2 Jan
2017
2 Jan
'17
10:34 a.m.
On 02/01/17 15:45, Noel Chiappa wrote:
Even at 1K pages, it shouldn't be anything like
that big, if scanned using
the most space-efficient encoding.
For _manuals_, scan at 300 dpi with Black+White encoding (i.e. 1 bit per
pixel), then store as TIFFs with CCITT Group 4 (fax) compression. That does a
typical page of text in ~45KB or so. So you're about an order of magnitude
high....
This manual (which is Rev C 14-APR-1989, and so 2 years older than the
one Al has made available) was scanned in 2002.
Back then I had access to a Lexmark something or other. The only thing
I'm certain of is that it was scanned at
600x600 dpi, B&W. I can't see the point in dropping to 300 dpi for B&W
... 400MB will be the average size of a
two page CV written in Word 20 years from now :-) For those who care,
it's easier to convert from 600dpi to
300dpi than the reverse.
Back then I would use Adobe to convert to CCITT G4 encoded TIFF and
repackage as PDF. (The current scanner
does that for me, or so it seemingly claims).
Maybe I forgot that step for this one. I do know that this one (and the
VAXBI STD) both had pages that were
sticking together by the time they came to me, so I had to separate them
all manually before scanning.
They are probably nowhere near as clean as a typical manual.
Picking on a few random samples and comparing to what I'm getting out of
the current scanner I can use,
I see a range from 240KB/page to 390KB/page. So I don't think I missed
out a step after all: I think it's in line
with what I generally see coming out of the scanner(s).
Antonio
--
Antonio Carlini
arcarlini at iee.org