My 52 things project for this week is a spray paint stencil featuring Benazir Bhutto the leader of the Pakistan Peoples Party who was assassinated this week. I started with an image from the Wall Street Journal and added the star and moon from the Pakistani flag and a peace symbol. The phrase is a play on the "Frodo Lives!" Middle Earth graffiti that was popular in the 60's. I put the first one up on the art van down the street. This was my first time doing a stencil. The next time I will laser cut the stencil from thicker stock. I used the nicest stock I had on hand, but it was really just regular paper and was too flimsy when it came time to spraying. I could laser cut it with more detail and end up with a stiffer and sturdier stencil if I used the laser cutter. Also I need to be more careful to paint the whole stencil as I missed some of them on the first try.

Here is the photoshop file for the stencil: bhutto-stencil.psd.

This week's creative project is a hack I've been meaning to work on for quite some time: 2d coordinate input via a handheld device and a pc 'web' camera. I plan on going a bit further with this one at some point so this is really just a first round project. Here's a short video that shows how it works:

All charged-coupled devices, or in other words all digital cameras, pick up infrared light as well as visible light. You can verify this simply by pointing any tv remote at your digital camera (try the one on your phone) and hitting a button on the remote. By covering the built-in iSight camera that comes on my Apple computers with a filter that only passes infrared light you can use an infrared emitter to indicate positioning. Infrared-only filters can be quite expensive, but you can make one very cheaply by using a combination of "Congo Blue" and "Primary Red" filters that are available at professional photography supply retailers. You buy these by the sheet, but you only need to cut out a small portion to cover the tiny iSight lens.

I could have simply used the remote that came with my iMac for the handheld input device, but I don't like how it blinks, plus I doubt its battery was meant to hold up to such long duration usage. Instead I made my own device using a 9 volt battery, an infrared LED and a couple of 68 ohm resistors connected in series with a 50 working mA current. I was pretty lazy and just taped/soldered all the parts together directly to the battery.

To do the input detection I at first attempted to write the application in ruby using RubyCocoa, but it turned out that there is a problem with it mangling the data from the camera (it mistakenly turns binary data from NSBitmapImageRep.bitmapData() into a ruby character string and there didn't seem to be any work around). So I ended up having to delve into Cocoa and Objective-C land for the first time. I've been exposed to a fair amount of computer languages in my life and Objective-C is easily the most bizarre and frustrating of all of them. It took me about 20 times longer to figure out how to accomplish simple tasks in Objective-C than it would have in C, C++, Java or ruby. The application uses the CocoaSequenceGrabber framework to read from the iSight camera. It then displays the live camera stream on the left and an x/y detection indicator on the right. You'll notice that the iSight flips the actual image, so I flip it back for the detection.

You can download the application here: Infrared Detector.dmg. It only works on a mac with a camera obviously. Follow the filter link above to get more details on obtaining the necessary filters, but you can sort of play with it without them if you put you finger over the isight camera so very little light comes in. The x/y location is determined as the first non-dark pixel the app runs across in the video stream.

Some future directions for this:

• Make a better emitter device that includes a convex lens to spread out the infrared light better. Right now the LED is very narrowly focused so you have to be pointing it almost directly at the camera.
• Hook the input into the mouse driver somehow. I'm not sure what to do about the mouse click. Perhaps I can use the microphone and just click my tongue (cluck?).
• Look into gesture recognition possibilities.
• Turn it into a "digital whiteboard" tool that will record pen movements as drawings. This can be done as you draw on an actual whiteboard.
• Make an infrared LED 3D scanner input device. This will involve more LEDs, this time mounted around the camera and shining on objects in front of it. It will work by determining distance as a function of pixel brightness.

A few months ago I bought a toy $40 digital 200x microscope called the Eyeclops. It outputs HD video directly to an RCA input on a TV or A/D converter. Today I used it to make a music video for Colours by Hot Chip.

My canvas for this piece was a printing of Salvador Dali's The Discovery of America by Christopher Columbus. I chose this one partially because I've been reading a book that corrects the myriad misconceptions most of us have about the native Americans before and after the arrival of Columbus, and partially because it depicted a pretty good face of just about the right size.

The video isn't quite what I'd hoped for. It was a bit hard getting it just right as I wanted to do it all in one take and it's difficult to manipulate the microscope lens just right. Plus the song itself moves a little too slowly. But overall I'm fairly pleased with this one.

Inspired by the family tradition of one of Mie's college buddies, we have started producing a homemade family holiday card each winter. Last year we riffed on Tesla's natural faux-hawk and went with a punk rock theme. This year I used Illustrator and Photoshop to create a mashup of three individual photos of Tesla, Mie and myself, a shot of the Golden Gate Bridge stolen from Flickr member pbo31 and a Japanese Dragon I found in Second Life. I put everything through VectorMagic to make it easy to adjust scaling of the individual images without losing anything, then imported the scaled layered vector images into photoshop for some finishing touches.

We'll be printing some of the cards out on nice paper and sending them through the mail, but here's the online version. Happy Holidays!

After I made the laser cut jolly roger pieces I ended up carrying them around town and giving them away to people at random or leaving them in places, like on a park bench or a bar or in some nook in the wall. I decided that was fun so this week while I was at Techshop I made a new piece to carry around with me. It's based on an Aztec artists' stone carving of an Ouroborus, a snake eating its own tail. Usually meant to symbolize infinity or cyclic nature, it is a symbol that has emerged in many different cultures, from the Greeks, to various African regions and of course the Aztecs. I chose to use an Aztec version because the copyright is expired and I've been reading a great book recently that covered some Aztec history and culture. I've posted the Corel Draw file I used with the laser cutter.