30 Mar
1998
30 Mar
'98
5:03 p.m.
I would like hear from anyone that has done any archiving of their
classic computer documents and manuals.
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
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
for color and 2.1 Mb for grayscale. Just last weekend I burned
my first CD of docs consisting of 26 color pages and 170 B/W
pages for a total of 454 Mb.( I didn't fill the CD bcause I was anxious
to try printing the files at work.)
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
lost. I assume I need to use a higher resolution for printing. I also have
quite a bit of background clutter on the printed page. I'm having no
problems seeing the smallest details when I magnify the pages in
Photoshop.
=========================================
Doug Coward dcoward(a)pressstart.com
Senior Software Engineer
Press Start Inc.
Sunnyvale,CA
Curator
Museum of Personal Computing Machinery
http://www.best.com/~dcoward/museum
=========================================
30 Mar
30 Mar
7:29 p.m.
I use a Fujitsu 600c to scan everything, using software that I wrote just
for archiving old manuals. I used the ImageBasic toolkit from Diamond Head
Software (purchased by my company for other purposes ;) ) that came
packaged complete with all kinds of neat utilities like de-speckle,
skew-fix, etc. It's nice to use because I set a few pre-set scanning modes
that set up the scanner for what I'm doing; noisy b/w, noisy colour,
text-only, detailed-graphics, etc.
Some suggestions:
1) Try scanning text or any B/W pages in B/W mode. Since the bits can only
be white/black, it can automatically get rid of a lot of background noise.
2) I think the loss of detail on the schematics may be due to the
resolution of your scanner, as well as noise showing up because of the
greyscale setting. Try them B/W and just adjust the contrast/brightness
until you lose the noise. The nice thing about Photoshop is being able to
edit sections of the page at a time, so you could clean up each little
section as you go.
3) Depending on what kind of printer you have, you might try playing with
the half-tone/dithering settings as well.
Most of my images of 8.5x11 are 50k-250k for B/W, 500k-1.5M for 16-shade,
and anywhere from 5-15 megs for colour (all at 600dpi). I usually print
them on an HP Laserjet 4si at 600dpi or an Apple LW16-600 with photo-grade
enabled.
Aaron
On Mon, 30 Mar 1998, Doug Coward wrote:
I would like hear from anyone that has done any
archiving of their
classic computer documents and manuals.
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
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
for color and 2.1 Mb for grayscale. Just last weekend I burned
my first CD of docs consisting of 26 color pages and 170 B/W
pages for a total of 454 Mb.( I didn't fill the CD bcause I was anxious
to try printing the files at work.)
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
lost. I assume I need to use a higher resolution for printing. I also have
quite a bit of background clutter on the printed page. I'm having no
problems seeing the smallest details when I magnify the pages in
Photoshop.
=========================================
Doug Coward dcoward(a)pressstart.com
Senior Software Engineer
Press Start Inc.
Sunnyvale,CA
Curator
Museum of Personal Computing Machinery
http://www.best.com/~dcoward/museum
=========================================
31 Mar
31 Mar
12:33 a.m.
Aaron Christopher Finney wrote:
I use a Fujitsu 600c to scan everything, using software that I wrote just
for archiving old manuals. I used the ImageBasic toolkit from Diamond Head
Software (purchased by my company for other purposes ;) ) that came
packaged complete with all kinds of neat utilities like de-speckle,
skew-fix, etc. It's nice to use because I set a few pre-set scanning modes
that set up the scanner for what I'm doing; noisy b/w, noisy colour,
text-only, detailed-graphics, etc.
Some suggestions:
1) Try scanning text or any B/W pages in B/W mode. Since the bits can only
be white/black, it can automatically get rid of a lot of background noise.
2) I think the loss of detail on the schematics may be due to the
resolution of your scanner, as well as noise showing up because of the
greyscale setting. Try them B/W and just adjust the contrast/brightness
until you lose the noise. The nice thing about Photoshop is being able to
edit sections of the page at a time, so you could clean up each little
section as you go.
3) Depending on what kind of printer you have, you might try playing with
the half-tone/dithering settings as well.
Most of my images of 8.5x11 are 50k-250k for B/W, 500k-1.5M for 16-shade,
and anywhere from 5-15 megs for colour (all at 600dpi). I usually print
them on an HP Laserjet 4si at 600dpi or an Apple LW16-600 with photo-grade
enabled.
Aaron
On Mon, 30 Mar 1998, Doug Coward wrote:
> I would like hear from anyone that has done any archiving of their
> classic computer documents and manuals.
>
> 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
> 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
> for color and 2.1 Mb for grayscale. Just last weekend I burned
> my first CD of docs consisting of 26 color pages and 170 B/W
> pages for a total of 454 Mb.( I didn't fill the CD bcause I was anxious
> to try printing the files at work.)
> 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
> lost. I assume I need to use a higher resolution for printing. I also have
> quite a bit of background clutter on the printed page. I'm having no
> problems seeing the smallest details when I magnify the pages in
> Photoshop.
>
>
>
>
>
> =========================================
> Doug Coward dcoward(a)pressstart.com
> Senior Software Engineer
> Press Start Inc.
> Sunnyvale,CA
>
> Curator
> Museum of Personal Computing Machinery
> http://www.best.com/~dcoward/museum
> =========================================
>
Hi Folks:
There is another thing that has an effect on output quality. That is
trying to print at a different resolution than what the scan was done
at.
Possible to enlarge the image? yes. But do it by multiplying the scan
dpi with an integer value to get the print dpi. Anything else, and
_something_ (either you, or the software) is making a guess at the value
of the intermediate pixles.
Chuck
--
-----------------------------------------------------------
He, who will not reason, is a bigot; William Drumond,
he, who cannot, is a fool; Scottish writer
and he, who dares not, is a slave. (1585-1649)
While he that does, is a free man! Joseph P. 1955-
-----------------------------------------------------------
Chuck Davis / Sutherlin Industries FAX # (804) 799-0940
1973 Reeves Mill Road E-Mail -- cad(a)gamewood.net
Sutherlin, Virginia 24594 Voice # (804) 799-5803
4:38 p.m.
BTW do any of you know of software that can do a good job converting color
screened images (like out of a newspaper or magazine) back to smooth color? I
have a theory that it's possible to extract more information than just one
pixel per screen dot, but I'm not quite sure. I used a high-end Arcus scanner
on a Mac once that did a beautiful job of this, but I don't know whether the
scanner or the software was really doing the work, and whether it did
something tricky to increase the resolution or just computed the color for the
area occupied by each screen dot and then interpolated.
--
_______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)bigfoot.com
(_ | |_) Shawn T. Rutledge http://www.bigfoot.com/~ecloud
__) | | \_____________________________________________________________
1 Apr
1 Apr
5:56 a.m.
Shawn,
If you were using Fotolook 2+ scanning software for the Arcus you possibly
engaged the "descreen" function (set to the correct line screen) which
automatically adjusts the scanner to compensate for screen angles and
minimizes moir?...however it is possible to adjust a moir?ed or "color
screened" image within Photoplop through a number of methods...depending on
the quality of the image, mode and detail...to achieve the best possible
result.
One of the easiest methods is Noise>Despeckle...this will usually do a fair
job but is usually best used in correcting badly compressed jpegs and
indexed gifs...it tends to leave ugly fragmented color boundaries and can
create that oh-so-stylish "plasticised" look we all aspire to...(joking.)
You can also try re-interpolating the image by setting your interpolation
to Bicubic, changing your image size to 200% (resampled) and then reducing
back to it's original size...this only works if maintaining sharpness is
not a factor and can sometimes exacerbate the problem. Also, Noise>Dust &
Scratches or a mild Blur>Gaussian Blur of 1 pxl or so will usually do the
trick but again, you are going to lose detail (running an unsharp mask of
30-50% can help)...
It is _always_ best to correct these problems at the scanning stage...that
is the only way to both maintain quality AND optimize
sharpness/detail...quick fixes will almost always degrade the image.
Not to ba a prude...but what on earth does this have to do with the
discussion regarding the collecting of classic computers? Archiving?
Hmmm... Most manuals are photocopied so scanning as hi-res line art is
definitely best (aliasing just seems to make text un-readable) but for
color brochures and whatnot I would definitely scan with the descreen set
to "Art Magazine (175 lpi)" with "Sharpness" set to LOW...if that
looks
wonky, try "Magazine (133 lpi)." With the image in Photoshop, adjust your
curves to improve contrast and saturation (most scans of printed matter
come out FLAT FLAT FLAT) and then run an unsharp mask. Voila. This should
really get the groove on...
van
BTW do any of you know of software that can do a good
job converting color
screened images (like out of a newspaper or magazine) back to smooth color? I
have a theory that it's possible to extract more information than just one
pixel per screen dot, but I'm not quite sure. I used a high-end Arcus scanner
on a Mac once that did a beautiful job of this, but I don't know whether the
scanner or the software was really doing the work, and whether it did
something tricky to increase the resolution or just computed the color for the
area occupied by each screen dot and then interpolated.
--
_______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)bigfoot.com
(_ | |_) Shawn T. Rutledge http://www.bigfoot.com/~ecloud
__) | | \_____________________________________________________________
........................................................................
@
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(D)/
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van burnham http://www.futuraworld.com
production manager
wired 520 third street fourth floor san francisco ca 94107 united states
........................................................................
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7:19 a.m.
Van Burnham wrote:
If you were using Fotolook 2+ scanning software for
the Arcus you possibly
engaged the "descreen" function (set to the correct line screen) which
Yep, that was it.
automatically adjusts the scanner to compensate for
screen angles and
minimizes moir?...however it is possible to adjust a moir?ed or "color
One of the easiest methods is Noise>Despeckle...this will usually do a fair
I've tried that.
You can also try re-interpolating the image by setting
your interpolation
to Bicubic, changing your image size to 200% (resampled) and then reducing
Why? I would think that sequence would be completely reversible.
One pixel becomes four pixels and then back again.
back to it's original size...this only works if
maintaining sharpness is
not a factor and can sometimes exacerbate the problem. Also, Noise>Dust &
Scratches or a mild Blur>Gaussian Blur of 1 pxl or so will usually do the
trick but again, you are going to lose detail (running an unsharp mask of
30-50% can help)...
Tried that too. That worked the best of what I have tried so far.
It is _always_ best to correct these problems at the scanning stage...that
is the only way to both maintain quality AND optimize
sharpness/detail...quick fixes will almost always degrade the image.
Well that was my experience with that particular scanning software but I just
want to know how they did it so I can reproduce the results in something
else.
I was thinking if your CCD has 300 DPI and you scan at say, the dot frequency
of 133 dpi, does it really sample all 300 pixels in an inch and then resample
downwards or does it just sample the CCD pixel that is closest to the dot
being scanned? If it does the former, then scanning at 300 DPI and then
down-converting to 133 DPI in Photoshop should be exactly equivalent; if it
does the latter, then I would expect really bad results because sometimes the
CCD element being sampled falls on a screen dot and sometimes it doesn't. In
reality the dot size is supposed to correspond to the darkness of that color;
so if you had an optical means to sample the entire "cell" consisting of the
screen dot plus the white space around it, the whole cell and nothing but the
cell, then you could get the color right for that cell, but the cells are not
an orthonormal array; the screens are slanted (and to make matters worse,
differently for different colors). So I think the optimal solution might be
to sample at a very very high resolution (many pixels per screen dot), edge
detect the screen dots, use that information to break up the image into cells,
average the darkness for all the dots in each cell, use that color to fill the
entire cell, and then resample that image downwards to the maximum achievable
resolution (whatever that is). As long as screen dots don't overlap you could
even do that separately for each color. I don't know if any existing software
does that. Maybe Fotolook did. Or maybe that's overkill; maybe just a few
samples per screen dot is enough. But I'm pretty sure skipping any of the
CCD's available dots is not a good idea, and I don't know if that's what my
scanner does when I tell it to sample at 133 dpi. (I have an HP IIcx.)
Not to ba a prude...but what on earth does this have to do with the
discussion regarding the collecting of classic computers? Archiving?
Not much but it is at least an interesting tangent isn't it?
(Sorry if we're boring anybody.)
--
_______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)bigfoot.com
(_ | |_) Shawn T. Rutledge http://www.bigfoot.com/~ecloud
__) | | \_____________________________________________________________
2 Apr
2 Apr
8:41 a.m.
Shawn,
I think your solution is getting a bit too...involved. Yes...overkill.
It is my _understanding_ that the Fotolook "Descreen" function scans the
image at your target resolution but then blurs each channel slightly in
order to eliminate the pixelization (since accurate technical data from
Agfa is *totally* a figment of my rich fantasy life, please realize that I
could be dead wrong on this one)...but I digress.
An easier solution to do your own descreening (sometimes this works better
than the scanner's software), is by scanning at a normal setting (100%
sharpness), at a much higher output resolution (4x)...then blur just enough
to break the pattern...now reduce the file size to your target resolution
and run an unsharp mask. Beautiful.
I ran a test for a lores cover scan:
1) scanned @300dpi, blurred, reduced to 72dpi and unsharp masked @75%
2) scanned @72dpi with a descreen set to 175lpi (we print at 150)
Since Fotolook automatically sharpens to compensate for the descreening
loss, scan 2 was oversharpened and contained some artifacting...scan 1 was
gorgeous.
van
note: Another trick is to actually rotate your image on the scanning bed
(like 20? or so) which usually knocks out the moir?...so long as the
corners don't get clipped. (I think we should return to the regularly
scheduled programming now.)
Well that was my experience with that particular
scanning software but I just
want to know how they did it so I can reproduce the results in something
else.
I was thinking if your CCD has 300 DPI and you scan at say, the dot frequency
of 133 dpi, does it really sample all 300 pixels in an inch and then resample
downwards or does it just sample the CCD pixel that is closest to the dot
being scanned? If it does the former, then scanning at 300 DPI and then
down-converting to 133 DPI in Photoshop should be exactly equivalent; if it
does the latter, then I would expect really bad results because sometimes the
CCD element being sampled falls on a screen dot and sometimes it doesn't. In
reality the dot size is supposed to correspond to the darkness of that color;
so if you had an optical means to sample the entire "cell" consisting of the
screen dot plus the white space around it, the whole cell and nothing but the
cell, then you could get the color right for that cell, but the cells are not
an orthonormal array; the screens are slanted (and to make matters worse,
differently for different colors). So I think the optimal solution might be
to sample at a very very high resolution (many pixels per screen dot), edge
detect the screen dots, use that information to break up the image into cells,
average the darkness for all the dots in each cell, use that color to fill the
entire cell, and then resample that image downwards to the maximum achievable
resolution (whatever that is). As long as screen dots don't overlap you could
even do that separately for each color. I don't know if any existing software
does that. Maybe Fotolook did. Or maybe that's overkill; maybe just a few
samples per screen dot is enough. But I'm pretty sure skipping any of the
CCD's available dots is not a good idea, and I don't know if that's what my
scanner does when I tell it to sample at 133 dpi. (I have an HP IIcx.)
........................................................................
@
/
/ Shift Lever
(D)/
\===================================== @ ================ Floor Plan ===
BMW |- - -Phase Shifter- - - -|--/ Get Wired!
- ------------]=[]@----------------------@ 415.276.4979
Trans- ] ]](A) Toll Free 1.888.208.6655 (B) ? (C) Rear Connection
mission ]]]]]]]]]]]]Driveshaft]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
] ]]
- ------------] web superstation of the stars...
van burnham http://www.futuraworld.com
production manager
wired 520 third street fourth floor san francisco ca 94107 united states
........................................................................
for immediate emergency wireless access send email to van-page(a)wired.com
van(a)wired.com van(a)futuraworld.com pingpong(a)spy.net vanburnham(a)aol.com
Not to ba a prude...but what on earth does this have to do with the
discussion regarding the collecting of classic computers? Archiving?
Not much but it is at least an interesting tangent isn't it?
(Sorry if we're boring anybody.)
--
_______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)bigfoot.com
(_ | |_) Shawn T. Rutledge http://www.bigfoot.com/~ecloud
__) | | \_____________________________________________________________
9806
days inactive
9808
days old
6 comments
5 participants
participants (5)
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aaron＠wfi-inc.com -
cad＠gamewood.net -
dcoward＠pressstart.com -
ecloud＠bigfoot.com -
van＠wired.com