Automatic Book Scanner To Bring Knowledge To Ethiopian Students

In 2013 the dean of an Ethiopian university addressed Maker Faire Hannover and outlined one of his concerns; that the high price of developed-world textbooks was holding back the cause of education for universities such as his own in developing countries. He was there to ask for help from the maker community to solve his problem, and a group of his audience took up the challenge to create an affordable and accessible automatic book scanner.

Their scanner builds on the work of Google engineer [Dany Qumsiyeh], whose open source linear book scanner turns pages by traversing the opened book over a triangular prismic former such that pages are turned by vacuum as they pass over carefully designed slots in its surface. Their modification replaces the vacuum with the Coandă effect, to more gently tease open each page and it is hoped reduce the chance of damaging the volumes being scanned.

The whole machine is controlled by a Raspberry Pi, and the scanning is performed by linear scanning optics, sensors, and electronics taken from flatbed scanners.

An important design goal of the project was to ensure that the scanner could be built without special tools or expertise that might be difficult to find in a developing country, as well as that it should be as inexpensive as possible. The frame of the machine is off-the-shelf extruded aluminium, and the body is acrylic sheet which can be cut to shape with a hand saw if necessary. It is estimated that the device will cost in the region of 500 Euros (about $568) to build.

More information can be found at the project’s web site (German language, Google translate link), including a selection of videos such as the one below the break showing the device in operation.

Writing from the perspective of having been peripherally involved in a professional book scanning operation at a large publisher the benefits of this machine are immediately apparent. Removing the binding and automatically scanning each page as an individual sheet produces a very fast and high quality result, but by its very nature damages the volume being scanned. This machine promises to deliver a solution to the problem of book scanning that is considerably less intrusive.

It is also worth noting that the project does not address any copyright issues that might arise from scanning commercially published textbooks, though this is more of a concern for the end user in terms of what they scan with it than it is for the maker.

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Finger Print Scanners Really Aren’t That Secure

Maybe you suspected this already, but researchers at MSU Computer Science just published a paper explaining just how easy it is to spoof a fingerprint scanner with a ink-jet printed scan of a finger.

We’re not talking about casting a new finger using superglue or anything, but rather using conductive ink you can literally print — on paper. A paper-printed-fingerprint that will unlock your smartphone. We’ve already told you fingerprints suck for security, but hopefully this drives the point home.

[Kai Cao] and [Anil K Jain] released this paper (Direct PDF link) outlining their technique. Using an existing scan of a fingerprint (which can be taken from your phone’s scanner), the image is mirrored, and then printed using a regular ink-jet printer, with all of its color cartridges replaced with AgIC4 silver conductive ink.
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Quickie WiFi Scanner

File this project under “Getting Stuff Done” rather than “Shiniest Things”. [filid] works with a local free-WiFi access group, and wanted to map out the signal strength (RSSI) and coverage of their installations. This is a trivial task for an ESP8266, and it was even easier for [filid] because he had already written some WiFi scanner code for the same hardware.

Basically, the device is a Neopixel ring connected to an ESP8266. If it detects a router that’s part of the Freifunk München network, it displays the RSSI on the ring in an attractive circular “bargraph”. When it doesn’t detect a Freifunk node, it displays the number of WiFi routers that it finds. It dumps a lot more detail over the serial port.

The code is short and sweet. Take a look if you’re just getting started with networking using the Arduino firmware on an ESP. Even if you don’t live in Munich, you’ll be able to tweak it to your own situation in a few seconds.

We want to see a GPS and an SD card added to this one, for a standalone wardriving-with-purpose setup. And while we admit that the small form-factor is probably appropriate for this project, how much cooler would it be if it glowed blue like Bilbo’s “Sting”?

Polarizing 3D Scanner Gives Amazing Results

What if you could take a cheap 3D sensor like a Kinect and increase its effectiveness by three orders of magnitude? The Kinect is great, of course, but it does have a limited resolution. To augment this, MIT researchers are using polarized measurements to deduce 3D forms.

The Fresnel equations describe how the shape of an object changes reflected light polarization, and the researchers use the received polarization to infer the shape. The polarizing sensor is nothing more than a DSLR camera and a polarizing filter, and scanning resolution is down to 300 microns.

The problem with the Fresnel equations is that there is an ambiguity so that a single measurement of polarization doesn’t uniquely identify the shape, and the novel work here is to use information from depth sensors like Kinect to select from the alternatives.

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Smart Phone Camera Turns Laser Cutter Into Hi-Res Scanner

Getting decent macro photos always seems to be a chore. Some important detail always seems to be just outside of the depth of field, or you have to be zoomed in so close that you get great detail in one spot but miss the big picture. [Nate B] had such a problem while trying to document some PC boards, and he came up with a nifty hack that uses a laser cutter and a smart phone camera to do the job.

Pv150a-front
Click for detail.

Having first tried scanning the boards with a flat-bed scanner but finding the depth of field unsatisfactory, [Nate B] then went on to his Samsung phone’s camera. Set to panorama mode, he manually scanned across the boards and let the camera stitch the images together. The results were better, but the wobblies got the better of him and the images showed it. He then decided to use a laser cutter — with the laser disabled, of course — as an impromptu X-Y stage to raster his camera above the boards. In a slightly cringe-worthy move, he gingerly clamped the phone to the cutter gantry, started the panorama, and let the cutter move over the board. This results in a rock-solid pictures of his boards with a lot of detail – perfect for his documentation. As a bonus, the honeycomb laser cutter bed makes for an interesting background texture.

Obviously anything could be used to raster a camera and achieve similar results, but full points here for maximizing available resources and not over-complicating a simple job. Yet another reason you can use to justify that laser-cutter purchase.

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Hacker Reads Magnetic Stripe Card With Flatbed Scanner

[anfractuosus] has been reading magnetic stripe card… optically!

While hackers routinely read and write stripe cards, this is the first time we’ve reported on optically imaging and decoding data from the magnetic stripe. [anfratuosus] used a magnetic developer which is designed to allow visual inspection of the magnetic stripe. The developer uses micron sized iron particles in a suspension which are dropped onto the stripe. To the particles, the magnetic stripe looks like a series of magnets lined up. Long magnets striperepresent 0s and short magnets 1s. With each bit the orientation of the magnet changes, something like the diagram to the right. The magnetic field is strongest where the poles meet. So the iron particles are attracted to these flux reversal points on the stripe creating a visible pattern . There’s an awesome video of the process in action below.

While magnetic developer was designed for debugging faulty recording systems [anfratuosus] went a step further scanning the “developed” card, and writing a tool to decode the images and extract the card data. [anfratuosus] doesn’t mention any particular application, we love this circuitous hack anyway!

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