Best common file format to use to create PDFs?

  • Thread starter Thread starter Zak
  • Start date Start date
Dances With Crows said:
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.
Click to expand...

I certainly never intended to imply otherwise.

FAX machines use non-square pixels; TIFF also supports non-square pixels
as well. For the most part, if a person is scanning a file using a
consumer flatbed scanner, the only application that would likely require
non-square pixels would be preparing the document for faxing.
 
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,
Click to expand...

I have hit a bit of a problem which I can solve only by using TIFF group
3.

The problem is that if I scan to TIFF group 4 and then edit in PSP, then
i find that the saved TIFF file is about 5 or 6 times the size of the
TIFF file before editing. This creates a horrible PDF with fuzzy edges.
Turns out that PSP was saving in LZW. However my PSP is ver9 and it
does not offer an option for TIFF group 4.

So I choose group 3 and I get a reasonably sized TIFF from PSP which
converts nicely into a PDF.

Can't work out why PSP does not offer Group 4.

PhotoShop is not much better and it seems, to me anyhow, to offer even
fewer compression options when saving to TIFF.
 
I have hit a bit of a problem which I can solve only by using TIFF
group 3.

The problem is that if I scan to TIFF group 4 and then edit in PSP,
then i find that the saved TIFF file is about 5 or 6 times the size
of the TIFF file before editing. This creates a horrible PDF with
fuzzy edges. Turns out that PSP was saving in LZW. However my PSP
is ver9 and it does not offer an option for TIFF group 4.

So I choose group 3 and I get a reasonably sized TIFF from PSP
which converts nicely into a PDF.

Can't work out why PSP does not offer Group 4.

PhotoShop is not much better and it seems, to me anyhow, to offer
even fewer compression options when saving to TIFF.
Click to expand...

Hmm. I am not sure my experiments have been as good as they ought to
have as Foxit and Adobe Reader seemed to get launched and I don't
recall which one was used when.
 
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