11/23+ Settings

From: Antonio Carlini <Antonio.Carlini_at_riverstonenet.com>
Date: Wed May 22 12:23:49 2002

> Ben Franchuk wrote:
>John Allain wrote:
>>
>> > Rather than pdf, consider ... LOT more compact
>>
>> How PDFs are made will effect their size.
>> On the moremanuals site I found some files
>> like m3100ma1.pdf at 800+KByte/page
>> and others, like SC41MS.pdf at 12-KBytes/page
>> it depends on the tools and care used.
>
>So what is the right tool!

The stuff I've scanned (like m3100ma1.pdf
mentioned above) is usually US Letter size
and done at 600 dpi bi-tonal (1 bit per pixel).
The scanner happens to LZW encode the
TIFF file. There is no option to G4 encode.

That usually turns out to be 200-400KB/page
but it so happens that one page in that
manual did not look too good. So I redid
that one page as greyscale (8 bits
per pixel) and that just so happens to
be over 50% of the total file size (i.e.
wipe that one page and you are looking
at more like 400KB/page). It's only 14 pages
or so, hence one greyscale page makes
a big difference.

I've seen someone else quote figures of
50-70KB/page for G4 encoded 300 dpi scans
of TOPS manuals, which I assume are the
typical US Letter size. Obviously going to
600dpi might be expected to produce a
factor of 4 increase (i.e. 200-300KB).
Or it might not - who can say with compression!

I don't see a SC41MS.pdf on that page so
I have no idea of the scanning resolution
or the encoding.

>Can one re-convert PDP^HF files?


I've found that using Acrobat 5 in the office
I can covert PDF to individual G4 TIFFs
(although this is *slow* but it is unattended)
and I can then re-import these (in groups
of 50 max) which is reasonably quick.

But it sucks away time. So if anyone else
needs them cut down, be my guest :-)

For the few that I've had to process manually
(i.e. book format, with pages individually
scanned as all-odd-ones, all-even-ones)
the conversion to G4 TIFF is a part of
the process I use to stitch everything
back together in reasonable time. In that
case I'm seeing a reduction of maybe 25%
in size (although I've not tried to measure
it on a reasonable sample ... so don't
quote me).

If the scanner gets an upgrade that allows
it to do G4 TIFF, I'll certainly use it. If a
tool turns up that can do unattended conversion
of TIFF-in-PDF -> G4 TIFF (or better yet,
G4-TIFF-in-PDF) I'll certainly use it.

Antonio
Received on Wed May 22 2002 - 12:23:49 BST