Thursday, April 30, 2009

CHI 2009: Musink

Musink: composing music through augmented drawing
by Theophanis Tsandilas, Catherine Letondal & Wendy E. Mackay
Univ. Paris-Du, Orsay Cedex, France

Musink pdf
Musink Video

This paper attempts to provide a transition between paper and computer for composers. It allows for composers to freely use their creativity on paper and translate it to the computer. Using OpenMusic software they recorded gestures from a pen on paper and put the gestures on the computer for the OpenMusic software to then use the gestures and put meaning to them.

According to their surveys and studies with composers the technique was supposedly liked. However, I am not sure how effective it would be in the real creative process when errors and scratch notes are prevalent.

Tuesday, April 7, 2009

UIST 2007 - Hybrid Infrared and Visible Light Projection for Location Tracking

UIST 2007 - Hybrid Infrared and Visible Light Projection for Location Tracking
by Johnny Chung Lee, Scott Hudson, Paul Dietz {Carnegie Mellon University & Mitsubishi Electric Research Labs}

This paper discusses their prototype for a hybrid infrared and visible light projector for location tracking. The idea of the prototype is to solve the application issues of many other interactive projection systems. An example of previous interactive projection systems can be seen in Figure 1. The problem with these projects for practical use is the difficulty of image alignment and location tracking, which the hybrid infrared and visible light projector attempts to solve.

In previous work the use of projecting a series of patterns which uniquely identifies each pixel in the projector's screen. See Figure 2. Using this technique but with invisible infrared light a projector can overlay the location discovery infrared lights on top of the viewing visible light to have an intractable projector.

The prototype created uses LED's as apposed to the expensive high wattage Xenon gas bulb used in DLP. The LED's consist of 24 high output visible-light LED's and 24 high output near infrared LED's shown in Figure 3. The prototype did not add RGB color arrays since it would be a trivial task for it to be added for commercial use. The infrared LED's then are received using Vishay 56KHZ IR receivers (hand held style pen).

For rear projected displays a style pen using the IR receiver is used to interact with the projected display. See Figure 5. For front projected display a style pen is not possible due to hand and body blocking the projected image. However, a hand-held focus lens can be held a short distance away to receive the IR reflected off of not only flat but spatial images as well. See Figure 6.

The authors also make note of the ease of replacing current rear projected display systems with their prototype and thus creating an interactable display device with only a few alterations.

The authors of the paper mention that the Nintendo Wii Controller uses IR LED emitters and a handheld IR camera for tracking but don't really go into any speculations on some potential applications. To me it seems very plausable for this technology to be used with console systems to allow for more procise controls using a handle held controller similar to that of the Wii Conroller. Also, remote controlers for the TV could become interactable controlers, pointing and clicking instead of scrolling.

Figure 1. Tracking the location of a hand-held surface and then projecting content to simulate an active display.

Figure 2. Two views of our projector output: a test pattern seen in infrared (left) and a visible light image (right)

Figure 3. Light source of 24 red (clear) and 24 infrared (dark) high-output light emitting diodes.

Figure 4. Inside our projector: A) LED light source B) culminating lens C) DMD device and D) projection lens.

Figure 5. A stylus with a light sensor (insert) used to interact with a rear-projected display.

Figure 6. A stylus utilizing a focusing lens (insert) for distant pointing on non-planar and discontinuous surfaces.