31 Mar
1998
31 Mar
'98
2:03 p.m.
At 11:03 PM 3/30/98 -0800, you wrote:
I'm currently using a UMAX 300P that claims a
maximum 24 bit color
resolution of 300x600 dpi. I'm scanning into Photoshop4 and saving
I have the same scanner.
in JPEG format. I'm trying to save as much
information as I can, so
pages that have any color besides black and white, I'm scanning
at 299 (that's the max for color) dpi in RGB and and everything else in
299 dpi grayscale. I'm averaging, for 8.5 x 11 pages, about 5.3 Mb
Actually, 300 is the max without interpolation. Stuff that's truly B&W
should be scanned in B&W mode. The problem is that grayscale picks up
variations in print strength, smudges, etc. B&W says "This dot is more
than x dark, it's black. This dot is less than x dark, it's white."
for color and 2.1 Mb for grayscale. Just last weekend I
burned
B&W will also save disk space.
I printed two of the highest detailed B/W pages
(schematics) today
at 400 dpi. The results were disappointing. All of the fine details were
The details will get smudged if you scan in grayscale. Also, print at the
same dpi as you scanned; printing at a higher dpi won't do you any good,
and your document will print 1/3 smaller.
lost. I assume I need to use a higher resolution for
printing. I also have
same as scanned.
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
31 Mar
31 Mar
4:27 p.m.
>in JPEG format. I'm trying to save as much
information as I can, so
JPEG is a bad idea for anything other than photos. It works best with subtle
color variations, and tends to make a mess of sharp details.
Actually, 300 is the max without interpolation. Stuff
that's truly B&W
should be scanned in B&W mode. The problem is that grayscale picks up
variations in print strength, smudges, etc. B&W says "This dot is more
than x dark, it's black. This dot is less than x dark, it's white."
That's good advice; however I think in theory the results are equivalent if
you first scan in grayscale, then use Photoshop to convert to B&W with the
default threshold. But Photoshop also lets you adjust the threshold when
converting to B&W, rather than leave it up to the scanner, and you can tweak
it to better compensate for the effects of old yellowed paper.
B&W images also compress astonishingly well with GIF, which is lossless and
thus preserves sharp details well. The good compression is due to the large
amount of white space in typical schematics and drawings.
My total output of scanned manuals has so far been two :-); it really is time
consuming when you try to touch up the pictures to look really great and fix
all the OCR errors and stuff. The manuals I did (which aren't computer
related) are at
http://www.goodnet.com/~ecloud/hamradio.html. I spent way too much time on
the pictures, but as an example, at the top of
http://www.goodnet.com/~ecloud/plboard/ss32.html is a schematic which is 539 x
269 pixels (a nearly ideal width for a typical browser window) and only 5K in
size! That's what GIF can do for you if the drawings are clean enough.
In the end, unless you have a lot of time to spend, you might be best off
getting Acrobat and using their scan-to-pdf feature (which I believe comes
with the standard payware product now). Supposedly, it tries to OCR, and
spellchecks, but if the OCR algorithm is sufficiently unsure about the
identity of a word, it just leaves the scanned bitmap in there instead. You
can manually fix those boo-boos later but in the mean time you have something
that looks really close to the original document. I haven't tried it, that's
just what I have heard. If it's as good as advertised, then PDF has indeed
found its niche (I don't believe in it for many other purposes; html is more
flexible and much better for use on the Internet whenever you have a digital
source to begin with).
--
_______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)bigfoot.com
(_ | |_) Shawn T. Rutledge http://www.bigfoot.com/~ecloud
__) | | \_____________________________________________________________
5:01 p.m.
;-) Clearing the snow from my glasses, I saw Shawn T. Rutledge typed:
Well, Photoshop is *way* too expensive for my blood... I like to use Paint
Shop Pro. One thing I do (for a small number of documents) is scan it in
with 256color B&W, then use the color exchanger with a threshold of 20 or
so, and make all the "near-whites" in the background to white, and all the
"near-blacks" to black. I could show this easier than speak it...
Why I do this: Reason 1: it makes a better looking scan, and besides, PSP's
color reduction algorithms are really great, so reducing the scan to 16
colors comes out top-notch. Reason 2 below.
JPEG is a bad idea for anything other than photos. It
works best with subtle
color variations, and tends to make a mess of sharp details.
Righto you are on this count.
Actually, 300
is the max without interpolation. Stuff that's truly B&W
should be scanned in B&W mode. The problem is that grayscale picks up
variations in print strength, smudges, etc. B&W says "This dot is more
than x dark, it's black. This dot is less than x dark, it's white."
That's good advice; however I think in theory the results are equivalent if
you first scan in grayscale, then use Photoshop to convert to B&W with the
default threshold. But Photoshop also lets you adjust the threshold when
converting to B&W, rather than leave it up to the scanner, and you can tweak
it to better compensate for the effects of old yellowed paper. B&W images also compress astonishingly well with
GIF, which is lossless and
thus preserves sharp details well. The good compression is due to the large
amount of white space in typical schematics and drawings.
Have you actually checked this? GIF's do compress well, and you are correct
on loseless... but if you are just GIFfing the scans, they do *not*
compress well. GIFs are just RLE compressed (That's Run Length Encoding
for all you non-gfx types out there) and if you don't have large blocks of
the exact same color, you'll get very poor compression. That's why I do
what I do above... making sure the "near-whites" and "near-blacks"
are
solid improves the compression 3 or 4 fold, reducing the color depth to 16
helps heaps as well (while still giving you "anti-aliasing" for readability).
Oh, and at least with Photoshop 4.0, it's stock JPEG encoding sux rox.
Badly. (I was too scared to try the GIF encoding... especially with
transparency). PSP is strides ahead on it's format interchangability.
Anywho, just my thoughts on the subject.
HTH,
Roger "Merch" Merchberger
--
Roger Merchberger | If at first you don't succeed,
Owner, MerchWare | nuclear warhead disarmament should
zmerch(a)northernway.net | *not* be your first career choice.
6:32 p.m.
New subject: Panasonic HHC
OK, it looks suspiciously like a calculator, but it does have a genuine
6502 in it, and the search engines tell me that you guys are the world's
leading authorities on this 1981 hand-held computer, so....
Can anybody tell me how I program in SNAP? Was there a developer's kit
for this thing? And how about periph's? I've got the printer/cassette
adaptor, but the RS232 module and TV adaptor would be cool. For the
wanna-be insurance salesmen out there, I'll offer you my two insurance
software ROM "capsules" (a $300 value!) as trading fodder :-)
-- Doug
1 Apr
1 Apr
2:54 p.m.
New subject: Panasonic HHC
No way! Is that _all_ those things were sold for? We had boxes full
of them at the insurance company where I work; they were returned when
we went to laptops. They gave away a whole bunch; I ended up with
two, complete with printers, but all I've got for software is this
stupid ten year old life insurance proposal software in whatever that
SNAP thing is. (They used EPROMs stuck on these special plastic
carriers with the pins bent underneath, and you just "snapped" them in
- wonder if that's where the name came from?) If you figure out
anything, let me know. In the meantime, if you're a non-smoker, it
looks like you could have gotten a good insurance rating in 1987...
On Wed, 1 Apr 1998 02:32:19 -0600 (CST), you wrote:
Can anybody tell me how I program in SNAP? Was there a
developer's kit
for this thing? And how about periph's? I've got the printer/cassette
adaptor, but the RS232 module and TV adaptor would be cool. For the
wanna-be insurance salesmen out there, I'll offer you my two insurance
software ROM "capsules" (a $300 value!) as trading fodder :-)
-- Doug
-Bill Richman
bill_r(a)inetnebr.com
http://incolor.inetnebr.com/bill_r
(Home of the COSMAC Elf Simulator!)
4:39 a.m.
Well, Photoshop is *way* too expensive for my blood...
I like to use Paint
Well I found a copy of 3.51 on Usenet for $100 a couple years ago and I intend
to keep using it as long as possible since 4.0's UI got a bit harder to use.
It's just one of the most intuitive, well-coded (actual efficient code, not
bloatware; imagine that for a modern Windows app!) apps I've ever seen. Since
it's multithreaded, it will also take advantage of multiple processors if you
have them.
Shop Pro. One thing I do (for a small number of
documents) is scan it in
with 256color B&W, then use the color exchanger with a threshold of 20 or
Well grayscale is usually 8-bit, thus what you call "256 color B&W" is
really
grayscale. Strictly speaking, B&W means just black and just white, no
in-betweens.
so, and make all the "near-whites" in the
background to white, and all the
"near-blacks" to black. I could show this easier than speak it...
This is what I was talking about, in Photoshop terms.
B&W images
also compress astonishingly well with GIF, which is lossless and
thus preserves sharp details well. The good compression is due to the large
amount of white space in typical schematics and drawings.
Have you actually checked this? GIF's do compress well, and you are correct
on loseless... but if you are just GIFfing the scans, they do *not* Oh, and at least with Photoshop 4.0, it's stock
JPEG encoding sux rox.
Hmmm, 3.51's is decent and offers multiple compression levels.
Badly. (I was too scared to try the GIF encoding...
especially with
It can export transparent gifs. However I've noticed sometimes wierd things
happen with the colors, like black and white get reversed, and I'm not sure if
it's Photoshop's bug, something wrong with the standard or a browser bug.
Anyhow for non-transparent gifs I've never had any problems.
--
_______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)bigfoot.com
(_ | |_) Shawn T. Rutledge http://www.bigfoot.com/~ecloud
__) | | \_____________________________________________________________
2 Apr
2 Apr
6:10 a.m.
At 11:39 AM 4/1/98 -0700, you wrote:
The multiple that PhotoShop 4 had was around 7 or 8 levels, and even in the
"high quality" compression levels the pictures looked (comparatively) horrid.
Paint Shop Pro offers 99 compression levels, so can be fine tuned for
compression
& image quality much better than PhotoShop 4.
Altho I have nothing against PS4, doing my work in it, then having to
export anything
in a loseless format, then load it into PSP (3,4,5, take your pick) to save
it as JPG
was rather a pain.
The JPG (lack of) quality from PS4 to me isn't worth the money (or the
50+Meg install.)
This is why there are some very good scanned images of Tandy 600's on the web!
See ya,
"Merch"
Well grayscale is usually 8-bit, thus what you call
"256 color B&W" is really
grayscale. Strictly speaking, B&W means just black and just white, no
in-betweens.
Uh, yea. That's what I meant to say. I'm a geek, not an artist.
I got thrown into this 'cause it pays the bills.
Oh, and at
least with Photoshop 4.0, it's stock JPEG encoding sux rox.
Hmmm, 3.51's is decent and offers multiple compression levels.
9531
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9533
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6 comments
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participants (5)
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bill_r＠inetnebr.com -
ecloud＠bigfoot.com -
sinasohn＠ricochet.net -
yowza＠yowza.com -
zmerch＠northernway.net