3 Sep
2006
3 Sep
'06
9:05 a.m.
Jules Richardson wrote:
Don wrote:
I tend to take good care of my drawings -- since they usually
are the ONLY "deliverable" that I produce ;-) So, even 30
year old designs are still on nice crisp (unwrinkled) paper!
(Hence the desire to scan all this stuff... keeping drawings
that "pristine" after all that time takes a LOT of effort)
I had earlier tried some gr[ea]y scale scans and
convinced
myself I must be doing something wrong (as the sizes were
just so much larger) so I didn't pursue them.
Hmm, a greyscale TIFF test would be the most important one I'd say -
something like 16 levels; 256 *might* be overkill.
What's readable to a human is important - but equally so is encoding
enough information such that scans of sub-standard source material
(dirty, torn etc.) could be post-processed on a per-case basis if needs
be, before passing to a subsequent OCR step. This is the bit where
bi-level scanning tends to fall down as it depends where the level
between white/black is as to what gets encoded for "damaged" sections of
a document. On pristine source material and at a high enough resolution
(so that viewing on a screen scaled-down gets rid of the jagged edges)
I'm sure it's otherwise fine. [N.B. the
gr[ea]yscale scans are much "softer" on the eyes
(no doubt due to the continuum of "value")]
Lots of the stuff I come across tends to have at least one or two
continuous-tone photos inside, which if I was scanning at bi-level
(which I never do) I'd have to treat as specific cases.