Build An Eye Tracking Headset For $90

February 12, 2013 by Brian Benchoff 41 Comments

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Eye tracking is a really cool technology used in dozens of fields ranging from linguistics, human-computer interaction, and marketing. With a proper eye tracking setup, it’s possible for a web developer to see if their changes to the layout are effective, to measure how fast someone reads a page of text, and even diagnose medical disorders. Eye tracking setups haven’t been cheap, though, at least until now. Pupil is a serious, research-quality eye tracking headset designed by [Moritz] and [William] for their thesis at MIT.

The basic idea behind Pupil is to put one digital camera facing the user’s eye while another camera looks out on the world. After calibrating the included software, the headset looks at the user’s pupil to determine where they’re actually looking.

The hardware isn’t specialized at all – just a pair of $20 USB webcams, a LED, an infrared filter made from exposed 35mm film negatives, and a 3D printed headset conveniently for sale at Shapeways.

The software for Pupil is based on OpenCV and OpenGL and is available for Mac and Linux. Calibration is easy, as seen in the videos after the break, and the results are amazing for an eye tracking headset thrown together for under $100.

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Quantifying Cloudiness With OpenCV

February 7, 2013 by Eric Evenchick 12 Comments

The Shard is the tallest building in Western Europe, and has a great view of London. The condos in the building are very expensive, and a tourist ride to the top of the building costs £24.95.

Since the value of the view is so high, [Willem] wanted to quantify the quality of the view at any given time. His solution is the Shard Rain Cam. This device combines a Logitech webcam with a Raspberry Pi to capture a time-lapse set of images. These images are fed to a Python script using OpenCV which quantifies the cloudiness.

[Willem] also had to build a weatherproof enclosure with a transparent window for the camera and RPi. ‘Clingfilm’, which is British for saran wrap, and mineral oil is used to improve the waterproofing of an IP54 rated enclosure.

The resulting data is displayed on www.whatcaniseefromtheshard.com, which provides an indication of whether or not the view is worth £24.95. All of the Python code is available, and is a good starting point for learning about image processing with OpenCV.

Finding 1s And 0s With A Microscope And Computer Vision

February 4, 2013 by Brian Benchoff 18 Comments

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One day, [Adam] was asked if he would like to take part in a little project. A mad scientist come engineer at [Adam]’s job had just removed the plastic casing from a IC, and wanted a little help decoding the information on a masked ROM. These ROMs are basically just data etched directly into silicon, so the only way to actually read the data is with some nitric acid and a microscope. [Adam] was more than up for the challenge, but not wanting to count out thousands of 1s and 0s etched into a chip, he figured out a way to let a computer do it with some clever programming and computer vision.

[Adam] has used OpenCV before, but the macro image of the masked ROM had a lot of extraneous information; there were gaps in the columns of bits, and letting a computer do all the work would result in crap data. His solution was to semi-automate the process of counting 1s and 0s by selecting a grid by hand and letting image processing software do the rest of the work.

This work resulted in rompar, a tool to decode the data on de-packaged ROMs. It works very well – [Adam] was able to successfully decode the ROM and netted the machine codes for the object of his reverse engineering.

Flatbed Scanner Eliminates The Perils Of Macro Photography

January 20, 2013 by Brian Benchoff 48 Comments

If you have ever played around with macro photography, you’ll know how hard it is to get a focused image of something that isn’t two-dimensional. For virtually every 3D object, you’ll have to deal with the depth of field – the small region where things are actually in focus. [David] came up with a neat homebrew solution for making sure everything in his macro photos is in focus using a discarded flatbed scanner and a Raspberry Pi.

[David]’s technique relies on focus stacking. Basically, [David] takes dozens of images of the same object, moving the camera closer by a fraction of an inch before snapping each frame. These pictures are stitched together with CombineZ, a piece of software used for extending the depth of field in images.

The hardware part of the build is a Raspberry Pi hooked up to a stepper motor driver and the shutter button of [David]’s camera. By attaching his camera to the carriage of a flatbed scanner, [David] can inch his camera ever closer to his object of study while grabbing the images for CombineZ.

The results are impressive, and would be nearly impossible to replicate any other way without tens of thousands of dollars in camera equipment.

Operation StratoSphere

January 18, 2013 by Jeremy Cook 7 Comments

Panoramic photos are nice, however a full 360 degree x 180 degree, or spherical panorama would be even better. [Caleb Anderson] decided to take this concept much further, attempting to extract panoramic photos from video taken at 100,000 feet using a high-altitude balloon and six GoPro cameras.

The overview of this project can be found here, and gives some background. The first task was to start prototyping some payload containers, which for a device that you have little control over once out of your hands is quite critical. As well as some background, there’s a cool interactive panorama of the first test results on this page, so be sure to check it out.

The “real” hacking in this experiment wasn’t a matter of putting a balloon into the stratosphere or recovering it, however. Chaining these images together into pictures was a huge challenge, and involved a diverse set of skills and software knowledge that most of our readers would be proud to possess. There are several videos in the explanation, but we’ve embedded one with the cameras falling out of the sky. Be sure to at least watch until (or skip to) just after 1:05 where all the cameras impressively survive impact! Continue reading “Operation StratoSphere” →

Polaroid Catcher Make Print Screen Do What It Says

January 16, 2013 by Mike Szczys 6 Comments

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As part of their coursework at ITP New York a group of students developed the Polaroid Catcher. It’s a way to make your digital experiences more permanent. When you have something on-screen that you’d like to keep as a memory you can print the screen on this old Polaroid camera. Of course you’re not going to get the chemical-filled container you may remember from ages past. But we thing you’d agree the nostalgic camera makes a nice enclosure for a modern image printer.

The workings of the system are shown off quite well in the clip after the break. But we’re always interested in the particulars of how they pulled it off. The system uses a Google Chrome extension to capture what is being displayed in the browser. Before the image is sent to the printer the user has the opportunity to frame up the subject of the photo. Once decided, the image is pushed to a Bluetooth photo printer using some scripts written by the team.

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Adapting Modern Cameras To Use Old Flash Units

January 16, 2013 by Mike Szczys 11 Comments

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We don’t think this one is going to bring back the days of one-time-use flash bulbs. But for camera enthusiasts who do have old flash units lying around this will be quite interesting. [Sven] worked out a method of interfacing this vintage flash with a modern camera.

The trick is to map the trigger signal from the camera to the flash module. Instead of patching into an electrical signal from the camera he’s using the light from the stock flash. He cut an optocoupler in half, keeping the receiving side of the part. This is molded in plastic that was shaped to surround the original flash unit. When that flash goes off the triac in the remaining half of the IC is activated. This is connected to a hot shoe mounted on an extension arm that is attached to the camera’s tripod mount. The shoe can be used to interface a few different styles of flash modules.

We don’t have an alternative use in mind right now. But chopping an optocoupler in half could come in handy for other applications that use a bright light as a trigger event.

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