This art installation uses buttons made of light. A projector fills up the walls and ceiling of a room while a webcam monitors the pattern for changes. When the luminosity of a given area changes due to a shadow, a midi event is triggered. The software that controls the system is written in C# and uses the Emgu CV library to handle the image processing. In the video after the break you can see that creating shadows with your hands prompts changes in the image as well as the sound.
[youtube=http://www.youtube.com/watch?v=zPm84nxa2dk]
Thanks to [Josh, Kyle, and Mike], it is now possible to wage (Nerf) war with an Arduino. The turret designed around it is capable of shooting 6 foam projectiles in close succession, between reloads. The faux weapon interfaces with a computer through the Arduino’s onboard serial link (via USB). Software on the PC sends commands to the Arduino, which then executes functions, such as panning, tilting, firing, and rotating the cylinder. The power for the firing itself comes from a 5 gal, 80 psi air compressor. The Java software on the host PC also does smarter things, like show streaming video from the turret’s webcam and even performs basic object tracking (with mixed success). All the code for building the brute is available on [Josh’s] website.
Sometimes, pets need to be trained to stay away from certain things. Over at sump.org, his cats needed to be kept out of his room. He used their natural fear of water by creating the waterwall, a motion-sensing device that sprays water. The project is incredibly simple and uses very few components. It is based around an IR intrusion detector and a windshield washer pump. Although that worked well enough, he also hooked it up to his computer via the parallel port so that he could take pictures as the cats (or people) are sprayed. Although the project is old, it shows how few components are really needed to achieve this kind of behavior.
Related: Motion detecting cat toy
[thanks todd]
[youtube http://www.youtube.com/watch?v=mlLY0zic7u0%5D
Embedded above is an interesting multitouch demo by [Lahiru]. The goal of the project was to find an easy way to retrofit current LCDs for multitouch. Instead of using infrared or capacitive recognition, it uses a standard webcam mounted overhead. To calibrate, you draw polygon around the desktop screen as the webcam sees it. The camera can identify the location of markers placed on the screen and their color. iDisplay can also recognize hands making the pinch motion and sends these as touch events via TUIO, so it works with existing touch software. It’s written in C++ using OpenCV for image processing with openFrameworks as the application framework.
[via NUI Group]
[youtube=http://www.youtube.com/watch?v=7vYKwih8Izk]
Reader, [Ben Godding], sends in the video for his senior design team’s automated paintball sentry. The frame is made of plasma cut aluminum. The paintball gun uses a custom hopper mounted remotely from the gun body. It has two webcams offering a 160 degree field of vision, and the image processing is done by a dual core pentium CPU booting windows xp off a compact flash card. The computer interfaces with the 1/4scale RC servos using a PIC24. The paintball sentry can either be configured via a computer GUI when a monitor is available or a baclkit keypad and 4×20 charachter display in the field.
Related: [Jared Bouck]’s paintball gun turret
[youtube=http://www.youtube.com/watch?v=phcsDNOglLI]
[Yezzer] has posted a video of a cool little project he’s working on. He has interfaced the Arduino and the Wii Nunchuck to control some servos. He mounted a standard USB webcam on it for good measure. There isn’t a whole lot of information, but he does include a few links to code he modified for the project. The movement is quite natural looking and seems like it would be a cheap way to get some good animatronic controls started. This might actually be a great way to control a robot for the Crabfu challenge, if they ever have another one.
Update: As [dokument] points out in the comments below, it looks like we’ve seen a set up that could be almost identical in the past.
[via the Hack a Day Flickr pool]
[youtube=http://www.youtube.com/watch?v=u3_cFel26J8]
[Tom] wrote in to tell us about his JavaScript project for motion detection. It ties together two ideas we’ve talked about recently. The first is doing image processing in-browser using Canvas(), which we’ve seen employed in captcha breaking. The second is offloading heavy processing to browsers, which we saw recently in the MapReduce implementation. [Tom] is using JavaScript to compare consecutive images to determine if there’s any motion. He did this as part of MJPG-Streamer, a program for streaming images from webcams. It can run on very limited hardware, but image processing can be very intensive. Doing the image processing in-browser makes up for this limitation and means that a custom client program doesn’t have to be written. You can find the code here and a PDF about the proof of concept.
