Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

An acrobat question

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An acrobat question

Post by cfmorrill » 07 Jan 2012, 09:46

So I'm at the beginning of the curve in learning to use Acrobat 9 for Mac to OCR my camera images. I installed acrobat pro o.k. Next, I attempted to OCR a very simple picture of a sign from a museum conference. Acrobat responded it could not do this as the image was greater than 45 X 45 inches. How the heck could it know? Any idea what makes it think images are a certain size in inches? The image was taken with a Canon Powershot point and shoot camera.


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Re: An acrobat question

Post by rob » 19 Jan 2012, 14:59

The images that come out of your camera have no dpi information in them, so there is no way to tell, absent any context, how big the features in an image are. But the default assumption is 72 dpi for whatever reason. My understanding is that OCR programs are optimized for text within a certain font size at 300 dpi, so it's possible that what Acrobat did is look at your image, note that the letterforms were quite huge (too many pixels per letter!), and assuming 72 dpi, 45 inches is 3240 pixels or so, and that may be what it based the "too large, 45x45 inches" output on.
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Re: An acrobat question

Post by blueblazer » 03 Feb 2012, 17:17

Try fixing the DPI's with Scan Tailor first.

You'll have to convert you PDF to TIFF the back again, but it should make things work well. I use Acrobat for my OCR and it tends to work alot better if you run everything through Scan Tailor first, no matter what it is.

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