Re: How Do I Scan Newsprint Without Bleedthrough?

  • Thread starter Thread starter Davy
  • Start date Start date
D

Davy

Hi Jim
When ever I scan a newspaper I sometimes put a black card, o
something black behind the page, about the only thing you can do
guess to stop 'print through' from the other side. Hope it helps

Dav
 
Davy said:
Hi Jim.
When ever I scan a newspaper I sometimes put a black card, or
something black behind the page, about the only thing you can do I
guess to stop 'print through' from the other side. Hope it helps.

Davy
Click to expand...

You can scan using B&W and adjust the threshold level until the background
print through disappears.

Also you can adjust the contrast level after the scan in a Photo Editor.
The idea is to adjust the white point until there is no print through
showing.

You clip the white end of the histogram.
 
You can scan using B&W and adjust the threshold level until the background
print through disappears.

Also you can adjust the contrast level after the scan in a Photo Editor.
The idea is to adjust the white point until there is no print through
showing.

You clip the white end of the histogram.
Click to expand...

I had a similar problem trying to scan some old letters my mother had written
from France in 1918. They were written on poor quality paper, sometimes in pen,
sometimes in ink, and sometimes in both, on both sides of the paper. A black
backing does help, but even then with these letters, and often also with old
newspaper advertisements, it is quite impossible to eliminate the bleed through
by the method CSM1 suggests without also effectively eliminating the content.

I did some experiments with scanning both sides of the document and then
subtracting the scan of the back from that of the front. This is decidedly
fiddly -- especially in getting the two sides to line up -- but it can give a
significant improvement. I have written some technical notes on the subject
which you can see at http://www.corybas.com/Technical/Experimental.htm.

I have since seen how I think this process could be significantly improved, but
I have not had time to test my ideas.

James McNangle
 
James said:
I had a similar problem trying to scan some old letters my mother had written
from France in 1918. They were written on poor quality paper, sometimes in pen,
sometimes in ink, and sometimes in both, on both sides of the paper. A black
backing does help, but even then with these letters, and often also with old
newspaper advertisements, it is quite impossible to eliminate the bleed through
by the method CSM1 suggests without also effectively eliminating the content.

I did some experiments with scanning both sides of the document and then
subtracting the scan of the back from that of the front. This is decidedly
fiddly -- especially in getting the two sides to line up -- but it can give a
significant improvement. I have written some technical notes on the subject
which you can see at http://www.corybas.com/Technical/Experimental.htm.

I have since seen how I think this process could be significantly improved, but
I have not had time to test my ideas.

James McNangle
Click to expand...

If I recall rightly Epson actually suggest the black paper behind the
document trick.
 
Davy said:
Hi Jim.
When ever I scan a newspaper I sometimes put a black card, or
something black behind the page, about the only thing you can do I
guess to stop 'print through' from the other side. Hope it helps.

Davy
Click to expand...

The black card is the best way to do this, black cheap construction
paper works too. I have a file called "black" and just print a black
page from the office laser printer. This works with book, too.
Especially with new paper I feel that a grey scale setting works better
than B&W which often drops text, when the drops are eliminated it is
blocking up other portions. So I use grey scale and if I need pure B&W
I'll set a black point on the text.

Tom
 
(e-mail address removed) (Davy) wrote in @fe12.news.easynews.com:
Hi Jim.
When ever I scan a newspaper I sometimes put a black card, or
something black behind the page, about the only thing you can do I
guess to stop 'print through' from the other side. Hope it helps.

Davy
Click to expand...

I use a piece of black matting/cardboard that was purcahsed at a craft
store.

A much better option for newspaper materials is taking the newspaper to
somebody that has a "quality" copy maching with a "good" toner cartridge
installed and coping the material to white pages.

There will not be any bleed through.

Then scan the white pages.
 
Don said:
(e-mail address removed) (Davy) wrote in @fe12.news.easynews.com:


I use a piece of black matting/cardboard that was purcahsed at a craft
store.

A much better option for newspaper materials is taking the newspaper to
somebody that has a "quality" copy maching with a "good" toner cartridge
installed and coping the material to white pages.

There will not be any bleed through.

Then scan the white pages.
Click to expand...

Presumably the copy machine has a scanner at its heart. So why does
the copy machine do it right, and the scanner not? What's different in
the settings?

Or does the copy machine NOT have a scanner at its heart? I'm not
quite sure what it COULD have...
 
Don said:
A much better option for newspaper materials is taking the newspaper to
somebody that has a "quality" copy maching with a "good" toner cartridge
installed and coping the material to white pages.

There will not be any bleed through.
Click to expand...

B#$@!*&^t!

I have a large collection of old black and white newspaper advertisements where
the ink from the printing and illustrations on the back of the page has bled
through the paper, and is obvious on the front. I also have a number of old
letters were the same thing has happened, and I have some colour advertisements
on cheap paper where the different coloured inks on the back of the paper have
bled through at different rates.

There is no way in hell any scanner -- however good -- will get a clean scan out
of these. The only possible way of getting a reasonable scan out of this type
of material is to scan both sides, superimpose the two scans, and subtract the
one from the other, with suitable scaling factorowns. All very time consuming
and tricky!


James McNangle
 
Presumably the copy machine has a scanner at its heart. So why does
the copy machine do it right, and the scanner not? What's different
in the settings?

Or does the copy machine NOT have a scanner at its heart? I'm not
quite sure what it COULD have...
Click to expand...


Perhaps it's "Ripley's Believe it or Not?"

I've scanned and copied 120 year old newspaper articles from a publication
known as "Horse Review".
The pages are oversized at 11 x 17 and the paper quality is very thin. At
times there is bleed through from a back page that has a very dark graphic,
however for the most part the text copies just fine.

Better quality copy machines have a higher depth-of-field that scanners.
I don't care to understand the technology, only to accept that it works
for me.
There have been some previous discussions between myself and another in
this same NG. This person was interested in scanning text lines from old
and yellowed Daily Racing Forms.
A copy machine negates the yellowing. Why, I'm not sure, nor do I care. My
only interest is that it works effectively.
 
Sorry if this has been previously mentioned in this thread, but have you
tried replacing/taping over your white insert in the lid of your scanner
with something matte black? As has been discussed here a few times, that
can help.

Doug
 
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