25 Jan
2006
25 Jan
'06
3:16 p.m.
jim stephens wrote:
This method resulte in a 1.8mb PDF. The pdf seems to
be as useful as
the one derived by the Steve, presumably from the jpg scans. I
scanned in a manual for bitsavers and found that just going with the
tif format, fax compress, etc resulted in an average page size that
about 1/4 the size or less of jpg images.
This has been mentioned many times, but JPEG was designed for continuous
tone (colour photographs). It is poor-to-bad on B&W, text and line
drawings. TIFF + G4 compression wins all the time for B&W and line
drawings.
I scanned in black and white, and that was the thing I
liked the
least, but for technical documents which are mostly line drawings and
text it is about the only way to keep an archive at a managable size.
I've not found a good solution for colour text and line drawings.
JPEG still is not the right answer (it still hates those high
frequency edges) but other formats I've tried all eat up
inordinate amounts of disk space. (The original TIFF scans
of some pages of some RSX-11 manauls I did weigh in at 24MB/page!).
Antonio
--
Antonio carlini
arcarlini at iee.org