Gregory Maxwell wrote: > For digitizing what?
Exactly, that's the first question. > Archive.org digitizes books using a pair of canon 1Ds (? perhaps > it was a 5D? In any case the 5DII would be sufficient now) on a > custom stand with a hacked up copy of gphoto2 to actuate the > cameras. That's Brewster Kahle doing things many years ago (2002? 2003?). Today, a much cheaper low-end digital SLR, or even compact cameras will give you the needed 10 or so megapixels. But again, if you need to pay your staff, a ten times more expensive camera might easily pay its own cost in increased speed, or increased shutter lifespan. > I'm not sure how they're dealing with curvature (I think they > just may lay a glass plate on the pages), but it would be easy > enough to solve using a laser pointer with a pattern generating > holographic grating and a second exposure to capture the page > distortion and some fairly simple software processing after the > fact. The Internet Archive apparently uses a fixed glass, and lowers the book cradle to turn pages, http://aipengineering.com/scribe/ Other designs have a fixed book cradle and lifts the glass, e.g. the Atiz DIY, http://diy.atiz.com/ I thought the Internet Archive design was very clever, since it keeps a fixed distance from lens to book surface (beneath the glass), until I saw the bkrpr.org where you just lift everything. That's a design for 2009! I haven't tried to build one myself yet. ---- However, you can capture lots of books (that can be opened fully) with a single camera, laying the book flat on a table with a glass on top. That's just like a flatbed scanner (but much faster) turned upside down. In January 2008, I used a 10 megapixel Canon EOS 400D (Digital Rebel XTi) with a 50 mm lens to shoot this, laying flat on a table under a glass, http://runeberg.org/stridfin/0226.html On that webpage, the image is reduced to 120 dpi (1.2 megapixel), but the original is 300 dpi (7.5 megapixel). The map shown is reused in http://en.wikipedia.org/wiki/Battle_of_Alavus That's an example of how one specialized book can be very useful for a limited Wikiproject. This book was published in 1909 for the 100th anniversary of the Finnish War (1808-1809), and digitized in 2008 for the 200th anniversary. -- Lars Aronsson ([email protected]) Aronsson Datateknik - http://aronsson.se Project Runeberg - free Nordic literature - http://runeberg.org/ _______________________________________________ Commons-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/commons-l
