Amanda P wrote:
> Cameras around $100 dollars are very low quality. You could get no where
> near the dpi recommended for materials that need to be OCRed. The quality of
> images from cameras would be not only low, but the OCR (even with the best
> software) would probably have many errors. For someone scanning items at
> home this might be ok, but for archival quality, I would not recommend
> cameras. If you are grant funded and the grant provider requires a certain
> level of quality, you need to make sure the scanning mechanism you use can
> scan at that quality.

To capture an image 8.5 x 11" at 300 dpi, you need roughly 8.4 
megapixels, which is well within the capabilities of an inexpensive 
pocket camera. (If you need 600 dpi, then you're in the 33.6 megapixel 
range.) As to whether the quality will be sufficient, this would depend 
on the goals and requirements of the project, but 300 dpi should be 
enough to get good OCR results for normal-sized text. Our very old 
version of PrimeOCR recommends 300 dpi, and suggests that 400 dpi may 
provide substantially better quality for text sizes smaller than 8 
point, while 200 dpi will be sufficient for text 12 points and up. At 
300 and 400 dpi on 19th Century small-print, variable quality texts, we 
are generally getting good to very good recognition: the quality of the 
original document itself is the limiting factor. More modern documents 
(and OCR software) should produce even better results. The cameras used 
by the Internet Archive are only 12 megapixels, though they are of 
substantially higher quality than a Canon PowerShot.

Some applications require very high quality images, and cheap cameras 
might not be able to deliver the goods, but if you just want to make 
sure the text of your documents is digitally preserved and/or available 
to read online, you don't really need all that much in the way of 
hardware. Using a pocket camera and a stand to digitize more than a few 
pages is going to be slow, clumsy and painful, but for many 
applications, the end result may be entirely acceptable.

-William