One of the bad things about being the “DIY BOOK SCANNER guy” is that people always ask “DOES IT TURN PAGES?”.

Well, my friends, it turns pages.

jck57/Monson’s Servo Auto Scanner.

DIY Page Turner from Berlin Hackerspace C-Base:

dtic was among the page-turning pioneers of our forum:
Revision 1:

Revision 2:

jck57/Monson is actually building a full-auto scanner, check out his other impressive engineering:

Few people know that Dell made high quality laptops with an all-metal chassis – the Precision line. This machine had an ultra-high resolution display, Quadro workstation graphics, and near-mil-spec construction. It has survived dozens of things that killed lesser machines. It has outlived every other computer I own. In the process, I’ve worn hand-and-arm-marks into the palmrests, scratches into the screen, polished the capacitive surface from the touchpad, and caused the paint to peel from the bottom. In a way, I think the super-crufty filesystem and ever-crowded desktop are also wear and tear. I feel at home on this machine.

This machine changed my life. I bought it in 2005 with money I earned working on Slator’s projects. On this machine, I came into my own as a 3D modeler[QT]. I authored You Are Not Dead, the album. I processed thousands of photographs and countless hours of video. This machine has been to Fargo, Moscow, Toronto, New York, Vancouver, Los Angeles, Kennedy Space Center, and Kandalaksha. These days, it runs my radio rig, decoding all kinds of interesting things. I think we still have a few solid years of work to do together.

In part, this was the goal of the Kinect hacking I’ve been doing, but for the moment, I’ve sidelined that effort to try out a bunch of other, simpler, cheaper approaches. I’m going to post some of them here to get them down on record and keep them from getting lost in the book scanner forum swell.

Although the forum post contains non-DIY Book Scanner methods, this post will only cover a few new things that we’ve developed in the forum, or that I’ve come up with myself. It’s not a complete list by any means. See the forum post for that.
Feel free to comment with new ideas or better resources.

METHODS:

1. Look at the lines of text or borders of images on a page and extract the page curvature from them.

Apps that do this:
Scan Tailor

Drawbacks: Not all books have clean lines to follow, and not all pages in all books have clean lines to follow. Not all lines of text are in the order you expect. Can’t work for concrete poetry or pages of drawings. However, this method does work well, when it works. Getting better all the time.

2. Using the Kinect for direct depth sensing of the book surface.

Apps that do this: Not exactly an app, but the libfreenect/OpenKinect driver gives the depth image.
Rob proposed the idea here and I got the first few depth images of books here — there’s a long way to go on this project and we could use a little help to see if the data straight from the device are worthwhile. It may also be possible to get a close-range PrimeSensor. I will be contacting PrimeSense to feel out the possibilities.

Drawbacks: Right now, the Kinect’s resolution is spread across a living-room size space. We’d like it spread across a few inches. I’m working on this.

3. Using Sharp sensors for extracting the curvature at several lines on a page.

Spamsickle proposed this here and though at first, I didn’t like the idea, after discussing it more with Spam and Rob, I have come to really like it, it is simple, efficient, and might work (if the Sharp sensors weren’t so awfully noisy/messy). I have the Sharp sensors laying around in a box and just need to build a rig for testing. The idea right now is to have a rod extending over the book with two of these sensors. By sweeping them across the surface of the book, you’d get the distance exactly.

Drawbacks: These Sharp sensors are noisy and they would need to be mechanically moved across the page to work.

4. Using a laser line to get a reliable line to follow for dewarping.

A laser pointer or diode can easily be made into a laser line by using a cylinder lens to expand the beam. The laser line, when projected on the book surface, distorts according to the page curvature. Using this laser line, we should be able to make a good guess at the 3D structure of the page and do dewarping. Or perhaps we could make a modified version of Scan Tailor that searches for bright lines. In any case, it is a promising area of research suggested by many including Rob, myself, and Vitorio.

I decided to try this out this morning (got up at 1AM, couldn’t sleep!) and the results looked very promising.

I didn’t have any cylinder lenses laying around (aaghhh!!!), so what I did was took a piece of “turning film” from the back of a cellphone display and put it in front of the laser pointer.

Laser pointer by itself:

Laser pointer plus turning film.

Then, I pointed the laser, from the side, toward the book. From straight down, obviously the laser beam will appear straight. However, if we project it from the side, we get something like this (actually this is two photographs of two projections superimposed on each other):

Laser image by itself (it’s noisy because I used the wrong camera settings but didn’t care to take the image a second time)

Image of the book:

Laser beams superimposed on book:

OK, the laser beam is not perfect because of the nature of turning film. A brighter laser with a better lens would give much better results. If you had two lasers, you could take just two shots — a laser beam shot, and a normal shot. Using the info from the two, you could obviously dewarp the page. I think this method is a winner. Cheap, handy, uses a single camera and a handful of solid state parts. Books which can lay flat are easy targets — not so sure about books in a cradle (that’s up next).

Drawbacks: Requires two lasers in a fixed position. Requires at least two photographs per page.

5. Using depth-from-defocus.

This technique is a bit subtle. Essentially it makes the assumption that what is in focus in a picture with shallow DoF is all in one plane. By shifting the the focus through a scene, the depth of each object can be recovered by watching for high frequency information. Unfortunately this method suffers for compact cameras because they do not have shallow DoF, and it fails in general because not all book pages contain high frequency content. An additional problem is that it requires many photographs of a page to work. EVEN SO, I was very, very excited to see Coded aperture imaging is explained here. I am building a coded aperture camera for other reasons, but honestly expect the depth resolution to be too coarse for book scanning. Among the many other drawbacks, that’s the big one.

7. Using RGB lighting to get the curvature of the book.

This is an idea I had just a week or so ago. If you mix a red, green, and blue light, you get white. White light is nice for scanning books, so we’re already +1. Now, if you put your lights at different points in space, when you interrupt them, you will get colored shadows. In this way, you can make colored shadows that reflect the shape of the book edge, and also identify the orientation of the lighting relative to the book. I think pictures show this idea best, so I mocked it up in Maya:

Drawbacks: Need RGB lights that are reasonably collimated to cast a sharp shadow. Setup would likely be physically large.

8. Difference-based lighting. Use light control to get better depth information from photographs.

Humans use the direction of light as a cue to depth. Most of our scanning rigs have two or more lights. There’s no reason we can’t use these lights in a smarter way to get better depth information. In particular, I’m thinking of Blender’s page splitter idea. The same idea has been proposed under numerous guises before, but I think it would work a lot better if we made better use of the lights.

So imagine that we have two lights.

Turn the left one on.

Then turn the right one on.

Now take the difference between the two — the page edges are clearly highlighted:

Now, you can make a virtual third light. Add the left and right images:

Looks pretty good!

Now you can play all kinds of games. Add the difference of each back to the original image, or something – edges and the center become highlighted.

Screwing around with contrast and stuff can get you even better data:

etc etc. The nice thing is that these are all easy to control (it’s easy to switch lights on and off) it’s only two shots per capture, and the image math is all dead-simple to start with, just addition and subtraction.

Here are the original images if you’d like to play with them.

Drawbacks… hard to say! I think there are some exciting possibilities here… the combination of computation + cameras is unbeatable for this kind of task.

Microsoft’s new Kinect sensor is garnering a lot of attention from the hacking community, but the technical specifics of how it works still aren’t clear. I am working to understand the technology at a fundamental level – my interest is in the optical side of Kinect. My ultimate goal is to make the sensor nearsighted, so that the depth resolution can be used to scan small objects. The first step in understanding a technology is to look at it — that’s why teardowns like this one at iFixit are so important.

Unfortunately for us humans the Kinect projector is infrared (or near-infrared) — probably somewhere between 900 and 1020nm. My guess is that it’s around 904nm, because it’s cheap to produce those lasers, but that’s just a guess; I haven’t measured anything yet. That means that by design, we can’t see the projection directly with our eyes. But we can see it with a camera. Almost all CMOS sensors in digital cameras ARE sensitive to infrared. In fact, they are so sensitive that there is a filter placed between the lens and the sensor to prevent IR from messing up your pictures. It’s called the IR cutoff filter.

The IR cutoff filter is easily identifiable. It’s a bluish piece of glass. It’s blue because the glass absorbs wavelengths that are just longer than red. This is an IR cutoff filter from an old video camera, you can clearly see how the filter just sits on top of the sensor:

Here’s the IR cutoff filter in my Sony NEX-5:

These filters are so effective in reflecting and/or absorbing IR that the reflected IR has been used to detect cameras in dark theaters! Yet another effective anti-piracy strategy… I see it’s been steadily declining since that was published in 2004.

Anyway, we need an IR sensitive camera to see what the hell is going on. I’d rather not use a cheap IR security cam — the resolution is just too low. And I’m not going to modify my NEX-5 for infrared (yet – but see Pete Ganzel’s excellent work on that!). So I’ll have to compromise and pick what is probably the most difficult option: modifying a compact Powershot camera. It’s difficult, because the filter in a compact camera is INSIDE a closed lens mechanism, and the camera was never designed to be disassembled. This tutorial will be a little incomplete, but should be enough to get any motivated person done with the same project. As all hackers know, it only takes one person to get the work done and share the results.

Start with a clean workspace. Like this one.

Disassemble the camera screw by screw. Don’t miss the hidden one inside the battery compartment.

Carefully pull the body apart:

The back will come off first. It may be blurry. Don’t let that bother you:

Next, the front:

Remove the display by removing the screw at the top left and unclipping these metal clips:

Next, carefully unclip the FFC (Flat Flexible Cables) from their mounts. Some will be pull-out, and some will have a brown plastic clip that must be flipped up to release the cable. The display will come free, but it will be embarrassed and hide from the camera.

Remove the keypad assembly, and unscrew all screws holding in the mainboard. Unfortunately, for the Powershot A540, I also had to unsolder this red and black wire which supply power to the flash. Since I hate the flash, and the camera is not dependent on it, I simply removed it for good. An IR cam has little use for a flash. Good riddance.

Under the mainboard, you can see the back of the sensor. There is a bit of hot glue on a metal plate which is supported by three screws. This is the sensor assembly; it is our target. Now, before I go much further, I need to say that the camera will be difficult to return to normal operation. The IR filter must be destroyed to get it out. This forever changes the focal characteristics of the camera unless it is replaced with flat glass (and I’m not doing that). So adjust your expectations of how perfectly the camera will focus from here on out, and all will be well.
Remove the mainboard.

Here is a better shot of the sensor assembly. The three screws are covered in hot glue. That is because next to each screw, there is a small spring which pushes up on the sensor assembly. In other words, it’s a little 3-way platform that the sensor is adjusted on. The exact position is fixed because it was calibrated at the factory for perfect focus. We are going to destroy that by removing all three screws very slowly. Slowly, because the three springs will pop out if we move too quickly.

Remove the three screws. Lift the sensor assembly free. Springs are visible.

Well, there it is. The IR cut filter, held in by two dabs of hot glue. Try to lift it with a small screwdriver or hobby knife. It will most likely break because it is very thin. Remove the little pieces. Admire their lovely blue hue.

Now comes the really hard part — you have to put the camera back together. I did so without the flash assembly in place, and I left a few screws out. My Dad taught me how to take things apart, and how to re-assemble them. He always called these “extra” screws “shipping screws”. Here are the shipping screws left out of this camera:

Alright! I’ve completed the very first tool in my Kinect hacking suite, a camera to look at the Kinect’s pattern. But the question is: Was all this worth it? Does this really tell us anything? See for yourself:

Before the infrared modification:

After the infrared modification:

Alright, looking good! Let’s make a movie:

This is kickass! Here’s what the sensor output looks like up close — this board is about .5M away from the camera (click for full resolution, slightly misfocused – this image is public domain – I make no claim to copy rights):

It’s interesting in a few different ways. One can easily see that the Kinect IR speckle-field is a 3×3 matrix of random dots. One can also see that they are differentiated by intensity and have a centered registration dot. So it is not purely random speckle.

IR cameras are good for more than Kinect hacking. Here are a few outdoor shots showing some IR effects.

Stay tuned as I build up a proper toolset for optical analysis and decipher just how these guys are using speckle to estimate depth.

YOU ARE NOT DEAD: A Guide to Modern Living

(Photos by Gabriel Collins!)

“Your dreams and dangerous notions, our cutting-edge advice”

VANCOUVER, BC: You are invited to view and review Black Pants Productions’ presentation of You Are Not Dead: A Guide to Modern Living, the theatrical wellness seminar.

You Are Not Dead is a site-specific, seminar-style performance inspired by civic duty propaganda, self-help manuals and popular theories on life management. Actors Adam Bergquist and Jessica Harvey will lead you through an efficient eleven steps that encourage you to embrace cognitive dissonance and be Not Dead. Topics covered include:

* Breaking the Five-Year Fail
* Assessing Your Mediacation
* Recognizing Your Debit to Society
* Stopping Identity Theft Before You Happen

…and much more.

Based on an e-book of the same name by writer/librarian Meg Holle and musician/hacker Daniel Reetz, the dynamic theatrical adaptation of You Are Not Dead offers incisive and humorous social commentary on pop-psychology and superficial empowerment. Produced and directed by UBC graduate and Yvonne Firkins Award-winner Danielle Marleau (Black Pants). Adapted for theatre by Meg Holle and Danielle Marleau with dramaturgical contributions by Rachel Peake (Solo Collective). Original audio-visual presentation by Daniel Reetz, and PowerPoint AI programming by Brandon Marback.

The show runs May 27 – June 5, 2010. All shows at 7:30 p.m. except May 30 at 2:00 p.m.
Tickets $18/20 in advance at Tickets Tonight or $25 at the door.

www.youarenotdead.ca

I’ve been waiting for the right moment to announce this in a big way — but I’m in the middle of it, and the right moment never seems to come. The time is now — before I’m dead, duplicitous, plane-crashed or burned out.

Krista Eide just wrote a great article about the project. I hope you’ll take a moment to check it out, and possibly donate — we need a bit more cash to realize it in the best possible way.

My job right now is making the images for the play — and I suspect I’m going to be at it for the next month or more. I just can’t tell you how totally awesome this thing is gonna be. You’ll see. Wish us all luck — myself, Danielle Marleau, Meg Holle, and the actors and dramaturgs polishing and preparing this thing for the next stage.

These are the sorts of things that are only justifiable to businessmen — Yes! make a one-of-a-kind undocumented connector, and then charge loads of money for cables and connectors, because we’re the only source! You can almost hear them laughing all the way to the bank extinction.

I recently acquired a Uniden Bearcat BCD396XT, which is a remarkable radio. The most salient feature of this radio is its ability to decode APCO25-standard broadcasts, which now comprise the majority of public service frequencies like police, fire, etc. But this radio goes a step further, allowing connection to a GPS (for “location based scanning”, a funny thing for a radio device, when radio was invented to overcome problems of distance) or to a computer for complete control. Problem is, the connector of interest is wacky.

This connector, though it kinda resembles USB connectors, does not transport a USB signal. It is a plain old serial connection. Why they chose to use this connector is beyond me. However, as a hacker, I want access to those pins. I could just open the radio and solder to the board, but it’s more elegant and flexible to find the connectors themselves. After taking some detailed photographs, and searching around a bit, I was able to find a replacement.

Detailed photographs:

Items on eBay — they can be had for about a dollar each, with shipping – a hell of a lot cheaper than the $20 asking price for the standard serial cable. The magic search words turned out to be “4 pin mini USB cable” (most are 5 pin, these 4 pin models appear on a few odd digital cameras and MP3 players).

Please note, these cables are only good for the connectors on the end. Plugging the radio into a USB port without a proper USB adapter is asking for pain.

Quoting Dr. Slator:

I am pleased to announce the winners of the South Beach
International Animation Festival have finally been announced
and posted online at

http://www.southbeachanimationfest.com/winners2009.htm

where the winner of the ‘Education’ division is
“Through the Virtual Cell” (http://www.imdb.com/title/tt1370799/)

Brian Slator

w0000000000000000000000000000000t!!!!!!!

I am pleased to announce the release of a major project — complete plans for a high-speed book scanner made from off-the-shelf cameras and salvage. With the help of Aaron Clarke, there is now software to complete the process, too.

The complete plans and software are on Instructables. Please vote for this project!

PageBuilder:

Big thanks to Aaron Clarke, Noah Bicknell, L, and everyone else who contributed. Couldn’t have done it without you.