MIT Researchers Can Read Closed Books (and defeat CAPTCHA)

Ten years ago, MIT researchers proved that it was possible to look through an envelope and read the text inside using terahertz spectroscopic imaging. This research inspired [Barmak Heshmat] to try the same technique to read a book through its cover. A new crop of MIT researchers led by [Heshmat] have developed a prototype to do exactly that, and he explains the process in the video after the break. At present, the system is capable of correctly deciphering individual letters through nine pages of printed text.

They do this by firing terahertz waves in short bursts at a stack of pages and interpreting the return values and travel time. The microscopic air pockets between the pages provide boundaries for differentiation. [Heshmat] and the team rely on these pockets to reflect the signal back to a sensor in the camera. Once they have the system dialed in to be able to see the letters on the target page and distinguish them from the shadows of the letters on the other pages, they use an algorithm to determine the letters. [Heshmat] says the algorithm is so good that it can get through most CAPTCHAs.

The most immediate application for this technology is reading antique books and other printed materials that are far too fragile to be handled, potentially opening up worlds of knowledge that are hidden within disintegrating documents. For a better look at the outsides of things, there is Reflectance Transformation Imaging.

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Gutenberg Clock Keeps Time by Reading Books

Gutenberg clock displaying text from a book

We’ve seen a wide variety of hacks that keep time, but [ch00f]’s latest build takes a new spin on counting the seconds. The Gutenberg Clock keeps time by reading books on a scrolling LED screen.

The content for the clock is sourced from the Project Gutenberg, which releases books with expired copyright for free. The library on the clock consists of around twenty thousand such books. Read at eighty words per minute, the clock won’t repeat a passage for the next thirty-three years.

While the clock doesn’t display time itself, it is synchronized to time. Two identical clocks should display the same text at the same time. To get the time, [ch00f] first tried hacking apart a cheap radio clock, which is synchronized to NIST’s 60 kHz broadcast. After reverse engineering the protocol with great success, stray RF energy from the display turned out to cause too much interference.

With the cheap solution out the window, [ch00f] built a custom breakout for an Adafruit GPS module and used it to get the time. This was his first RF board, but it worked out fine.

Books are loaded onto a FAT filesystem on an SD card, and [ChaN]’s FatFS is used to interpret the filesystem. A microcontroller then sends the text out at a constant rate to a serial port on the display which he hacked his way into.

The project is a neat mix of art and electronics. Stick around for a video overview after the break.

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Making a Bathymetric Book by Hand and Searching for an Easier Way

We first saw this Bathymetric Book at our local hackerspace, Sector67, quite some time ago. [Caroline Rose] gave a seven minute presentation on the project as part of the monthly meeting which is open to the public. You can get a pretty good feel for the book that includes a to-scale depth representation of Crater Lake in the introductory post which she recently published. Each page makes up one topographical ring of the lake. Put them all together and you’ve got a really amazing way to explore the watery depths of the deepest lake in the United States.

The book you see above is hand made. She downloaded the depth data from the US Geological Survey, then put it through some processing in order to print one elevation level on each page. That’s when the work really began. She cut out every page by hand! The four-plus hour task was grueling. And just for a bit of added punishment she even made a second book. But at Tuesday night’s follow-up presentation she said never again.

[Caroline] developed a much faster and still accurate technique for producing the bound-book depth maps. She is using a laser cutter and a different binding technique. By using folded packets of paper, rather than individual pages, she is able to cut out three double-sheets at once — including holes for the binding thread and the outline of the finished pages themselves. This cuts the process down to about four minutes of laser cutter time.

For now you’ll have to settle for a time-lapse video of the hand-cutting process (embedded below). But we hope to post an update when she makes more information about the laser-cut version available.

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Hand bind your own books


This guide will show you how to bind books by hand. The process from start to finish isn’t very difficult as long as you follow each step along the way. The final product looks great, and we can’t think of a better gift… as long as you have something meaningful on the pages.

We never really thought about the direction of the fibers in a sheet of paper, but that’s the first thing you’ll have to take into consideration here. You want the fibers running up and down when the book is in a bookcase. Next the sheets are organized into stacks of four, then folded in half forming eight pages. After stacking these packets together a series of lines are marked on the folded side. Holes are then punched from the inside at each mark using a sturdy needle. This is where the stitching for the binding will happen. Bands are added using coarse linen thread. After stitching these in place and knotting, glue is added and finally a piece of cloth is adhered to the binding and a portion of each inside cover. From there it’s onto fabricating the cover before pressing the finished project as seen above. What a piece of work!

[via Reddit]

Bilbio-mat is an awesome yet simple used book vending machine

You’ll find this used book vending machine at The Monkey’s Paw in Toronto, Canada. For two Loonies you can buy a random book from the machine’s hopper. Silly? Absolutely. But as you can see from the video after the break, the act of buying a book this way is a lot of fun, and we always like to see the insides of a machine like this.

[Craig Small’s] creation looks vintage, and the chugga-chugga and mechanical bell that accompany each sale go along well with that appearance. Of course the machine is new. A trio of hoppers behind the façade hold stacks of books at a forty-five degree angle. Each stack is raised one at a time by a winch and pulley. Once the top book on the stack is high enough to slide into the dispenser chute the winch stops and the bell rings. A simple solution to dispensing something that is not a standard size.

Because the Biblio-Mat is meant to clear out the discount books, slight damage caused by falling down the chute won’t even be noticed. And if you end up really loving the book you can digitize it by running it through one of these.

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DMG Lib: Digital Mechanism and Gear Library

Reader, [klemens], suggested DMG Lib to us when we posted about a similar site. DMG-Lib is an amazing source of information. It’s primary downside is that a great portion of the text is in a language other than English, though in some ways this is a plus. Latin, Italian, German, and many other languages held the position of being the chief scientific language of the world long before English, and this repository holds entire books about mechanisms in those languages. Some of the books range all the way back to the 1500s. The mechanism animations are very good on this site and play smoothly. While it’s a little harder to search than KMODDL due to the language oddities, it’s still an extremely useful and interesting site to add to the hacker’s information toolbox.

Book Scanner Kits now available

[Daniel Reetz] wants you to be able to scan books. This has been a goal of his for quite some time, and now he’s bringing a kit into play. We’ve always liked book scanners here, many of us have extensive libraries or even peculiar selections we would like to share. [Daniel] is starting off with a short run of these scanners. Once all the bugs are worked out, there should be plenty available for everyone. The kit includes the frame, LED lighting, bicycle levers, and cables. You have to add glass, books, and a camera.

Of course, if you still want to design and build your own, there are TONS of variations available in the forums at

[via Adafruit]

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