compact. At least it will if it wasn't created
by saving a Word doc as HTML or using Front Page to create it. Those
are huge. OTOH converting to a pdf is faster and much easier and I do
use them when the pdfs are relatively small.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com