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Scanning to B & W vs. Gray Scale?

 
 
Chumly
 
Reply Fri 3 Dec, 2010 10:19 pm
Hi A2k'ers,

When scanning @ 600 DPI to PDF files:

Are there any disadvantages in scanning to gray scale, outside of the larger file size? I am talking about scanning @ 600 DPI to PDF only. Not other resolutions or other file types.

There seems to be several advantages to scanning to Gray Scale AFAICT:

1) One of my OCR programs tells me it's more accurate with gray scale.

2) I've noticed when scanning hand written text in pencil, it works much better with gray scale.

I wonder though...if I have hard copy I wanna scan, but the text is a bit faded, would I get a clearer scan by choosing black and white instead of gray scale?

The reason I ask is...if the source text is a bit faded, then instead of interpolating the text in shades of shades of gray, it would interpolate all text as pure black, so it would come out with more contrast than the original faded text...or am I wrong here?

Thanks!
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Type: Question • Score: 1 • Views: 11,802 • Replies: 17
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Rockhead
 
  1  
Reply Fri 3 Dec, 2010 10:30 pm
@Chumly,
what's a pencil?
Ceili
 
  1  
Reply Fri 3 Dec, 2010 10:32 pm
try both.
Chumly
 
  1  
Reply Fri 3 Dec, 2010 10:59 pm
@Ceili,
I have.
0 Replies
 
Chumly
 
  1  
Reply Fri 3 Dec, 2010 11:03 pm
@Rockhead,
...tool that gets shorter with use.
Rockhead
 
  1  
Reply Fri 3 Dec, 2010 11:05 pm
@Chumly,
seen any bears lately?
Chumly
 
  1  
Reply Fri 3 Dec, 2010 11:10 pm
@Rockhead,
Just Psychedelic Furs...Pretty in Gray Scale.
0 Replies
 
hingehead
 
  2  
Reply Sat 4 Dec, 2010 02:53 pm
@Chumly,
Yep, scanning low contrast text can be a lot clear in B&W, but light blemishes in the paper can suddenly become prominent depending on thresholds.
Chumly
 
  1  
Reply Sat 4 Dec, 2010 04:25 pm
@hingehead,
Ah I see...Adobe Acrobat Pro 9 has a despeckler which seems to help, have you tried it?
hingehead
 
  2  
Reply Sat 4 Dec, 2010 04:32 pm
@Chumly,
Acrobat pro drives me insane - I use it professionally and I'm at a loss why an OCR'd file gets so big - why can't it just store the UTF-8 code and call an external font? But no, it wants to store the original scanned bitmap of the letter. File size matters in the context we use it. Read Out Loud is kind of fun though.

I am talking CS 3 though, haven't had a play in CS5.

We use paperport for despeckling.
Chumly
 
  1  
Reply Sat 4 Dec, 2010 08:23 pm
@hingehead,
Ah then you’re just the guy I need to talk to please kind sir!

When scanning at home, I go from my Canon MF4150 to Adobe Acrobat Pro 9 and it despeckles and deskews. However Adobe Acrobat Pro 9 cannot deskew at more the 17 degrees (I think it is) so I've read you need Photoshop (or equivalent) and have to adjust each page manually (what a pain in the butt if true).

What I would much prefer is a despeckling and deskewing all-in-one application that can handle larger angles than 17 degrees.

As far as OCR I am open to suggestions as to which you think is best.

In fact I am open to any suggestions you have to get the best possible scans from text that is faded, and/or old, and/or photocopied too many times, and/or speckled, etc.

--------------------------------------------------------------------------

Here is another question I hope you can help with. When scanning at work I've been trying to find a simple easy method to handle larger scanned pdf files, but I have not been able to.

When using the Canon ImageRUNNER 7086 to scan documents to pdf, they get forwarded as attachments via email. The problem is the pdf file gets chopped into small scraps of about 800 KB to 2 MB each. That translates to only about six double-sided pages at 600 DPI per attachment. This means larger pdf scans use many separate emails. This turns out to be very impractical and time consuming because I have so many divided files to deal with.

Is there some way to stop the Canon ImageRUNNER 7086 from dividing a scanned pdf into many separate emails? Or is there some way I can scan to pdf and then access the file via FTP? Or is there some way I can scan to pdf and have the file available on the network Shared Drive? Or is there some way to access the file via USB or Ethernet directly from the Canon ImageRUNNER 7086 to my laptop?

The bottom line is, I wish to simply and easily and quickly scan lager documents @ 600 DPI to pdf as a single file, and then offload the file to my laptop.

Also the Canon ImageRUNNER 7086 seems to only scan to pdf in Black and White and not Gray Scale, but why might that be? It will scan to tiff @ 600 DPI, but I do not if that would be a good thing or not. What say you?

----------------------------------------------------------------------------

Also as a general question for both home and work, if I have a document scanned in as a pdf @ 600 DPI can I despeckle and deskew later or does that process have to be done while the data is actually being transmitted by the scanner in real time?
Rockhead
 
  1  
Reply Sat 4 Dec, 2010 08:49 pm
@Chumly,
are you studying to be a spy?

I used to have one of those little pen cameras. worthless crap...

but your equipment sounds groovy.
Chumly
 
  1  
Reply Sat 4 Dec, 2010 09:04 pm
@Rockhead,
No such luck!

I teach Electrical for a living and there are a number of Instructors at our Technical Institution that have been here for 30 years. Thus they have a large collection of hard-copy material suitable for distribution in my class.

However I need to scan it all in, and categorize it etc, to be of any practical long term use to me.

If I do not scan it all in, and categorize it etc. I'll end up with tons and tons of hard-copy material and I'll have to sort through and copy it each and every time I want to give the students some handouts for homework etc.

So any advice you might have about streamlining and improving efficiency and scan accuracy would be appreciated.

I have been on a technical legal website (I forgot the name) in which people spend great deals of time and energy scanning and categorizing hard-copy to pdf but I cannot recall the name of the forum website, and I did not get any useful information. Not to say that there would be no useful information there if I could remember the forum website's URL.
Rockhead
 
  1  
Reply Sat 4 Dec, 2010 09:09 pm
@Chumly,
gotta say, being a spy sounds much more fun and exciting.

but at least you have that large penis working for you...
0 Replies
 
Chumly
 
  1  
Reply Sat 4 Dec, 2010 09:27 pm
Everything comes down to size at some point.
0 Replies
 
hingehead
 
  1  
Reply Sun 12 Dec, 2010 08:07 pm
@Chumly,
Sorry Chumly - you floated off the first page of my posts.

We're stuck with Xerox scanning with Paperport to build docs and acrobat CS4 to OCR publish files. There may be something better out there but we don't have leeway to experiment.

I posted my question about Acrobat's weird PDF OCRing to a listserv but got only commiserations and no answers.

Can't help you with the Canon imagerunner - don't suppose you have an onsite support contract? You might luck out actually contacting Canon, or downloading a manual? This isn't meant to sound like I'm teaching you to suck eggs - you've probably already done this, but I don't know squat outside our tools and that's what I'd do in your situation.
0 Replies
 
hingehead
 
  1  
Reply Sun 12 Dec, 2010 08:08 pm
@Chumly,
Missed your last question!

You don't have to despeckle in realtime.
0 Replies
 
Chumly
 
  1  
Reply Sun 12 Dec, 2010 11:12 pm
Thanks hingehead!
0 Replies
 
 

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