I haven't done any work at all on dewarping, but I have done away with the platen and contented myself with scanning "warped" pages for the past couple of years.
If I've said this before I apologize for repeating myself, and for letting the answer from someone who knows better slip my mind, but it seems to me that the two laser line scanning assumes the page is "cylindrically" warped, i.e., that the variance from flat is constant from the top of the page to the bottom. That may be a reasonable assumption in some cases -- it looked like Steve's video had him holding the pages at the sides, while the book was flat on the table, and that probably makes the warp pretty cylindrical.
I've noticed however that many times the warped pages I create are more conical than cylindrical, and I'm wondering if this method would still be workable. I still use a 90-degree cradle to hold my books, and two cameras to shoot, but I hold the pages down at the bottom of the book with one or two fingers. Typically, this means that the top of the book bows out more than the bottom, and the shape of the warped page would be more like a cone than a cylinder. It doesn't really matter, because I'm not shooting with lasers anyway, but I wondered what kind of results people are getting by generating a height map using two laser lines. If you calibrate from a flat table, maybe this technique could still handle more conical warping, but it seems like it would be a lot more difficult to calculate than (I assume) the height as a function of the distance between the two lines.
But what I really returned to this thread to seek, and since I don't see it, to mention, is that LeapMotion device
. Apparently there was a lot of buzz about it last summer, but I only heard about it recently, which is just as well since I'm not the most patient person. It's not set to ship until May 13, 2013, so being out of the loop hasn't cost me much.
The specs say it has 0.01 mm precision, and senses over a 2-foot radius, so it would almost appear to be designed for scanning small 3D shapes like books. I'm not sure what flexibility the SDK will provide, because I just applied and who knows where that will go. I'm sure their drivers are written to detect and track hands, fingers, and motion, but it should be possible to get 3D information somehow before all that post-processing happens; at least, I hope so.