Gadget Watch: Control a PC with body motions

LAS VEGAS (AP) — Don't trash your keyboard and mouse just yet. But three companies at the International Consumer Electronics Show demonstrated depth-sensing cameras that let you to control your computer by moving your hands or body.
Microsoft's Kinect add-on for the Xbox 360 console has already popularized these cameras for gaming. Now, the technology is being set loose for use on other devices. However, like many gadgets shown at the annual Las Vegas-based extravaganza of phones, PCs and TVs, the cameras aren't quite ready for the mass market.
The companies showed off their cameras to give software developers and gadget makers a chance to work with the technology and incorporate it in their products. For the rest of us, it's a taste of what the future might hold.

WHY IT'S HOT: The cameras represent another challenge to the keyboard-and-mouse regime, which is already being eroded by touch screens. If you're in front of a depth-sensing camera, you don't have to touch the screen to control it with your fingers or hands. (This works with non-depth-sensing cameras as well, but they're not as good at figuring out what you're doing.) At the PrimeSense booth, visitors could browse and play the contents of a digital video library with hand gestures — basically, anything you'd do with a mouse today. The Israeli company's camera goes into the Kinect and is now sold separately as the Asus Xtion.
BEHIND THE LENS: The cameras can tell how far away things are in their field of vision. PrimeSense does this by sending out an invisible pattern of light, and registering how it's deformed when it hits objects. SoftKinetics' camera works almost like radar, but with light: it sends out infrared light and measures how fast it comes back. Where it takes longer, it figures out that that part of the image is further away.
THE DOWNSIDE: If you buy one of these now, there isn't much you can do with it, unless you're a software developer. The Asus Xtion comes with a few simple Kinect-like games for your PC. For all of these cameras, the depth-sensing range is limited to about 12 feet, and at the far end of the range, accuracy is reduced. That means finger gestures may not be picked up from across the living room.
AVAILABILITY: Microsoft said it will start selling a "Kinect for Windows" camera starting Feb. 1st, for $249. Asus started selling the Xtion in December for $149. SoftKinetics, a Belgian company, started selling its camera around the same time for $499.