What's the best way to enhance the image of text to an image where
the text is more recognizable?

Sometimes when you scan a page of text, the text isn't clean.
What's the best graphic method to improve the readability of a
scanned page of text?

-- 
||||||||||||||||     Nehmo Sergheyev     ||||||||||||||||

"Nehmo" <nehmo54@hotmail.com> wrote in message
news:1122662601.132100.238030@o13g2000cwo.googlegroups.com...
> What's the best way to enhance the image of text to an image where
> the text is more recognizable?
>
> Sometimes when you scan a page of text, the text isn't clean.
> What's the best graphic method to improve the readability of a
> scanned page of text?


The best way would be to use OCR software and import actual text into
whatever layout you are using.

"Nehmo" <nehmo54@hotmail.com> wrote in message 
news:1122662601.132100.238030@o13g2000cwo.googlegroups.com...
> What's the best way to enhance the image of text to an image where
> the text is more recognizable?
>
> Sometimes when you scan a page of text, the text isn't clean.
> What's the best graphic method to improve the readability of a
> scanned page of text?
>
> -- 
> ||||||||||||||||     Nehmo Sergheyev     ||||||||||||||||

A good scaner and good OCR software should have little problem. Scaning as 
Black and White and say 300 ppi can help if its bad paper and print
> 

"Nehmo" <nehmo54@hotmail.com> wrote in news:1122662601.132100.238030
@o13g2000cwo.googlegroups.com:

> What's the best way to enhance the image of text to an image where
> the text is more recognizable?
> 
> Sometimes when you scan a page of text, the text isn't clean.
> What's the best graphic method to improve the readability of a
> scanned page of text?
> 

Scan at a very high resolution ie 600 or more

-- 
f=Ma well, nearly...

On 29 Jul 2005 11:43:21 -0700, "Nehmo" <nehmo54@hotmail.com> wrote:

>What's the best way to enhance the image of text to an image where
>the text is more recognizable?
>
>Sometimes when you scan a page of text, the text isn't clean.
>What's the best graphic method to improve the readability of a
>scanned page of text?

 Use OCR software.

 -- 

Hecate - The Real One
Hecate@newsguy.com 
Fashion: Buying things you don't need, with money
you don't have, to impress people you don't like...

Nehmo wrote:
> What's the best way to enhance the image of text to an image where
> the text is more recognizable?
>
> Sometimes when you scan a page of text, the text isn't clean.
> What's the best graphic method to improve the readability of a
> scanned page of text?

The OCR suggestions are good if content is your goal, but since you
asked for graphic methods to improve the image, first use your
scanner software's settings of the black and white points and the
gamma, adjusting them to taste. After that, it depends on what makes
the text unclean. Can you describe the dirt, or better yet put a
sample scan on the web somewhere and post its URL? Alternatively,
sign on to one of the Corel newsgroups listed at
http://tinyurl.com/2pt9o, where you can attach images to your posts.
-- 
Fred Hiltz,  fhiltz at yahoo dot com
C-Tech volunteer

OCR apps require a lot of human input to get a good output,
particularly if the text is difficult to read.  I'm talking about
enhancing the readably of an _image_ of text.

-- 

||||||||||||||||     Nehmo Sergheyev     ||||||||||||||||

"Nehmo" <nehmo54@hotmail.com> wrote in message 
news:1122662601.132100.238030@o13g2000cwo.googlegroups.com...
> What's the best way to enhance the image of text to an image where
> the text is more recognizable?
>
> Sometimes when you scan a page of text, the text isn't clean.
> What's the best graphic method to improve the readability of a
> scanned page of text?


If  you're scanning black or dark text on a light background, I've found 
plain old contrast works the best - other solutions for other combinations.

Flo

"Nehmo" <nehmo54@hotmail.com> wrote in 
news:1122679112.497919.324050@o13g2000cwo.googlegroups.com:

> OCR apps require a lot of human input to get a good output,
> particularly if the text is difficult to read.  I'm talking 
about
> enhancing the readably of an _image_ of text.
> 

If you've followed the other suggestions to make sure you have 
done a high quality scan and you're still having problems making 
it look good, then I suggest you follow Fred's suggestion and post 
the image (or a portion of it) so that we can see what you mean by 
dirty.

I'm assuming from your comment about OCR software that the 
original was already difficult to read, which would make it 
tougher for OCR software to decipher it and make it difficult to 
expect to get a good scan either (i.e., the dirtiness is a result 
of a bad original, not the scanning process).

Regards,

JoeB

[What a strange list of newsgroups you've posted this in!  It's nearly 
off-topic in all but the paint-shop-pro and photoshop groups, so I've 
set followups to there.]

Nehmo wrote:
> What's the best way to enhance the image of text to an image where
> the text is more recognizable?
> 
> Sometimes when you scan a page of text, the text isn't clean.
> What's the best graphic method to improve the readability of a
> scanned page of text?

The best way is, obviously, to recreate the image using an image editor 
and retype the text manually or use OCR and hand-edit.

Anything less is a compromise between quality and ease of application, 
and that's going to be a matter of personal choice.

Meanwhile, here's a recipe that I've used, given poor scans to start with:

* enlarge the image to 600dpi or so, using software that interpolates 
the pixels to do the enlargment.  (Better yet, scan at 600dpi to start 
with.)

* use a "threshold" function to convert the image the black and white, 
manually adjusting the threshold for the best result.

* manually remove the worst of the black-dot noise, if any.

* reduce the image back down to the desired resolution, again using some 
  software that interpolates values rather than simply doing sampling.

Also, if the scan is uneven so that a full-image threshold doesn't work, 
you might find the bitmap-processing software that comes with the 
"potrace" (po-trace, not pot-race!) software -- it's designed for 
specifically that purpose.  (For that matter, the potrace documentation 
talks a little bit about this sort of thing.)

- Brooks


-- 
The "bmoses-nospam" address is valid; no unmunging needed.

One of the things I do is make sure that if the page is thin, that your
scanning, is that I put a sheet of white paper behind it.  This is
especially important if it's a book as it helps to eliminate background
noise from the opposite page.

Then, after it is scanned, if opposite page information has bled through or
the image appears somewhat grey or dirty, I merely adjust the contrast and
brightness to get a cleaner image . . . from time to time it may be
necessary to sharpen or clarify the image some.

Hope this helps.

If you are using OCR, then just scan directly to the OCR program.  Most OCR
programs say that 100-150 dpi is okay, but I always scan at 300dpi.  OCR is
only basing what it's reading on the clarity of the text.  It really doesn't
know what it's reading, just comparing to what it's been programmed to, to
the image you scanned.  So the image should be as clean as possible, unless
you want to do a lot of proofing.

-- 
Chuck

"Nehmo" <nehmo54@hotmail.com> wrote in message
news:1122679112.497919.324050@o13g2000cwo.googlegroups.com...
> OCR apps require a lot of human input to get a good output,
> particularly if the text is difficult to read.  I'm talking about
> enhancing the readably of an _image_ of text.
>
> -- 
>
> ||||||||||||||||     Nehmo Sergheyev     ||||||||||||||||
>

Chuck wrote:
> One of the things I do is make sure that if the page is thin, that your
> scanning, is that I put a sheet of white paper behind it.  This is
> especially important if it's a book as it helps to eliminate background
> noise from the opposite page.

Actually, if it's really bad, black works better, since the text on the 
other side of the page is black -- and thus it "disappears" against the 
black background.

- Brooks


-- 
The "bmoses-nospam" address is valid; no unmunging needed.

"Fred Hiltz" <not@home.ca> wrote in message 
news:jOednZ2dnZ2Iwc63nZ2dnTc2d9-dnZ2dRVn-yp2dnZ0@adelphia.com...
> Nehmo wrote:
>> What's the best way to enhance the image of text to an image where
>> the text is more recognizable?
>>
>> Sometimes when you scan a page of text, the text isn't clean.
>> What's the best graphic method to improve the readability of a
>> scanned page of text?
>
> The OCR suggestions are good if content is your goal, but since you
> asked for graphic methods to improve the image, first use your
> scanner software's settings of the black and white points and the
> gamma, adjusting them to taste. After that, it depends on what makes
> the text unclean. Can you describe the dirt, or better yet put a
> sample scan on the web somewhere and post its URL? Alternatively,
> sign on to one of the Corel newsgroups listed at
> http://tinyurl.com/2pt9o, where you can attach images to your posts.
> -- 
> Fred Hiltz,  fhiltz at yahoo dot com
> C-Tech volunteer
>

An easy way to post an image to the web is to use the free service at
http://www.theimagehosting.com/
just click on browse, find the image on your computer and it's uploaded. No 
registering or anything like that. Then you get various styles of links you 
can use. Takes about a minute. You can use a link that shows only your 
image, but when posting to newsgroups I usually use one that shows the image 
within their web page so that others will see that they can use it too.

--Art 

"Brooks Moses" <bmoses-nospam@cits1.stanford.edu> wrote in message
news:42EB21B6.3040504@cits1.stanford.edu...
> Chuck wrote:
> > One of the things I do is make sure that if the page is thin, that your
> > scanning, is that I put a sheet of white paper behind it.  This is
> > especially important if it's a book as it helps to eliminate background
> > noise from the opposite page.
>
> Actually, if it's really bad, black works better, since the text on the
> other side of the page is black -- and thus it "disappears" against the
> black background.
>

thanks for that tip . . .

-- 
Chuck

I'm asking about image of text improvement, that's  _after_ you
have the image, perhaps already in jpeg format. I'll provide an
example: people often make photostats of small-font law books on a law
library's copy machine. These Photostats are later scanned and put on
a drive as a jpeg.  These images do not OCR well, and if you used an
OCR app and turned the jpeg into, let's say, a .doc, you'd have to
recreate the formatting as well.

So is there a usual method of improving the readability of an image of
text (dark text on a light background)?

Contrast adjustments are a logical effort, but I, personally, haven't
been able to improve readability much with those.

I'm not talking about one particular example, I asking in general.
The common factor would be that the resolution of the image of the text
has deteriorated - the edges of the text are blurred to varying
extents.

--
||||||||||||||||     Nehmo Sergheyev     ||||||||||||||||

nehmo54@hotmail.com wrote:
[snip]
> So is there a usual method of improving the readability of an
> image of text (dark text on a light background)?
>
> Contrast adjustments are a logical effort, but I, personally,
> haven't been able to improve readability much with those.
>
> I'm not talking about one particular example, I asking in general.
> The common factor would be that the resolution of the image of
> the text has deteriorated - the edges of the text are blurred to
> varying extents.

There is no "usual method." Thinking back on projects where I have 
cleaned up text, I have almost always used a histogram adjustment, 
frequently used unsharp mask, frequently used the salt and pepper 
and despeckle filters, occasionally used color separations, 
occasionally used edge preserving smooth, and occasionally used high 
pass filtering.

Others will have used other techniques, I am sure. It depends a lot 
on the particular image and somewhat on your own tastes. That is why 
we asked for samples.
-- 
Fred Hiltz,  fhiltz at yahoo dot com
C-Tech volunteer 

nehmo54@hotmail.com wrote:

> I'm asking about image of text improvement, that's  _after_ you
> have the image, perhaps already in jpeg format. I'll provide an
> example: people often make photostats of small-font law books on a law
> library's copy machine. These Photostats are later scanned and put on
> a drive as a jpeg.  These images do not OCR well, and if you used an
> OCR app and turned the jpeg into, let's say, a .doc, you'd have to
> recreate the formatting as well.
> 
> So is there a usual method of improving the readability of an image of
> text (dark text on a light background)?
> 
> Contrast adjustments are a logical effort, but I, personally, haven't
> been able to improve readability much with those.
> 
> I'm not talking about one particular example, I asking in general.
> The common factor would be that the resolution of the image of the text
> has deteriorated - the edges of the text are blurred to varying
> extents.

You have a whole sack of poo.

JPEG is a crap format, especially for text. It is a lossy compression 
method, and it discards text particularly well.

The best method is to rescan them properly.

Eric

Harry Limey wrote:
> "Nehmo" <nehmo54@hotmail.com> wrote in message
> news:1122662601.132100.238030@o13g2000cwo.googlegroups.com...
> 
>>What's the best way to enhance the image of text to an image where
>>the text is more recognizable?
>>
>>Sometimes when you scan a page of text, the text isn't clean.
>>What's the best graphic method to improve the readability of a
>>scanned page of text?
> 
> 
> 
> The best way would be to use OCR software and import actual text into
> whatever layout you are using.
> 
> 
OCR works well when the scan is good, so your suggestion won't solve his problem.  With 
PSP 8, I find that unsharp mask helps a scanned page of text to work better with my OCR 
program - Read Iris Pro.  Like other OCR programs, Read Iris Pro wants scans made at 300 ppi.

Hi,
Well, there are many ways to improve image quality, some very good
suggestions have been given here.

Some techniques are background noise filtering, others are removal of
"grid" items, or pixels that cannot possibly be text, and applying
filters to smooth the text.

Unless one sees the image though, one cannot really suggest the best
method.

Could you send me your image to info AT ideatechnosoft DOT com? You
could also send us your current results. Your data and image will
remain confidential.

Best Regards,
Milind Joshi
IDEA TECHNOSOFT INC.
http://www.ideatechnosoft.com

Try using "levels" rather than contrast.  With levels play with using the
sliders on either end and in the middle.  Much better than contrast.  When
you use the contrast tool...you contrast the whole image.  WHile using
levels (or curves) you can darken your darks and lighten your lights...trust
me..it works...it just takes a bit of getting used to.

i never ever ever ever ever ever use the brightens and contrast tool.  THat
was lesson #1 at NYU.


"Milind Joshi" <milind.a.joshi@gmail.com> wrote in message
news:1123180020.205116.130700@g43g2000cwa.googlegroups.com...
> Hi,
> Well, there are many ways to improve image quality, some very good
> suggestions have been given here.
>
> Some techniques are background noise filtering, others are removal of
> "grid" items, or pixels that cannot possibly be text, and applying
> filters to smooth the text.
>
> Unless one sees the image though, one cannot really suggest the best
> method.
>
> Could you send me your image to info AT ideatechnosoft DOT com? You
> could also send us your current results. Your data and image will
> remain confidential.
>
> Best Regards,
> Milind Joshi
> IDEA TECHNOSOFT INC.
> http://www.ideatechnosoft.com
>

I had some success with Photoshop filters on 300 dpi tiff scans.
Time  consuming though because it has to be done page by page.