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

Microsoft Kinect: infrared depth maps for dewarping?

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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rob
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Microsoft Kinect: infrared depth maps for dewarping?

Post by rob » 05 Nov 2010, 08:57

So apparently for US$150, you get a device that turns what it sees into a color image and a depth map via infrared. The infrared camera is apparently 320x240, which could be enough data to dewarp book images in real time? But first you might have to wait for the US$2000 bounty for an open-source driver to be claimed.
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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by spamsickle » 05 Nov 2010, 09:29

I dunno. I see this:
We have heard claims that the system can measure distance within 1cm of accuracy at two meters. While that's great in concept, early reviews are showing that you don't get anywhere near that accuracy in the real world—yet.
which (even at 1 cm accuracy) doesn't seem to me to be precise enough for viable dewarping.

If I didn't already have a platen which pretty much flattens things for me, I'd probably be thinking along the lines of two cameras and a projected grid.

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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by daniel_reetz » 05 Nov 2010, 13:44

I am of the opinion that it could be very useful for book scanning. A depth map takes any image-based guessing out of the equation. I'd love to see it tied to an ordinary SLR or something.

I will drop $100 on any open pot for Kinect hacking (you may see my comment on Adafruit to the same effect).

There are a lot of other ways to get a depth map, too. I have some in the works, but we should talk about some of that when we meet next week. :)

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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by daniel_reetz » 05 Nov 2010, 13:53

Fact is, we can probably mod the thing to be "nearsighted" and spread all that resolution over a very thin section (meaning, the thickness of a book).

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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by spamsickle » 05 Nov 2010, 17:58

daniel_reetz wrote:Fact is, we can probably mod the thing to be "nearsighted" and spread all that resolution over a very thin section (meaning, the thickness of a book).
If you're going that route, why not start with something like the GP2D120, which costs $15 and has a range of 2 to 12 inches? http://www.acroname.com/robotics/parts/ ... 2D120.html Maybe that's too close, but these systems come with different ranges. I don't know what the precision is, but I assume you could hook one up to some robotics to do up/down right/left scanning.

I don't know if platen materials (acrylic, glass, or maybe someday Gorilla Glass) reflect IR or not. I'd think even with the information you need to do dewarping, the less of it you have to do, the better.

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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by daniel_reetz » 06 Nov 2010, 00:04

Spam, I love ya man, but I don't think you're quite getting the idea of a depth camera -- it gives you per-pixel depth over the whole scene. Here's an example image: http://cache.gawkerassets.com/assets/im ... eos_97.jpg

Here's one rendered from a 3D environment, nice and clean: http://www.formz.com/forum2/messages/142/19101.jpg

I've used the Sharp thing you linked quite a few times at work. First off, it only gives you depth at a single point. Second, it's easily confused by all kinds of things, including IR from lights (nevermind what the datasheet says). They are noisy. They are confused by materials by different reflectances. I guess I COULD scan it across an entire book and slowly build up a depth map, but that would take forever-- the Kinect runs at 30fps! A bit faster than I can flip.

If you had a depth map of a page, you could dewarp it with just that information. You know I'm a platen guy -- if you can flatten it, do. But I also look forward to building book scanning systems that have nothing to do with the hardware we've been developing. In fact, I have some of them in a rough form, they're just not ready to be released quite yet.
I'd think even with the information you need to do dewarping, the less of it you have to do, the better.
Agreed, 100%... but there are a lot of situations in which a platen is just not ideal...

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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by spamsickle » 06 Nov 2010, 04:14

daniel_reetz wrote:I don't think you're quite getting the idea of a depth camera
I'm sure that's true. I ran across the link I posted while looking for details on how the Kinect works.
daniel_reetz wrote:the Kinect runs at 30fps! A bit faster than I can flip.
Yeah, I've seen the video from Japan where they're scanning some Dick and Jane type book by flipping through it. It looks intriguing, but it's way beyond anything I ever expect to be able to build.
daniel_reetz wrote:I also look forward to building book scanning systems that have nothing to do with the hardware we've been developing. In fact, I have some of them in a rough form, they're just not ready to be released quite yet.
Well, put me on the waiting list, and get back to work!

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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by univurshul » 06 Nov 2010, 12:09

Not a bad deal for a home-use 3D scanner, granted we mod it to do more than the occasional Jazzercise game.

Here's that flipper/gamer-change/magic bottle of Sapporo:
univurshul wrote: Here's another technology to flipping & scanning that's gonna crush every hardware delusion of grandeur: http://www.youtube.com/watch?v=tCOXC5PTJj8&feature=fvw

They're drinking better beer in Japan. Or not drinking at all.

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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by univurshul » 06 Nov 2010, 12:49

...and what about this?:

http://blog.ponoko.com/2010/09/14/maker ... d-scanner/

A DIY 3D scanner? --Probably doesn't doesn't produce a scan rate as the Kinect

...Where are you guys getting your laser cutters?

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Re: Microsoft Kinect: infrared depth maps for dewarping?

Post by daniel_reetz » 06 Nov 2010, 14:31

univurshul wrote:...and what about this?:

http://blog.ponoko.com/2010/09/14/maker ... d-scanner/

A DIY 3D scanner? --Probably doesn't doesn't produce a scan rate as the Kinect
Yeah, I'm not sure the 3-phase stuff is the right way to go, and it's dependent on old hardware...
univurshul wrote:...Where are you guys getting your laser cutters?
I won mine...

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