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

Laser Scan Methods

DIY Book Scanner Skunk Works. Share your crazy ideas and novel approaches. Home of the "3D structure of a book" thread.
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Re: Laser Scan Methods

Post by duerig » 06 Dec 2014, 19:58

mhr, that is an intriguing thought. I very much like the idea of being able to scan as fast with this technique and not wait for an extra shot. I've even semi-seriously toyed with the idea of using a colored LED bulb (green, say) to light the book and take a single picture, using the green color channel for a grayscale picture and the red channel for the lasers.

I don't know enough about light and optics to know if the polarization method would work. But the pre-requisite is being able to take two camera pictures and figure out which pixels on one are matched with which pixels on the other. So I think that is the place to start. If you have two cameras a known distance apart, how do their fields of view map onto one another? This has to be a solved problem because this is how '3d' cameras work right now. So that is the direction to look into.

If we have that, then things might be sped up with or without polarization. Turning on and off lights/lasers takes almost no time at all. So whether the two photos are really simultaneous or whether they are offset by a couple-hundred milliseconds, this would work.

As an aside, I know that many DSLRs are capable of very fast multi-shots. You can turn them on 'continuous mode' and take up to 5 frames a second or so of full-size photos. But I haven't yet figured out how to make it go that fast when controlling them via gphoto. So that is another avenue to explore as well.

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