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scanning tecchniques?

R

rebeltaz

Experienced Member
Joined
Nov 9, 2008
Messages
195
Location
Shelby, AL
I have VIC-20 and Plus/4 (both Commodore) manuals that I would like to scan and make available on my web site (I will link to them here as well) since I cannot find them in PDF anywhere.

I discussed, in another topic, how to scan bound materials, but I need to know the best DPI to scan at. I assume that a single PDF is preferred. I know I prefer it that way. I also know to use a sheet of black construction paper behind each page to prevent bleed through.

Any other advise would be great. I just can't believe that, with the amount of info available on these systems, no one else has every scanned these two manuals!
 
Would you store that as one big PDF full of images or perform OCR on the text, recreating the font and layout to a more light-weight and professionally scanned document? Many manuals are available as e-texts, that is with any illustrations removed or replaced by ASCII graphics. I don't know if these particular manuals exist, but at least the VIC-20 Programmer's Reference Guide is once scanned in that format.
 
Because storage is getting cheaper, I have started doing two things:

  1. Using Acrobat's OCR-but-retain-the-images mode so that PDFs of full images can be searchable, and
  2. Run the images through a better OCR program to produce an ASCII .txt

This gives everyone what they want.
 
200 or 300 DPI might be right, but don't do bitmaps. Grey-scale works much better and is much easier to read.

I scan at 300 DPI grey-scale at a minimum, and color if necessary. I touch up the originals a little bit, then try OCR. I also keep the original images around. Converting to searchable PDF files is a good way to distribute.

What are people using for OCR and PDF generation now? I'm using an old copy of Acrobat and looking at upgrading.
 
rebeltaz said:
I have VIC-20 and Plus/4 (both Commodore) manuals that I would like to scan and make available on my web site (I will link to them here as well) since I cannot find them in PDF anywhere.

I discussed, in another topic, how to scan bound materials, but I need to know the best DPI to scan at. I assume that a single PDF is preferred. I know I prefer it that way. I also know to use a sheet of black construction paper behind each page to prevent bleed through.

Any other advise would be great. I just can't believe that, with the amount of info available on these systems, no one else has every scanned these two manuals!
Click to expand...

Actually, I believe that I have the VIC-20 manual on my Web site:
http://www.classiccmp.org/cini/systems.htm

Look 1/3 down the page in the Commodore section.

I scan most stuff at 300DPI using a high-volume scanner here at work. Manuals that I don't want to destroy or that don't come appart (like bound books), I Xerox copy first, then scan. 300DPI is probably overkill, but I can downsample if I have to using Acrobat Version 9 (what I have here at work; I use A8 at home).
 
Hi Rich
Could you pleas fix one of your PDFs. The IMSAI
manual only shows 1/2 of the schematic for the
CPA front panel ( fig3 on page 150 ). It would be
great to have the entire schematic on line.
Dwight
 
The schematic on page 150 (Chapter 4) is actually specific to the modification that is circled. I have all of the schematics -- why I didn't scan them previously I don't know. I will do it tomorrow at work and post a revised PDF this weekend.
 
I posted both the C64 manual and the revised IMSAI binder this evening. Just a warning, the C64 manual is 63mb. I haven't been able to get it much smaller with optimization without going to B&W from grayscale (there are some detailed pictures that I thought warranted grayscale). I suppose at some point I could downsample all but the most detailed pages, but I wanted to get this posted.
 
RichCini -> How do you prevent the "bent page" look on manuals that don't come apart? Your scans are fantastic BTW :)
 
rebeltaz said:
RichCini -> How do you prevent the "bent page" look on manuals that don't come apart? Your scans are fantastic BTW :)
Click to expand...

Thanks!

Usually what I do is copy them on a Xerox machine and press lightly on the cover. Be careful with old bindings since the glue can break. Some shading is inevitable but if the book is smaller than 8.5x11, you can crop the page to its final size, eliminating some of the shadow. Alternatively, if you scan to JPG first, you can edit the files with a regular graphic editing program to eliminate the shadow.

I scan right to PDF so I mostly use cropping.
 
There are scanners that are specifically for scanning books; they have glass that runs right up to the edge of the unit, and you hang your book there. They also typically come with slightly specialized scanning software that looks for bending/shadowing in one side of the scan and tries to correct it.
 
Trixter said:
There are scanners that are specifically for scanning books; they have glass that runs right up to the edge of the unit, and you hang your book there. They also typically come with slightly specialized scanning software that looks for bending/shadowing in one side of the scan and tries to correct it.
Click to expand...

That would be awesome.. Any idea on a model? Or how I should search for that?
 
I would google "book scanner" or "book scanners" for a few starting points. I recall the cheaper ones were around $300.

There are some AWESOME ones meant for fragile books (they hold the book open at a 90-degree angle, use a high-res camera to take pictures from above, and use light suction cups to turn pages) but those have 5-digit costs.
 
Trixter said:
they hold the book open at a 90-degree angle, use a high-res camera to take pictures from above
Click to expand...

I don't think I could swing three digit prices, much less five!:(

I was thinking about trying to make something like that myself. I have several digital cameras with macro lens sets that I could use. Doesn't sound too hard. I think the hardest part would be getting the lighting right.
 
Back in the days of non-digital photography, there was a device called a "copy stand".

This was a flat board, a column with a height adjustable tripod mount and a pair of gooseneck lamps (one on each side of the column).

The lamps gave flat lighting while the tripod mount could be raised or lowered to give the exact coverage.

They have, probably, long since fallen out of favour and might be found for cheap or nothing, with a little searching.
 
I'm sure copy stands are still around, afterall the need for non blurry pictures and even lighting hasn't gone away - photoshop/gimp nonwithstanding.

Normal cameras don't exactly replace scanners though. There will always be a problem with the limits of diffraction in optics. The wavelength of visible light is not going to change any time soon. :) That is why you can't get more than 1000x out of an optical microscope unless you go to shorter and non-visible wavelengths - and very expensive optics! Early photocopiers using lenses, improved the situation by using monochrome (green) light and designing the lens for that specific frequency. They also used extremely high f-stops to avoid the blurring effect of the light being bent by the edge of the apeture. Scanning technology is much better for many things.

Ah, the days of real photography. (sigh)

Edit: By "high f-stops" I meant large diameter...sorry. The stop is actually the diameter divided by the focal length. I should have said "low" f-stops" because you get a low number when you have a large diameter.
 
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rebeltaz said:
I don't think I could swing three digit prices, much less five!:(

I was thinking about trying to make something like that myself. I have several digital cameras with macro lens sets that I could use. Doesn't sound too hard. I think the hardest part would be getting the lighting right.
Click to expand...

No, the hardest part would be a high-enough resolution camera. Even a 10MP camera is sorely lacking enough resolution to make proper OCR possible.
 
Trixter said:
I would google "book scanner" or "book scanners" for a few starting points. I recall the cheaper ones were around $300.

There are some AWESOME ones meant for fragile books (they hold the book open at a 90-degree angle, use a high-res camera to take pictures from above, and use light suction cups to turn pages) but those have 5-digit costs.
Click to expand...
I used to get really good results copying books from an old Xerox analog copier we had at work that was photographic instead of optical. Instead of having a green light bar scan back and forth, it had a lens down inside the glass and it would trigger a strobe when making a copy, just like a camera flash. You just had to remember to look away during the flash or else you'd be seeing spots for a while! :lol:
 
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